Glossary

A subsurface aquifer that can store and permeate water. Aquifers are important sources for drinking water abstraction and irrigation.

With the ArtDiver module, groundwater levels from data loggers can be optimally validated. ArtDiver supports multiple data logger formats of different brands and goes through the entire validation process of (1) Importing data logger files, (2) Compensating atmospheric pressure with KNMI atmospheric pressure, (3) Optimal height correction of the data logger measurement series based on control measurements and (4) Correction of (technical) errors in the measurement series and possible assignment of quality labels. In addition, ArtDiver offers extensive visualisation and tools for (automatic) identification of errors such as dryfall, outliers and possible drift and the data can be exported to various file formats.

Groundwater located in a sealed aquifer sandwiched between two impermeable layers. The water in an artesian layer is under pressure and, when a well is drilled in the aquifer, can spontaneously flow to the surface without the need for pumping. This phenomenon is known as an artesian well. The difference between artesian and phreatic water is mainly its pressure and location in the soil structure.​

Water located in the unsaturated zone of the soil, between the groundwater and the soil surface. Soil moisture is crucial for plant growth and agriculture.Water located in the unsaturated zone of the soil, between the groundwater and the soil surface. Soil moisture is crucial for plant growth and agriculture.

The Basisregistratie Ondergrond (BRO) is a central, digital registration of data on the Dutch subsurface. The system aims to collect reliable and standardised data on soil and subsoil and make it accessible to public authorities, businesses and citizens. The data in the BRO are used for policy-making, scientific research, licensing and ensuring sustainable use of the subsurface.

Key aspects of the BRO:

1. Recording objects: These are specific types of data recorded, such as groundwater monitoring wells, geotechnical sounding surveys, drill samples, and hydrogeological models. These objects are divided into different domains, including groundwater monitoring, soil and ground investigation, and soil quality.

2. Legal obligation: Since the law came into force on 1 January 2018, public bodies are obliged to provide and use subsurface data in public law tasks. This ensures that everyone uses the same reliable information for construction projects or environmental surveys, for example

3. Innovation and accessibility: The BRO makes subsurface data accessible not only to professionals but also to citizens. This contributes to transparency and makes it possible to support broader innovations, such as 3D models and digital applications for urban development

4. Collaboration: The BRO system collaborates with existing systems, such as DINO of the Geological Survey of the Netherlands (TNO), to make all subsurface data as complete and reliable as possible

The BRO is thus a crucial part of the Netherlands' digital infrastructure for managing subsurface data, helping with long-term sustainable use and policy-making.

Dawaco BV's BROLab is a database-independent system for submitting data to the Source Holder Portal.

As a Source Holder, from 1 January 2018, you must provide well data to the BRO and are also responsible for the reliability of that data. Using BROLab, you can validate the data to IMBRO standards and deliver it directly to the BRO, regardless of the data storage system used at your facility.

BROLab is intuitive and user-friendly. You don't need to understand SOAP protocols, RESTfull APIs, XML files, xsd's and the like. You provide good quality data collection and BROLab takes care of the rest.

The phenomenon whereby groundwater is sucked up into fine pores of the soil by capillary action, sometimes above the groundwater level. This is important in agricultural and soil research.

Datalab is a data management platform specifically designed for collecting, managing and analysing hydrological data. It can be used to integrate various data sources, such as water level measurements, precipitation data and water quality measurements. Datalab offers powerful analysis capabilities and reporting tools, making it a valuable tool for water managers and hydrologists working with large amounts of data. It enables users to recognise trends, model scenarios, and support decisions.

DAWACO is a software platform specifically designed for managing hydrological and groundwater and ecology-related data. It is used to collect, process, analyse and visualise large amounts of water data. DAWACO supports the management of groundwater, surface water and ecology monitoring networks by automatically integrating data from various sources, such as pressure sensors, monitoring wells, rain gauges, telemetry systems and hand observations.

The software offers a wide range of features, including:

Real-time data collection: Continuously collects and processes data via telemetry from water monitoring points.

Data validation: Checks measurement data for consistency and errors, ensuring data reliability.

Reporting: Generates detailed reports on water levels, groundwater levels, and trends based on historical and current data.

Visualisatie: Uses graphs, maps and dashboards to make water level data transparent, which supports decision-making.

Scenario-analysis: Helps in modelling different water management scenarios, such as the effect of groundwater abstraction or climate change.

DAWACO is widely used by water managers, engineers, hydrologists and ecologists in the Netherlands and other countries to carry out accurate and effective groundwater and ecology management, and helps formulate policies around water use, desiccation and protection of water resources.

Dawaco is a collaboration between Real World Systems and Waterlabs, aimed at developing innovative solutions for water and ecology management and technology. Dawaco BV acquired Dawaco software from Royal Haskoning DHV in 2022. In 2024, Dawaco BV focuses on providing total solutions and unburdening. To this end, hardware measuring various parameters and fieldwork have also been added to the portfolio.

The amount of water flowing through a given point per unit of time, expressed, for example, in litres per second (l/s) or cubic metres per second (m³/s). Essential in surface water and groundwater management.

A measure of the pressure of water above a measurement point, often measured in metres of water column. It is used to determine the water level in relation to atmospheric pressure.

A device that measures pressure in liquids or gases. For water levels, a pressure sensor measures the pressure of the water above the sensor, which can be converted to the height of the water column (water level).

Eutrophication is the process by which an ecosystem, usually an aquatic system such as a lake or river, receives excessive amounts of nutrients, especially nitrogen and phosphorus. This leads to an increase in biological production, especially of algae and other aquatic plants. Eutrophication can have both natural and man-made causes and has various ecological and social consequences.

Causes of eutrophication

Drainage of nutrients: 

Agriculture: Agricultural fertiliser use can lead to nitrogen and phosphorus runoff into nearby water bodies, especially during rainfall events.

Wastewater: Discharges of untreated or poorly treated wastewater from households and industry often contain high concentrations of nitrogen and phosphorus.

Urbanisation: Urbanisation often leads to paved surfaces that cannot absorb rainwater, resulting in increased nutrient runoff to water bodies.

Land-use changes: Deforestation, urbanisation and other land-use changes can increase runoff of water and nutrients to water bodies.

Consequences of eutrophication

Algal blooms: An excess of nutrients leads to rapid growth of algae, resulting in algal blooms. Some of these algae can be toxic and harmful to aquatic wildlife and human health.

Oxygen deficiency: When algae die, they are broken down by bacteria, leading to an increase in oxygen consumption in the water. This can lead to oxygen deficiency (hypoxia) and even the death of fish and other aquatic organisms.

Loss of biodiversity: Eutrophication can reduce biodiversity in aquatic ecosystems. Oxygen deficiency and the proliferation of certain types of algae can crowd out other organisms, leading to an unbalanced ecosystem.

Water quality: Water quality is affected by the presence of algae and their breakdown products, which can affect drinking water quality and harm recreational activities such as swimming and fishing.

Economic impact: Eutrophication can have significant economic consequences, such as reducing fishing, disrupting recreational and tourism activities and increasing the cost of water treatment.

Management and control of eutrophication

Lowering nutrient runoff: Reducing agricultural fertiliser application and improving water management can help reduce nutrient runoff to water bodies.

Wastewater management: Improving wastewater treatment to reduce nitrogen and phosphorus emissions is crucial to combat eutrophication.

Restoration of wetlands: Wetlands can act as natural filters that remove nutrients from water. Restoring or creating wetlands can help improve water quality.

Education and awareness: Awareness of the causes and impacts of eutrophication is important for engaging communities and farmers in developing sustainable practices.

Monitoring and research: Regular monitoring of water bodies for nutrients and the impact of eutrophication helps to intervene in time and evaluate the effectiveness of management measures.

Summary

Eutrophication is a serious environmental problem that results from excessive inputs of nutrients into aquatic ecosystems. It leads to algal blooms, oxygen depletion, loss of biodiversity and degradation of water quality. Effective management, monitoring and promotion of sustainable practices can combat eutrophication and restore the health of water bodies.

Groundwater located in the saturated zone of the soil, directly above the impermeable layer. This water is under atmospheric pressure and can be reached through shallow wells. Phreatic water is the most accessible form of groundwater and is often used for drinking water and irrigation.

The Groundwater Formation Resistivity Dossier (FRD) is a specialised report used in hydrogeology to evaluate the electrical resistivity of underground formations for the purpose of identifying and assessing groundwater reservoirs. As in the oil and gas industry, resistivity measurements are an important tool in groundwater exploration and management as they help determine the types of fluids present in underground formations, with an emphasis on fresh and salt water. 

Key Aspects of Groundwater FRD:

1. Resistance in groundwater research

Electrical resistivity is used to characterise underground materials and distinguish between different types of water (fresh water, brackish water or salt water) and other geological features such as clay or rock.

Fresh water usually has a higher resistance compared to salt water, which is a good conductor because of the dissolved salts.

The resistivity of a formation can also indicate whether the subsurface is permeable, as in the case of sand and gravel layers that allow groundwater flow.

2. Applications in Groundwater exploration

Aquifer Mapping: By measuring resistivity, hydrogeologists can identify and map the extent and depth of aquifers (water-bearing formations).

Assessment of Water Quality: Resistivity measurements can help assess the salinity of groundwater, which is crucial in determining whether the water is suitable for drinking water, irrigation or industrial use.

Detection of contamination: FRD can be used to detect contamination in groundwater, especially when contaminants change the conductivity of groundwater, such as chemicals from industrial discharges or agricultural runoff.

3. Resistance logging tools for Groundwater

Electrical resistivity tomography (ERT): a widely used geophysical method for groundwater investigations, providing 2D or 3D resistivity profiles of the subsurface.

Vertical Electrical Sounding (VES): a technique in which electrical resistivity measurements are taken at different depths to assess subsurface layers and identify water-bearing formations.

Induction and electromagnetic tools: Used in boreholes to measure formation resistance and identify groundwater zones.

4. Interpretation of groundwater FRD

Resistance curves: These show the variation in resistivity with depth and help identify aquifer zones, water quality and impermeable layers such as clays that can confine or separate aquifers.

Water saturation and porosity: Resistivity data, often combined with porosity information, are used to estimate the volume of water in the formation and determine its flow properties.

Aquifer boundaries: Resistivity data can define the upper and lower boundaries of aquifers and distinguish between zones with different water qualities.

5. Archie's Equation for Groundwater

As in oil and gas exploration, Archie's Equation is used to estimate water saturation in formations, with specific adjustments for groundwater studies. By using resistivity and formation porosity, hydrogeologists can estimate the volume and quality of groundwater in the subsurface.

6. Applications of the Groundwater FRD

Groundwater management: FRD helps water authorities and hydrogeologists manage groundwater resources by providing information on the location, quality and quantity of groundwater.

Drilling for Wells: When planning new wells, the FRD can indicate where the best yield of potable water can be found.

Environmental monitoring: Resistivity data from the FRD can be used to monitor changes in groundwater over time, especially in areas affected by pollution or overexploitation.

Groundwater Resistivity and Lithology

The resistivity of formations varies with lithology (rock or soil type).

For example:

Sand and gravel quivers: typically have higher resistance values when filled with fresh water.

Clay or shale: Very low resistance due to their conductive nature, even when dry.

Saltwater zones: Low resistance due to high conductivity of dissolved salts.

Importance of Groundwater FRD:

Water security: The FRD provides crucial information to ensure that groundwater abstraction and management is done in a sustainable manner.

Prevention of Pollution: Helps monitor and detect pollution, enabling timely action to protect water quality.

Sustainable Development: Guides planning and decision-making in water management so that groundwater use does not exceed natural recharge capacity.

Conclusion

The Groundwater Formation Resistivity Dossier (FRD) is an essential tool for identifying, evaluating and managing groundwater resources. It provides detailed insights into subsurface conditions, allowing hydrogeologists to make informed decisions about water availability, quality and sustainability.

The Groundwater Analysis Report is a detailed document that evaluates the chemical, physical and biological properties of groundwater. The purpose of this report is to assess groundwater quality, identify possible contaminants and determine its suitability for various purposes such as drinking water, irrigation or industrial use.

Key Sections of a Groundwater Analysis Report:

1. chemical analysis

The chemical composition of groundwater is crucial in determining water quality and suitability for consumption or other uses. This includes:

pH level: Indicates whether the water is acidic, neutral or alkaline. A pH between 6.5 and 8.5 is usually considered acceptable for drinking water.

Electrical conductivity (EC): Used to measure the salinity of water. Higher conductivity values may indicate salt water or pollution.

Total dissolved solids (TDS): Indicates the number of minerals, salts and metals dissolved in the water. Higher TDS values can affect water quality and taste.

Hard minerals: Such as calcium and magnesium, which determine water hardness. Hard water can cause problems with household appliances and pipes.

Heavy metals: Such as lead, mercury, cadmium and arsenic, which can be harmful to health.

Nutrienten: Such as nitrate and phosphate, which may indicate agriculture-related pollution.

2. physical analysis

This section focuses on the physical properties of water, such as:

Turbidity: A measure of water clarity caused by particles such as clay, silt or biological substances. Turbid water can be an indication of pollution or presence of sediment.

Colour and smell: Colourless and odourless water is usually a sign of purity. Discolouration or an unpleasant odour may indicate contamination by organic matter or chemicals.

Temperature: The temperature of groundwater can affect the solubility of gases and minerals.

3. biological analysis

Microbiological tests: These tests are performed to check for the presence of pathogenic microorganisms such as coliform bacteria, Escherichia coli (E. coli) and other harmful bacteria or viruses. The presence of these microorganisms may indicate faecal contamination or other biological contamination.

Algae and other biologicals: Sometimes biological substances, such as algae, can also be present in groundwater, indicating possible surface water influences.

4. Pollution survey

This part of the report evaluates the presence of pollutants that may result from industrial, agricultural or urban activities. Examples include:

Pesticides and herbicides: Chemicals used in agriculture that can enter groundwater through runoff or infiltration.

Organic contaminants: such as solvents, oils and fuels that may originate from industrial activities.

Chemicals such as PFAS (poly- and perfluoroalkyl substances): These can come from industrial sources and are increasingly becoming a concern due to their persistent nature and adverse health effects.

5. hydrogeological context

The report often contains information on the hydrogeology of the area where the groundwater was tested. This includes:

Location of groundwater source: The geographical location, depth of the well or spring, and the type of aquifer from which the water is drawn.

Water level: Water levels in wells or aquifers can help assess groundwater availability and monitor changes in water levels.

Infiltration areas and flow directions: Provides insight into groundwater origin and potential sources of contamination.

6. Comparison with Standards

This section compares the measured values of the various parameters with the relevant national or international drinking water standards and guidelines. Examples of standards are:

WHO (World Health Organisation) Drinking water standards

National drinking water standards (such as the Dutch drinking water standards laid down in the Drinking Water Decree)

EU Water Framework Directive: This directive sets requirements for the water quality and ecological status of ground and surface waters in the European Union.

7. Recommendations and Conclusions

Based on the analysis of groundwater, recommendations are made for its use. This may include:

Fitness for consumption: Is the water safe to drink? If not, what treatment methods can be used to make the water suitable?

Use for irrigation: Does the water contain salt or minerals that could be harmful to crops or farmland?

Environmental management: Are any measures proposed to protect water quality from further pollution?

Importance of the Groundwater Analysis Report:

Public Health Protection: The report helps identify potential health risks in drinking water sources, such as bacterial contamination or the presence of harmful chemicals.

Environmental and Groundwater Management: By detecting pollution early, appropriate measures can be taken to preserve water quality and prevent further damage.

Policy-making support: The report provides data for local and national authorities to make informed decisions on water management, water distribution and environmental protection.

Sustainable Water Use: The report helps determine the sustainability of water resources by analysing whether the water quality is suitable for long-term use.

Conclusion

The Groundwater Analysis Report is an essential tool for assessing groundwater quality. It provides a comprehensive overview of the chemical, physical and biological properties of the water, as well as the presence of contaminants. Based on this analysis, stakeholders can make decisions on the safe use of the water for various uses, such as drinking water, agriculture, and industrial processes.

GLF (Groundwater Level File) refers to a collection of data and information on groundwater levels in a given area. A GLD systematically documents fluctuations in groundwater levels and is often used in hydrological research, water management and environmental monitoring.

Goals of a Groundwater Level File:

Monitoring groundwater levels: A GLD contains data on the elevation of groundwater over a given period. These data are usually collected through a network of monitoring wells or monitoring wells.

Management of water resources: The information in a GLD helps water managers assess the availability of groundwater for drinking water extraction, agricultural irrigation and industrial uses.

Assessment of seasonal variations: By monitoring groundwater levels over a longer period of time, trends in seasonal variations or changes due to climate change can be analysed.

Early warnings of problems: A GLD can provide early warning signals of problems such as groundwater overexploitation, salinisation (if salt water infiltrates groundwater), or soil subsidence due to falling groundwater levels.

Supporting policy and decision-making: The file provides crucial information for governments, water boards and companies making decisions on the use and protection of groundwater resources.

Elements in a GLF:

Measured data of groundwater levels: Regular groundwater level measurements.

Location information: The geographical location of the measurement points.

Hydrological analysis: Evaluation of trends, such as rising or falling groundwater levels.

Reports: Overviews and interpretations of measurement results, often with recommendations for water management.

A GLF is an essential tool for sustainable groundwater management, focusing on ensuring the long-term availability and quality of groundwater.

A GMN stands for "Groundwater monitoring network". This is a network of monitoring points used to monitor groundwater quality and quantity. The purpose of a groundwater monitoring network is to collect data on various aspects of groundwater, such as:

Groundwater level: This measures the height of groundwater in different layers of the subsurface.

Groundwater quality: This includes testing the chemical composition of groundwater, such as the presence of minerals, pollutants (such as nitrates or heavy metals), and biological parameters (such as bacteria).

Groundwater flow: This concerns the direction and velocity of groundwater in the subsurface, which is important to understand how water moves through different layers.

Functions of a GMN

Monitoring of drinking water sources: An important purpose of the groundwater monitoring network is to monitor the quality of groundwater used for drinking water.

Management of groundwater resources: By monitoring how much groundwater is available, governments or water companies can ensure sustainable use of this water resource.

Detection of contamination: The monitoring network helps in early detection of contaminants such as chemicals that may enter groundwater from agriculture, industry or spills.

Climate change and groundwater: GMNs are also used to study the effects of climate change, such as changes in groundwater recharge due to changing precipitation patterns.

The Groundwater Monitoring Network is an essential tool for sustainable management of groundwater resources and ensuring water quality for various uses, including drinking water, agriculture and industry.

Water trapped in the pores and cracks of soils and rocks below the Earth's surface. This water plays a crucial role in hydrology and water management.

The set of activities aimed at managing groundwater, such as measuring water levels, managing water levels and preventing dehydration or salinisation. This is important for water quality, agriculture and nature conservation.

GroundwaterOffice is a complete management system for monitoring and analysing groundwater data. The software provides tools for managing groundwater monitoring networks, processing measurement data and generating reports. GroundwaterOffice also supports advanced analyses of groundwater flows, groundwater-surface water interactions, and the impact of groundwater abstraction. It is used by hydrologists, governments and research institutions for managing groundwater resources, modelling aquifers and setting sustainable abstraction limits. 

The process of extracting water from aquifers via pumps or wells. This is often done for drinking water, agriculture and industry, but can lead to lowering of groundwater levels and salinisation.

The elevation of groundwater relative to a reference plane, usually ground level. This is often measured with piezometers or pressure sensors.

The study of water flows on and below the Earth's surface, including precipitation, runoff, evaporation and groundwater flow. Hydrology is essential for understanding water management and climate effects.

Hydros is a software package for modelling hydrological systems and water flows in surface water and groundwater. It allows users to simulate water balances, analyse rainfall-drainage relationships, and evaluate the impact of climate change on water resources. Hydros is widely used by governments and engineering firms to optimise water systems and manage risks such as floods and droughts. It also supports decision-making processes in water management and spatial planning. 

The process by which water from the earth's surface sinks into the soil and recharges groundwater. This can be influenced by soil structure, vegetation and climate.

A network of physical devices, such as sensors and measuring instruments, that are connected via the internet and exchange data. In water management, IoT is used to remotely monitor pressure sensors, groundwater level gauges and other equipment and analyse the collected data in real-time. This facilitates more efficient water management and faster decision-making.

The process of adjusting a pressure sensor or other measuring instrument so that it provides accurate and reliable measurements. Calibration is essential for obtaining accurate water level measurements.

Climate change refers to long-term changes in temperature, precipitation and other weather patterns on Earth. These changes can be caused either naturally or by human activities, but current climate change is mainly driven by human activities, such as burning fossil fuels, deforestation and industrial processes. The impacts of climate change are profound and have a wide range of environmental, economic and social implications. 

Causes of climate change

Greenhouse gases: Emitting greenhouse gases, such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), from human activities is the main cause of current climate change. These gases trap heat in the atmosphere and raise global temperatures, leading to what is known as the greenhouse effect.

Deforestation: Cutting down trees reduces the earth's capacity to absorb CO2, contributing to rising concentrations of this greenhouse gas in the atmosphere. Deforestation also disrupts local climates and hydrology.

Land use: Changes in land use, such as the conversion of natural ecosystems to agricultural land or urban areas, affect local and regional climate systems. These changes can reduce soil fertility and disrupt water cycles.

Industrialisatie: The growth of industry, especially in developing countries, has led to an increase in greenhouse gas emissions from burning fossil fuels such as coal, oil and gas.

Effects of climate change

Rising temperatures: Average global temperatures are rising, leading to more extreme weather events such as heat waves, droughts and heavy rainfall.

Change in precipitation patterns: Climate change affects precipitation patterns, which can lead to flooding in some areas and drought in others. This has significant implications for agriculture and water supply.

Melting ice sheets and sea level rise: Melting ice sheets in Greenland and Antarctica contribute to sea level rise, threatening low-lying coastal areas and island states.

Ecosystem change: Many ecosystems and species are threatened by climate change. Changes in temperature and precipitation can lead to the loss of biodiversity as species cannot adapt quickly enough or migrate to more suitable areas.

Health problems: Climate change also affects public health. Increased temperatures can lead to an increase in air pollution, allergies and the spread of infectious diseases.

Socio-economic impact: The effects of climate change can lead to food insecurity, water shortages and migration of people in search of better living conditions, which can lead to conflicts over scarce resources.

Addressing and mitigating climate change

Reducing greenhouse gas emissions: Reducing greenhouse gas emissions is essential. This can be achieved by switching to renewable energy sources such as solar and wind power, promoting energy efficiency and implementing sustainable transport solutions.

Renewable energy: Investing in and switching to renewable energy sources helps reduce dependence on fossil fuels and reduce CO2 emissions.

Sustainable land use: Promoting sustainable land use, such as agroecology and reforestation, can help reduce CO2 emissions and preserve biodiversity.

International cooperation: Climate change is a global problem that requires international cooperation. Treaties such as the Paris Agreement are crucial to oblige countries to reduce their emissions and take joint action on climate change.

Climate change adaptation: Besides mitigation, adaptation is also necessary. This includes developing strategies to reduce the impact of climate change on communities and ecosystems, such as building flood defences and improving water supply and agricultural practices.

Summary

Climate change is a complex and urgent problem with significant environmental, economic and social impacts. It requires concerted efforts at local, national and international levels to address its causes and mitigate its impacts. By promoting sustainable practices and policies, the world can work towards a more resilient future in the face of climate change challenges.

Agricultural activities include a wide range of practices carried out to grow and produce food, fibre, and other products. These activities have significant impacts on the environment, biodiversity and water resources. The following is a detailed overview of the main aspects of agricultural activities, including their benefits and drawbacks.

Major agricultural activities

Crop production: This includes growing different types of crops, such as cereals (e.g. wheat, maize), vegetables, fruits and oilseeds. The choice of crops depends on local climatic and soil conditions.

Animal production: This includes raising animals for meat, milk, eggs and other products. Livestock production can range from small-scale farms to large-scale industrial production systems.

Irrigation: Getting water to crops is essential in areas with limited rainfall. Irrigation practices can range from traditional methods (such as canals) to modern techniques (such as drip irrigation).

Soil management: These include practices aimed at maintaining and improving soil health, such as crop rotation, no-till (minimum tillage) and adding organic matter.

Use of fertilisers and pesticides: Fertilisers are used to promote crop growth, while pesticides are applied to control pests and diseases. The use of these chemicals must be carefully managed to minimise negative impacts on the environment.

Agricultural technology: Modern technologies, such as precision agriculture, drones, and genetic modification, are increasingly being used to increase agricultural efficiency and yields.

Benefits of agricultural activities

Food production: Agriculture is essential for food production and contributes to food security for the world's growing population.

Economic contribution: The agricultural sector is an important contributor to the economy of many countries, especially in developing countries. It provides employment and supports local communities.

Biodiversity: Diversity in crop and livestock production can contribute to biodiversity and ecosystem stability. Traditional farming practices can also promote diversity of plant and animal species.

Renewable resources: Agriculture uses natural resources such as sunlight, water and soil, which contributes to the circular economy if managed in a sustainable way.

Disadvantages of agricultural activities

Environmental impact: Intensive agricultural practices can lead to soil erosion, water pollution from fertiliser and pesticide run-off, and the decline of biodiversity.

Water wastage: Traditional irrigation techniques can lead to water losses and over-exploitation of water sources, with negative impacts on ecosystems and drinking water supplies.

Climate change: The agricultural sector contributes to greenhouse gas emissions, such as methane (from livestock production) and nitrous oxide (from fertilisers), which contribute to climate change.

Reliance on chemicals: The use of fertilisers and pesticides can lead to soil and water pollution, and can have harmful effects on human and animal health.

Sustainable agricultural practices

Agro-ecologies: This is a holistic approach to agriculture that uses natural processes and biodiversity to produce food.

Organic farming: Organic farming practices avoid synthetic fertilisers and pesticides and promote soil and ecosystem health.

Permaculture: This is a system design aimed at creating sustainable farming systems that promote biodiversity and reduce the ecological footprint.

Integrated crop protection: This is an integrated approach to pest management that uses both chemical and biological methods to manage pests, with a focus on minimising the use of harmful chemicals.

Summary

Agricultural activities are crucial for food production and economic development, but they also have significant impacts on the environment. It is important to promote sustainable agricultural practices to minimise negative impacts on ecosystems and the health of the planet. Through efficient use of resources and technologies, the agricultural sector can contribute to a sustainable future for both people and nature.

The National Groundwater Quality Monitoring Network (LMG) is a network of monitoring points operated by the Dutch government to monitor groundwater quality on a national scale. Created to understand groundwater quality throughout the Netherlands, this monitoring network focuses on monitoring the effects of human activities, such as agriculture, industry, and urban development, on groundwater.

Goals of the National Groundwater Quality Monitoring Network

National groundwater quality monitoring: The LMG provides an overall picture of groundwater quality in the Netherlands, collecting information on groundwater composition and the presence of contaminants.

Meeting international obligations: Data from the LMG are used to comply with reporting obligations arising from European regulations, such as the Water Framework Directive (WFD). This directive obliges the Netherlands to systematically monitor and report on the quality of water bodies, including groundwater.

Evaluate policies and measures: The LMG provides crucial information to assess the effects of policy measures. For example, the results can provide insight into the effectiveness of measures taken to combat pollution from, for example, agriculture (fertilisers, pesticides) or urban and industrial activities.

Identify long-term trends: By taking measurements at fixed locations and at regular intervals, long-term trends in groundwater quality can be identified. This helps identify improvements or deteriorations in water quality, which may be caused, for example, by climate change or land-use changes.

Operation of the National Groundwater Quality Monitoring Network

The LMG consists of hundreds of monitoring points strategically distributed throughout the Netherlands. These monitoring points are located at different depths to provide insight into the quality of both shallow and deep groundwater. The monitoring network is managed by Rijkswaterstaat, in cooperation with other organisations such as water boards and drinking water companies.

Frequency of measurements: Monitoring points are usually sampled annually or once every two years. This gives a regular overview of quality and any changes over time.

Parameters to be measured: As with the Provincial Monitoring Network, various chemical and physical parameters are measured, such as nitrate, ammonium, heavy metals, pesticides, and organic pollutants. Water quality is also measured based on, for example, acidity (pH), conductivity, and oxygen content.

Distribution of measurement points: The monitoring points are located in different types of areas, such as agricultural land, natural areas, and urban areas, to get a complete picture of the national groundwater quality.

Relationship with other monitoring networks

The LMG is complementary to regional and provincial monitoring networks, such as the Provincial Groundwater Quality Monitoring Network (PMG), but has a national focus. It provides a broader, national overview, while provincial monitoring networks are often more specific to regional groundwater quality issues.

Importance for drinking water and environment

The National Groundwater Quality Monitoring Network is of great importance because groundwater is a primary source of drinking water in the Netherlands. About 60% of Dutch drinking water comes from groundwater. Monitoring the quality of this water is essential to ensure that it remains safe and clean for human consumption. In addition, groundwater is also important for nature, especially for ecosystems that depend on a stable, clean water supply.

Conclusion

The National Groundwater Quality Monitoring Network is a crucial tool for monitoring and protecting groundwater quality in the Netherlands on a national scale. The data collected not only help comply with European directives, but also contribute to the development of sustainable water management and the protection of essential water sources for drinking water and nature.

In hydrology, ground level refers to the surface of the ground, or the level of natural or artificial soil in a given area. The ground level forms the separation between the soil and the atmosphere and is often used as a reference point in measurements of groundwater levels, water levels and other hydrological data.

Use of ground level in hydrology

Hydrological studies use the ground level as a reference to determine the following, among other things:

Groundwater level: This is the height of groundwater relative to ground level. For example, if the groundwater level is 1 metre below ground level (1 m-mv), it means that the groundwater is at one metre below the ground surface.

Water levels: Measurements of flooding or drainage, for example, also consider the relationship of water levels to ground level.

Drainage and infiltration: The position of the ground level is important for understanding how water drains from the surface and how it infiltrates into the soil.

In essence, ground level is a crucial reference when analysing the interaction between water and land.

A network of sensors and monitoring points used continuously to monitor water levels, groundwater quality, and other hydrological parameters. Monitoring monitoring monitoring networks can be primary, secondary or focused on specific purposes, such as ecological management or infrastructure protection. The aim is to record changes in real-time or on a regular basis.

A reference altitude used in the Netherlands to measure water levels, groundwater levels and elevations. NAP is approximately equal to the mean sea level. Water levels and groundwater levels are often reported in relation to NAP, for example as "5 metres above NAP" or "2 metres below NAP". This is a standard for water management and spatial planning in the Netherlands.

Scenarios used in groundwater management to model the impact of different amounts of groundwater abstraction, e.g. for irrigation or drinking water.

Organic micropollutants refer to a diverse group of organic compounds that are present in the environment in very low concentrations, but can be potentially harmful to human and environmental health. These contaminants often include substances that are not naturally degradable and can arise from various human activities, such as industry, agriculture, and domestic use.

Examples of organic micropollutants

Medications: Residues of pharmaceuticals entering wastewater, such as antibiotics, painkillers, and endocrine disruptors.

Personal care products: Compounds such as parabens and microplastics found in cosmetics and detergents.

Plastics: Components of plastic products that can degrade in the environment and accumulate in water bodies.

Pesticides: Organic pesticides used in agriculture that can enter watercourses via runoff.

Industrial chemicals: Compounds such as dioxins and PCBs (polychlorinated biphenyls) released from industrial processes.

Causes of organic micropollutants

Wastewater discharges: Many organic micropollutants enter the environment through wastewater from households and industries that are not properly filtered.

Agricultural activities: The use of pesticides and fertilisers in agriculture can lead to run-off of pollutants into water bodies.

Waste management: Improper disposal of drugs and chemicals can lead to contamination of soil and water.

Atmospheric deposition: some substances can enter the environment through the air due to combustion and other industrial activities.

Effects of organic micropollutants

Health risks: Exposure to organic micropollutants can lead to health problems such as endocrine disorders, cancer, and immunosuppression. This can affect both humans and animals.

Ecological impact: organic micropollutants can have harmful effects on ecosystems, for example by reducing biodiversity or disrupting food chains.

Water quality: The presence of organic micropollutants in drinking water can reduce water quality and compromise safety for human consumption.

Accumulation in food chains: Some organic micropollutants can accumulate in organisms and spread through the food chain, leading to elevated concentrations in top predators, including humans.

Management and control of organic micropollutants

Wastewater treatment: Improving wastewater treatment processes can help remove organic micropollutants more effectively before releasing water into the environment.

Sustainable use of chemicals: Promoting the use of less harmful chemicals in agriculture and industry can help reduce pollution.

Regulation: Stricter regulations on the use and disposal of organic substances can help reduce the introduction of these contaminants into the environment.

Public awareness: Education and awareness campaigns can help people understand how to handle chemicals and medicines responsibly to minimise environmental impact.

Monitoring: Regular monitoring of water and soil quality for the presence of organic micropollutants can help identify problem areas and implement targeted measures.

Summary

Organic micropollutants are harmful substances that occur in low concentrations in the environment but can have serious effects on human and ecosystem health. Through effective management strategies, sustainable practices and awareness raising, the impact of these contaminants can be reduced, contributing to a cleaner and healthier environment

Overabstraction refers to the situation where more water is withdrawn from an aquifer system or water body than can be naturally replenished. This phenomenon occurs in both groundwater and surface water systems and can lead to serious ecological and economic problems.

Causes of overextraction

Intensive water harvesting: Agriculture, industry and urban areas can create significant demand for water. This leads to excessive abstraction of groundwater or surface water, often without regard to natural supply systems.

Population growth: In areas with rapidly growing populations, the demand for water for drinking, sanitation and irrigation can exceed natural water supplies.

Climate change: Changes in precipitation patterns due to climate change may reduce the natural replenishment of aquifers while increasing water demand.

Irrigation practices: Inefficient irrigation techniques in agriculture can lead to increased water consumption and hence over-exploitation of groundwater.

Consequences of overextraction

Lowering the water table: Overabstraction leads to a lowering of the water table, which means that springs, wells and other water bodies have less water available.

Loss of biodiversity: Ecosystems dependent on aquatic habitats may suffer from water deprivation. This can lead to the loss of biodiversity and disturbance of natural habitats.

Decreasing water quality: When the groundwater table drops, it can lead to higher concentration of contaminants in the remaining water, reducing water quality.

Saltwater intrusion: In coastal areas, overexploitation of groundwater can lead to saltwater intrusion, with saltwater intruding into freshwater supplies. This has negative impacts on drinking water supply and agriculture.

Declining agricultural productivity: Declining groundwater levels can lead to lower crop yields, especially in areas dependent on irrigation, which can lead to food insecurity.

Economic impact: The consequences of over-abstraction can lead to higher water management costs, reduction in agricultural production and negative effects on the local economy.

Management and control of over-abstraction

Sustainable water management: Implementing sustainable water management practices can help reduce water demand and preserve water supplies. This includes using efficient irrigation techniques and water-saving technologies.

Restoring aquifers: Promoting natural replenishment of aquifers by restoring wetlands and improving runoff management can help conserve water resources.

Limiting water abstraction: Setting limits on the amount of water that can be withdrawn from aquifers and water bodies can help prevent over-abstraction.

Monitoring water resources: Regular monitoring of groundwater and surface water levels helps identify trends in water abstraction and take timely action.

Education and awareness: Raising awareness about the importance of water conservation and sustainable use of water can encourage communities to use water resources responsibly.

Summary

Overabstraction is a major problem arising from the overabstraction of water from natural systems. It can lead to falling water tables, loss of biodiversity, reduced water quality and negative economic impacts. Sustainable water management, monitoring and education can reduce the impact of overabstraction and preserve water resources for future generations.

The property of a material (such as soil or rock) that determines how easily water can flow through it. This affects the speed of groundwater flow.

Pesticides are chemicals used to control pests, diseases and weeds in agriculture and other sectors. They are essential for improving crop yields and protecting food supplies, but their use also raises concerns about environmental and health impacts. Below is a detailed overview of pesticides, including their types, benefits, drawbacks and alternatives.

Types of pesticides

Insecticides: These are aimed at controlling insects that damage crops. Examples include pyrethroids, neonicotinoids and organophosphates.

Herbicides: These pesticides control weeds that compete with crops for water, nutrients and sunlight. Examples include glyphosate and 2,4-D.

Fungicides: Fungicides are used to control fungal diseases that can affect crops. Examples include azoles and strobilurins.

Rodenticides: These are aimed at controlling rodents such as rats and mice, which can cause damage to crops and buildings.

Bacteriocides: These control bacterial infections that can affect crops.

Benefits of pesticides

Increased yields: Pesticides help protect crops from pests and diseases, leading to higher yields and food security.

Cost savings: Pesticide use allows farmers to reduce costs by minimising losses due to pests and diseases.

Efficiency: Pesticides are often effective in controlling specific pests quickly and in a targeted manner, contributing to the efficiency of agricultural production.

Food protection: The use of pesticides helps protect food for consumers by reducing fungi and other pathogens.

Disadvantages of pesticides

Health risks: Exposure to pesticides can be harmful to human health, with possible effects ranging from acute poisoning to long-term health problems such as cancer and endocrine disruptions.

Environmental impact: Pesticides can be harmful to the environment, especially to non-target organisms such as bees, birds and other beneficial insects. They can also reduce biodiversity and disrupt the ecosystem.

Resistance: Pests can develop resistance to pesticides, reducing their effectiveness. This can lead to a cycle of increasingly potent and potentially harmful chemicals.

Pollution: Pesticides can enter the environment through run-off and drip, leading to pollution of water bodies and soils.

Alternatives to pesticides

Biological control: Using natural enemies of pests, such as predatory insects and parasites, can help control pests without chemicals.

Agroecological practices: This includes promoting biodiversity, using crop rotation and establishing flower beds to attract beneficial insects.

Integrated Pest Management (IPM): IPM combines various control methods, including chemical, biological and cultural techniques, to effectively control pests with minimum negative impact on the environment.

Sustainable farming practices: Practices such as improving soil health, water management and minimising ecosystem disturbance can reduce reliance on pesticides.

Management and regulation

Regulation: Pesticides are regulated in many countries to ensure human and environmental safety. This includes approval before sale and use of pesticides and guidelines for safe application.

Monitoring: Regular monitoring of pesticide use and effects helps identify problems and develop effective risk management strategies.

Research and development: Investing in research into new, less harmful pesticides and sustainable agricultural practices is crucial for the future of agriculture and the environment.

Summary

Pesticides are important tools in agriculture that help protect crops and increase food production. However, their use is associated with significant health and environmental problems. Promoting alternative pest control methods and sustainable agricultural practices can help minimise the impact of pesticides and strike a balance between production and environmental conservation.

PFAS, or per- and polyfluoroalkyl substances, are a group of more than 4,700 chemical compounds characterised by a strong fluorine-containing carbon chain. These substances are known for their water- and fat-repellent properties, which is why they are used in a wide range of industrial and consumer products. PFAS are often referred to as "forever chemicals" because they are difficult to degrade in the environment and in the human body..

Applications of PFAS

Industrial use: PFAS are used in various industrial processes, such as making coatings, abrasion-resistant materials, and as foams in firefighting.

Consumer products: They are often found in products such as:

1. Anti-stick pans
2. Water-repellent clothing
3. Cleaning products
4. Floor coverings
5. Food packaging (e.g. packaging for fast food)
6. Fire-fighting foam: Specific PFAS compounds are often used in fire suppression systems, especially in fires of liquids and petrochemicals.

Health risks from PFAS

Exposure: Humans can ingest PFAS through food, water, air, and contact with products containing PFAS. The most common exposure often comes through contaminated drinking water.

Health problems: Exposure to PFAS has been associated with several health problems, including:

1. Hormone disruptions
2. Elevated cholesterol
3. Immunosuppression (reduced immune response)
4. Thyroid problems
5. An increased risk of certain types of cancer (such as kidney and testicular cancer)
6. Reduced immunity: There is evidence that PFAS can reduce the effectiveness of vaccines, leading to reduced immunity to infection.

Environmental impact of PFAS

Persistent contamination: PFAS are very persistent and can accumulate in the environment. They are often found in water bodies, soil and sediments, and can persist for years without being degraded.

Contamination of drinking water: Many communities face PFAS contamination in their drinking water supplies, especially near industrial sites or areas where firefighting foam has been used.

Ecological impact: PFAS can be harmful to aquatic organisms and other animals, leading to disruptions in ecosystems and food chains.

Management and regulation of PFAS

Regulation: Many countries and regions have taken measures to restrict or ban the use of certain PFAS compounds. This includes setting legal limits for PFAS in drinking water and developing guidelines for their safe use and disposal.

Monitoring: It is important to carry out regular monitoring of water, soil and sediments for PFAS contamination to identify risks to human health and the environment.

Clearance: There are efforts to clean up contaminated sites and develop technologies that can effectively remove PFAS from water and soil.

Alternatives: The development and promotion of PFAS-free alternatives to the products currently containing PFAS is essential for reducing dependence on these substances.

Conclusion

PFAS are an important group of chemicals used in numerous applications, but which also cause significant health and environmental problems. It is crucial to minimise exposure to PFAS through effective regulation, monitoring and developing safe alternatives. Awareness of PFAS risks and environmental impact is also an important step towards a healthier future.

An instrument used to measure the pressure of groundwater, allowing the height of the water table to be determined.

Piezometer, or "piezos", is a corruption of piezo-resistive pressure sensor. Its operation is based on measuring change in electrical resistance of a material due to an applied pressure. This principle is often used in sensors that measure water pressure, for example in groundwater and surface water monitoring.

Application in water level measurement

In hydrological applications, the measured pressure is used to calculate the height of the water column (and thus the water level). The sensor measures the total pressure, and to determine the exact water depth, the air pressure (atmospheric pressure) is usually compensated via a reference or a second sensor.

Example:

Suppose the pressure sensor is located 10 metres below the water surface.

The sensor records a certain pressure corresponding to the weight of the water column above the sensor.

This pressure is converted to a water height of 10 metres.

Advantages of a piezo-resistive pressure sensor over ceramic or thin/thick film sensors:

High sensitivity: They can detect very small pressure changes.

Compact: The technology allows sensors to be small and robust, which is useful for measuring in difficult environments such as groundwater wells.

Reliable: They are durable and work well in harsh conditions, such as underwater or in varying temperatures.

Very stable

In short, a piezo-resistive pressure sensor converts the mechanical pressure of a water column into an electrical value, which is then used to accurately determine the water level or pressure.

The Provincial Groundwater Quality Monitoring Network (PMG) is a network of monitoring points used by provinces in the Netherlands to systematically monitor groundwater quality. This monitoring network was set up to understand the state of groundwater, monitor the effects of human activities on groundwater quality, and comply with legal obligations, such as those arising from the Water Framework Directive (WFD) and other environmental legislation.

Goals of the Provincial Groundwater Quality Monitoring Network

Protecting groundwater quality: The monitoring network helps provinces check whether groundwater quality meets environmental standards. This is vital to protect drinking water sources and natural areas that depend on clean groundwater.

Monitoring trends: By measuring various parameters in groundwater, such as concentrations of nutrients (e.g. nitrate and phosphate), heavy metals and other contaminants, trends in groundwater quality over time can be identified. This helps identify deteriorations or improvements.

Beleidsondersteuning: The data collected through the monitoring network support provinces in developing environmental policies. They help determine the effectiveness of measures taken to prevent or reduce pollution and ensure sustainable groundwater management practices.

Reporting requirements: Information from the PMG is used to meet national and European reporting obligations, such as those under the Water Framework Directive. This obliges provinces and other water managers to monitor and report the quality of water bodies, including groundwater.

Operation and management

The monitoring network consists of a large number of monitoring points placed at strategic locations, for example in agricultural areas, nature reserves and around drinking water catchments. At these locations, groundwater is regularly sampled and analysed for the presence of pollutants.

Frequency of measurements: Measurements are carried out periodically, often annually or biennially, depending on the site and the specific objectives of the monitoring.

Parameters: The measurements can cover a variety of chemical parameters such as nitrate, phosphate, chloride, pesticides, heavy metals and organic pollutants.

Collaboration: Het Provinciaal Meetnet werkt vaak samen met andere instanties, zoals waterschappen, Rijkswaterstaat, en drinkwaterbedrijven, om een zo breed mogelijk beeld te krijgen van de grondwaterkwaliteit in een provincie.

Importance for sustainability and drinking water

The PMG plays a crucial role in ensuring the quality of groundwater, which is an important source of drinking water in the Netherlands. By identifying early changes in groundwater quality, provinces can intervene in time and take measures to address problems such as pollution from agriculture, industry or urban developments.

Summary

The Provincial Groundwater Quality Monitoring Network is an essential tool for monitoring and protecting groundwater quality in the Netherlands, supporting sustainable water management and protecting the environment and public health.

A groundwater pumping well is a specially constructed well used to pump groundwater for various purposes, such as drinking water extraction, irrigation, industrial processes, or lowering the groundwater level in a particular area.

Here are some key features of a groundwater pumping well:

Construction: A sump pit consists of a deep bore in the ground, often with a pipe fitted with filter sections that allow water to pass through while holding back sediments.

Function: The purpose of the sump pit is to pump groundwater from an aquifer. The water is raised via a pump and can then be used or treated, depending on the application.

Applications: Pump wells are used for drinking water extraction, irrigation in agriculture, industrial applications and sometimes for water management, such as lowering groundwater levels in construction projects.

Bewaking: Besides water extraction, a pumping well can also be used for monitoring groundwater levels or quality in a given area.

Pump wells play a crucial role in areas where groundwater is an important source of water. The use and management of these wells must be done carefully to avoid overexploitation and negative impacts such as salinisation or desiccation.

The amount of open space in soil or rock that can hold water. High porosity means more space for groundwater storage.

The most important and extensive network of monitoring sites used for monitoring water levels, both groundwater and surface water. This monitoring network is often designed to cover a large area and provides high-quality data crucial for long-term analysis and policy-making.

Groundwater well regeneration is a process of restoring an existing groundwater well (such as a pumping well or monitoring well) to regain its original capacity and efficiency. Over time, groundwater wells can become clogged by, for example, accumulation of sediments, minerals, organic matter or bacterial growth, which reduces water permeability and harms the productivity of the well. Well regeneration helps remedy these problems without having to construct a new well. 

Here are the key steps and methods for pit regeneration:

Mechanical cleaning: This involves using techniques such as brushing, scraping, or air injection to physically clean the filter sections of the well. This helps to remove deposits or clogged sections.

Chemical cleaning: Chemicals, such as acids or oxidising agents, are introduced into the well to dissolve deposits such as calcium, iron, manganese or biofilms that have adhered to the well wall.

Hydraulic cleaning: High-pressure water or air is injected into the well to flush out accumulated sediment and other blockages. Sometimes methods such as "surging" are also used, in which water is pumped through the well in a pulsating manner to loosen blockages.

Regeneration with specific equipment: There are also special techniques, such as ultrasonic sound waves or pulsing systems, that can be used to solve deeper blockages without having to physically open the well.

Benefits of well regeneration:

Restoration of water yield: The main objective is to improve the permeability of the well, which will restore its productivity to its original level.

Cost-saving: Regenerating an existing well is usually much cheaper than constructing a new well.

Longer lifespan: Regeneration extends the life of the well and ensures sustainable use of groundwater.

Regular regeneration is important to maintain the efficiency of groundwater extraction and to keep the well healthy for long-term use.

A well clogging test in groundwater is a method of investigating whether a groundwater well (such as a pump well or monitoring well) is suffering from clogging. Clogging can occur due to various causes, such as the accumulation of sediments, minerals (such as iron or lime), biofilms or other organic materials in the filters or on the walls of the well. These blockages reduce the flow of water and reduce the efficiency of the well.

Objectives of a well clogging test:

Diagnosis of blockage: The test helps determine whether the well is clogged and to what extent this affects the flow rate (water yield).

Identification of the cause: The test can determine the cause of the blockage, such as sediment, bacterial growth, chemical deposits or a combination of factors.

Planning maintenance or regeneration: The results of the test provide insight into the need and urgency of performing pit regeneration or other maintenance work.

How is a well clogging test performed?

Pump and flow measurements: One of the first steps is to measure the current flow rate (how much water the well delivers per unit time) and the associated pressure. This is compared with the original flow rate when the well was constructed. If the flow rate has decreased significantly, this often indicates blockage.

Fall and ascent test (pumping test): This involves pumping water from the well while accurately measuring the lowering of the groundwater level (the "fall" of the water level). A delayed response of the water level to pumping may indicate a blockage in the filter sections of the well.

Analysis of pumped water: The water pumped during the test can be analysed for the presence of sediments, bacteria or chemicals such as iron or lime deposits. This can give more insight into the cause of the blockage.

Video inspection (optional): Sometimes a camera is placed in the well to visually determine whether physical blockages are present, such as silt, limestone deposits or biofilm.

Results of a well clogging test:

Complete blockage: If the flow is very restricted and the pressure is greatly increased, this may indicate a severe blockage, requiring immediate regeneration.

Partial blockage: If the flow is only slightly reduced, it may be possible to solve the problem with smaller interventions, such as cleaning or light chemical treatment.

No blockage: If the test shows that there is no blockage, the cause of the low flow rate may lie elsewhere, such as changes in the groundwater layer.

In summary, a well clogging test helps detect blockages in the well and determine their cause, so that targeted measures can be taken to restore the efficiency of the well.

The process by which groundwater is recharged by infiltration of precipitation or surface water. Recharge is essential for maintaining aquifers.

The process by which water slowly rises from the soil or flows to the surface through cracks and pores in the subsurface. Seepage can occur near dykes, rivers or irrigation canals.

The height to which groundwater rises in a pipe or well, measured from the measurement point to the groundwater level. The head is a measure of the potential energy of groundwater and can be used to determine the flow direction and pressure of groundwater. In an artesian aquifer, the head may be higher than ground level, which means that the water is under pressure and will naturally rise to the surface.

A reference system for height measurements used in Belgium, similar to the NAP in the Netherlands. TAW stands for the measured mean sea level, and water levels, groundwater levels and elevations are often related to it. TAW helps determine water management measures and hydrological analyses.

The technique whereby data is remotely collected and transmitted to a central location, usually via wireless links. In the context of water management, telemetry is often used to transmit real-time measurement data of water levels, groundwater levels and water quality sensors to a management system such as DAWACO. This enables continuous monitoring of water levels and other parameters without physical presence at the site.

A time series refers to a series of consecutive measurements of groundwater level or groundwater quality over a given period of time. These data are usually collected at fixed time intervals (e.g. daily, weekly or monthly) to monitor and analyse changes in groundwater level or composition.

In the context of groundwater, time series can provide insights into:

Seasonal fluctuations: Groundwater levels can fluctuate due to natural seasonal influences, such as rainfall, drought or temperature changes.

Impact of human activities: Changes in groundwater levels due to irrigation, water harvesting, construction projects or other activities affecting the water balance.

Climate change: Long-term trends in the time series may indicate the impact of climate change, such as rising temperatures and changing precipitation patterns, on groundwater levels.

Water quality: By analysing time series of groundwater quality (such as pH, conductivity, or contamination), researchers can identify changes in groundwater chemical composition.

With time series, researchers can make predictions, recognise trends and optimise the management of water resources.

The process by which water from the Earth's surface, including water from soil and plants, passes into the atmosphere in gaseous form. Evaporation plays an important role in the water cycle.

Rewetting is the process of rewetting or restoring an area or ecosystem after a period of drought or desiccation. This can lead to an increase in soil moisture, restoring vegetation and improving the hydrology of the area. Rewetting is an important aspect of environmental management and ecological restoration, especially in areas affected by human activities such as drainage, deforestation or agriculture. 

Causes and techniques of rewetting

Restoration of natural hydrology: Humidification can be achieved by restoring natural hydrological processes, such as reopening natural watercourses or restoring wetlands. This can improve water retention in an area.

Restricting drainage: In areas where drainage has been constructed for agriculture or development, closing drainage systems can help keep water in the area, leading to humidification.

Creation of marshes and wetlands: Creating or restoring marshes and wetlands can help retain water and improve biodiversity. These areas act as natural water buffers and can reduce flooding.

Water management: Modifying water management systems, such as raising water levels in nearby water bodies, can also contribute to humidification. This can help promote water infiltration into the soil.

Benefits of humidification

Biodiversity restoration: Humidification can increase biodiversity in an area by creating suitable habitat conditions for different plant and animal species. Many organisms, such as amphibians and aquatic plants, thrive in moist environments.

Improving water quality: Wetlands and other humidification techniques can help filter contaminants from water, improving overall water quality. They can also absorb nutrients from the water, reducing eutrophication.

Climate regulation: Humidification can contribute to climate change mitigation through carbon sequestration in peatlands. These areas store large amounts of carbon dioxide, which can help reduce greenhouse gases in the atmosphere.

Water retention and flood management: Waterlogging can improve water retention in an area, reducing the risk of flooding. This helps in regulating water balance and preventing erosion.

Challenges and considerations

Conflict with agriculture: Wetting can sometimes conflict with agricultural practices, especially in areas where drainage is essential for crop production. This requires careful planning and consideration of the interests of different stakeholders.

Management and maintenance: The restoration and maintenance of wetlands require ongoing efforts and resources to ensure that ecosystems remain healthy and can perform their functions.

Knowledge and involvement: It is essential to ensure the involvement of local communities and share knowledge about the benefits of vernalisation and water resources management.

Summary

Rewetting is a valuable process for ecological restoration and sustainable water management. It promotes biodiversity, improves water quality and helps manage the impacts of climate change. By restoring natural hydrological systems and creating wetlands, rewetting can play an important role in protecting ecosystems and ensuring sustainable water resources for the future.

The process by which groundwater or soil becomes saturated with salts, often as a result of groundwater abstraction or irrigation. Salinisation can threaten agricultural land and ecosystems.

Acidification is the process by which the pH of water or soil decreases, making it more acidic. This can have significant effects on ecosystems, plants, animals and the overall health of the environment. Acidification can be caused both naturally and by human activities, and it is common in aquatic systems and on agricultural land.

Causes of acidification

Burning fossil fuels: The combustion of fossil fuels (such as coal, oil and gas) in power plants, vehicles and industrial processes emits sulphur dioxide (SO₂) and nitrogen oxides (NOₓ). These gases can react with water vapour in the atmosphere, resulting in the formation of sulphuric acid and nitric acid, which return to earth as acid rain.

Agricultural practices: The use of certain fertilisers and pesticides can increase soil acidity. When ammonium-based fertilisers are used, ammonia in the soil can be converted into acids.

Natural processes: Natural processes, such as volcanic activity, can also contribute to acidification through the release of sulphur and nitrogen oxides.

Deforestation: Deforestation can lead to a change in soil chemical composition, reducing the buffering capacity of soil against acidification.

Effects of acidification

Impact on water quality: Acidification of water bodies can lead to a decline in biodiversity. Many fish and other aquatic organisms are sensitive to changes in pH. Low pH levels can hamper the growth and reproduction of these organisms.

Soil health: Acidification can change the chemical composition of soil, depleting essential nutrients such as calcium and magnesium. This can lead to reduced plant growth and agricultural productivity.

Damage to ecosystems: Ecosystems such as forests, marshes and ponds can be affected by acidification, leading to loss of biodiversity and disruption of food webs.

Human health: The effects of acidification can also have indirect effects on human health, especially through the food chain. Changes in water quality and biodiversity can affect the availability of food resources.

Corrosion of infrastructure: Acidification can also lead to corrosion of buildings, bridges and other infrastructure, especially if acid rain comes into contact with stone and metal.

Management and control of acidification

Reducing emissions: Reducing sulphur and nitrogen oxide emissions by promoting cleaner energy sources and more efficient technologies is crucial to reduce acidification.

Use of buffer substances: Adding lime or other alkaline materials to acidic soils can help raise pH levels and reduce the negative effects of acidification.

Sustainable land use: Promoting sustainable agricultural practices can help minimise the impact of fertilisers and chemicals on soil acidification.

Monitoring and research: Monitoring pH values of soil and water bodies helps to detect acidification early and take targeted management measures.

Education and awareness: Awareness of the causes and impacts of acidification can encourage communities and policymakers to take action and promote sustainable practices.

Summary

Acidification is a major environmental problem resulting from human activities and natural processes. It has significant impacts on water quality, soil health, biodiversity and human health. By reducing emissions, promoting sustainable land use and monitoring the effects of acidification, we can reduce its negative impact and ensure the health of ecosystems and the environment.

A calculation of the incoming and outgoing volumes of water in a given area. This takes into account precipitation, evaporation, runoff and groundwater flows. It helps manage water resources.

The vertical column of water above a particular measurement point, such as a pressure sensor. The height of the water column is often used to determine the pressure and thus the water level. The pressure at the bottom of the water column can be converted to the height of the water level relative to the measurement point.

Water abstraction refers to the process of extracting water from a particular source, such as a river, lake, or aquifer (aquifer), for various purposes. This can be done either naturally or by human activity. In the context of groundwater, water abstraction specifically means extracting groundwater from the soil through wells or springs.

Important aspects of water abstraction

Applications

Drinking water: Water abstraction is often used to extract drinking water for households and communities.

Agriculture: In agriculture, groundwater is extracted for irrigation to grow crops, especially in dry areas.

Industry: Industries use extracted water for production processes, cooling, and as a solvent.

Ecosystem management: water abstraction can also be applied for the management of wetlands and other ecosystems.

Methods

Wells: Water is extracted through pumping wells or artesian wells. Pump wells use a mechanical pump, while artesian wells use natural pressure in the aquifer to raise water to the surface.

Surface water: Water abstraction can also take place via pumping or diversion of water from rivers, lakes or canals.

Regulation: Water abstraction is often subject to regulation to prevent overexploitation. This may include requiring permits, and limits on the amount of water that can be abstracted.

Management of water resources is crucial, especially in areas with limited water resources, to ensure sustainable use and protection of ecosystems.

Environmental impact

Decline in groundwater levels: Excessive water abstraction can lead to lowering of groundwater levels, which can harm flora and fauna.

Salinisation: In coastal areas, excessive abstraction can lead to salinisation, with saltwater intruding into aquifers.

Changing hydrological systems: Water abstraction can affect local hydrology, leading to changes in river flow, soil moisture and ecosystems.

Sustainability: Sustainable water abstraction involves balancing the needs of people with the protection of natural water resources. This may involve implementing reclamation processes and water reuse.

Summary

Water abstraction is an essential process for water supply and economic activities, but it must be carefully managed to avoid negative environmental impacts and ensure water availability for future generations. It requires monitoring, regulation and sustainable practices to ensure that water resources are used effectively and responsibly.

The height of the water surface relative to a reference point. Often measured using pressure sensors in groundwater or surface water monitoring.

A Framework of rules to stop the deterioration of the status of water bodies in the EU and achieve good status for Europe's rivers, lakes and groundwater.

https://environment.ec.europa.eu/topics/water/water-framework-directive_en

A salinator is a term used in groundwater management and water quality monitoring, especially in areas prone to salinisation. The salinator plays an important role in preventing the negative effects of saltwater intrusion into freshwater sources, especially in coastal areas or in areas where groundwater levels are low.

Functions of a salt keeper

Monitoring salinity levels: Salt guards are often equipped with sensors or measuring devices that can continuously monitor salt concentrations in groundwater. These measurements help identify changes in water quality, such as rising salinity levels.

Detection of salinisation: Salinisation can occur when fresh groundwater is supplemented by salt water from the sea or other sources. A salinator helps detect this process in time, allowing appropriate action to be taken to prevent further salinisation.

Management of water abstraction: In areas where water is withdrawn, a salt keeper can help assess the impact of this withdrawal on salt concentrations. This is especially important in areas with low groundwater levels, where the risk of saltwater intrusion increases.

Advising water managers: Data collected by salt watchers can be used to develop policies and advise water managers on the sustainable use of water resources. This can help formulate guidelines for water abstraction and other activities that affect water quality.

Education and awareness: Saliners also play a role in educating communities and stakeholders about the risks of salinisation and the need to manage water resources responsibly.

Importance of salt guards: Freshwater resource management: In coastal areas, protecting freshwater resources is crucial, especially for drinking water supply and agriculture. Salt marshals help ensure freshwater quality.

Sustainability: By intervening in a timely manner when salt concentrations rise, salt guards can contribute to sustainable water management, which is essential for the long-term availability of water in vulnerable areas.

Summary

A salt keeper is a crucial tool in managing water quality monitoring and preventing salinisation in freshwater sources. By monitoring salinity levels and advising water managers, a salinator helps protect the quality of water resources and promote sustainable water practices.