Hydrology is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydrologist. Hydrologists are scientists studying earth or environmental science, civil or environmental engineering, and physical geography. Using various analytical methods and scientific techniques, they collect and analyze data to help solve water related problems such as environmental preservation, natural disasters, and water management.
Water pollution is the contamination of water bodies, usually as a result of human activities, that has a negative impact on their uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come from one of four main sources: sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. Water pollution is either surface water pollution or groundwater pollution. This form of pollution can lead to many problems, such as the degradation of aquatic ecosystems or spreading water-borne diseases when people use polluted water for drinking or irrigation. Another problem is that water pollution reduces the ecosystem services that the water resource would otherwise provide.
A bioindicator is any species or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other small water crustaceans that are present in many water bodies can be monitored for changes that may indicate a problem within their ecosystem. Bioindicators can tell us about the cumulative effects of different pollutants in the ecosystem and about how long a problem may have been present, which physical and chemical testing cannot.
Rain gardens, also called bioretention facilities, are one of a variety of practices designed to increase rain runoff reabsorption by the soil. They can also be used to treat polluted stormwater runoff. Rain gardens are designed landscape sites that reduce the flow rate, total quantity, and pollutant load of runoff from impervious urban areas like roofs, driveways, walkways, parking lots, and compacted lawn areas. Rain gardens rely on plants and natural or engineered soil medium to retain stormwater and increase the lag time of infiltration, while remediating and filtering pollutants carried by urban runoff. Rain gardens provide a method to reuse and optimize any rain that falls, reducing or avoiding the need for additional irrigation. A benefit of planting rain gardens is the consequential decrease in ambient air and water temperature, a mitigation that is especially effective in urban areas containing an abundance of impervious surfaces that absorb heat in a phenomenon known as the heat-island effect.
The International Commission for the Protection of the Danube River (ICPDR) is an international organisation with its permanent secretariat in Vienna. It was established by the Danube River Protection Convention, signed by the Danube countries in Sofia, Bulgaria, in 1994.
An hydrological transport model is a mathematical model used to simulate the flow of rivers, streams, groundwater movement or drainage front displacement, and calculate water quality parameters. These models generally came into use in the 1960s and 1970s when demand for numerical forecasting of water quality and drainage was driven by environmental legislation, and at a similar time widespread access to significant computer power became available. Much of the original model development took place in the United States and United Kingdom, but today these models are refined and used worldwide.
Water supply and sanitation (WSS) in the European Union (EU) is the responsibility of each member state, but in the 21st century union-wide policies have come into effect. Water resources are limited and supply and sanitation systems are under pressure from urbanisation and climate change. Indeed, the stakes are high as the European Environmental Agency found that one European out of ten already suffers a situation of water scarcity and the IEA measured the energy consumption of the water sector to be equivalent to 3,5% of the electricity consumption of the EU.
Water supply and sanitation in Spain is characterized by universal access and good service quality, while tariffs are among the lowest in the EU. Almost half of the population is served by private or mixed private-public water companies, which operate under concession contracts with municipalities. The largest of the private water companies, with a market share of about 50% of the private concessions, is Aguas de Barcelona (Agbar). However, the large cities are all served by public companies except Barcelona and Valencia. The largest public company is Canal de Isabel II, which serves the metropolitan area of Madrid.
River basin management plans are a management tool in integrated water resources management. They generally contain descriptions of the water resources in a drainage basin and water allocation plans.
The following outline is provided as an overview of and topical guide to hydrology:
The Urban Waste Water Treatment Directive 1991 European Union directive concerning urban waste water "collection, treatment and discharge of urban waste water and the treatment and discharge of waste water from certain industrial sectors". It aims "to protect the environment from adverse effects of waste water discharges from cities and "certain industrial sectors". Council Directive 91/271/EEC on Urban Wastewater Treatment was adopted on 21 May 1991, amended by the Commission Directive 98/15/EC.
The Vindel River is a river in northern Sweden. It is a tributary to Ume River and the biggest tributary river in Sweden. It lends its name to the Vindelfjällens Nature Reserve, one of the largest protected areas in Europe, totaling 562,772 ha. Since it is partially located within the reserve, it is permanently protected from hydroelectric development. Downstream from where Vindelälven merges with Umeälven Sweden's largest hydropower plant is located. Considering that the river is not unregulated all the way to the ocean, but just in the part of it formally called Vindelälven, the decision to call it "unregulated" or "permanently protected from hydropower" is to be taken with a grain of salt. The river Vindel and its tributaries were important routes for transporting timber in northern Sweden, up until 1976. To ease the movement of logs downstream, wooden dams were constructed, side streams were cut off and tributaries were straightened and cleared. These changes significantly affected the river ecosystem and populations of wild fish, mammals, mussels and other species of aquatic and riparian habitats. The changes therefore negatively impact the favourable conservation status of species and habitats within the Vindel River Natura 2000 network site. Actions to restore the tributaries of the Vindel River to a more natural state are considered a priority by the Swedish environmental protection agency, the Västerbotten county administrative board, and the EU under the Habitats Directive and the Water Framework Directive (WFD). The general objective of the Vindel River LIFE project was to achieve a ‘good status’ for the waters of the Vindel River with reference to the Water Framework Directive, and ‘good conservation status’ for the species in the project area under the Habitats Directive. The aim was to reduce the negative impacts of fragmentation and channelisation caused by timber-floating infrastructure in tributaries of the Vindel River system. The work was focused on a number of river stretches, altogether spanning just over 44 km, with the aim of removing 73% of the obstructions to natural river flow, placing large boulders and fallen trees in the water to simulate natural conditions and to reconnect streams to the tributaries to open up breeding areas for migrating fish. The Vindel River LIFE project restored streams in the tributaries of the Vindel River basin, by removing timber-floating infrastructure, replacing large obstacles into the water, and creating and restoring fish spawning grounds. These ecosystem restoration measures resulted in improved water quality, and improvements in conditions for protected species, in line with national and EU policy. The project’s work had clear socio-economic benefits in the project area.
The Croatian Meteorological and Hydrological Service is a public entity for meteorology, hydrology and air quality in Croatia.
The Drinking Water Directive 2020 is an EU law that protects the quality of drinking water and forms part of the regulation of water supply and sanitation in the European Union.
The term environmental persistent pharmaceutical pollutants (EPPP) was first suggested in the nomination in 2010 of pharmaceuticals and environment as an emerging issue in a Strategic Approach to International Chemicals Management (SAICM) by the International Society of Doctors for the Environment (ISDE). The occurring problems from EPPPs are in parallel explained under environmental impact of pharmaceuticals and personal care products (PPCP). The European Union summarizes pharmaceutical residues with the potential of contamination of water and soil together with other micropollutants under "priority substances".
Vulnerable waters refer to geographically isolated wetlands (GIWs) and to ephemeral and intermittent streams. Ephemeral and intermittent streams are seasonally flowing and are located in headwater position. They are the outer and smallest stems of hydrological networks. Isolated wetlands are located outside floodplain and show poor surface connection to tributaries or floodplains. Geographically isolated wetlands encompass saturated depressions that are the result of fluvial, aeolian, glacial and/or coastal geomorphological processes. They may be natural landforms or the result of human interventions. Vulnerable waters represent the major proportion of river networks.
International Commission for the Protection of the Rhine (ICPR) and its contract shows alignment with the UN Convention on international watercourses and has proven effective in its goals for the Rhine and the Rhine Basin. It was necessary for a treaty to come through the countries in the Rhine basin as it provides water based on industrial and agricultural needs and provides drinking water to over 20 million people.
The beam origin concept is used to describe the mechanisms governing the ecological condition of running waters. It is based on the positive influence of sections in very good condition on sections in less good condition. The idea was first introduced in 2008 by the German Council for Land Stewardship to reach the goals defined in the Water Framework Directive of the European Union.
The Deltarhine region is a river basin district of the Rhine basin, consisting of the Dinkel, the Berkel, and the Oude IJssel regional river basins. It covers 11,000 square kilometres and straddles the German-Dutch border, with 65% in the Netherlands and 35% in Germany.
Denmark is geographically a small state, but has substantial maritime influence. This prominence is attributed to its expansive coastline, which is the 16th longest in the world, alongside a sizeable Exclusive Economic Zone and stature as a major Arctic power. Denmark is also home to A.P. Møller – Mærsk, the world's second largest shipping company and Ørsted, the industry leader in offshore wind, and ranks as the fifth largest seafaring nation in the world.
