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  2. Human impact on river systems - Wikipedia

    en.wikipedia.org/wiki/Human_impact_on_river_systems

    Water pollution occurs when water bodies, such as rivers, lakes and oceans are contaminated with harmful substances. These substances degrade the water quality and are toxic to humans as consumers and to the environment. [7] The contamination in a river can come from a point source or non-point source pollution. [8]

  3. List of most-polluted rivers - Wikipedia

    en.wikipedia.org/wiki/List_of_most-polluted_rivers

    Severe risk of making the main source drinkable water for Owerri non-potable. [7] Modjo River: Central Ethiopia: One of the two most polluted rivers in Ethiopia. [8] [9] Toxic industrial chemicals [8] [9] Nairobi River Kenya: The rivers are mostly narrow and highly polluted, [10] though recent efforts to clean the rivers have improved water ...

  4. Water pollution - Wikipedia

    en.wikipedia.org/wiki/Water_pollution

    Water pollution (or aquatic pollution) is the contamination of water bodies, with a negative impact on their uses. [1]: 6 It is usually a result of human activities. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come from ...

  5. Aquatic ecosystem - Wikipedia

    en.wikipedia.org/wiki/Aquatic_ecosystem

    Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species. [12] A dam produces negative effects that continue down the watershed. The most important negative effects are the reduction of spring flooding, which damages wetlands, and the retention of sediment, which leads to the loss of deltaic ...

  6. Human impact on the environment - Wikipedia

    en.wikipedia.org/wiki/Human_impact_on_the...

    Human impact on the environment. From top left, clockwise: satellite image of Southeast Asian haze; IAEA experts investigate the Fukushima disaster; a seabird during an oil spill; depiction of deforestation of Brazil's Atlantic forest by Portuguese settlers, c. 1820 –25; acid mine drainage in the Rio Tinto; industrial fishing in 1997, a practice that has led to overfishing.

  7. Stream ecology - Wikipedia

    en.wikipedia.org/wiki/Stream_ecology

    A large reason for stream restoration is to remove nitrogren and phosphorus pollution. Excess nitrogen and phosphorus from anthropogenic activities have partaken in stream and river quality concerns such as drinking water contamination, hypoxia, and algal blooms. [10] There are different approaches one may take to offset these effects.

  8. Mercury contamination in California waterways - Wikipedia

    en.wikipedia.org/wiki/Mercury_contamination_in...

    This involved the redirecting of water from the river into a narrow channel, into a large canvas hose, and iron nozzle. Then these water cannons which were called monitors it would shoot a very high pressure stream that would break apart hillsides. The water, slurry, and debris, mostly gravel would flow over large sluices and drainage tunnels. [3]

  9. Human impact on marine life - Wikipedia

    en.wikipedia.org/wiki/Human_impact_on_marine_life

    The release of nitrogen oxides (N 2 O, NO) from anthropogenic activities and oxygen-depleted zones causes stratospheric ozone depletion leading to higher UVB exposition, which produces the damage of marine life, acid rain and ocean warming. Ocean warming causes water stratification, deoxygenation, and the formation of dead zones.