Human Impact on the Hydrologic Cycle CP

Human Impact on the Hydrologic Cycle CP

There are many ways through which Man impacts hydrological cycle, some of the important impacts are following

 1. Deforestation

2. Green House Effect

3. Irrigation

4. Discharges

1. Deforestation

The removal of trees has a major impact on the water cycle and the local or global climate. Trees release water vapours when they transpire, and it further creates a humid environment. This water vapour evaporates into the atmosphere where it accumulates before precipitating back to the Earth as rain, sleet or snow. If trees are cut down, there is less water to be evaporated into the atmosphere and subsequently less rain.

2. Green House Effect

Human activity such as the burning of fossil fuels leads to the overall increase of the Earth’s temperature. Raising the Earth’s temperature results in an increase of evaporation, melting of ice or other processes of the water cycle that adversely affect the climate on Earth.

3. Irrigation

With increasing human population our demands have increased. We need more food and to produce more food we need more water. Irrigation is the artificial watering of land and is used for watering land that does not get enough rain. Irrigation removes water from its natural sources and often causes leaching and run-off in the land where it is used. This removal of nutrients from the land results in more use of fertilizers by the farmers to keep their lands more productive. As a result waterways become more polluted.

4. Discharges

Before rainwater merges into the river it mostly picks up a whole range of pollutants. In rural areas the pollutants mostly include pesticides, herbicides, fertilizers, wastes from faulty septic systems and improperly handled manure. Such rain water flowing through contaminated streams, may affect plant and animal population in the water bodies. In urban areas the pollutants include gas, oil, pet waste, fertilizers, pesticides, salt and treated human waste from sewage treatment plants. Such waste when dumped into the water bodies contaminates the water bodies and in turn affects the water cycle.