Impact on the Environment:

The severity of the drought is gauged by the degree of moisture deficiency, its duration, and the size of the area affected. If the drought is brief, it is known as a dry spell or partial drought.

Drought causes serious environmental imbalances, which are summarized below:

1. Water-supply reservoirs become empty, wells dry up and there is acute water shortage.

2. Groundwater level is also depleted because of less recharge.

3. Soil degradation and erosion occurs. Soil cracks because of shrinkage during desiccation (Fig. 18.4).

4. There is extensive crop damage.

5. People become impoverished and there are diseases due to malnutrition.

6. Widespread damage to flora and fauna air including domestic animals.

Prevention, control and mitigation:

Rains are caused by a number of natural factors like air currents, wind direction, etc. Thus, droughts are a natural phenomenon, beyond human control and prevention. Though, global warming may have changed the pattern of rainfall in the recent times. In modem times, by the use of satellites, we can predict the weather pattern over a particular area. Drought-like conditions can be overcome by better water harvesting techniques. Certain precautions can be taken in drought prone areas, which relate to management of water resources, proper agricultural techniques and relief by different agencies.

Management of water resources:

These include the following:

1. Conservation of water through rainwater harvesting, building check dams, bunds, etc.

2. Construction of reservoirs to hold emergency water supplies.

Proper agricultural techniques:

These include the following:

1. Increased use of drought resistant crops.

2. Proper irrigation techniques, such as drip and trickle irrigation that minimize the use of water.

3. Over-cropping and overgrazing should be avoided.

Relief measures: