Consider the following statements with reference to drought: A period ...
- The term ‘drought’ is applied to an extended period when there is a shortage of water availability due to inadequate precipitation, excessive rate of evaporation, and over-utilization of water from the reservoirs and other storages, including the groundwater.
- A period of below-normal rainfall does not necessarily result in drought conditions. Hence statement 1 is correct.
- Some rain returns to the air as water vapor when water evaporates from water surfaces and from moist soil.
- Plant roots draw some of the moisture from the soil and return it to the air through a process called transpiration. The total amount of water returned to the air by these processes is called evapotranspiration. Sunlight, humidity, temperature, and wind affect the rate of evapotranspiration. When evapotranspiration rates are large, soils can lose moisture and dry conditions can develop. During cool, cloudy weather, evapotranspiration rates may be small enough to offset periods of below-normal precipitation, and drought may be less severe or may not develop at all.
- Types of Droughts:
- Meteorological Drought: It is a situation when there is a prolonged period of inadequate rainfall marked with mal-distribution of the same over time and space.
- Agricultural Drought: It is also known as soil moisture drought, characterized by low soil moisture that is necessary to support the crops, thereby resulting in crop failures. Moreover, if an area has more than 30 percent of its gross cropped area under irrigation, the area is excluded from the drought-prone category.
- Hydrological Drought: It results when the availability of water in different storages and reservoirs like aquifers, lakes, reservoirs, etc. falls below what the precipitation can replenish. Hence statement 2 is correct.
- Ecological Drought: When the productivity of a natural ecosystem fails due to a shortage of water and as a consequence of ecological distress, damages are induced in the ecosystem.
Consider the following statements with reference to drought: A period ...
Explanation:
Statement 1: A period of below-normal rainfall does not necessarily result in drought conditions.
This statement is correct. Drought is not solely determined by below-normal rainfall. Drought is a complex phenomenon that involves multiple factors such as precipitation, evaporation, soil moisture, and water storage. While below-normal rainfall is a common trigger for drought, it is not the sole determinant. Other factors such as high evaporation rates, excessive withdrawal of water from reservoirs, and poor water management practices can also contribute to drought conditions even in the presence of normal or above-normal rainfall.
Statement 2: Hydrological drought is a situation when the water availability in different storages and reservoirs falls below what precipitation can replenish.
This statement is also correct. Hydrological drought refers to a situation where the water availability in various storages and reservoirs, including groundwater, rivers, lakes, and dams, falls below what can be replenished by precipitation. It occurs when the demand for water exceeds the available supply, leading to water scarcity and potential impacts on agriculture, ecosystems, and human populations.
Conclusion: Both statements are correct.
Summary:
Drought is not solely determined by below-normal rainfall, and other factors such as evaporation rates and water management practices can contribute to drought conditions. Hydrological drought occurs when the water availability in storages and reservoirs falls below what can be replenished by precipitation.