The climate and weather systems of the earth are constantly changing. As part of these dynamic processes, extreme temperatures, rain and air movement will occur naturally. Thus, periods of usual dryness (known as drought) are a normal feature of climate and weather systems in all countries. Drought is a climatic anomaly characterized by poor moisture.And it is supplying resulting from below normal rainfall, irregular distribution of rain, increased need for water or a combination of all factors. Drought is a climate catastrophe that is usually below the rainfall. These are also characterized by irregular distribution of rainfall, increased water requirement or poor moisture supply as a result of a combination of all factors.
To a meteorologist, it is the absence of rain. while to the agriculturist, it is the deficiency of soil moisture in the crop root zone to support crop growth and productivity. For the hydrologist, it is the reduction of water levels in lakes, reservoirs, etc. While for the city administration, it can mean a shortage of drinking water availability.
TYPES OF DROUGHTS
We may broadly classify droughts into the following three types:
1. Meteorological drought: A situation with the 25% decrease from normal precipitation over an area is called meteorological drought.
2. Hydrological drought: Prolonged weather droughts can be hydrological droughts. Which is a sign of a decrease in surface water and consequently drying of reservoirs, lakes, rivers, and rivers.
3. Agricultural drought: When soil moisture and rainfall are inadequate during the healthy season to support healthy crops causing heavy crop loss is called agricultural drought.
1. Moisture-holding capacity of the soil: In areas, wherever the moisture-holding capability of the soil is high prolonged dry periods might not have an effect on growth. In areas wherever retention capability is low, dry periods of solely per week could end in reduced yields.
2. Rainfall Period: Deficiencies of moisture supply at critical stages, e.g., germination and flowering, can significantly reduce yields of crops. In some countries, it uses moisture satisfaction models to produce forecasts at different stages within the normal growing season.
3. Role of Irrigation: The link between rainfall and yield is weaker in irrigated rather than rained areas. Thus, the role of local rainfall in the irrigated water supply is important to meet the moisture requirements.
EFFECTS OF DROUGHT
Of all the natural hazards, droughts pose the greatest economic impact and affect a large number of people. Such as
1. Environmental impacts of droughts Animals and plants die from drought.
2. Surface waters such as lakes, rivers, ponds, creeks, streams, and lagoons dry out during extended dry conditions which destroy natural habitats.
3. Reduction in soil quality decreases soil activities which kills soil organisms. As a result, it becomes easier for desertification to occur.
4. Drought conditions make it unsuitable for plants and vegetation cover to survive.
5. Migration of animals and wildlife during it leads to death most of the time.
6. It also impacts on domestic economic phases.
Reducing the risks and therefore the impacts associated with drought requires that much greater emphasis placed on preparedness & mitigation. Such as
Structural Mitigation :
It involves the construction of traditional water harvesting structures like canals, tanks, etc. Water harvesting can also carry out by either allowing the runoff water from all the areas to a common point or allowing it to infiltrate into the soil, increasing the groundwater level.
Non-structural Mitigation :
(a) Drought Monitoring: Monitoring and early warning help decision-makers to take timely decisions at all levels. Proper monitoring of all components of the hydrological system is the only mechanism to detect the onset of drought and its potential impact on land and population.
(b) Drought Awareness Programmes: In areas that are normally affected by drought, Government, NGOs, local corporate and other key players should bring awareness on water conservation, livelihood planning, land-use-planning, traditional water conservation strategies, etc.
(c) Land Use Planning: Land use based on its capability helps in optimum use of land and water and can prevent undue demand created because of misuse.
(d) Livelihood Planning: It identifies those livelihoods which are least affected by drought.
(e) Crop Insurance: This is insurance given to the farmers, who have lost their crops because of the lack of water supply.