Drought Management
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region. Although droughts can persist for several years, even a short, intense drought can cause significant damage and harm the local economy.
Types of Drought
- Meteorological Drought
Meteorological drought is the amount of dryness and the duration of the dry period. Atmospheric conditions that result in deficiencies of precipitation change from area to area. - Agricultural Drought
Agricultural drought mainly effects food production and farming. Agricultural drought and precipitation shortages bring soil water deficits, reduced ground water or reservoir levels, and so on. Deficient topsoil moisture at planting may stop germination, leading to low plant populations. - Hydrological Drought
Hydrological drought is associated with the effects of periods of precipitation shortages on water supply. Water in hydrologic storage systems such as reservoirs and rivers are often used for multiple purposes such as flood control, irrigation, recreation, navigation, hydropower, and wildlife habitat. Competition for water in these storage systems escalates during drought and conflicts between water users increase significantly. - Socioeconomic Drought
Socioeconomic drought occurs when the demand for an economic good exceeds supply as a result of a weather-related shortfall in water supply.
Drought Monitor
Drought monitors are prepared using:
- SPI calculated from point rainfall data
- NDVI from remote sensing
- Water availability in reservoirs
- Soil Moisture data
- Field reports.
- Sub-surface water situation
Drought advisories are prepared using:
- SPI calculated from point rainfall data
- Water availability in reservoirs
- Soil Moisture data
- Field reports
A drought impact is an observable loss or change at a specific time because of drought. Drought risk management involves hazards, exposure, vulnerability and impact assessment, a drought early warning system (DEWS) (monitoring and forecasting, see Box below), and preparedness and mitigation (WMO, UNCCD and FAO, 2013). It is important that drought indicators or indices accurately reflect and represent the impacts being experienced during droughts. As droughts evolve, the impacts can vary by region and by season.
Drought early warning systems
Drought early warning systems typically aim to track, assess and deliver relevant information concerning climatic, hydrologic and water supply conditions and trends. Ideally, they have both a monitoring (including impacts) component and a forecasting component. The objective is to provide timely information in advance of, or during, the early onset of drought to prompt action (via threshold triggers) within a drought risk management plan as a means of reducing potential impacts. A diligent, integrated, approach is vital for monitoring such a slow-onset hazard.
The Integrated Drought Management Programme (IDMP) was launched by the World Meteorological Organization and the Global Water Partnership at the High Level Meeting on National Drought Policy in March 2013. IDMP works with a wide range of partners with the objective of supporting stakeholders at all levels. IDMP provides its partners with policy and management guidance through globally coordinated generation of scientific information and sharing best practices and knowledge for integrated drought management. It contributes to the Global Framework for Climate Services (GFCS), especially regarding the GFCS priority areas of disaster risk reduction, water, agriculture and food security, energy and health. It especially seeks to support regions and countries in developing more proactive drought policies and better predictive mechanisms. This handbook contributes to that objective.