A drought is a stage during which farmers are urgently waiting for rain because the soils run dry. The rivers have low water levels and the vegetation turns its color from green to yellow during the period of the growing season. Droughts are slowly emerging over time. Different drought measurements indicate different levels of severity, which can depend e.g. on the duration of dryness, or the response of the vegetation to dry conditions, or the amount of water stored in rivers, water reservoirs or in the soil.
With climate change, droughts will become more frequent and more severe. We need to plan for preventing droughts proactively by looking at how much water is needed and what kind of water resources are available under different drought conditions. We need to better understand which community and which agricultural land are at risk to droughts and why, and then we need to identify measures for prevention and build capacity locally. Examples for drought risk reduction measures are introducing more drought-resistant crops or livestock in at-risk regions, and establishing fodder banks and water reservoirs during periods of no drought, which can reduce the potential impacts during the next drought.
If not managed well, droughts can trigger a vicious circle where human well-being, the economy and the environment spiral downwards fast. If there is not enough water for agricultural production, farmers lose their harvest and livelihoods, the population is exposed to high food prices on the market and the most vulnerable face food insecurity. The need for more agricultural land to produce enough food under drought conditions might lead to deforestation, which reduces the capacity of the environment to store water. If there is not enough water for personal hygiene, people get sick, and if there is even not enough safe drinking water, the population may run into conflicts.
In 2017 and 2018, we have seen several exceptional water crises around the globe. Cape Town in South Africa was about to reach Day Zero, the day when water taps would have run dry in the city. The east coast of Australia recorded less than a fifth of its typical rainfall per season, the US drought monitor detected highest level of drought severity in central US states, and farmers in Germany were applying for governmental aid to overcome their financial losses due to lost harvests in the dry and hot summer in Europe. There is no single reason that can explain all these drought events, and each of them has its own narrative. South Africa for example was experiencing the late impacts of an exceptional drought in the years 2015/2016, which was at that time mainly triggered by the strongest recorded El Niño year, where warm surface temperature in the tropical Pacific Ocean brought warm and dry winds to South Africa. From there onwards, water levels in the reservoirs were continually decreasing, due to high demand of the growing population in the city of Cape Town combined with water losses due to leakages in the supply system and relatively dry weather conditions.
Those parts of the world which will not take preventive actions and to which drought will come as a surprise will be affected the most. Countries and regions most at risk usually share the following characteristics: Regions with large share of degraded land, where the livelihood of people depend on agriculture, where irrigation schemes cannot help to overcome lack of rain and those with little resources and capacities to cope with a drought. However, there are many different scenarios on how different parts of the world will be affected by droughts, ranging from the high-tech industrialized agricultural or energy sectors, which can experience large-scale economic losses due to severe drought conditions, to small-scale farmers who fully depend on the farm income.