Droughts in the context of "Water stress"

Water scarcity (closely related to water stress or water crisis) is the lack of fresh water resources to meet the standard water demand. There are two types of water scarcity. One is physical. The other is economic water scarcity. Physical water scarcity is where there is not enough water to meet all demands. This includes water needed for ecosystems to function. Regions with a desert climate often face physical water scarcity. Central Asia, West Asia, and North Africa are examples of arid areas. Economic water scarcity results from a lack of investment in infrastructure or technology to draw water from rivers, aquifers, or other water sources. It also results from weak human capacity to meet water demand. Many people in sub-Saharan Africa are living with economic water scarcity.

There is enough freshwater available globally and averaged over the year to meet demand. As such, water scarcity is caused by a mismatch between when and where people need water, and when and where it is available. This can happen due to an increase in the number of people in a region, changing living conditions and diets, and expansion of irrigated agriculture. Climate change (including droughts or floods), deforestation, water pollution and wasteful use of water can also mean there is not enough water. These variations in scarcity may also be a function of prevailing economic policy and planning approaches.

The United Nations General Assembly designated the 1990s as the International Decade for Natural Disaster Reduction (IDNDR).

Its basic objective was to decrease the loss of life, property destruction and social and economic disruption caused by natural disasters, such as earthquakes, tsunamis, floods, landslides, volcanic eruptions, droughts, locust infestations, and other disasters of natural origin.

Throughout Russian history famines, droughts and crop failures occurred on the territory of Russia, the Russian Empire and the USSR on more or less regular basis. From the beginning of the 11th to the end of the 16th century, on the territory of Russia for every century there were 8 crop failures, which were repeated every 13 years, sometimes causing prolonged famine in a significant territory. The causes of famine were different, from natural (crop failures due to drought or disease) and economic and political crises; for example, the Great Famine of 1931–1933, colloquially called the Holodomor, the cause of which was, among other factors, the collectivization policy in the USSR, which affected the territory of the Volga region in Russia, Ukraine and Kazakhstan.

The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive several hundred millimeters of rain per year, they have long dry seasons that last several months and vary with geographic location. These seasonal droughts have great impact on all living things in the forest.

Deciduous trees predominate in most of these forests, and during the drought a leafless period occurs, which varies with species type. Because trees lose moisture through their leaves, the shedding of leaves allows trees such as teak and mountain ebony to conserve water during dry periods. The newly bare trees open up the canopy layer, enabling sunlight to reach ground level and facilitate the growth of thick underbrush. Trees on moister sites and those with access to ground water tend to be evergreen. Infertile sites also tend to support evergreen trees. Three tropical dry forest ecoregions, the East Deccan dry evergreen forests, the Sri Lanka dry-zone dry evergreen forests, and the Southeastern Indochina dry evergreen forests, are characterized by evergreen trees.