Drought produces a complex web of impacts that spans many sectors of the economy
and reaches well beyond the
area experiencing physical drought. This complexity exists because water is integral
to society's ability to produce goods and provide services.
Impacts are commonly referred to as direct and indirect.
Direct impacts include reduced crop, rangeland, and forest productivity,
increased fire hazard, reduced water levels,
increased livestock and wildlife mortality rates,
and damage to wildlife and fish habitat.
The consequences of these direct impacts illustrate indirect impacts.
For example, a reduction in crop, rangeland, and forest productivity
may result in reduced income for farmers and agribusiness, increased
prices for food and timber, unemployment, reduced tax revenues because of reduced
expenditures, foreclosures on bank loans to farmers and businesses,
migration, and disaster relief programs.
The types of drought impacts are described below.
- Economic Impacts
Many economic impacts occur in agriculture and related sectors, because of the
reliance of these sectors on surface and groundwater supplies. In addition to
losses in yields in both crop and livestock production,
drought is associated with insect infestations, plant disease, and wind erosion.
The incidence of forest and range fires increases substantially during extended periods of droughts,
which in turn places both human and wildlife populations at higher levels of risk.
Income loss is another indicator used in assessing the impacts of drought.
Reduced income for farmers has a ripple effect. Retailers and others who provide goods
and services to farmers
face reduced business. This leads to unemployment, increased credit risk for financial
institutions, capital shortfalls,
and eventual loss of tax revenue for local, state, and federal governments.
Prices for food, energy, and other products increase as supplies are reduced. In some cases, local
shortages of certain goods result in importing these goods from outside the drought-stricken
region. Reduced water supply impairs the navigability of rivers and results in increased transportation costs because
products must be transported by alternative means.
Hydropower production may also be significantly affected.
- Environmental Impacts
Environmental losses are the result of damages to plant and animal species, wildlife habitat,
and air and water
quality, forest and range fires, degradation of landscape quality, loss of biodiversity,
and soil erosion. Some of
these effects are short-term, conditions returning to normal following the end of the drought.
Other environmental effects last for some time and may even become permanent.
Wildlife habitat, for example, may be degraded through the loss
of wetlands, lakes, and vegetation. However, many species eventually recover from
this temporary aberration.
The degradation of landscape quality, including increased soil erosion, may lead to a
more permanent loss of biological productivity.
- Social Impacts
Social impacts involve public safety, health, conflicts between water users,
reduced quality of life,
and inequities in the distribution of impacts and disaster relief. Many of the
impacts identified as economic
and environmental have social components as well. Population migration is a
significant problem in many
countries, often stimulated by a greater supply of food and water elsewhere.
Migration is usually to urban
areas within the stressed area, or to regions outside the drought area.
Migration may even be to adjacent countries.
When the drought has abated, the migrants seldom return home, depriving rural
areas of valuable human resources. The drought migrants
place increasing pressure on the social infrastructure of the urban areas,
leading to increased poverty and social unrest.