Fresh groundwater resources and their use in emergencies.

Fresh groundwater resources of some medium and large cities (with population over 500000) are analyzed. The use of fresh groundwater for public water supply in individual regions (federal districts of the Russian Federation) and cities is demonstrated. A relationship was found to exist between the size of urban population and the use of fresh groundwater resources. It has been shown that the larger the city (in terms of its population), the lesser the contribution of groundwater to the public water supply. The use of fresh groundwater in Russia and the United States is compared. The effect of considerable groundwater withdrawal on the hazard of land subsidence is briefly characterized. Present notions of excessive groundwater exploitation are considered. Available statistical methods are used to forecast the population of medium and large cities in Russia. Current and expected drinking water demand in the population of federal districts as a whole and individual cities during emergency periods are considered. The values of the current and expected demand in the population are correlated with the explored and approved usable groundwater resources, making it possible to assess the availability of drinking groundwater resources in emergency periods for federal districts of the Russian Federation and the chosen cities. [ABSTRACT FROM AUTHOR]