Hydrogeology and groundwater

Since ancient times Afghanistan uses groundwater as a source of irrigation and water supply (groundwater wells, holes). Engineering hydrogeological studies can be divided into two stages: the first stage in 1956-1961, and the second in 1961-1980.

At the first stage, data on groundwater were received following single route studies. Regular hydrological and engineering-geological activities (surveys) under foreign technical assistance (USSR) were started in 1962 by the Geological Department at the Ministry of Mining and industry. Initially, the search and exploration covered large regions with a view to determine prospective water-bearing systems and set tasks of detailed studies.

At the same time, a comprehensive exploration was conducted in areas where it was planned to develop new irrigable lands or raise water availability for old irrigated lands. Engineering survey for developing projects and a scheme for irrigation development in the northern region of the country played a big role in studying groundwater. A large-scale comprehensive hydrological and geological survey conducted in 1962-1963 evaluated natural groundwater resources of a quaternary aquifer by C category, recommended types and sites of operational water intakes. Hydrological maps and maps of middle-scale quaternary deposits were made, which also enabled to evaluate and describe general prospects for use of mineral, thermal and saline waters (carbonic acid, hydrogen-sulphidous, methanic gasing mineral waters with sulphate and sulphate-chloride composition, hot weakly saline and very hot sources).

Considering stratigraphic principle, a number of different water-bearing deposits and aquifers were identified within Afghanistan. Of this number, almost 90% of groundwater resources liable for use in the national economy were ascribed to quaternary water-bearing zones, the systems and basins of which therewith coincide with the location of water supply and irrigation objects.

In 1970, hydrological zoning of the territory of the country was carried out based on geomorphologic-structural principle (V. Belyanin, V. Sobolev and G. J. Atai), and three areas were marked as primary structures: artesian Upper Amudarya, folded Central Afghan and hydrological South Afghan.

Within each area, particular groundwater basins were marked, which, according to conservative estimates, are characterized by over 300 m³/sec or about a quarter of surface flow of rivers in Afghanistan. At that, no more than 70 m³/sec (22%) were used (by the beginning of 1990).

The table below presents explored groundwater supply for irrigation and water supply and its withdrawal per area by 1978.

Hydrological areas	Natural resources, m3/s
	Total	Registered sampling
Upper Amudarya	28.2	2.91
Central Afghanistan	56.8	30.4
South Afghanistan	111.78	22.01
TOTAL:	196.78	55.32

In regions with a high shortage of surface flow, there is a real opportunity to use groundwater as an additional source for irrigation and water supply (regions in Sistan, Helmand river lowlands, in Farah Rud, Harirut, Balkh, Khulm and other river valleys), where in summer the flow of rivers almost runs low. In river valleys, groundwater can be taken through wells with a depth of 30-40 m, in desert, steppe and submountain areas 60-80 m, more rarely 100 m. the output of wells mainly amounts to 30-100 l/sec and 10-20 l/sec only in some districts.

Afghanistan is rich in groundwater resources. It is necessary to point, firstly, to the expediency of further research activities to specify zoning, assess water quality, make recommendations on location and designs of water intakes, secondly, with a view to regional systematic estimations of useful groundwater storage in prospective deposits. First of all, such activities should be renewed in basins experiencing a scarcity of surface flow and having considerable fertile lands and favorable climatic conditions.

The studies of “Gidroingeo” for scheme “Water supply to pastures and agricultural lands in North Afghanistan” revealed that in 1987-1988 in North Afghanistan half a cubic meter of groundwater was taken by 723 springs, 276 operational wells, 592 shaft wells and 15 groundwater wells with overall discharge of 16.1 m³/sec. Total groundwater resources in North Afghanistan were estimated 48.93 m³/sec or 1526 million m³ a year.

On the territory of Amudarya zone, groundwater basins were marked out: Pyanj-Kokca, Talukan, Kunduz, Baglan and others with a depth of 5-30 m. The freshest waters are connected with surface and irrigation water. Total resources amounting 1 km³ a year, of which only 10% are used, show that cheapest and most accelerated reserves for involving water resources lay just here.