Afghanistan: An Overview of Ground Water Resources and Challenges
2006; Wiley; Volume: 44; Issue: 5 Linguagem: Inglês
10.1111/j.1745-6584.2006.00251.x
ISSN1745-6584
Autores Tópico(s)Politics and Conflicts in Afghanistan, Pakistan, and Middle East
ResumoGroundwaterVolume 44, Issue 5 p. 626-627 Free Access Afghanistan: An Overview of Ground Water Resources and Challenges First published: 31 August 2006 https://doi.org/10.1111/j.1745-6584.2006.00251.xCitations: 14AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Afghanistan: An Overview of Ground Water Resources and Challenges by Vincent W. Uhl, Uhl, Baron, Rana & Associates Inc., Water Resources Consultants, Lambertville, NJ 08530; [email protected] Afghanistan, a land-locked country in central Asia, is 647,500 km2 in area and characterized by extensive desert plains, high mountain ranges, and scattered fertile valleys along the major rivers. Most of the cities, towns, villages, and settlements are along major and minor river valleys. The Hindu Kush, the westernmost extension of the Himalaya-Pamir Mountain Range, cuts the country in half from northeast to southwest. Irrigation is important to the main economy, which is agriculture (crops and livestock). Surface water accounts for >80% of irrigation water. Ground water has traditionally been developed and used for irrigation purposes through the use of karezes (also referred to as qanat, foggara, and falaj—a karez is essentially a horizontal well in which the discharge of the upper portion of an aquifer is brought to the surface by a hand-dug tunneled conduit), springs, and shallow hand-dug open wells. In recent years, deep-drilled wells (tubewells) have become more common, particularly in the southeastern river basins (Tarnak, Ghazni, Kabul, and Loghar among others). Most urban centers and towns depend on ground water for drinking, commercial, and institutional water supply. Ground water is an underused resource in certain parts of the country and, more than likely, overused in others. Hydrology Afghanistan has a dry continental climate, and 90% of the country’s annual precipitation occurs between December and April, mostly falling as snow. In the summer, Afghanistan receives mostly warm dry air from the north and northeast with very little precipitation. The amount of precipitation correlates directly with altitude, varying from 1000 mm at altitudes >4000 m in the northeast. In an average year, precipitation from snowmelt is approximately 150,000 million m3 (Mm3) and from rainfall ∼30,000 Mm3, yielding a total annual precipitation for the country of 180,000 Mm3 (180 km3). Most of the rivers, including all perennial rivers, originate in the mountains of the Hindu Kush range in the center of the country and flow toward Afghanistan’s borders (Figure 1). Most river systems have maximum flow in the spring and early summer months from snowmelt, and lower flow in the fall and winter months. The Hindu Kush mountains decrease in altitude from the northeast toward the southwest. The rivers originating in the higher northeastern part of this mountain range have more sustained flow as compared to the rivers originating from the central and lower parts of the range. Figure 1Open in figure viewerPowerPoint Afghanistan’s river basins. The four major river systems include • The Kabul River and the southeastern tributaries of the Indus (11%) • The Helmand River and its tributaries, and the western-flowing rivers, including the Farah Rud and Khash Rud rivers as well as the Rigestan Desert to the south (49%) • The Hari Rud and Murghab rivers in the west (10%) • The northern-flowing rivers, including the Shirin Tagab, Sare Pul, Balkh, and Khulm rivers, and the Amu Darya River and its tributaries, which include the Kunduz, Kokcha, and Wakhan rivers (30%). The Kabul River is a tributary to the Indus River in Pakistan, and this is the only river system originating in Afghanistan that reaches the ocean. The Helmand River and its tributaries drain to the Siestan Depression located at Afghanistan’s southwest border with Iran; the Hari Rud and Murghab rivers flow to the Tejen Oasis in Turkmenistan; and the Amu Darya and the northern-flowing rivers drain to the inland Aral Sea. The principal aquifer systems include (1) Quaternary deposits in the major river valleys (intermontane basins) particularly in the Kabul River basin, the river systems in the eastern Helmand River basin (Ghazni, Tarnak, Arghistan, and Arghandab), the Hari Rud River, and certain river systems within the northwestern rivers (northern-flowing rivers) and Amu Darya basins; (2) the semiconsolidated Neocene-age deposits in the Kabul River and other river basins; and (3) carbonate rock aquifer systems on the northern flank of the Hindu Kush range and along portions of the Helmand River basin in Oruzgan Province on the southern flank of the Hindu Kush. Large springs are present on the north side of the Hindu Kush range with flows up to 3300 L/s in the Balkh River valley. The consolidated rock aquifer systems in the country are largely unexplored. Over 95% of the ground water usage is for irrigation, although most cities and towns also rely on ground water for drinking supply. Total ground water usage (FAO [Food and Agricultural Organization] 1996, 1999, 2001) is estimated at 2800 Mm3/year; total ground water recharge (Uhl and Tahiri 2003, Uhl 2005) is estimated to range from 10,500 to 16,500 Mm3/year. Impacts on ground water resources The major impacts to ground water resources include (1) long-term reduced ground water recharge due to deforestation and poor land-use practices in the watersheds at large; (2) water level drawdown from increased deeper tubewell pumpage in the eastern Helmand River tributaries, in the Kabul River basin, and in some urban centers and the drying up of shallow wells and karezes; and (3) suspected water quality impacts in the urban and town areas from improper waste water disposal, poor drainage, and disposal practices. The nature and magnitude of these impacts to the principal aquifer systems have not been defined or quantified in detail. However, anecdotal evidence of water level impacts from the increasing use of drilled wells, particularly in the eastern Helmand River basin and Kabul River basin, has been provided in several reports and studies (e.g., Norwegian Church Aid—Afghanistan Program 2002, Uhl and Tahiri 2003, Uhl 2005). Impacts to shallow sources of ground water supply, including hand-dug wells and karezes, have been attributed to the increased development of the ground water resources in these basins as well as to periods of drought. Footnotes Editor’s Note: We invited Mr. Uhl to contribute this article as part of our ongoing series on international ground water. References FAO. 1996. Afghanistan, promotion of agricultural rehabilitation and development programmes, water resources and irrigation. FAO Project TCP/AFG/4552. AREV. Islamabad, Pakistan: UN Food and Agricultural Organization. FAO. 1999. Provincial Landcover Atlas of Islamic State of Afghanistan. Utilization of remote sensing for the inventory and monitoring of agricultural land in Afghanistan. FAO Project AFG/90/002. UN Food and Agricultural Organization. FAO. 2001. Dr. Sayed Sharif Shobair. Current Drought Situation in Afghanistan. Kabul, Afghanistan: UN Food and Agricultural Organization. Norwegian Church Aid—Afghanistan Program (NCAAP). 2002. Guidelines for Sustainable Use of Groundwater in Afghanistan. Uhl, V.W. 2005. Afghanistan groundwater resources overview. In paper presented at WMO, IAEA, UNEP and FAO sponsored Workshop in Cairo, Egypt, April 2005. Uhl, V.W., and Q.M. Tahiri. 2003. Afghanistan, a Country Wide Overview of Groundwater Resources and Challenges. Lambertville, New Jersey: Uhl, Baron, Rana & Associates, Inc. Citing Literature Volume44, Issue5September–October 2006Pages 626-627 FiguresReferencesRelatedInformation
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