Theme 4-9-Assessment of water harvesting structures - Case studies in three different parts of Iran

Abstract

Iran is placed among the dry region of the world and does not receive plenty of precipitation annually. The annual precipitation of about 413 bm3 is negligible as compare to its total geographical area (1648000 km2). Moreover, this amount is unevenly distributed within the country and therefore, certain areas of the country experience acute shortage of water, which largely depend on groundwater resources. In these areas, due to over exploitation of groundwater the drop in water table has been serious and consequently has effected the basic human activities. To tackle the problem, the government has undertaken watershed management practices. The prime aim is to mitigate destructive floods and harvest excess runoff water by means of artificial recharge structures. It is evident that a number of crucial factors affect applicability of artificial recharge, which are different for divers region of the country. The present paper intend to evaluate the impact of water harvesting structures on quantity and quality of groundwater, coastal zone saline water intrusion and flood mitigation for three case studies in SW, NW and West central Iran. Since these areas are located in different climatic-geological settings the importance of site selection, physical and hydrologic parameters of watershed on efficiency of harvesting structures are discussed. Keeping the above in mind, the feedback on efficiency and depiction of factors causing unproper functioning of the system would help how to encounter ever existing difficulties in establishing such structures.