سال انتشار: ۱۳۹۰

محل انتشار: اولین کنفرانس بین المللی و سومین کنفرانس ملی سد و نیروگاههای برق آبی

تعداد صفحات: ۱

نویسنده(ها):

Nol Artifical –

چکیده:

The increasing demand for water in many regions around the world has led to the implementation of more intensive water management measures to achieve more efficient utilization of limited water supplies. Traditionally, most water supply systems have been based on either surface water or groundwater. Water supply from groundwater sources becomes more important during long dry periods and in arid areas. However, the use of groundwater for water supply has led to a situation where natural replenishment cannot match exploitation rates, leading to falling groundwater levels. Artificial recharge is one method that allows for management of augmentation of groundwater resources when the natural replenishment of groundwater occurs very slowly. In artificial recharge schemes aquifers are treated as a naturally-regulated system which may be used to store surface water, thereby leveling out seasonal variations in surface water availability and providing a steady supply of potable water. Induced recharge from surface water and storage of surface waters during flood periods to maintain and improve supply in the dry season are very important ways of increasing groundwater resources. Artificial recharge is a process by which excess surface water is directed into suitablegeological formations using infiltration basins, ditches, wells, dams, or sprinkler systems. Other techniques with surface spreading methods may also be identified: spate irrigation consisting of watering terraced fields, check dams across wadis, allowing water to percolate into the alluvial aquifer, underground dams to prevent groundwater from flowing away immediately after it is stored in the aquifer and sand dams. All these technologies provide for the artificial enhancement of natural recharge. Bank filtration, or induced recharge, can be used if there is a direct hydraulic connection between an aquifer and a surface water body. In most artificial recharge schemes, aquifers are used for water storage and reuse. There are many factors affecting the recharge of aquifers – water availability for recharge, porosity, transmissivity, storage coefficient, aquifer homogeneity, aquifer isotropy etc. The chemical, physical, and biological compatibility of the two kinds of waters has to taken into account. Great care must be taken with regard to the vulnerability of the aquifer to prevent infiltration of water polluted by persistent contaminants.