بررسي آب زيرزميني در دشت ورامين جهت استفاده از آبياري اراضي كشاورزي

Survey of Varamin Plain Groundwater for Use on Farmlands Irrigation

Varamin plain have areas more than 130000 ha and about 60000 ha of its are agricultural lands. Because of decrease surface water, excavation of deep and semi-deep wells on the plain to be prevalent very plenty, and therefore study of groundwater that is mainly of irrigation water resources in the total of plain, its very necessary; in this research for study of groundwater for use of irrigation, at first pizometer and usable wells quality and quantity data was prepared and then water table and flow path of groundwater was studied and calculated critical deep of water table and influence of water table on the lands degradation was surveyed ,and also with use of villcoks diagram, irrigation ability map was drown and areas of its different classes was calculated, the results show, that use of groundwater for irrigation in the northeastern of plain should be attention very plenty, because this part of plain have water table lower than other area and if trend of its decease continue to will take place salinization o fgroundwater and therefore soil degradation , decrease of production and desertification will start. At the other hand, in the southwestern of plain 9354 ha have groundwater level lower than 3 m, that agricultural practice not possible in this part. Only part of the plain that can be use from groundwater with any limitation, is central part of plain that is mainly farmland and at the other part should to take into consideration, selection of type of production, type of irrigation systems, drainage condition and soil infiltration.