كليدواژه :
كشاورزي , آب هاي زيرزميني , Aquifers , نقشه هاي پيزومتريك , آزمايش پمپاز , pumping tests , piezometric maps , آبخوان , Equations of Theis and Jacob , دشت فومنات
چكيده لاتين :
This study was carried out in the occidental part of the alluvial plain of Guilan (plain of Foumenat) in order to determine the potentials of the ground water resources of this area and to examine their qualitative variations. We started our work with collecting and examining the basic general data on the area: Inventories concerting climatological and geological information. Then factors affecting water balance were determined. We drew up numerous maps relating to area hydrogeological: piezometric cards, maps of water table contours below the natural terrain, and then we attempted to measure the annual oscillation aquifers. With the data from pumping tests, the characteristic hydrodynamics of the aquifers, that is, the transmissibility (T), storage coefficient(S) and the linear loss ratios of load (B) and non linear of load (C), thus representative line equation for some wells has been determined. A hydrochimic study and the qualitative variations have been studied. The concentration of the ions Ca, Mg, Na, K, Cl, S04, C03, HCO3, P, NNH4, N-N02, N03, Fe and certain heavy elements like Pb, Cd and Hg, as well as other parameters such as EC, pH, BOD, COD and TDS were determined. Our study has shown that Foumenat plain has high groundwater potential. The aquifers of this area consist of one free aquifer with weak discharge and many confined aquifers or artesian aquifers with appreciable discharge. However due to lack of proper consideration of drilling techniques and unsuitable equipment, exploitation discharge of the wells is not satisfactory. The chemical composition of water surfaces and underground show that the water resources often have a good quality for the agricultural and human consummation. Interpretation of the results obtained also shows a gradual increase for the electric conductivity, Na and Cl in the general direction of water flow, but this condition does not apply for other ions. The concentration of Fe is oppreciable in the aquifers. upstream, but it is not available in the aquifers of we cannot observe on important quantity of nitrate in the aquifers. The results of analyses do not show the existence of heavy elements (Pb, Cd, and Hg), and the base of the international standards established for clean water, the quantities of BOD and COD do not show any problems of pollution.
