Consideration of nitrate seasonal variations in groundwater of Ajabshir plain

   Abstract:
      The Ajabshir plain is a coastal fertile plain that is located in east of Uriomye lack. Nowadays, increasing of nitrate concentration in groundwater is one of the contamination types that threaten some of water bearing layers as well as Ajabshir plain aquifers. Various factors can be cause high amount of nitrate concentrations in groundwater which, from their the atmospheric sources, chemical fertilizers, domestic and industrial wastes, septic tanks and plant residuals are the most important. Due to excessive groundwater abstractions from this plain, the unit hydrograph of the water level is declined about 6 meters from year 1375 to 1383. Deterioration of the water quality in the area especially contamination with nitrate is considerable.
   For evaluating the nitrate concentration range in the aquifer two series of samples (wet and dry seasons 1383) were collected from 35 deep and shallow pumping wells and analyzed to determine the main physicochemical components as well as nitrate amounts. Analysis showed that Maximum nitrate values for the wet season from the deep and shallow wells are 12.4 and 45.88 mg/l, respectively. For the dry season its range form 45.86 to 135.62 mg/l. In this research effective factors in nitrate concentration values and its variations in time and space is considered.