Spatial Distribution of Nitrate Ion in Andimeshk Groundwaters using the Geostatistical Methods

According to the importance of groundwater resources in providing of human needs, lack of control and inappropriate management of these resources can lead to the problems such as nitrate pollutions arising from the use of chemical fertilizers in agricultural lands. With generalized point data to the area using the geostatistics methods can be determine the pollution content in areas without sampling. This research was conducted with aiming to zoning the groundwater nitrate pollution content in some of Andimeshk agricultural lands. For this purpose, samples were taken from 55 wells and nitrate content was obtained in each of the wells based on mg/lit nitrate. Geostatistical methods that were used include kriging, cokriging and inverse distance weighting. After normalization of the data and drawing the variogram, kriging method (i.e. RMSE: 1.4) with fewer errors than the cokriging (i.e. RMSE: 1.42) and IDW (i.e. RMSE: 1.46) was chosen as the appropriate method of zoning. Finally, the nitrate zoning map was drawing by using geographical information system. Nitrate maps can be used as an important tool for decision makers in the field of management.