Salinity assessment of groundwater for irrigation to prevent soil salinization

Electrical conductivity(EC)is considered as the most important indicator for assessment of groundwater quality.Determination of suitable interpolation method for derivation of groundwater quality variables map such as EC is dependent on region conditions and existence of enough data.For determining groundwater EC,341 groundwater samples were randomly collected from the central regions of Guilan province,paddy soils,in northern Iran.Interpolation methods including inverse distance weighting(IDW),global polynomial interpolation(GPI),local polynomial interpolation(LPI),radial basis function(RBF),ordinary kriging(OK)and empirical Bayesian Kriging(EBK)were used to generate spatial distribution of groundwater EC.The results indicate that EBK is a superior method with the least RMSE,MAE and the highest R 2.The generated maps can be used to identify the regions in the studied area where groundwater could be allowed to be extracted and utilized by farmers to reduce adverse effect of the scarcity of surface water.