Application of Different Geostatistical Methods for Interpolation of EC and SAR Values in Groundwater with Emphasis on Basin Infiltration Changes

Document Type : Research Paper


1 PhD Student, Water Engineering Department, Ferdowsi University of Mashhad

2 Professor, Water Engineering Department, Ferdowsi University of Mashhad

3 Assistant Professor, Water Engineering Department, Ferdowsi University of Mashhad

4 MS. Student, Water Engineering Department, Zabol University


Awareness from spatial variability of quality parameters is important tool for understanding the region talent and how to manage of land. So in this research to analysis electrical conductivity and the ratio of absorption of sodium in groundwater using Earth statistical methods. For this purpose, information dependent on analysis of 169 wells of water in Neyshabour plain with climate of semi arid  is based on last sampling in 1386 were used. Earth statistical methods used For Zoning parameters listed include Ordinarykriging, Logkriging, Cokriging, IDW and SPLINE model. for evaluation of methods are used from cross validation techniques with Standards of MAE, MBE, RMSE and R2 Between actual and estimated data. Studies have shown that spatial correlation in EC and SAR is so very in Neyshabour plain. Results of EC and SAR maps using Cokriging and  exponential and spherical model showed areas of North East Plains, aquifer is located under the influence of surface and groundwater supply, include  values EC less than  1.5 dS/m and 2.5 mg/lit, the aquifer quality in above mentioned range towards the plain central regions gradually decreased and within the granule regions of aquifer (South and West regions of aquifer) formation of the alluvium is not desirable, EC and SAR values will increase in this range is higher than 12 dS/m and18 mg/lit. Finally, the quality of Neyshabour plain groundwater from viewpoint EC and SAR in terms of impact on soil permeability was investigated. The EC and SAR anomaly maps were drawn and shown that with increasing salinity levels in water drop pezometer correlated.