Evaluate and mapping groundwater quality using geostatistics for sustainable land management in Darb El-Arbaein, South Western Desert, Egypt

Abstract

The objective of this study was to propose a simple method to assess the groundwater quality and to map their spatial variation in terms of suitability for irrigation in Darb El-Arbaein area. 36 surveyed wells with GPS data were used to assess and maps the groundwater quality. Multivariate Factor Analysis/Principal Component Analysis was used in order to develop a water quality index (WQI). The results of analyses have been used to map and predict models for water quality. The ordinary Kriging (OK) method was used to produce the spatial patterns of water quality. Based on these results, the distribution pattern of groundwater quality parameters such as EC, Cl-, and SAR are produced. The results showed that Circular semivariogram model was best fitted for chloride and Cd parameters where spherical model fitted best for Ni and Zn parameters. Stable semivariogram model was best fitted for Pb and SAR parameters where J-Bessel model fitted best for EC parameter. High salinity was due to high chloride concentration in the groundwater. Three of the 36 groundwater samples fall in the moderate WQI. Most of the samples (26) fall in the Doubtful WQI category. Seven samples fall in the higher WQI category. Groundwater samples that fall in the low salinity hazard class and high WQI can be used for irrigation of most crops and the majority of soils. The WQI for the samples ranges from 47.9 to 88.6. The irrigation water quality index distribution maps delineated an area of 266.66ha are suitable for irrigation in village 3-4 and area of 382.35ha are moderate suitability in village 1-2.