Distribution Maps of TDS Concentration using GIS at Assiut, Egypt

Research Article

Austin J Hydrol. 2016; 3(1): 1020.

Distribution Maps of TDS Concentration using GIS at Assiut, Egypt

El-Dakar MA¹*, Sefelnasr A² and Senosy MM²

¹Egyptian Environmental Affairs Agency, Assiut RBO, Egypt

²Geology Department, Faculty of Science, Assiut University, Egypt

*Corresponding author: Marco A. El-Dakar, Egyptian Environmental Affairs Agency, Assiut RBO, Egypt

Received: June 24, 2016; Accepted: September 15, 2016; Published: September 21, 2016


The scarcity of water is one of the main issues in Egypt. In particular, the extreme climate in the form of less frequent rainfall affects the groundwater availability. Moreover, groundwater has been depleted by the increase in population. In this research, the spatial distribution of groundwater salinity has been developed, and the prediction of groundwater Total Dissolved Solid (TDS) has been made by using geostatistical analysis in Geographic Information System (GIS) software. The study area is the western flood plain from the River Nile in Assiut governorate located in the Upper Egypt. Ordinary kriging method was applied to map the spatial distribution of the ground water chemistry for period 22 month (2009-2010). In predicting the Total Dissolved Solid (TDS) concentration of groundwater distribution maps show increasing toward the western part of the Nile valley closed to western plateau. The lowest value of the Total Dissolved Solid (TDS) concentrations of wells was in the areas close to the River Nile, where the TDS concentration was low than 200pmm around the year 2009 except in January, October, November and December, while the highest value of TDS concentrations was in the area closed to Western Plateau in December 2009 and January 2010 (1000ppm).

Keywords: Groundwater quality; GIS; Geostatistics; Ordinary kriging; Semivariogram; Spatial distribution; TDS concentration


In order to discuss the role that groundwater may play in the management of regional water resources, the both surface water and groundwater are present in relatively significant quantities in a region. Actually, surface water and groundwater are not necessarily independent water resources. Base flow in streams is nothing more than groundwater emerging at ground surface. In this way, rivers and lakes, in direct, continuous hydraulic contact with adjacent or underlying aquifers serve as boundaries to the flow domain in the latter. By controlling groundwater levels in the vicinity of a spring, its discharge is controlled, or even stopped completely. The above considerations apply not only to water quantity, but also to water quality defined, for example by some chemical species or microorganisms carried with the water. Polluted surface water may easily reach and pollute groundwater and vice versa [1].

Both surface water and groundwater are susceptible to man-made pollution, which usually requires costly remediation and treatment operations for its removal. In certain formations, pollutants may travel large distances in an aquifer without being attenuated. As for mineral contents in general the groundwater is more liable to picking up minerals in solution, although the range of concentrations encountered is very large. The removal of such minerals is usually very expensive. When groundwater does get polluted, the restoration of quality and the removal of pollutants is a very slow, hence, lengthy and sometimes practically impossible. This is due to the very slow movement of groundwater, especially in layers of very fine material, imbedded in formations of higher permeability and to adsorption and ion exchange phenomena on the surface of the solid matrix. These phenomena are especially significant when fine grained materials are present in an aquifer [1].

The assessment of spatial correlation in hydro chemical variables is an important tool in the analysis of groundwater chemistry especially in arid and semiarid zones. In geostatistical methods, kriging technique is quite popular. The technique is applicable to cases such as determining groundwater level, estimation of hydro chemical distribution of soil properties, and other estimations [2] have compared various variogram models, i.e., spherical, exponential, and Gaussian semivariogram models to fit the experimental semivariogram in identifying the spatial analysis of groundwater levels in small part of Rajasthan area, India. The results indicate that the kriged groundwater levels satisfactorily matched the observed groundwater levels. The role of Geographic Information System (GIS) software’s in analyzing spatial distribution of groundwater has been investigated by many authors such as [3,4]. Studied groundwater potential zonation for basaltic watersheds [5]. Investigated disasters and risk reduction in groundwater [6]. Applied the probabilistic based frequency ratio in groundwater potential [7,8]. Applied an integrated geostatistic and GIS technique in groundwater [9]. Estimated groundwater vulnerability to pollution and [6] Studied prediction of groundwater potential zones.

The objectives of the present research are to investigate the application of various spatial models and data transformation to interpret the spatial distribution of the groundwater Total Dissolved Solid (TDS) at the western flood plain from the River Nile in Assiut governorate located in the Upper Egypt. In this study, kriging techniques in the framework of GIS software (ArcGIS Geostatistical Analyst) are used.

Description of the study area and data collection

Assiut governorate is located on the River Nile at about 375 kilometers south of Cairo. It occupies a stretch of low land about 25926 square kilometers located between latitudes 27°8’ and 27°40’ North and longitudes 30°40’ and 31°18’ East (Figure 1). It is bordered from the east by the River Nile then a limestone Eocene plateau known locally as El-Gabal El-Sharki and from the west by another Eocene plateau known as El-Gabal El-Gharbi.