ENVIRONMENTAL,HYDROGEOLOGICAL AND GEOCHEMICAL SURVEY USING SATELLITE IMAGES AND GIS TECHNIQUES IN MID-EUPHRATES

Abstract

This project will be performed for executing regional geochemical and environmental reconnaissance survey using soil and water sampling in Al-Hilla and Al-Diwaniya governorates for geo-environmental information system for a sustainable development and management of the area, besides using satellite images to detect and classify soil salinity in the area. 183 surfaces soil samples have been collected systematically based on the grid net. The examined elements in this work are Pb, Cr, Cu, Zn, Co, and Ni. Chemical properties of soil such as pH and the presence of salt (TDS, SO3) are also analyzed. The geochemical results show that the distribution and concentration of the heavy metals in the studied soils is within the average concentration given for the reported world soils of arid and semi arid regions, and the soil of the studied area is still free from pollution. In general, the concentrations of Cr, Ni, and Co are high in Iraqi soils, and highly dependent on their content of parent rocks, which is mainly due to the influence of igneous and sedimentary complexes in the Turkey and Syria, derived by Euphrates River. To perform hydrogeological study of the area, samples were collected from 18 different locations (12 from wells as groundwaters, and 6 from rivers as surface waters). Physical and chemical properties of waters were determined, by measuring electrical conductivity, total dissolved salts, pH, and analytical of cations and anions. In general, there were differences in concentrations and properties of the waters samples, due to the lithological nature of the soils bearing waters and the influence of agricultural and using pesticides, beside that, the location of the sampling in the both rivers and wells. In general, there was an increasing in salinity in the groundwaters toward south and southwest, because of increasing in concentration of Na+, SO3¯, and Cl¯ due to nature of the sediments and agricultural and human activities. Surface and groundwaters in the area is suitable for drinking for human, animals, and agriculture, except waters of one the wells in the area which was polluted due to the influence of using pesticides and the human activities. Spatial analysis of soil salinity and soil structural stability were studied to the whole area. Indices of SI, and BI were used to classify and map salinity soil and level of salinity in the area. As well as there are relations between the values of (SO3 and TDS analysis) with the reflectance values in imagers that have been used in the study. The results also show that well-developed saline crusts are associated with high reflectance in the visible and near-infrared spectra.