Groundwater exploration in the South of Urmieh - North-West Iran Using Remote Sensing and GIS

GROUNDWATER EXPLORATION IN THE SOUTH OF URMIEH- NORTHWEST OF IRAN USING REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEMS

Shortage of water required for drinking and agricultural uses, is a subject with a vital
importance in most arid and semiarid regions. The area of this study is one of semi_arid
regions located in South West of Urumieh lake, North West of Iran, bounded by N 37,00' , 37,15' latitude and E 45,05' , 45,30' longitude which is composed of Permian dolomitic limestones and limestones and post_Jourasic granite_granodiorites with a very low primary porosity/permeability character. To delineate groundwater potential zones in this area, our main attention then were focused on identifying secondary porosity/permeability indicators such as lineaments, vegetation cover, lithology, drainage pattern, drainage density and etc. In this regard, a remote sensing and Geographic information system based methodology was selected. To meet the goals defined above, Landsat ETM, IRS (pan), SPOT and ASTER data, Digital Elevation Model (DEM) and digital image processing techniques of filtering, False Color Composite (FCC), Principal Component Analysis (PCA), rationing and classification have been applied for information extraction purposes. Information layers extracted for analysis and interpretation stage were then integrated with other data and modeled through the use of existing GIS software's and their related analytical functions. Finally, based on determined Ground Water Favorability Index (GWFI) for different sub zones, layers, weighting and overlapping, a Ground Water Potential Index (GWPI) were defined which respectively utilized for groundwater potential zoning and preparation of GWPI map of the region. Within the 6 different sub zones defined, two sub zones labeled with High and Very good potential areas were highly recommended for further development and exploration purposes. Geophysical investigations in target areas confirm the methodology. Based on the obtained results of the study, it can be concluded that multi resolution remote sensing data are very useful tool to extract information of groundwater exploration. Also application of geographic information systems to find target areas for groundwater exploration are effective to save time and cost.