Abstract:
Exploration of groundwater resources requires recognition of regions and their potential sources. Because of high importance in the karstic regions and their significant role in providing needed water, efforts to explore new sources of Karst, is inevitable. Checking discontinuities is always an important issue in karst studies. Because of high discontinuities in rock masses, permeable areas will be created , they cause appropriate groundwater paths to flow . Recognition of these regions is possible through geophysical methods based on physical characteristics of these areas such as density or resistivity. Using geophysical methods in water and geotechnical methods has less history to oil field investigations and mining exploration, but has been accelerated in recent years . In this research we have tried to investigate the usage of various geophysical methods, such as how to detect and identify underground water using these methods . We can noted of geophysical applied methods for groundwater potentiometric such as geoelectric methods, ground penetrating radar, electromagnetic, gravitometry, magnetic and seismic surveys.
Machine summary:
"3. Geoelectric methods The main geophysical methods for groundwater studies and water exploration is electrical methods in which by using the difference between the electrical resistivity of the subsurface and ground water ,finding water potential is done.
According to measuring ,we can present three A -Preparing profile or maps of changing in apparent resistivity in specified depth B - Investigating variation of apparent resistivity in depth (using probing) C -The combination of these two methods to create images of the subsurface classes resistivity This method is used for vertical and horizontal discontinuities studies in the earth electrical properties and also in exploring abnormal mass conductors and even today ,it is applied extensively in the hydrologic studies and investigations in order to examine subsurface and to explore ground water tables, in particular [2].
6. Application of Gravimetric method in water explorations The main geophysical methods for groundwater studies and exploration methods are electrical methods but gravity method also can take an important role.
Soltan et al in 2008 ,when conducting a study on an aquifer in Egypt, could detect a groundwater table by combining techniques of specific resistance, gravimetric and Magnetic method.
In this study we used of resistivity methods for detecting subsurface aquifer and isolating subsurface layers from each other, gravimetric method to explore the water resources through identifying the underground structural trends and Magnetic method to show the depth of bed rock and also the water table depth and sediment [9]."