Looking for information that is necessary to estimate the amount of recharge in basaltic and granitic rock. Please suggest other methods which are not expensive to determine the recharge.
We used GIS data (DEM, soil, landuse) and interpolated climate data to estimate areal annual evapotranspiration rates using a simple ETa model. Remote sensing is used to derive the landuse map. By substracting ETa from precipitation we derived annual total runoff. We then devided the total runoff into surface runoff and base flow, which equals annual groundwater recharge, using base flow indices. These indices were derived from the analysis of discharge measurements and GIS data (DEM, soil, landuse, geology). Please find the related paper in the attachment.
This is a difficult challenge. You cannot directly estimate the recharge. You must use a model to estimate the input/output for the aquifer. A widely used is SWAT model that uses the LandUse/LandCover (LULC) and an average water consumption for the different types of LULC. So if you know the rainfall and the water budget with SWAT, you can estimate the volume of water that percolates up to the aquifer. In this case, RS/GIS helps for the LULC mapping.
You can download some papers from :
http://www.shiva-anr.org/published_paper.html
It is a project in South India regarding water and GCC.
This is the link of a recent paper that might be useful to you. Theycused Landsat and SRTM data + Land use/landcover, drainage density, slope map, contact density, lithology, etc., and modeled in GIS.
first you should have the shape file or map of granite and basaltic rocks, the recharge map ( you might have the excel file of the data) or you may use the sampling method for the area to make the excel file or map file. then you should have the images or renders and RGBs. the next step is due to your expertise and how you can deal with the data.
you can check the paper by Mahjoor Lone and if you want to delineate recharge zones this paper is good, but if you want to estimate recharge rate then you need to consider other parameters like ET, Runoff along with Land use and soil maps.
We used GIS data (DEM, soil, landuse) and interpolated climate data to estimate areal annual evapotranspiration rates using a simple ETa model. Remote sensing is used to derive the landuse map. By substracting ETa from precipitation we derived annual total runoff. We then devided the total runoff into surface runoff and base flow, which equals annual groundwater recharge, using base flow indices. These indices were derived from the analysis of discharge measurements and GIS data (DEM, soil, landuse, geology). Please find the related paper in the attachment.
If you have any time series of groundwater levels they may be very informative:http://onlinelibrary.wiley.com/doi/10.1029/2009WR008572/abstract
Beware of estimating the recharge using soil moisture balance models if there is the likelihood of any preferential flow through your soil/subsoil as they may be very misleading - see this paper for a comparison of methods in a Ugandan weathered basement context which may have parallels to your case: http://www.iwaponline.com/jwc/001/jwc0010234.htm
Taiwan central weather burea(CWB) has study the remote sensing method to estimate the value of soil moisrure variable while precipitation, please see the attach file, bur it is written in chinese, the equations may help you, good luck.