In this research, GRACE satellite data have been used in order to
investigate the possibility of estimating the amount of groundwater used
in agriculture. The level-2 data of the GRACE satellites have been used
to estimate the monthly groundwater level changes in central plateau
catchment in Iran during the period of 2003 to 2013. One degree grid is
used along with corrections of soil moisture, canopy, rainfall and
snowfall from GRACE satellite data with the CLM4 hydrology model. The
results revealed the amount of current groundwater in Iran and
agricultural usage from groundwater have been determined (the largest
consumer of groundwaters). verification of the results has been done by
comparing the GRACE satellite data and piezometric wells data.
Furthermore, ArcMap (ArcGIS) software were used for data analysis.