Monitoring groundwater level changes of Mianrahan aquifer with GRACE satellite data

Determining groundwater changes in Iran, which is located in arid and semi-arid regions, is of particular importance. In this regard, Kermanshah province with 950,000 hectares of agricultural land and gardens is one of the agricultural hubs of the country and the water level in the aquifers of the province, especially in the eastern part of the province is more severe. In this study, by examining the water level of the observational wells of Mianrahan aquifer in Jamishan basin and spatial zoning of these changes using Kriging method in GIS software, the current situation of the region has been investigated. In order to evaluate GRACE satellite data with JPL, GFS, CSR, CRI data centers, coding in Google Earth Engine cloud computing environment has been used. Monthly and annual changes of liquid water equivalent (LWE) were calculated. Comparing the results of different data centers show that JPL data center with coefficient of R = 0.66 has the highest correlation with observational data. The amount of soil moisture, snow water equivalent and plant canopy water was extracted from the GLDAS model and subtracted from the amount of TWS extracted from the GRACE satellite and was compared with the observed values, which shows that the trend of decreasing groundwater level is equal to -2.26 cm. Calculations are made on the scale of one square degree and units are expressed in centimeters.