Study of soil organic carbon changes in two critical and vulnerable areas of Qahavand plain rangelands using remote sensing and GIS

Organic carbon is a major source of soil organic matter and an indicator of soil quality in natural ecosystems. Therefore, monitoring soil organic carbon reservoirs under different circumstances seems necessary to understand the global C cycles. The present study was aimed to evaluate soil organic carbon content in two critical and vulnerable sites of the Qahavand rangeland ecosystem which has experienced extensive desertification in the last decades. The soil sampling from 20 cm was done at 63 points at random locations in two critical and vulnerable sites. Then, 9 different indices of vegetation and light Including NDVI, RVI, SAVI, MSAVI, TSAVI, OSAVI, WDVI, NDBI and BI related to 63 sampling point was calculated based on satellite images. Furthermore, the NDVI, RVI, SAVI, MSAVI, TSAVI, OSAVI, NDBI and BI indices showed a relatively good Pearson correlation with soil organic carbon content with the R2 values of 0.41, 0.38, 0.38, 0.41, 0.40, 0.39, -0.44 and 0.48. These results represent the possibility of using Landsat 8 satellite image indices to monitor soil organic carbon reservoirs in the Qahavand plain.