Contribution of SAR images to determination of surface moisture on the Menemen Plain, Turkey

Abstract

Due to recent climate changes and variability, drought has become a serious threat to Turkey, and its monitoring is of the highest priority. Remote sensing has certain weaknesses for monitoring droughts. Monitoring moisture levels using merely optical images may be inadequate in some cases due to the existence of natural plant cover and agricultural crop texture. The monitoring of moisture levels by meteorological satellites in recent years provides information only on smaller scales. Large-scale studies necessitate the use of active systems. In this study, the contribution of SAR images to moisture level observations was investigated in a selected study area, enabling different levels of soil moisture to be studied simultaneously. In this respect, a Radarsat-1 Fine Beam mode image of May 2006 pertaining to the low lands of Menemen Town, Izmir, was fused with a Satellite pour l'Observation de la Terre (SPOT)-2 satellite image of the same date, and the variation of grey values in each band was studied. Finally, the moisture level of the soil was observed despite the plant cover using the Fuse algorithm from the PCI software. Thus, the variable soil moisture levels determined using the gravimetric method were found to be highly correlated with the grey values obtained from image fusion.