Monitoring of fluvial systems by RS and GIS (Case study: Talar River, Iran)

Abstract

Fluvial rivers are as important indicators of environmental changes. The present study carried out for some changes of morphological parameters in plain part of Talar River using aerial photo during 1968 and 2013 with helping remote sensing and GIS. In this research, seven sections of morphological parameters were determined at last 7 km of Talar River after channel map had been extracted for each year. The results showed that during study time average river width (W) for all seven kilometers study river have decreased about 25.5, also flow length of study river increased for 8 meters. In this study River Network Change Index determined for all seven sections during study time periods. RNCI in this study is about -0.7 meters per year, and the main process in this part of Talar River is sedimentation. Results of study showed that, section number 1 is the most variable section and section number 4 is the most stable section. During study time Caspian Sea has retreated about 150 meters and the delta of Talar River was changed during last decades. This study showed that Talar River have two behavior in morphology during last 45 years. First 26 years (1968-1994) is the stable time and last 19 years is the variable time spatially sedimentation. The main reason of parameters change can be hydrologic regime and ecological condition change as the river were damaged extremely during study period by human impacts.