Analysis of meander evolution of Dez River in agricultural and mountainous areas by Google Earth Engine (GEE) and GIS

 The rivers are vital natural resources for human activities. Knowledge of the structure and dynamics of rivers is important to understand river characteristics. Differences due to the season in river flow lead to unsteady sediment transport capacities that cause riverside erosion and the development of meandering channels. Channel migration might produce a crucial problem for water supply and hydraulic structures. Therefore, the study of a stream channel dynamical is necessary. In this research, we investigate the meander evolution of the Dez River in agricultural and mountainous areas by GEE and Geographical Information System (GIS) during 1995 - 2021.

  To study the meander evolution of the Dez River, the Sinuosity Index (SI) of the river in the mountainous and agricultural areas was calculated. Then the slope and The Digital Elevation Model (DEM) maps were prepared using NASA SRTM. Also, the soil texture map was derived from the U.S. Department of Agriculture (USDA) system and the monthly runoff map was prepared in GEE.

 The results showed that SI in the mountainous area was constant (2.10), but it changed in agricultural areas (2.10-2.14). Also, the slope in agricultural areas was 1-4 degrees, the elevation was 30-36 meters, and the soil type was loam and clay loam. Due to the increase in runoff in recent years and the erodibility of the riverbed, it seems that the meander evolution of the Dez River is due to soil type and runoff increase.