The Impressibility of Flood Regime from Rainfall and Land Use Changes in Cheshmeh Kileh Watershed

Assessing the impact of changes in rainfall and land use on flood is a key issue in watershed management. However, their simultaneous effect has received less attention. The aim of this study was to investigate the impressibility of flood from rainfall regime and land uses in Cheshmeh Kileh Tonekabon watershed. For the present study, data from five rain gauge stations in the region and Haratbar hydrometric station were used. First, the land use map of 1984, 2001 and 2017 was prepared using a Random Forest algorithm in the Google Earth Engine. Then, rainfall and discharge components were used to investigate the impressibility of flood on the rainfall regime. In order to quantitative estimate the minimum and maximum flood indices and Flow Duration Curve, IHA 7.1 software and EFC approach were used. Investigating the effect of rainfall regime variables on flood showed that there is no significant trend in precipitation data in the statistical period. On the other hand, the area of forest lands in 2017 compared to 1984 decreased by about 21.25%, but rangeland, agricultural and residential areas increased by 24.16, 315.00 and 225.47 percent, respectively. The percentage of difference between 1, 3, 7, 30 and 90 days maximum indicators, Rising Rate and Large Flood in 2017 compared to 1984, respectively 193.17, 156.02, 124.87, 77.22, 57.93, 197.22 and 207.66 percent increased, which indicates the impressibility of flood flow indicators from land use changes.