Global NEST Journal, Vol 21, No 2, pp 245-252 Copyright© 2019 Global NEST Printed in Greece. All rights reserved Samie M., Ghazavi R., Vali A. and Pakparvar M. (2019), Evaluation of the effect of land use change on runoff using supervised classified satellite data, Global NEST Journal, 21(2), 245-252. Evaluation of the effect of land use change on runoff using supervised classified satellite data Samie M. 1 , Ghazavi R. 1,* , Vali A. 1 and Pakparvar M. 2 1 Dept. of Watershed Management, Faculty of Natural Resources and Earth Sciences, University of Kashan, Iran 2 Fars Agricultural and Natural Resources Research and Education Center Received: 17/02/2018, Accepted: 07/03/2019, Available online: 13/03/2019 *to whom all correspondence should be addressed: e-mail: ghazavi@kashanu.ac.ir https://doi.org/10.30955/gnj.002631 Abstract The main objective of this study was to determine the effect of land use change on runoff in Chenar Rahdar watershed. Land use map of the studied basin was determined using Landsat satellite imagery for 2004 and 2015 using ENVI software. After applying the necessary corrections to the images and field surveys to take the educational points, supervised classification technique and maximum probability algorithm were applied to mapping land use change in the study area. According to results, 6 classes of land use were investigated (bare land, rain fed land, forest land, water agriculture land, rangelands and urban lands). In this study, 21 model parameters were calibrated with monthly runoff using 2004-2012 data and validated using 2012-2015 data. The efficiency coefficient for calibration and validation were between 0.88 and 0.94, respectively. The land use changes trend within the time interval showed that the highest percentage of incremental changes is related to urban lands with 108.45%, whereas, the highest decline was observed for agricultural land with 12.46%. In order to investigate the effect of land use change on surface runoff, different land use maps were applied to SWAT model, supposing constant condition for other parameters of the model. The results show that surface runoff increased by 11%, in 2015 compared to 2004. Comprehensive water management can reduce surface runoff in the watershed. The results showed that if all uncertainties were minimized, the calibrated SWAT model can give acceptable runoff simulation results regarding the land use change. These results can be useful for water and environmental resource managers. Keywords: Land use; rain runoff; SWAT model; Chenar Rahdar. 1. Introduction The hydrologic cycle at the watershed scale is a complex process that affected by climate, the physical characteristics of the watershed (i.e., geology, terrain, soil properties, vegetation), and human activities (i.e., land use practices, reservoir regulations, water transfer project). A number of studies shows that it is insufficient for climate change alone to interpret streamflow trends in some watersheds, while human uses such as land use/cover change especially soil and water conservation can also change hydrological processes and impact the streamflow trends (Liang et al., 2013; Azeb et al., 2018). To appraise the hydrological and sediment impacts of environmental change, the commonly used methods are the paired catchment approach, statistical analysis, and hydrological modeling. Among these approaches, a hydrological method is an appealing option, since it is the most suitable trend for using as a part of scenario studies (Khoi and Suetsugi, 2014). The impact of land use changes on runoff is a present topic in hydrologic research and is often assessed by rainfall-runoff model simulation (Naef et al., 2002; Joorabian et al., 2017). Land use changes have been investigated in Golestan province, northeast of Iran during 2000-2013 using Landsat ETM image (Varamesh et al., 2017). The Results of this study indicate that the main land use change in this study area was the conversion of forest and rangeland to agricultural and residential land uses. Pikounis et al. (2003) evaluated the hydrological effects of specific land use changes in a catchment of the Pinios watershed in Thessaly, Greece. They examined the effect of land use change using three land use scenarios including complete deforestation and expansion of urban area and expansion of agricultural land, in the Trikala sub-basin. All the three scenarios led to an increased streamflow during the wet season and a decreased during the dry season. Githui et al. (2009) investigated the impacts of land-cover change on runoff using SWAT model, in Nzoia catchment, Kenya. Land-cover change scenarios namely the worst- case and the best-case scenarios were generated. The results of historical land-cover change indicated the increased area of agricultural from 39.6% to 64.3% between 1973 and 2001, while the decreased forest cover from 12.3% to 7.0%. The land-cover scenarios generated changes in runoff of almost –16% and 30% for the best