The arid desert ecosystem is very fragile, and the change of its river discharge has a direct impact on irrigation and natural environment. River discharge attenuation coefficients is a key index to reveal the stability of desert river ecosystem. However, due to the harsh conditions in desert areas, it is difficult to establish a hydrological station to obtain data and calculate the attenuation coefficients, so it is urgent to develop new methods to master the attenuation coefficients of rivers. In this study, Taklamakan desert river was selected as the research area, and the river discharge of the desert river were estimated by combining low-altitude UAV and satellite remote sensing technology, so as to calculate the attenuation status of the river in its natural state. Combined with satellite remote sensing, the surface runoff in the desert reaches of the Hotan River from 1993 to 2017 were estimated. The results showed that the base of runoff attenuation in the lower reaches of the Hotan River is 40%. Coupled UAV and satellite remote sensing technology can provide technical support for the study of surface runoff in desert rivers within ungauged basins. Using UAV and satellite remote sensing can monitor surface runoff effectively providing important reference for river discharge monitoring in ungauged catchments.The attenuation coefficients of river discharge is the key index for maintaining fluvial ecosystems and arises through evaporation and infiltration during transport, which is usually calculated from the flow rate during the dry season [9,10]. The process of driving river attenuation depends on a series of physicochemical and biological parameters such as river velocity, temperature, vertical hydrological exchange of surface runoff and groundwater [11,12]. In the past 30 years, some relatively mature computational methods have been developed [13][14][15][16], which can be mainly divided into hydrological methods, hydraulic methods, habitat simulation methods and holistic analysis methods. These methods require a lot of information and require a long time of investigation, which tends to be carried out in areas with abundant hydrological data. However, large portions of total River Basins across the globe are either poorly gauged or completely ungauged [17][18][19], and hydrological observation networks are continuously deteriorating [20]. Therefore, there is a lack of research on surface runoff in ungauged catchments of arid desert [21][22][23], and the study on river attenuation is basically blank, resulting in high variability of attenuation rate in rivers, which complicates the prediction of environmental flows [24,25].Calculating the streamflow in ungauged catchments is surrounded by uncertainty, and is thus a challenging, yet vital task for water management. New and easily accessible satellite data have been increasingly steadily in recent years. Many studies have been conducted using satellite data to estimate river discharge [26][27][28]. Traditional methods for estimating river discharge mainly a...