Analysis of reservoir environment evolution from 2000 to 2020: A case study in the Guanting Reservoir, China

Changes in different areas of the reservoir itself constitute the overall performance of the reservoir. This study obtains hydrological information based on continuous satellite images, and then makes zoning analysis of the reservoir to determine the best condition of good and stable operation of the reservoir. Based on a series of Landsat images, taking the Guanting Reservoir in Beijing, China as an example, this study quantitatively analyzed the distribution and changes in the laws of water volume and water surface temperature of the Guanting Reservoir from 2000 to 2020. Additionally, based on stability, the natural zoning of the reservoir area is carried out. The water surface range was obtained using the water index method. The water surface temperature was obtained by the radiative transfer equation method, which was analyzed in combination with the Reservoir Area Dynamic Degree (RADD) and Reservoir Shoreline Development Index (RSDI). In the last 21 years, the trend of water surface temperature of the Guanting Reservoir during different seasons has reversed. The year 2013 was a turning point, prior to which, the Guanting Reservoir experienced an obvious decline period (area reduction rate of 68.38%), followed by a rapid recovery period (area expansion rate reached 200.68%). When the reservoir water volume is relatively stable and RSDI is large, it is the best operation condition. According to the analysis of RSDI and average water surface temperature for many years, the stability of the reservoir is obtained for zoning. The unstable area of the reservoir or the general stable area, the water surface coverage and the water surface temperature change greatly, which is the area where the environment is most easily changed. The distribution of aquatic plants is consistent with the relatively unstable area of the reservoir. This study provides a valuable method for the rational management of reservoir submerged area. It also provides a basis for the rational planning of the reservoir area.