Research on ice regime evolution of the Fengman Reservoir based on satellite remote sensing images

Based on the ENVI 5.1 software platform and by using the Landsat-7 and Landsat-8 satellite remote sensing images, ice regime interpretation and surface temperature retrieval were performed for the Fengman Reservoir, which is located in Jilin City. Afterwards, the patterns of the overall ice regime evolutions and their relations with thermal variations of the Fengman Reservoir were investigated. The results indicated that: during the whole ice season, the ice regime was significantly influenced by the water thermodynamics of the Fengman Reservoir due to the steady inflow conditions; in the freeze-up period, the reservoir surface water temperatures showed a pattern, with the temperature lower in the middle area of the reservoir, higher in the area in front of the dam and the end area of the reservoir, the freeze-up started from the middle area of the reservoir and expanded to the area in front of the dam and the end area of the reservoir, and the area in front of the dam froze up at last; in the steady freeze-up period, vertical water temperature of the reservoir was inversely distributed underlying the ice cove, ice thickness was unevenly distributed along the reservoir, and an open water flow of 10 km to 30 km existed in the end area of the reservoir; in the break-up period, the surface water temperatures declined from the area in front of the dam to the end area of the reservoir, and the thawing started from the end area of the reservoir to the area in front of the dam in the form of over-mature break-up.