Application of NOAA/TIROS Satellite Data to Snowmelt-Runoff Model of Heihe Basin in Qilian Mountain
Zhang Shunying and Zeng Qunzhu (Lanzhou Institute of Glaciology and Geocryology, Academia Sinica)
Snow melt runoff of snowcover in Qilian mountain, plays an important part in agriculture irrigation in Hexi district from April to May. A snowmelt runoff model was developed by the authors using statistic method. This model has been used to simulate daily streamflow on the 2.452km2 Babao basin and 4,589km2 Heihe basin. The simulated runoff volumes of April and May of 1980-1984 were within 7, 15.0, 3.7, 0.4 and 0.2 percent, respectively, of the measured runoff in Babao river. The daily fluctuations of discharge were also simulated by the model in the two rivers, reaching a higher accuracy. The snowcover extent is an important paramater in the model. It comes from NOAA TIROS 6, 7 and 8 series satellite images. Low resolution TIROS image was put on the easel of Zoom Transfer Scope, the image was enlarged, rotated and stretched in order to match it with the map at 1: 1.500,000 scale. How to get the precise snowcover extent data from NOAA/TIROS satellite images has been discussed, too.