Changing Characteristics of Land-Use and Land-Cover in theHeihe River Basin, China during 1987—2000
ZHANG Yu~(1, 2), LIU Gui-min~1, MA Hai-yan~1, WANG Gen-xu~(1, 3) 730000, China; 2. Hydrological andWater Resources Reconnaissance Bureau of Gansu Province, Lanzhou Gansu 730000, Cof Western China's Environmental System, MOE, Lanzhou University, Lanzhou Gansu 730000, China; )
Land-use and land-cover change is one of the important issues in global change research because it is not only the significant component but also the major reason of global change. Based on a certain division of land-use and the TM data of the Heihe River basin from 1987 to 2000, and from the changing amplitude, changing rate and spatial dynamic degree of land-use and land-cover, in this paper, the changing characteristics of land-use and land-cover in the Heihe River basin are analyzed, and a contrast among the upper reaches, the middle reaches and the lower reaches is made. In this course, nine quantity indexes that aim at a single land-use type, area land-use type and area integrated land-use type, respectively, are used. From the study, the following conclusions are drawn: (1) The land-use and land-cover change are very serious in the whole river basin, especially in the middle reaches. The plantation, building land, water area and grassplot change most markedly. (2) The plantation, building land and desert land in the upper reaches are changing most rapidly. The plantation, building land, water area and other lands that are difficult to be used are also changing very quick. However, in the middle reaches lands change relatively slowly. (3) Plantation, building land and those lands difficult to be used are relatively stationary, but other lands change quite actively. So, the land-use and land-cover change is very complicated in the middle reaches of the Heihe River.