Abstract:

In combination with the methods of RS, GIS and Statistics, the process and trend of LUCC in the Area of Middle and Lower Reach of Jialingjiang River are thoroughly studied by establishing mathematical models in the range, speed, trend index and regional differences of LUCC based on the remote sensing imagery data of 1972, 1986 and 2000. The main results are as follows. (1) From 1972 to 2000, the areas of grassland, farmland and unused land are respectively decreased by 26834.18 hm²、6886.68 hm² and 217.84 hm², while those of woodland, cultivated land and water area are respectively increased by 19844.89 hm²、12964.45 hm² and 1129.36 hm². Disconnecting the period by 1986, the area of cultivated land and water area increased at all times, while those of grassland and unused land decreased, and woodland decreased in the first period and then increased in the second period. The farmland was in reverse considering the change of area. (2) From 1972 to 1986, based on the order of the output speed, the six kinds of these land-uses were arranged by grassland, woodland, farmland, unused land, water area and cultivated land. As to the input speed, the order is cultivated land, woodland, grassland, farmland, water area and unused land. In view of general change index, these land-uses were ranked as grassland, cultivated land, woodland, farmland, water area and unused land. The input speed of cultivated land and water land was beyond their output speed remarkably, while that status of woodland was on the contrary, which was in the state of balance. From 1972 to 1986, to separately calculate the indexes in the same way as above, the respective arrangement of the results were unused land>grassland>farmland>water area>woodland>cultivated land, cultivated land>unused land>woodland>water area>grassland>farmland, and cultivated land>unused land>grassland>woodland>water area>farmland. Cultivated land was not quite stable, whose input speed was beyond output speed notably. (3) The land use of Chongqing, Jiangbei and Hechuan had changed mostly in the period according to the change index, and the results were from 0.231% to 0.272%. The values in Gungyuan, Wangcang were from 0.114 to 0.126%. The values in Jiange, Cangxi, Langzhong, Nanbu, Xichong, Nanchong Pengan, Yuechi and Wusheng were from 0 to 0.090%.

Key words: Land use/cover change, the area of middle and lower reach of Jialingjiang River, the input speed, the output speed, the state of alance