Dynamic Change And Driving Forces Analysis Of Land Use Structure In Gansu Province

Based on land change data of Gansu Province from 1997 to 2004, the land use structure of the spatial and temporal changes were studied using different indictors such as the contribution rate changes, the average intensity index, the speed of change, Lorenz curves and so on. And the style of land use structure was classified by means of Least Square Error. Finally, with SPSS statistical software and DPS statistical software, it identified the change factors of land use structure.The results showed as following:1. Temporal changes in the land use structure of Gansu Province: From 1997 to 2004, cultivated land,grassland and water areas reduced in Gansu Province, and cultivated land areas reduced relatively larger. The change of the woodland areas was biggest, totally increased 430612.4 hm2 within 8 years, which reflects that the woodland played an important part in the change of the land use structure in the Gansu Province. On the side of the cities (cantons), cultivated land and grassland areas took on a downward trend, except for Jinchang city, which shows a slightly upward trend; Garden plot, woodland and traffic land areas have increased; grassland, water and unused land areas have changed differently, however, changes are not large every year; Residential and industrial land areas have become an increasing trend, except for Pingliang city, which shows a slight reduction, and Jiayuguan city expresses the largest growth rate, 4.08%.2. Spatial changes on the land use structure in Gansu Province: From 1997 to 2004, the spatial changes of land use structure were little. Lorenz Curves of water, grassland and residential and industrial land were close to the absolute uniformity line, which showed that the three style of land use distribution were more disperse in Gansu Province. Lorenz Curves of unused land and traffic land were not far from the absolute uniformity line. Lorenz Curves of cultivated land, garden plot and woodland were farthest from the absolute uniformity line, which showed that the three style of land use distribution did not balance; it was the same as the Gini coefficient. 3. There were four styles of land use structure which were dominated by unused land, grassland, cultivated land and woodland respectively in Gansu province. Styles of land use structure had significant differences in Gansu province. Land use structure was simple in Hexi district, and it was complex in Hedong district. From 1997 to 2004, because of the increase of unused land, only the styles of land use structure of Lanzhou city and Jiuquan city have undergone a notable change.4. Among eight indicators, GDP, the urbanization rate, the retail sales of consumer goods and the value of gross industrial output have a very high correlation. GDP which stood for socio-economic index influenced residential and industrial lands; population change was the main driving forces of water, cultivated land and grassland; and unused lands were influenced obviously by gross output value of agriculture.5. Based on driving factors of changes in land use structure of Gansu Province, there were three factors: socio-economic development, population and the Comparing economic interests. In addition, policy on returning cultivated land to woodland affected cultivated land changing into woodlands.