Research On The Dynamic Change Of Land Use Using Remote Sensing And GIS

The land is the basis of economic activities for human beings; the land use is the mode and intensity as to produce materials; and the dynamic changes of the land use is the reflection of trend in the land use mode. The dynamic changes are distinguished from the change quantity, structure and degree. It is important to have a general and objective viewpoint to the dynamic changes to understand the present rational and irrational land use mode in order to provide reference to the long-term and sustainable land administration. The Remote Sensing (RS) method provides abundant information,and Geographical Information System (GIS) has powerful functions in data processing and spatial analysis. The combination of RS and GIS,which is characterized by little labor, high efficiency and low expense , has inestimable advantages compared with the traditional methods,and is highly practical in monitoring dynamic changes of the land use.With the aid of present-day Remote Sensing & GIS technology, this paper analyzes the spatial-temporal changes of land use during 1990-2005 in Ordos city from quantity,extent and spatial structure of land use. It is derived from TM images of 1990,2000 and 2005 in Ordos through picking up three terms land use data. Then point out the dynamic change law of land use. By using mathematical statistic method and natural and social economy data,this study analyzes the driving force factors of land use change on nature,social and economy aspects. The results of this research are as follows:(1) From the status quo in 2005,grassland and unused land accounted for 61.14% and 27.12% for the absolute superiority of land-use types in Ordos city,and the differences of land use space structural are obvious in banners and counties.(2) During the year 1990-2005 in Ordos city,there has been a marked change in the amount of land. As a whole woodland increase 56%,and grassland,water area and unused land have decreased. According to analysis of dynamic degree of land use, the increase of woodland is the quickest, and annual average is 3.73%;as for development threshold of land use, the development threshold of land use types from 2000 to 2005 year are higher than from 1990 to 2000, it's obvious in woodland, grassland and construction land.(3) To the extent of land use change,composite index of land use has increased during the year of 1990-2005 in Ordos city. It shows that the extent of land use change is in the degree of development period,but the level of use is low and the pace of development is slow.(4)Six kinds of land use changes existed in spatial differences in Ordos city. During the years of 1990-2000,grassland and water area were the least difference of land use types,and the biggest difference was the land use type of woodland. The difference of land use change was not obvious during the year of 2000-2005. From land use diversity index,we can see the diversity of land use was on the rise slowly in time scale and the south-eastern banners and counties was in whole higher than the north-west in space. It illuminated that land-use type was in rich year after year,slow rise in complexity in Ordos city.(5) The change of land use is the result of the function of natural and socio-economic factors together. The change of temperature and precipitation affect the change of grassland and unused land directly. Physiognomy, soil, the state's policies,population and socio-economic development together impact the change of land use way.