GIS Supported Evaluation Study Of Available Land Resource In Qing Yang City

China was a populous county. The per capita level of land，farmland，woodland andgrassland were lower than the world average. With the development of social economic and thecontinued growth of population，the contradictions between population and land in China wouldbecome increasingly acute. To use the limited land resources rationally was important tocoordinate the relationship between population and land. A planned development and utilizationof the reserve land resources，to a certain extent，could effectively alleviate the contradictionbetween people and land. However，the development of reserve land resources was constrainedby a variety of natural，technical，social and economic factors. It was an urgent task currently toseek a more secure and reliable development and utilization strategy. Using the sophisticatedGIS technology to study depth the reserved land resources development had an important role tostrength land resources survey，planning，management，protection and rational use of land. It hadfar-reaching significance to comprehensively promote the construction on the informationtechnology of land and resources and to accelerate the pace of modern management of land andresources.This research was as an example of Qing Yang City in Gansu Province，based on the secondland survey data and socio-economic statistical date in Qing Yang City，as the basis of thetechnical regulations on the provincial division of the main functional areas and the planningof main functional area in Gansu Province，with the county to the evaluation unit，we used theGIS spatial analysis techniques to evaluate the available land resources in Qing Yang City. In order to provide the basis for the division of main functional areas in Qing Yang City, the maincontents were as follows:(1) The evaluation on the abundance of available land resourcesIn order to study the number、the quality and spatial distribution of available land resourcesin Qing Yang City，we used the GIS spatial analysis technology to overlay the map of land use，the model map of digital elevation and the hierarchical map of slope，to calculate the area of theavailable land resources in Qing Yang City，and use the K-means clustering analysis to classifythe abundance. The results showed that：the area of the available land resources in Qing YangCity was3848.61km2，the per capita area of the available land resources in Qing Yang City was0.14hm2/per. The available land resources in Qing Yang City were relatively abundant，but itwere not balanced distribution in each counties，the quality of the available land resources waspoor，there were a lot of constraints and difficulties on land use.(2) The quality evaluation of the available land resourcesTo study the quality situation of the available land resources in Qing Yang City，weselected the evaluation indexes in four areas about topography, geological conditions, climate,geographic conditions of land use. To construct the quality evaluation system of the availableland resources. Then we used AHP to determine the weights of indexes，and use the spatialanalysis function in ArcGIS10.2to determine the quality situation of the available landresources in Qing Yang City. The evaluation results showed that the quality situation of theavailable land resources in Qing Yang City had four level land. The area of the first land was70605.00hectares，accounted for18.35%of the total area on available land resource. The areaof the second land was63639.95hectares，accounted for16.54%of the total area on availableland resource. The area of the third land was91177.20hectares，accounted for23.69%of thetotal area on available land resource. The area of the forth land was159438.93hectares，accounted for41.43%of the total area on available land resource.(3) The potential evaluation of the available land resourcesAccording to the abundance and quality evaluation of the available land resources in QingYang City，we selected the evaluation indexes and built the evaluation indexes system onquantity and quality two factors of the available land resources，using the spatial analysisfunction in ArcGIS10.2to determine the future potential of the available land resources in QingYang City. The evaluation results showed that the potential level of the available land resources in Qing Yang City had four potential level. The potential total area of the available land resourcesin Qing Yang City was261845.05hectares.The area of the first potential level land was16903.87hectares，accounted for6.46%of the total area on available land resource. The area ofthe second potential level land was120285.58hectares，accounted for45.94%of the total areaon available land resource. The area of the third potential level land was80013.35hectares，accounted for30.56%of the total area on available land resource. The area of the forth potentiallevel land was44642.25hectares，accounted for17.05%of the total area on available landresource.