Study On The Land Use Survey At County Level Based On Satellite Image With High Space Resolution

The survey of land use at county level is the basic work for land management and the actual accurate data resource of land cover in our country. Traditional means of land use survey at county level costs a great quantity of manpower and material resource, but with low effectiveness. The development of Remote Sensing (RS)> Geographic Information System(GIS) and Global Position System(GPS) and the presence of satellite image with high spatial resolution have provided highly effective and reliable information resources and an advanced method for the survey and dynamic monitoring of land resources.On the bases of analyzing traditional means of land use survey, the paper draws conclusions mainly on aspects such as survey method, image processing, image interpretation, establishment of land use database at county level, and the mapping of 1:10000 land use maps. How to survey land use at county level based on satellite image with high spatial resolution has been studied. And technological flowchart and the survey method have been put forward in this paper. The final surveyed data of land use is of high precise and practice and can meet the needs of the land use survey at county level in our country.The land use survey in partial area in Wangmo County, Guizhou Province has been worked out as an example based on the satellite image of QiuckBird with a spatial resolution of 0. 7m. Enhancement, resolution mergence, and geometric corrections have been conducted in ENVI firstly. Two enhancing ways have been adopted: one is edge enhancement and the other is resolution mergence between panchromatic image and multi-spectra image with principal component convert, which enhanced the image difference between the land use types. Thena geometric correction of the enhanced image has been conducted with polynomial ways and piecewise policy, using 32 GCP (Ground Control Points) surveyed with post processing differential GPS and 31 GCP selected on the maps. And then, the land use classifying system for the studied area has been established according to issued by our country in 2001, and an interpretation key table has been established based on site investigation. Next the information about land use compartment and matching attribute were obtained with the interactive interpretation software developed on the platform of ArcView. To ensure the quality of interpretation, "two times interpretation" has been adopted. The interpretation results have been verified with matrix, which is established by site investigated data and interpreted data, and the precision reaches 98. 26% based on the calculation. Further more, layers with GeoWay have digitized other geographic information, and attribute tables were established according to the requirement. At last overlaying analysis, database establishment, and land use type mapping have been conducted in the software of ArcGIS.It has been indicated by the study that, compared with the traditional means, the land use survey at county level based on satellite image with high spatial resolution is of advantages on high technology, high precision, short working time, low cost of large scale survey, and easily kept, transported, copied, revised, and shared of the final digital products. Furthermore, it can establish land information system more easily, and carry out dynamic updating and monitoring of the land resource.