Study On Rapid Extraction Of Productive And Constructive Project Land Parcels In The Loess Plateau

The productive and constructive project(PCP)is one of the main sources of man-made soil and water loss in the Loess Plateau.Acquiring the location and boundary attributes of PCP land parcels is critical to soil and water conservation supervision and management.PCP land parcels hold a huge quantity and a dispersive distribution,while the studies on rapid extraction are rare.Traditional ways of mapping PCP land parcels mainly rely on manual interpretation of remote sensing images,which is time-consuming,subjective and expensive.Based on the GF-1 2m-resolution fusion image and the 8m-resolution multi-spectral image in Hengshan district,this study adopts several object-oriented methods to extract PCP land parcels,and to explore a optimized extracting strategy.Firstly,on the basis of the classification system,the analysis of the ground objects features is taken and extracting markers are confirmed.Then,combining the single-/multi-resolution segmentation method with the CART or fuzzy classification method,four object-oriented extracting strategies are built.Final extracting results are achieved after automatic extraction and post-processing procedures.Results show that five kinds of marked objects,which are buildings and structures,harden grounds,bare land,coal covered areas and water areas,are reliable to sign PCP land parcels in the Loess Plateau,and that the multi-level extracting strategy based on the 2m-resolution fusion image is the best extracting strategy for the study area:the accuracy of extracting block-type PCP land parcels exceeds 98%while of line-type PCP land parcels exceeds 86%,and the overall time is 80%less than the traditional method.The technical flow is built based on the strategy,and validated in Lingwu City,which is considered fit to extracting PCP land parcels in the Loess Plateau.Compared to manual interpretation,the technical flow shows a fantastic advantage on extraction efficiency with a high accuracy,which can be applied for rapid extraction of PCP land parcels in a large region in the Loess Plateau.A better technical support will be provided by the optimized strategy for efficient and accurate implementation of soil and water conservation supervision and management.