Wetland resource investigation of the north suburban of the Zhangye City Based on the Airborne CCD images

摘要

The CCD images were obtained during the intensive observation period of the Watershed Allied Telemetry ExperimentalResearch. 49 scenes of CCD images with 1-m spatial resolution were used for the pre-processed and investigation on thenorth suburban wetland resource for the Zhangye City. The pre-processing includes radiometric correction, preliminarygeometric correction, preliminary image mosaicing, offset position processing, color matching, differential GPSmeasurement of the Ground Control Points, geometric 'precision correction. The image mosaicing exists a series ofproblems. The biggest problem is the disagreement of the hues. The software of Geoway ColorPro was used to match thecolors. The manual interpretation method was applied to extract the patch boundary and type from the mosaiced image.Some questionably patch types were confirmed based on the field investigation. Three main conclusions can be obtainedaccording to the investigation.. Firstly, the wetland patches are more fragmentized than the patches of the other land usetypes. Secondly, the wetland area occupies 45.8 percentages of the total investigation area. The first three wetland typesare herb swamp, forest and shrub, and Inland salt marsh. Finally, the investigation results were widely applied to thedifferent departments of the local government.