滇西北纳帕海湿地景观变化及其评价研究

Landscape Change and Assessment of Napahai Wetland in Northwestern Yunnan

以1974、1994和2000年遥感影像为数据源,在GIS技术支持下提取湿地景观信息,通过权重排序选取核心景观指数,研究了滇西北纳帕海湿地近30年来的景观格局变化,并以其为评价指标就景观层次上湿地环境变化进行了定量评价。结果表明,(1)基质景观改变,1974、1994年为湿地类型,2000年成为非湿地类型,以草甸景观占主导地位;(2)景观格局变化明显,1974～1994年景观呈分离、破碎、形状复杂的格局,多样性略有增加,2000年呈现紧密结合、破碎化略有降低、形状简单的格局,多样性大幅降低;(3)定量评价表明,1974年为Ⅱ级,湿地环境质量良好,1994年与2000年同为Ⅳ级,湿地环境质量较差,在景观层次上体现出湿地退化的特征。

Based on the remote sensing images of 1974,1994 and 2000,the wetland landscape information of Napahai wetland in Northwestern Yunnan was extracted supported by GIS.Major landscape indices were selected adopting the method of variation coefficient to analyze the landscape changes and assessment the wetland environment changes on landscape level.Results showed：1）.the matrix of the Napahai landscapes was wetland types in 1974 and 1994,however,it was transformed into the ever-increasing human land use types from 1994 to 2000,the dominant landscape type became meadow.2）.landscape pattern changes obviously,it showed a dispersed,fragmentized and complicated shape,as well as increased diversity form 1974 to 1994.However,the landscape became compactness,the fragmentation and diversity of landscape was decrease,the shape became simple form 1994 to 2000.3）.quantitative assessment showed： the assessment grade of 1974 was Ⅱ which indicated the quality of wetland environment was well,however,it was Ⅳ in 1994 and 2000,that indicated the quality of wetland environment was poor and the characteristics of wetland degradation obviously on the level of landscape.