基于熵权TOPSIS模型和GIS的黔北农产品区土壤养分空间分析及综合评价

Spatial Analysis and Comprehensive Evaluation on Soil Nutrients in Northern Guizhou Agricultural Product Area Based on Entropy Weight-TOPSIS and GIS

通过实地采样和室内分析的方法,对黔北农产品区农用地1 037个土壤样品进行了检测分析,以全氮、有效磷、速效钾、有机质、pH值为评价指标,运用GIS,GS+技术和熵权TOPSIS模型法对农产品区的土壤养分进行了分析与综合评价。结果表明:(1)研究区土壤速效钾含量丰富,全氮、有效磷含量为中等,土壤为酸性与中性土壤,较适合农作物生长,但其有机质含量相对缺乏。(2)半方差函数模型拟合结果显示有机质、速效钾、全氮、pH值符合指数模型,有效磷符合球状模型,而有机质、速效钾的空间变异结构特征较强,全氮、pH值、有效磷的空间变异结构性弱。(3)研究区土壤养分综合指数空间分布图分析显示,北部和西部地区共2.55%的面积为极高水平,以岛状为主;西南、东南、南及北部地区共32.43%的面积为高水平,以带状为主;研究区55.45%的面积为中等水平,集中连片,以面状为主;西部、中部、东部部分区域共9.45%的面积为低水平,以带状和岛状为主;0.11%的面积为极低水平。研究结果为掌握黔北农产品区养分丰缺状况、变异机理、空间分布和为其精准施肥奠定了基础。

About 1 037 farmland soil samples from the agricultural product areas of Qianbei were analyzed.pH value,total N,available P,available K,organic matter were used as the indicators,the nutrients of soil samples of agricultural product areas were analyzed and evaluated with GIS,GS＋ technology and entropy TOPSIS model.The results showed that：（1）in the study area,the soils were acidic or neutral,with abundant available K,medium total N,available P and relatively low organic matter,which is suitable for crop growth;（2）the semi-variance function models proposed that the organic matter,available K,total N,pH value fitted the exponential model and available P fitted spherical model,as well as the spatial variability structure of organic matter,available K were strong,and pH value,total N,available P were relatively weak;（3）the spatial distribution map of soil nutrient index showed that 2.55% of the area in the northern and western regions is high level with the island distribition;32.43% of the area of the southwest,southeast,south and north regions was high level with band distribution;55.45% of the study area was medium level,with the concentrated and surface distributions;9.45% of the western,central and eastern part of the region was low level,with banded and island distributions,and the 0.11% of study area was very low.Theresults lay the foundation for mastering the nutrient abundance,the variation mechanism,the spatial distribution and the precise fertilization for the agricultural product areas in the north of Guizhou Province.