kernelDensity http://mapfw.tangshannanhu.com/iserver/services/spatialAnalysis-NanHuJingQuShiLiangTu/restjsr/spatialanalyst/datasets/%E5%86%9C%E6%9E%97%E7%89%A7%E6%B8%94%E4%B8%9A@%E5%8D%97%E6%B9%96%E6%99%AF%E5%8C%BA%E7%9F%A2%E9%87%8F%E5%9B%BE/densityanalyst/kernel