两个项目用到arcgis的zonal static as table功能，发现如果矢量有重叠的话，会导致其像元值只会被统计一次。对于此种情况，就采用遍历矢量要素，生成内存图层，然后对每一个矢量进行区域统计，得到结果再汇总。
在前人摸索的基础上，原教程是通过arcpy.list来汇总结果，但是发现会特别慢，因此本文通过py的dbfread模块来统计栅格值。
import arcpy,arcgisscripting,os from arcpy.sa import * from arcpy import env # Local variables: env.workspace=r"D:\cs.gdb"
#矢量图层 CY50 = "CY50"
#栅格图层 rk="rk"
#得到cursor
inRows = arcpy.SearchCursor(CY50) inRows.reset() inRow = inRows.next()
#开始遍历，根据其OBJECTID来依次遍历（gdb中的数据不存在FID字段，任一唯一字段即可）
count=0 while inRow:
count+=1 print "{0} is being processed".format(inRow.OBJECTID)
#内存图层的名称 lyr = "Zone {0}".format(inRow.OBJECTID)
#创建内存图层，详情见toolbox中的创建内存图层帮助 arcpy.MakeFeatureLayer_management( CY50, lyr, '"OBJECTID" = {0}'.format(inRow.OBJECTID))
#生成结果表的路径 tempTable = "{0}/DBF_{1}.dbf".format(dbfPath, inRow.OBJECTID) try :
#对该内存图层进行区域统 ZonalStatisticsAsTable(lyr, "OBJECTID", raster, tempTable, "DATA") except BaseException as e : print ("") inRow = inRows.next() from dbfread import DBF
#然后读取dbf汇总#切换到dbf生成的表格，将结果读到字典中
#读取dbf的函数，参数1为区域统计dbf生成的路径，第二个为矢量的个数
def readDBF(dbfpath,count): os.chdir(dbfpath) my_dic=dict() for i in range(count+1) : s= "DBF_" + str(i) + ".dbf" print("查找路径为"+dbfpath+"的表"+s) if (os.path.exists(s)): table = DBF(s, load=True) try: my_dic[str(i)]=table.records[0]['SUM'] except BaseException as e: my_dic[str(i)]=0 else : my_dic[str(i)]=str(0) return my_dic my_dicRK=readDBF(dbfpath,count)
#将结果字典写入到目标图层中
for s in my_dicRK.keys(): print(s+":"+str(my_dicRK[s])) #将字典的值，依次写入到结果图层中 os.chdir(dbpath) with arcpy.da.UpdateCursor(CY50,["rk_v","OBJECTID","rkbd_v","jz_v"]) as cursor2: for inRow2 in cursor2: try: inRow2[0]=my_dicRK[str(inRow2[1])] inRow2[2]=my_dicRKBD[str(inRow2[1])] inRow2[3]=my_dicJZ[str(inRow2[1])] cursor2.updateRow(inRow2) except BaseException as e: print(e)
