利用遥感与GIS分析珠江三角洲农田流失的空间分布规律及影响因素 --以东莞市为例

近年珠江三角洲出现了迅速的城市化的过程,大量的农田被推平作为非农业用地,其中有相当一部分的土地资源被不合理地浪费掉.分析这种土地利用变化的过程,可以为有效地利用土地资源提供规划依据.本文利用遥感与GIS相结合的方法,探讨了东莞市农田流失的时空分布规律.通过熵的计算,对快速的城市扩张过程进行了定量化的监测.并利用重力模型,研究造成这种现象的影响因素.研究发现,东莞市某些镇近年来的农田流失尤为严重.

AN ANALYSIS OF THE SPATIAL DISTRIBUTION OF AGRICULTURAL LAND LOSS AND ITS DETERMINANTS IN DONGGUAN WITH REMOTE SENSING AND GIS

The integration of remote sensing and GIS is useful for the nuderstanding of agricultural land loss in thetemporal and spatial dimensions with some independent variables which can be retrieved from GIS database. Itcan help to identify the influences of social and physical factors on the land loss. The adult of the analysisreveals that the land loss in Dongguan in 1988 ~ 1993 mainly took place in the areas nearby urban (town)centres or roads. The well-known Shannon's entropy, which is an index for measuring discrete probability distribution, is used to deSCribe the distribuhon pattern of agricultural land loss and to measure the process ofthe diffusion of urban It is interesting to see that there is a stmng conant between the dilation in 1988~ 1990 and that in 1990 ~ 1993. The diffusion of the urban in 1988 ~ 1990 was limited whereas that in1990 ~ 1993 was astonishingly stiDng. The probability of agricultnd land loss can be expressed with a gravitymodel. The result of the regression indicates that there is a strong correlation between the amount ofagricultural land loss and these three factors-the CDP value, the area of available flat land in the town, andthe cost negroly distance from the toWn to Hong Kong.