重金属超标农用地安全利用的地类转换模式研究

Land Type Transfer Mode for the Safety Utilization of Heavy Metals over Standard Agriculture Land

在快速城镇化的背景下,通过转换农用地类型实现研究区重金属超标农用地的安全利用。采用单因子指数法对研究区农用地重金属元素Cd、Pb、Cu污染状况进行评价,依据农用地安全利用标准,采用地类转换的方式调整超标程度严重的农用地类型。结果表明:(1)地类转换对研究区重金属超标农用地安全利用影响显著。从相对污染程度变化情况来看,所有点位相对污染程度均降低。绝大部分点位污染等级降低一到三级不等,个别点位虽单因子污染指数减小,但污染等级没有发生变化。(2)从地类转换后的结果来看,有些地类转换调整之后虽然相对污染等级降低,但污染指数仍大于3;另一种情况是经过地类转换,污染指数有所降低,但污染等级并未发生改变。(3)从分布情况来看,主要分布在中部城镇建成区附近,城镇周边分散有个别地块,地类转换之后,超标程度较重区域向集中分布区域中心缩减,城镇周边明显减少。

The purpose of the study metals over standard agricultural land. was to explore a transfer mode of land type for the safety utilization of heavy Firstly, this paper used the single factor index method to evaluate the pollution levels of heavy metals such as Cd, Pb and Cu and their spatial distributions in agricultural land of the study area. Then, the type of agricultural land with serious pollution levels and spatial distribution was transferred in accordance with the integrated evaluation standards of soil environmental quality. This study showed that land type transfer had a significant effect on the safety utilization of heavy metals over standard agricultural land. The relative pollution levels of all points reduced from the point of view of the changes in the relative pollution level. The pollution levels of most of points got lower one to three grades. In addition, one-way pollution index of individual point decreased, but the pollution level was not changed. From the results of land type transfer, the relative pollution level of some points reduced, but the pollution index was still more than 3. That of some points reduced, but the relative level of pollution did not change, the pollution level was mainly distributed near the middle of town and scattered in individual plots around the surrounding towns. After the conversion of land types, more severe pollution area reduced to the centers of the distribution area, significantly around the surrounding towns.