【摘要】 为研究温榆河流域城市化过程中土地利用变化对非点源污染负荷的影响,基于GIS(地理信息系统)和RS(遥感),利用二次开发改进后的长期水文影响评价(L-THIA)模型,采用实地测得的EMC(事件平均浓度)数据,模拟了1992年和2009年非点源污染负荷量。结果表明,1992—2009年的城市化过程中商业用地、交通用地和住宅用地分别增加了13.95%、20.46%和85.76%,农业用地和水域分别减少40.04%和9.64%,导致非点源污染负荷量(总磷除外)明显增加。其中,总氮增加了3.31%,氨氮增加了12.20%,BOD5(5日生化需氧量)增加了11.87%,CODMn(化学需氧量)增加了7.62%,TOC(总有机碳)增加了15.46%,总磷下降了12.84%。交通用地、商业用地的非点源污染产出能力最强,应该成为非点源污染的重点控制区域。更多还原

【Abstract】 This paper intends to analyze the impact of land use pattern changes in the process of urbanization on the non-point source pollution load in Wenyu river basin. In the paper,we have adopted a widely used model Long Term Hydrologic Impact Assessment(L-THIA) for our study of non-point source pollution.The input data of the said L-THIA model are supposed to include the land use pattern,the soil type,the long-term rainfall data,the CN value and EMC data,though the EMC data in the above model is not necessarily associated with the situation in the study area. To make the results of assessment more accurate and more trustful,it is suggested to use the improved model of L-THIA to simulate the non-point source pollution load. In so doing,it is necessary to add a corrected CN value to the improved model. In our investigation,we have adopted the on-spot field measured non-point source pollution concentration data as the EMC data,while choosing the TM images of Wenyu river basin surveyed in 1992 and 2009,with the result of land use pattern and data concerned gained from a supervised classification.Through careful calculation and long-term consultation by using the expertise,the results of our investigation and consultation indicate that,the land area used for planting woods serves as the chief land-use pattern in Wenyu river basin from 1992 to 2009,with the urbanization trend leading to the ultimate changes in the land use pattern,with the increase of the land blocks used for the commercial,transportation and residential purposes by 13. 95%,20. 46% and 85. 76%,respectively,whereas the land area used for farming and water conservation dropped by 40. 04% and9. 64%. It is just for the land use pattern changes that has caused a significant increase in the non-point source pollution load(except for the total phosphorus). Statistically speaking,the total nitrogen content has increased by 3. 31% whereas the ammonia nitrogen has risen by 12. 20%. At the same time,BOD5,CODMn and TOC have all increased by 11. 87%,7. 62% and 15. 46%,respectively. Due to the shrinking area of farming land,the total phosphorus content in the total land area has dropped by12. 84%. While the grassland and woodland output the least nonpoint source pollution load,the residential land areas tend to follow. However,the land for transportation and commerce make the most contribution to the non-point source pollution load,which implies that the non-point source pollution has been strongly affected by human activities. Therefore,the land for transportation and commerce should be the emphatic control area of the nonpoint source pollution.更多还原