The Research of Land-Use Optimization Approach Based on Non-Point Source Pollution Controlled
|School||Nanjing Agricultural College|
|Course||Management of land resources|
|Keywords||Land use structure optimization Landscape structure optimization Linear programming model Minimum cost distance model Non-point pollution Yixing City|
At present, the water environment problem caused by non-point pollution beeomes more and more serious, threats to human survival and the development of the society seriously, has been a common concern at home and abroad, in order to solve the non-point pollution problem, scholars conducte many researches, the content mostly focused on the effects of non-point pollution caused by land use. The result shows that non-point pollution has been caused by human activity of unreasonable land use,which has a close relationship with land sue structure and landscape pattern,and so on. throughly, the research how to control the non-point pollution by land-use optimum is scarce, even there isn’t a systematic theoretical analysis framework, therefore, land-use optimum based on the control of agricultural non-point source pollution will be an urgent problem to solve currently.This article puts forward an analysis frame of land utilization optimizing ways for controlling the non-point pollution, based on multi-objective harmonizing theory, "origin", "collect" landscape theory, and-use optimum basic theory and so on. First, it analizes the effect principle that land use influences non-spot pollution, and there is a quantitative analysis for non-point pollution output response result of the different types of land use; then it optimizes land use structure through the linear programming model, and optimizes land utilization spatial structure pattern using the least cost distance model; finally Yixing city as an example, using an empirical study, the results of the study are as follows:(1)It analizes the effects of land use for non-point pollution by both the qualitative and the quantitative methods. The results indicate that total N output coefficient relations of non-point pollution for the different types of land use as:rural residential land (77.19 kg/hm2)> urban use land (42.38 kg/hm2)> cultivated land (26.50kg/hm2)> garden land (21.29 kg/hm2)> unused land (1.72 kg/hm2)> woodland (1.71kg/hm2); total P output coefficient relations of non-point pollution for the different types of land use as:rural residential land (23.50 kg/hm2)> urban use land (7.47kg/hm2)> cultivated land (2.07kg/hm2)> garden land (1.67kg/hm2)> unused land (0.42 kg/hm2)> woodland (0.41 kg/hm2)。(2)Land use structure is optimized by using linear programming model. The results indicate that garden, other agricultural land, rural residential areas land, independent mining land, special land and unused land have been in reduce state, among which, decrease amplitude of the rural residential land is the biggest. The woodland, urban use, transportation and land for water facilities have been in increase state, among which, increase amplitude of Woodlands and urban use is the biggest. The results of economic and ecological benefit comparison of land use structure adjusted before and after shows, economic benefit adjusting after can increase 11176.04 million yuan, at the same time, total N and P adjusting after greatly reduced, among which, total N reduces 654.96 tons, the total reduces 248.37 tons; in order to protect Water quality, using minimum cost distance surface model, combined with the landscape pattern and the ecosystem services value analysis method,determines the optimum ecological location of vegetation buffer,according to the spatial structure optimization principle, determines the reasonable width of vegetation buffer, so that, which constructes ecological Ann area barrier west lake.