Comparison Research Of Environmental Impact Assessment Methods Of Land-use Planning In Karst Area

To adjust land-use structure and layout of land use as the core of the land-use general planning, the implementation of which will cause long-term, complex, comprehensive, and irreversible effects on the regional ecological environment. Township land-use planning at the lowest level of the planning system in China, it is the basis of manage and carry out of the land-use planning, its preparation level is directly related to the scientific, rational and sustainable utilization of the resources of regional land. The ecological environment of Karst area is very fragile, and it is a sensitive area of land use change, which is an important limiting factor of the regional sustainable development. Therefore, it has important practical significance to carry out the study of the environmental impact assessment of the township-level land use planning in Karst area.This paper discusses the function of the township land-use planning and the connotation of land use planning environmental impact assessment in Karst area based on the connotation of the land-use general planning and its environmental impact assessment. Shuijiang Town of Nanchuan Distrct as a research area, which is a classic Karst area, select the "PSR", grid cell method, the ecosystem service value as the comprehensive evaluation methods of its new land-use general planning, and validating the scientific and practical of the three evaluation methods. The results of the study show that:According to the evaluation results which to carry out environmental impact assessment on regional land use planning, especially the ecological fragile area, such as karst area. It could timely feedback to the adjustment of the land-use planning environmental impact, and provide a reference for the future planning revision. It also can make the environmental impact caused by the defects of the planning scheme to eliminate or reduce as much as possible to ensure the positive direction of the environment and promote the coordinated and sustainable development of regional man-land relationship.Select the "PSR" model, ecological service value method and the grid element method as the evaluation method basis on the summarizing of the environmental impact assessment methods of the general land-use planning."PSR" model is an effective method of the land-use planning environmental impact assessment, it can accurately reflect the ecological environment impact by the land-use general planning. Ecosystem services value method can directly reflect the land ecosystem service functions by the land-use general planning according to calculate the total value and the changes of the ecosystem service functions of the land use. The grid cell method can take into account the difference of index in space by make the grid unit as evaluation unit. Combined two kinds of evaluation method not only can directly reaction the ecological environment impact of the land use structure adjustment, but also can directly reflected in the grid layer of the ecological environment impact results of the adjust of land use structure and layout optimization. And it can facilitate analysis and evaluation the space impact of the ecological environment by the land-use general planning.Selected the number of population, per capita GDP, per capita arable land area, per capita urban construction land, the proportion of construction land, protection area of basic farmland, forest coverage, water area, ecological construction land area, control targets of cultivated, the supplementary arable land of the land remediation, the area of agricultural land convert to construction land and the area of arable land occupation by the construction every year as the evaluation indicators, which according to the principle of establishing the index system and in accordance with the ideas of "PSR" index system, and combined with the local ecological state and the revision case of the land-use master plan of Shuijiang. These index reflect the impact of the ecological environment of the land use change, and the index easy to acquired and workable.To estimate the new planning environmental impact of the Shuijiang Town by the method of "PSR" model, ecological service value and the grid element. The results of the comprehensive evaluation show that the score of the recent planning program is15.2141, and it of the forward planning program is15.7793. The forward score is higher than the resent score. By the planning target year, the area that the ecological environment condition variation R is positive will amount to96.11%of the total, however, only2.11%of the region becomes negative. It show that the planning program has a very favorable impact on the ecological environment of the town, and it illustrate that the feasibility of this planning program from the perspective of ecological and environmental protection. And it plays an important role to the coordinated development of the regional man-land relationship.