繁昌县后备土地资源多宜性评价

合理评价后备土地资源适宜性是有效进行后备土地资源的开发利用和农业结构调整的前提。以繁昌县后备土地资源为例,以区域自然与人为因子对其进行初步筛选,在此基础上建立适宜性评价指标体系,结合生态位适宜度理论构建多宜性评价模型,运用加权平均模型和限制因子模型,对后备土地资源评价单元耕地、园地和林地3种土地利用类型的生态适宜度及限制性生态因子进行评价。结果表明:(1)繁昌县59.38%的后备土地资源不能进行开发,能够开发且对生态环境影响较小的后备土地资源为387.03hm2;(2)繁昌县生境环境较为良好,对各土地利用类型的适宜性较强;单一土地利用类型评价中后备土地资源生态位适宜度值最大值为0.966 5。其中,耕地适宜性最高,林地次之,园地最低;(3)多宜性评价表明繁昌县后备土地资源中耕地适宜性面积最大,林地次之,园地最小;(4)限制繁昌县后备土地资源开发利用的生态因子主要为:排水条件、pH值、障碍层深度。为改善后备土地资源开发利用的生境条件,今后应重视土地质量管理,加强农田水利设施建设,使其适合开发利用的需要。

RESEARCH ON MULTI-SUITABILITY EVALUATION OF RESERVED LAND RESOURCES IN FANCHANG COUNTY

Suitability evaluation of reserved land resources provides a scientific basis for reasonable exploitation and utilization of unused lands. It's also a foundation for effectively agricultural structure adjustment to reasonable suitability evaluation of reserved land resources. Suitability evaluation of reserved land resources plays an important role in many aspects. First of all, it can be used to ensure effective utilization of regional reserved land resources. Secondly, the regional ecological environment can be improved through suitability evaluation of reserved land resources. Thirdly, in the process of suitability evaluation of reserved land resources, the structure and layout of land use can be optimized. The purpose of this study is to provide reference for the policy decision making and management of subsequent land reclamation work. In this paper we took the whole unused lands in Fanchang County as the evaluating object. The reserved land resources were preliminary screening based on the consideration of the impact of regional natural and human factors on reserved land resources development. And on this basis a suitability evaluating indicator system was established, which included four aspects, i.e., terrian condition, soil condition, irrigation and drainage conditions, and locational conditions. A multi-suitability evaluation model of reserved land resources by introducing the niche-fitness method was constructed. The means of weighted average and limiting factor models were adopted to quantitatively analyze niche-fitness and restrictive factors for cultivated land, garden land and forest land. The result shows that the proportion of reserved land resources that could not be developed is 59.38%. The total area of reserved land resources that could be developed is 387.03 hm², which has little influence on the ecological environment. The habitat conditions in Fanchang County are really suitable for different land use types. Suitability evaluation result of one land use type shows that the niche-fitness peak value in Fanchang County is reaching 0.966 5, and the suitability of cultivated land is the highest, which is at grade 1 and 2, accounting for 84.09%, garden land which is at grade 1 and 2 accounting for 72.46%, forest land which is at grade 1 and 2 accounting for 82.30%. In terms of niche-fitness evaluation, area of cultivated land ranks first, forest land comes next, and garden land is the last. Drainage condition, pH, and barrier layer depth are the primary niche factors which restrict the development and utilization of reserved land resources in the area. We concluded that, to improve the ecological niche of various land use types in the study area, and to improve the habitat conditions of reserved land resources development and utilization, in the future we should pay more attention to the land quality management, to strengthen the construction of irrigation and water conservancy facilities, and to make it suitable for the needs of the development and utilization.