武汉汉阳湖区土地资源评价研究

Assessment of Land Resources in Hanyang Lake Watershed of Wuhan

在Arc/info地理信息系统支持下,以武汉汉阳湖区为例,选取自然生态指标、社会经济指标和区位指标,建立了土地资源评价体系,对汉阳湖区的土地资源质量进行了科学评价。评价中运用层次分析法确定评价因子的权重,同时利用Arc/info系统强大的空间分析和图形操作功能,将图形和属性数据统一管理,加强了评价的整体性和准确性。评价结果符合当地实际情况,评价指标的选取以及评价所采用的方法体系,为城市湖泊地区进行土地资源评价提供了参考。

Land resources is one of the basic resources to the survival of human being. Whether it can be used properly is a key problem to regional sustainable development. The purpose of land resources assessment is to identify the properties and qualities of land in various positions and situations, then to demonstrate their best utilization directions by quality classification. Hanyang is now undergoing an accelerating process of urbanization. It is a typical urban lake watershed. Disorder of land use and unsuitable exploitation intensity have brought much pressure on land sustainabillty and water quality. In this paper, taking Hanyang as a case, Analytic Hierarchy Process （AHP） and multifactor integrated assessment model were applied to establish an assessment system of land resources. The assessment system was composed of natural ecological factors, social economic factors and location factors. It put the same emphasis on natural properties of land resources, such as hydrological and geological conditions, as their social economics and location properties, which made it different from the traditional classification of town ground. Considering the impacts on land quality engendered by surrounding lakes and regional ecological situation, habitat environmental and ecological indicators were integrated into assessment system, so the qualities of land resources were reflected more thoroughly and typically. AHP was used in this study to obtain the weight of each indicator. The method can quantify decision-makers＇ experiential opinion, and combine data, expert attitude and analyzerg external judgment together. More than 20 experts on geography and ecology and relevant specialists who were familiar with the actual situation of Hanyang, were invited to fill the judgment matrix sheet. This made assessment system more authoritative in determining weights of all quantitative and qualitative indicators. Then a computer program was applied to calculate the weights, operated on the MATLAB mathematical software platform. As a result, four most important factors in assessment system were land use intensity, soil foundation bearing capacity, emporium impact and ecological sensitivity. After finishing the assessment system, property data and pictures were dealt with at the same time under the Geographic Information System（GIS） technology, which shortened the assessment period and improved the accuracy of results significantly. Using GIS technology, land database including space and property data could be developed, and with its spatial analyst models, assessment units and data could be obtained easily. Associating assessment system with GIS models, every assessment unitg synthetic score was also got. According to these scores, the quality of land resources in Hanyang was classified into five levels, and the percent of each level from I to V was 2.5%, 16.1%, 32.2%, 30.3% and 18.9%, respectively. With GIS software package, the distribution map of results is drawn. The results showed that the land resources with best quality were located in both sides of Hanyang avenue. Land around lakes like Longyang and Moshui lakes had great potential in the future due to its adjacency to water landscape and good eco-environment, and its quality was better than other land comparatively. The assessment result accorded with the actual state of Hanyang in higher extent than previous assessments. It could give much advice to regional land utilization planning, and especially conduced to harmonize land exploitation and regional eco-environment protection. The selection of assessment factors and the whole methods system used provided a reference for the assessment of land resources in similar areas.