汶川地震重灾区泥石流灾损土地利用及生态修复模式——以北川县都坝河小流域为例

汶川地震诱发了大量泥石流灾害,灾损土地利用和生态修复是灾区产业重建面临的重要课题。以北川县都坝河小流域为研究对象,通过调查灾损土地禀赋、灾害特征、土地需求,采取多因素耦合和关键因子限制分析法,探讨灾害胁迫条件下的经济活动与生态修复之间的互馈作用,结果表明：（1）流域新增土地供给源主要为泥石流灾损土地,土地资源化利用受灾害、聚落和产业结构控制;（2）灾损土地根据成因划分为沟口堆积型、沟道冲淤型以及岸坡侵蚀型,三者的肥力、安全性及交通条件等特征具有显著差异;（3）基于“因灾分区、耕地优先、产业共建、美居造景”的原则,建立了灾损土地的利用方式和生态修复模式,并选取杨家沟进行验证,沟域灾损土地利用方式为生态林地、产业林地及优质耕地,分别占比28.5%、56.3%、15.2%,生态修复措施主要为提高土地安全度、提升植被覆盖率和增强水保功能。该研究建立的震区土地利用和生态修复模式可有力协调人地矛盾、发展绿色经济和提升人居环境。

The debris flow disaster land use and ecological restoration measures in Wenchuan earthquake hard-hit disaster areas: A case study in the small watershed of Duba River

Abundant debris flows and disaster lands have been induced by the Wenchuan earthquake in Longmen Mountain area, Southwest China. The disaster land use and ecological restoration are the most important aspects of the mountain industrial reconstruction. By focusing on the Duba River Basin of Beichuan county as an object, through investigating the conditions of disaster land, characteristics of debris flow and demand of land resource, taking the analysis methods of multi-factor coupling and the key limiting factor, this paper explores how the disaster and development influence the land use and ecological restoration. The results were as follows: The new sources of land supply in Duba River Basin are mainly debris flow disaster lands, and the utilization of disaster land confronts three great limiting conditions, such as the risk of high-frequency debris flow, dynamic settlements, and industrial structure. Through spatial and temporal variation analysis and geo-hazard characteristics, we identify three types of disaster land, such as deposited type, gully erosion type and gully bank erosion type, which shows that there are significant differences in the fertility, safety and traffic conditions. Therefore, based on the following four principles, which contains to divide land use areas according to disaster risks, to give the first priority to the cultivated land in land use, to take into account the needs of industrial development in land utilization, and to improve human settlement environment by ecological restoration, with hazards prevention and evaluation, this paper proposed an idea of the debris flow ecological restoration and built debris flow hazard ecological restoration mode, and applied it to Yangjia gully as an example. In the Yangjia gully watershed, the types of land use were ecological forest land, industrial forest land, and high-quality cultivated land, accounting for 28.5%, 56.3%, and 15.2%, respectively. The ecological restoration measures are mainly taken to improve the vegetation coverage of forest land and to enhance the function of soil and water conservation of cultivated land. The land use and ecological restoration model established in this study, which is based on disaster risk and industrial development, can effectively coordinate the contradiction between human and land, develop the green economy and enhance the environment of human settlements.