汶川地震灾毁耕地灾度评估

汶川地震与洪灾相伴对灾区耕地产生了巨大的破坏作用。该文从灾后农业生产恢复重建的角度出发，基于综合集成的灾害系统观，以江油市乡镇为统计单元，选取耕地承灾体灾情、孕灾环境、恢复重建压力10项指标，利用R型因子分析方法，建立耕地灾度综合指数模型；在ArcGIS技术支持下，将江油市划分为不同的耕地灾度区。研究结果表明，江油全市40个乡镇中，有18个乡镇（占全市面积的45.31%）的耕地重度受损，主要分布在市域的中部和西部山地与丘陵的过渡地带和丘陵地带，其中，无法复垦的耕地占受灾面积的7.76%；有10个乡镇（占全市面积的22.17%）的耕地中度受损，主要分布在西北部山地以及轻度和重度受损的过渡区，其中，无法复垦的耕地占受灾面积的4.39%；有12个乡镇（占全市面积的32.52%）的耕地轻度受损，主要分布在东部平坝以及平坝与丘陵的过渡地带，其中，无法复垦的耕地占受灾面积的0.76%。研究结果以期为地震灾区分类指导开展灾毁耕地复垦和农业生态系统恢复重建提供科学依据。

Hazard degree assessment to arable land damaged by Wenchuan Earthquake

Wenchuan Earthquake with floods played a huge role in the destruction to arable land of catastrophe areas. In this paper, from the point of view of the recovery and reconstruction of agricultural production after the earthquake disaster, based on the integrated view of disaster system, an Arable Land Hazard Degree Index Model was established, which took township of Jiangyou City as the basic statistical unit. Ten indicators, such as disaster situation, pregnant disaster environment and the rebuilding pressure of arable land of the bearing disaster body, were selected, and R-type factor analysis method was used. Then supported by ArcGIS, Jiangyou City was divided into different hazard degree zones of arable land. The results showed that, among the 40 towns in Jiangyou City, there are 18 towns, accounting 45.31% of city land were severely damaged, mainly distributed in the central city western mountainous and hilly transition zone and the hilly areas, in which 7.76% disaster area could not carry on land reclamation; while there were 10 towns, accounting 22.17% of city land were moderately damaged, mainly locating in the northwestern mountains, as well as the transition zone between the mildly and severely damaged arable land area, in which 4.39% disaster area could not carry on land reclamation; and there were 12 towns accounting 32.52% of city land were mildly damaged, mainly spreading in the eastern plains and the transition zone of plains and hills, in which 0.76% disaster area could not carry on land reclamation. The results can be used to guide the cultivated land reclamation and provide scientific basis for agricultural ecosystems restoration.