中文摘要：

采用分级系统对评价区域内的风险源以及生境进行等级评定，通过分析风险源、生境、风险受体之间的相互作用关系，构建针对不同生境类型和不同风险源类型的城郊农业环境风险评价模型，并以长沙市作为案例区，按照行政界线划分为9个风险评价单元，选择耕地、园地、林地、草地和水域为生境类型，选取种植业、养殖业和农村生活为风险源，将水质、土壤质量和生物多样性定为评价终点，对长沙市城郊农业环境风险进行定量评价。结果表明，岳麓区为高风险区，相对综合风险值达108．11；天心区和芙蓉区为中风险区；开福区、雨花区、长沙县、宁乡县、望城区和浏阳市属于低风险区。近郊区比远郊区承受着更大的环境风险，受城郊农业活动的压力作用更明显。在远郊区，种植业是首要风险源，各类生境中水域的环境压力较大；而在近郊区，尽管不同地区的首要风险源不同，但各地耕地所受环境压力均较大。

英文摘要：

A relative risk model was constructed for environmental risk analysis of suburban agricultures consisting of different types of habitats and risk sources, by using a rating system to evaluate risk sources and habitats in the study zone and analyzing interactions between risk sources, habitats and risk receptors. A case study was conducted of Changsha City. In the study, the suburbs of the city were divided into nine risk evaluation units in light of their administrative boundaries, and five types of habitats （cultivated land, vegetable garden, woodland, grassland, and waters） , three risk sources （ crop farming, livestock breeding and rural daily life ） and three assessment endpoints （ water quality, soil quality and biodiversity） were set for quantitative environmental risk assessment of the suburban agricultures of Changsha. Results show that Yuelu District is a high risk area with a relative integrated risk value being 108.11 ,Tianxin District and Furong District are moderate risk areas, and the others （ Kaifu District, Yuhua District, Changsha County, Ningxiang County, Wangcheng District and Liuyang City） are low risk areas. Environmental risk is greater in the suburbs than in the outer suburbs, especially the stress from farming activities. In the outer suburbs, farming is the primary risk source and among the habitats, waters are under higher environmental stress. Although primary risk sources vary from area to area, farmlands are subject to greater environmental stress than the other habitats.