城市地貌环境的脆弱性研究

On the fragility of urban geomorphic environment

城市地貌环境具有两大地域系统（城市建成区与城市边缘区）和三类地貌单元（自然地貌体、人工地貌体和自然－人工复合地貌体）．由于城市中人类活动产生的反馈效应日益强化，城市地貌环境具有明显的脆弱性，表现为；环境的变异敏感度高，环境的持续利用性降低和环境对灾变的承受弹性较小．城市边缘区是城市地貌环境的脆弱带．依据上述分析，对四川省２３个城市进行了城市地貌环境的脆弱性系统评价，包括参评因子的选取和量化，计算公式以及评价等级的划分确定．

An urban geomorphic environment(UGE) is composed of 2 regional systems(the urban built-uparea and the urban fringe)and 3 geomorphic units(natutal landforms,man-made landforms and compound landforms).UGE becomes fragile obviously with the growing nitensification of feedback effectswhich was caused by human activities in urban areas.The fragility is shown by:the increasing environ mental susceptibility to variation,the lowering sustainable utilization and the weakening elasticity ofbearing capacity of UGE to catastrophic processes.The urban fringe is a fragile belt of UGE.A system atic evaluation on fragilities of UGE,including the selection and quantification of evaluational parame ters, the evaluational formula and determination of evaluational grades,was made in the studying onUGE of the 23 cities in Sichuan province.