三峡库区巴东复杂斜坡区工程地质环境质量研究

Evaluation of engineering geo-environment quality of Badong complex slope area in the Three Gorges Reservoir region of the Changjiang River

为探索满足城镇规划建设尺度（1：10000～1：50000）需要的工程地质评价方法，本文以三峡库区巴东县新城区所在的扇形斜坡区为例，系统建立了山地区域大比例尺工程地质环境质量评价的工作程序，包括地质环境要素调查、地质环境信息系统（GEGIS）建立、因子体系选定与图层编制、因子赋值与权重确定、数学模型选择、图层迭加计算、结果分析与检验、工程地质环境质量评价与区划，初步探索了地质环境功能区划的基本内容。基于MapGIS技术，采用1：16000的航摄地形图，通过系统的野外调查和分析计算，编制了巴东复杂斜坡区的高程、地形坡度、冲沟密度、山洪危险、工程地质岩组、斜坡类型、基岩埋深、三峡水库175m水位浸润区埋深、三峡水库175～145m水位变动带岩土体工程地质性质、斜坡变形或岩土应力集中区埋深、地震动参数异常和人类活动方式等12个因子图层。通过巴东复杂斜坡区工程地质环境质量计算、抽样检验和分区评价，提出了地质环境功能区划：A级区是1、2级工程地质环境质量区，面积约6．6km^2，占全区面积的36．8％，地质环境容量大或较大，这类区域可规划为城镇集中建设区；B级区是3级工程地质环境质量区，面积约5．6368km^2，占全区面积的31．52％，地质环境容量中等，这类区域可以作为林、草或休闲地和农村社区，沿江地段规划码头、港口等；C级区是4、5级工程地质环境质量区，面积约5．64km^2，占全区面积的31．5％，是历史滑坡多发区，地质环境容量较小或小，这类区域可开发为果园和城镇蔬菜基地，不宜规划为永久建筑区。

To explore geologic working method for the scale need of urban planning（ 1 ： 10 000 - 1：50 000）, taking Badong County slope region in the Three Gorges of the Changjiang River as an example, a working program for large scale engineering geo-environment quality evaluation is synthetically established which consists of geo-environment factors investigation, establishment of geo-environment information system （GEGIS）, ascertainment of factor system and its layer, factor value and its weight, mathematics model selection, layer overlaying calculation, result analysis and validation, and geo-environment quality evaluation and zoning. The basic contents of geo-environment function zoning are tentatively researched. With MapGIS, on the basis of synthetic field survey and analysis, twelve factor layers are compiled using 1 ： 16 000 topographic map, such as height, slope gradient, gully density, torrential flood, geologic fabric, slope type, bedrock buried depth, buried depth of 175m water level absorption field, rock mass engineering geologic property of fluctuation belt of 175 - 145m water level from the Three Gorges Reservoir of the Changjiang River, buried depth of slope deformation or stress concentration region, earthquake dynamic parameters and mans activities. According to engineering geo-environment quality computing,a few example validation resuits and zoning evaluation, the geo-environment function zoning is advanced in this paper. A-grade function region is one of geo-environment quality of 1 or 2 level, about 6.6km^2 , taking about 36.8 % of the whole area. For large geo-environment capacity, A-grade region can be planned as town construction area. B-grade function region is 3 level geo-environment quality section, about 5.636 8km2, taking about 31.52% of the whole area. For moderate geo-environment capacity, B-grade region can be planned as forest, lawn or fallow field and county, so much as wharf or harbor, etc. along the river. C-grade function region is one of geo-environment quality of 4 or 5 level, about 5.64km^2 , taking about 31.5% of the whole area. For having small geo-environment capacity resulting from landslide prone area in geological history, C-grade region can be used as orchard or vegetable depot, while not suitable for permanent construction region.