山区河流系统健康评价方法研究     

王丽萍  郑江涛  周婷  周晓蔚 《资源与生态学报(英文版)》2010,1(3):221+216-220

本文通过对山区河流的基本特征研究,从生态功能和人类服务功能两大角度建立了山区河流健康评价系统,并基于投影寻踪理论构建了山区河流健康评估指标体系。以中国西南地区某典型山区河流为研究对象,本文对该河流水电开发前后的健康状况进行了研究。结果显示水电开发后河流综合健康状况较现状有显著提高。在此基础上,本文进一步通过对投影指标体系的结构特征分析,提出了维持河流健康的对策。  相似文献   

北京山区沟域经济发展的空间结构   总被引：1，自引：0，他引：1  

张义丰  贾大猛  张宏业  谭杰  宋思雨  孙瑞峰 《地理学报(英文版)》2011,21(2):331-345

Valley economy is a new mode in mountainous area development that is defined by various characters of valley development, and is a distinguishing economical geographic pattern for mountainous area development. The special spatial coupling relations in the distribution of different mountainous elements in valleys are new subjects for the mountain development studies, and such studies are meaningful both for researches and practices. Based on the long term researches on mountainous area development and following a brief exploration into the connotations and the spatial organizing process of valley economy, the authors analyzed the present situations of the development of valley economy in Beijing’s mountainous areas, studied the characteristics and the impacts of the spatial structural changes of the valley economy in Beijing’s mountainous areas, and finally proposed a rational arrangement of the spatial structure of the valley economy in Beijing’s mountainous areas. It is considered in this study that valley economy plays an important role in the development and functional transformation in Beijing’s mountainous areas in the new epoch. Firstly, valley economy is not outlined by the administrative boundaries, and it connects most of the villages in the mountainous areas roughly along the major transportation lines. Therefore, valley economy can exert positive influence on the development in the mountainous areas, at least in the aspects such as the rearrangement of industrial structure in the mountainous areas and the coordinated development of rural and urban areas. In addition, it is found that the valley economy in Beijing’s mountainous areas is evolved in a spatial organizing stage of secondary concentration, which is characterized by resource-saving, ecological protection and industrial optimization. Therefore, the development of valley economy will be helpful to the coordination between ecological protection and economic development in the mountainous areas, and will promote the integrated development of the mountainous areas. The developing mode of the valley economy in Beijing’s mountainous areas will provide the basis for the decision-making in the transformation of the functional roles of Beijing’s mountainous areas, and on the other hand, will present experiences for the studies in the mountainous areas outside of Beijing.  相似文献   

云南省宣威市农耕区土壤重金属元素分布影响因素及生态风险评价   总被引：1，自引：0，他引：1  

秦元礼  张富贵  彭敏  张利  唐瑞玲  成杭新 《地质与勘探》2022,58(2):360-368

为探究云南省碳酸盐岩风化区重金属污染特征及分布影响因素,选取云南省宣威市农垦区为研究对象,利用1:5万土地质量地球化学调查成果,通过分析表层土壤重金属元素累积特征及分布规律,并结合土壤理化性质及地形因素等数据,研究驱动农垦区土壤重金属元素富集的影响因素,并利用富集指数法(EF)和潜在生态风险评价(RI)进行污染评价.结...  相似文献   

Sustainable groundwater extraction in coastal areas: a Belgian example   总被引：1，自引：0，他引：1  

Alexander Vandenbohede  Emmanuel Van Houtte  Luc Lebbe 《Environmental Geology》2009,57(4):735-747

Water extractions in coastal areas have to deal with salt water intrusion and lowering of hydraulic heads in valuable ecosystems. Therefore, sustainable management of fresh water resources in these areas is crucial. This is illustrated here with two water extractions in the western Belgian coastal plain which extract groundwater from a phreatic dune aquifer. One water extraction faced problems with salt water intrusion, while lowering of hydraulic heads was an issue for both. To remedy the salt water intrusion, it was found that decreasing the extraction rate was the only solution. To offset this and to increase hydraulic heads around both extractions, it was decided to artificially recharge the aquifer of the second extraction with tertiary treated wastewater. By taking these interventions, the combined production capacity of the water extractions was increased with 56% whereas 27% less water was extracted from the dune aquifer itself. Extraction history and the effects of interventions are illustrated for both water extractions with water quality data and fresh water head observations. A more detailed insight in groundwater flow and fresh–salt water distribution in the aquifer is provided by simulating the evolution of the water extractions with a 3D density dependent groundwater flow model.  相似文献   

北京平原区新构造活动及其引发的不良地质现象分析     

赵忠海 《地质灾害与环境保护》2009,20(2):66-70

在地质环境综合调查及地质灾害调查区划工作基础上,结合物探、钻探、槽探及区域地质等资料,对北京平原区的新构造活动及其引发的不良地质现象进行了认真地分析和探讨。  相似文献   

居住区环境更新与城市本土性——以北京农展南里环境改造规划为例     

王淑芬 《中国勘察设计》2009,(7):63-66

城市居住环境是城市本土性的重要载体。旧居住区环境改造应以场地固有的地域特点、历史文化沉淀为基础,培育小区本土化的环境格局和多样化的景观空间体系。本文以农展南里环境改造规划为例,来探讨如何提升住宅老区活力,挖掘居住环境的本土性,实现一个有机、舒适、便捷、安全、美观、有地域文化和特色的现代复合型可持续发展的居住环境。  相似文献   

中国中部农区企业集群的竞争优势研究--以河南省虞城县南庄村钢卷尺企业集群为例   总被引：17，自引：3，他引：14  

李小建  李二玲 《地理科学》2004,24(2):136-143

中国中部农区企业集群的竞争优势来源既具有一般企业集群的共性——它是规模经济、分工经济和网络联系三者共同作用的结果,又具有其特殊的个性——模仿创新的普遍发生、中原文化背景、制度扶持和较低的劳动力、土地等要素成本起决定作用。以河南省虞城县南庄村钢卷尺企业集群为例,详细分析了中国中部农区企业集群竞争优势的内在来源。  相似文献   

Seasonal evolution of runoff generation on agricultural land in the Belgian loess belt and implications for muddy flood triggering   总被引：1，自引：0，他引：1  

Olivier Evrard  Karel Vandaele  Charles Bielders  Bas van Wesemael 《地球表面变化过程与地形》2008,33(8):1285-1301

Muddy floods due to agricultural runoff are a widespread and frequent phenomenon in the European loess belt, and particularly in central Belgium. These floods are triggered when high quantities of runoff are generated on cropland and cause severe erosion. Three soil surface characteristics are relevant to determine the runoff potential of cultivated soils: soil cover by crops and residues, soil surface crusting and roughness. These characteristics have been observed on 65 cultivated fields throughout 2005. A heavy rainfall event representative for events triggering muddy floods in the region (60 mm h^?1 during 30 minutes) has been simulated using a 0·5 m² simulator on fields with the 17 most observed combinations of soil surface characteristics in central Belgium. Runoff is not observed in the case of (ploughed) bare uncrusted soils, nor in the case of soils covered by crops showing a transitional crust and a moderate roughness (1–2 cm). In the cases where runoff has been observed, mean runoff coefficients ranged from 13% (wheat in July) to 58% (sugar beet or maize in May and June). Grassed buffer strips (GBSs) and grassed waterways (GWWs) show a higher runoff coefficient (62% for GBSs and 73% for GWWs) than most cultivated soils (13–58%). Furthermore, it is demonstrated that small plot measurements can be used to estimate runoff generation at the field scale. A classification of runoff generation risk based on the surveys of soil surface characteristics has been applied to common crops of central Belgium. February as well as the period between May and September are the most critical for runoff at the field scale. However, it appears from monitoring of a 16 ha catchment that the highest runoff volumes and peak discharges are recorded between May and August after heavy rainfall, explaining why 85% of muddy floods are recorded during this period in central Belgium. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

福建及邻近地区地震烈度衰减关系研究   总被引：1，自引：0，他引：1  

蔡辉腾  韦永祥  郑师春  欧秉松 《地震研究》2008,31(1):20-26

对福建及邻近地区地震烈度资料进行等效处理、近远场补点、数据加权处理,改进衰减模型和统计方法,加强了对大震近、远场的控制,建立了适合本地区的地震烈度衰减关系,并对比分析了Ra和Rb取值、补点和加权对烈度衰减关系的影响.  相似文献   

山东及近邻区地震烈度衰减关系探讨   总被引：4，自引：1，他引：3       下载免费PDF全文

苗庆杰  许萍 《地震工程学报》2008,30(3):282-287

利用山东及近邻区34个地震的70条等震线数据,通过最小二乘法回归分析得到了山东及近邻区地震烈度衰减关系;同时根据地形与地质构造特征将山东及近邻区分为土层覆盖区和基岩出露区,分别拟合出了各自的地震烈度衰减关系.  相似文献