河北生态环境建设与京津协同发展障碍因素及思路建议

本文就河北生态环境建设与京津协同发展中障碍因素进行初步探讨,并提出破解障碍因素的具体思路建议。在对行政区划、产业发展、环境与发展的矛盾、市场化资源配置机制、环京津贫困带及环境属地管理模式六大障碍因素分析基础上,认为河北生态环境建设与京津协同发展,要站在京津冀协同发展战略高度,在京津冀协同发展框架下统筹规划,确立以市场为纽带的新型合作关系,实现区域内各方的密切配合、通力合作。以此为理念,提出破解河北生态环境建设与京津协同发展障碍因素的几点思路建议。     

重庆主城区次级河流表层沉积物重金属污染特征及风险评价

山地城市次级河流因季节性降雨容易导致沉积物中污染物形成"二次污染",沉积物可能具有重金属潜在生态风险.本文采集了重庆市主城区19条次级河流表层沉积物,分析了7种重金属元素(V、Cr、Ni、Cu、Zn、Cd和Pb)的污染水平,解析了重金属污染来源,并从流域层面评价次级河流表层沉积物重金属的潜在生态风险.结果表明,与背景值(中国土壤元素背景值)相比,除V外,其它6种重金属元素超标1.1~6.7倍.富集系数分析和主成分分析显示,沉积物中重金属V、Ni和Pb均未发生富集(富集系数小于1.5),且主要来源于自然源.Cd、Zn、Cu和Cr平均富集系数分别为6.63、2.31、1.90和1.40,均存在不同程度的富集;Cr、Zn和Cu主要来源于工业废水的排放.主城区次级河流表层沉积物重金属潜在生态风险指数RI值范围为77~382,均值为228,总体属于中等生态风险等级.空间分布上,重庆主城区西北部汇入嘉陵江的次级河流表层沉积物重金属表现出较高的生态风险,东南部汇入长江的次级河流表层沉积物表现为相对较低的风险.     

基于水域面积法的山区河流水电站下游生态流量定值研究

水电站的大量兴建导致下游河道萎缩退化甚至断流,如何改变水电站运行调度方式,维持下游河道一定的生态流量、保障河流健康成为国内外普遍关注的问题.本文在传统水文学方法的基础上融入生物栖息地法思想,以河流生态系统的生物多样性为功能目标,用河道流量反映河流的水文过程,河道水域面积反映河流生态系统的生物多样性,创新性地提出考虑河道水文生态特性的生态流量定值方法——水域面积法.以北江上游浈江二级支流罗坝水为例进行分析计算.计算结果表明:枯水年罗坝水生态流量为2.26 m3·s-1,占多年平均流量的25.97%;平水年生态流量分月控制,生态流量过程与建站前流量过程基本一致.根据枯水年的生态流量值和平水年各月份的生态流量值,结合水电站的运行调度规则,换算成一定时期内的径流量来确定该时期内水电站需释放的水量,进而对水电站下游河道的生态功能进行保护和修复.     

绿洲边缘新月形沙丘表层沉积物粒度与重金属分布特征

本文以乌兰布和沙漠绿洲边缘工业化城市乌海市下风向典型新月形沙丘为研究对象,分析了新月形沙丘各部位0~10 cm沙物质、沙丘前50 m处大气降尘的粒度及重金属元素变化特征,探讨了重金属物质的来源及其与粒径的相关性,评价了重金属的潜在生态风险.结果表明:沙丘各部位沉积物粒度均以细砂为主,较对照沙丘极细砂含量增高而中砂含量减少.而降尘主要以极细砂、粉粒为主,降尘在沙丘表面的沉降堆积使沙丘表层沙物质细化.沙丘与降尘的重金属含量均为FeMnCrZnCu;Mn、Cu、Zn、Cr含量均高于背景值且发生富集.Mn、Zn含量在空间分布上呈中等变异;Fe、Cu含量在空间分布上为高度变异.Mn、Zn、Cu含量与细颗粒含量呈显著正相关,Zn、Cu含量与中砂含量呈负相关,Fe含量与细砂和中砂含量均呈负相关.Cu、Zn、Cr为人为污染因子,Mn、Fe为自然源因子,但Cr、Mn、Fe又受到自然地质背景和人类活动的共同控制.乌海市下风向新月形沙丘属于低生态风险状态,为轻度污染,需加强废气的治理控制以防重金属污染的进一步加深.     

河南省武陟县大田土壤重金属形态分布及潜在生态风险评价

为了解河南省武陟县大田土壤重金属Cr、Cd、Pb、As、Cu、Se、Ni和Co的形态分布和生态风险情况,在该区域采集了12个表层土壤(0～20cm)样品,采用修正的BCR连续提取法进行形态分析,探讨其生物有效性,并采用Hakanson指数法评价了重金属的潜在生态风险.结果表明,土壤中不同重金属的形态分布差异很大,其中,Cr、As、Ni和Co均主要以残渣态存在,分别占其总量的66.6％、61.4％、50.7％和41.8％;Cu和Se主要以可氧化态存在,分别占其总量的43.8％和67.8％;Pb主要以可还原态存在,占总量的61.1％;Cd主要以酸提取态存在,占总量的53.3％.生物有效性分析表明,Cd的可利用态K1为0.933,生物有效性是最大的,对土壤生态系统的潜在危害性较大,其次是Pb和Co;Cu和Se在土壤环境发生变化时,很容易再次释放到外界环境中;Cr、As和Ni不易被外界生物利用.潜在生态风险评价结果显示,以国家土壤环境质量标准二级标准为参比值时,Cr、Cd、Pb、As、Cu和Ni的单项潜在生态风险程度均为轻微,综合潜在生态风险处于轻微等级.     

黄河三角洲海岸带生态承载力综合评价

为全面、深入认识黄河三角洲海岸带的海洋资源和生态环境特征、海洋产业结构及海洋经济发展的优势、劣势条件,选取工业废水排放量、固体废渣排放量、万元GDP能耗、岸线利用率、人均可开发海域面积、人均海岸线长度、海洋初级生产力、污染海域占海域总面积的比例、生物多样性指数、人口密度、人均海洋经济产值、GDP年均增速、科研与开发投入和环境保护支出等压力、状态、响应3类14个指标,采用压力-状态-响应模型对黄河三角洲海岸带生态承载力进行了综合量化评价.结果表明,2006-2010年黄河三角洲海岸带的承载指数和压力指数呈下降趋势,承压比则总体上呈上升趋势.根据评价结果,提出了构建高效生态产业体系、优化黄河三角洲产业空间布局、对传统产业进行生态化改造、发展新兴生态产业、保护黄河三角洲海岸带生态环境、对黄河三角洲海岸带海洋资源进行高效集约利用等提高黄河三角洲海岸带生态承载力的对策.     

基于RS&GIS的长白山地区生态安全评价研究

以遥感影像数据、专题数据、DEM数据、气象站实测数据和统计数据为数据源,采用极差法、层次分析法、综合指数法、RS&GIS等方法对长白山地区的生态安全进行了评价.结果表明:长白山地区生态安全水平呈现出明显的空间差异性,整体由中部向东西两端逐渐降低.各生态安全等级面积从大到小为临界安全等级、较安全等级、不安全等级、较不安全等级、安全等级.统计了各行政单元的平均生态安全指数和等级构成,各县市生态安全水平从高到低为长白县、抚松县、安图县、和龙市、临江市,各县市的生态安全等级构成也有所差异.长白山地区生态安全水平以临界安全等级为主,整体上生态环境质量一般,系统服务功能受到了一定程度的破坏.     

Multi-level water governance – the case of the Morsa River Basin in Norway

Management of fresh water resources meets a range of often conflicting interests. Waterways usually run across political and administrative borders and hence make management difficult and collective action politically challenging. In order to meet these challenges, multi-level bioregional approaches to water management have been called for. Such an approach is institutionalised in the EU's Water Framework Directive (WFD). This paper presents the experiences of the Morsa water sub-district in southern Norway, a pilot for implementing the WFD. The paper discusses Morsa in the light of four principles for multi-level water governance: management on a bioregional scale; polycentric governance; public participation; and an experimental approach to water governance. Contrary to widely held assumptions that collective action in polycentric networks will be difficult because actors will follow their own narrow interests, the findings demonstrate how this is not an absolute truth, and how social action cannot be fully explained by rational action theories. The analysis concludes that the relative success of Morsa relates to a complex of factors, including openness of practices and active involvement of key actors, strong but including leadership, and a knowledge based ‘hybrid’ type of multi-level network combining horizontal and vertical network governance.     

Implementing SDG 15: Can large‐scale public programs help deliver biodiversity conservation,restoration and management,while assisting human development?

Among the Sustainable Development Goals (SDGs), the proposed SDG 15 promotes activities that, inter alia, “Protect, restore and promote sustainable use of terrestrial ecosystems”. An important potential contribution in achieving SDG 15 is through public programmes designed to jointly promote human development through poverty alleviation and improvement of human livelihoods and biodiversity conservation/management/restoration. An analysis of twenty public programmes with such joint objectives yielded twelve lessons learned. In addition to financial commitments, government and intergovernmental agency input for such public programmes includes ensuring political will and appropriate legal frameworks. Local communities and civil society provide input through traditional and indigenous ecological knowledge and stewardship. Appropriate shared inputs in development and the implementation of such public programmes, with communication between local community, broader civil society, the scientific community and governments will result in: better use and management of biodiversity; alleviation of poverty; security of livelihoods and better governance systems. The Ecosystem Approach of the Convention on Biological Diversity provides an ideal framework when planning and implementing new programmes. Application of the lessons learned to new public programmes will ensure that the answer to the question posed in the title is an emphatic “Yes”, and assist with the achievement of SDG 15.     

Modeling Streamflow and Water Quality Sensitivity to Climate Change and Urban Development in 20 U.S. Watersheds

Watershed modeling in 20 large, United States (U.S.) watersheds addresses gaps in our knowledge of streamflow, nutrient (nitrogen and phosphorus), and sediment loading sensitivity to mid‐21st Century climate change and urban/residential development scenarios. Use of a consistent methodology facilitates regional scale comparisons across the study watersheds. Simulations use the Soil and Water Assessment Tool. Climate change scenarios are from the North American Regional Climate Change Assessment Program dynamically downscaled climate model output. Urban and residential development scenarios are from U.S. Environmental Protection Agency's Integrated Climate and Land Use Scenarios project. Simulations provide a plausible set of streamflow and water quality responses to mid‐21st Century climate change across the U.S. Simulated changes show a general pattern of decreasing streamflow volume in the central Rockies and Southwest, and increases on the East Coast and Northern Plains. Changes in pollutant loads follow a similar pattern but with increased variability. Ensemble mean results suggest that by the mid‐21st Century, statistically significant changes in streamflow and total suspended solids loads (relative to baseline conditions) are possible in roughly 30‐40% of study watersheds. These proportions increase to around 60% for total phosphorus and total nitrogen loads. Projected urban/residential development, and watershed responses to development, are small at the large spatial scale of modeling in this study.