以底栖动物为指示物种对长江流域水生态进行评价

采用底栖动物作为指示物种对长江流域的水生态进行了调查研究和生态评价。在长江上游支流、中下游干流及沿江湖泊上选取36个代表性样点进行生态考察和底栖动物采样、鉴定和分析。采用Hilsenhoff生物指数和水化学分析对样点水质进行评价，对比分析了各样点底栖动物的结构组成及多样性。上游支流大部分样点水质清洁；中游干流及沿江湖泊水质受到轻度到中度污染；下游干流水质污染加重。底栖动物多样性在上游支流中最高，中游湖泊较高，干流中下游较低。总结得出了4种河床演变条件下的底栖动物群谱。上游支流河床稳定的河流底栖动物密度较大，物种丰富，多样性高；侵蚀下切的河流底栖动物密度、物种数和多样性较低；淤积抬升的河流底栖动物密度、物种数和多样性更低一些；河势散乱且河床运动剧烈的支流物种丰度和密度均很低甚至为零，生态条件差。     

洪泽湖地区土地利用与景观格局演变

基于多时点 TM/ETM影像解译数据,运用遥感、GIS和景观生态学方法,分析洪泽湖地区近 18 a的土地利用变化和景观格局演变过程,揭示该地区内各种土地利用时空变化特征,并得出3个时期景观类型分布特征、景观格局变化的趋势及特征。结果表明：（1）区域内土地利用变化显著,整体处于不平衡的状态,主要表现为耕地持续减少、建设用地迅速增加、林地先增后减及草地和水域略有增加;（2）研究区景观结构和景观异质性发生了较大变化,斑块数目增加、平均斑块面积减少,景观多样性指数、景观均匀度指数总体上升,在区域景观破碎化程度加剧的同时,各景观类型间差异缩小,景观结构趋于多样化、均匀化和破碎化。最后,指出人类活动,尤其是经济建设是土地利用景观格局变化的主要因素,并对地区的生态可持续发展提出了相应建议     

长江中上游地区土壤侵蚀机制及过程试验研究

基于中国大陆水蚀地区土壤侵蚀的主要影响因子-土壤抗侵蚀性指标进行的35个一级控制性测点试验对比研究和野外人工降雨原位试验,重点讨论了长江中上游地区土壤侵蚀形成的机制和过程。结果表明长江中上游地区土壤侵蚀主要表现为在降雨和土壤蓄满壤中流参与下的重力侵蚀过程。在形成上表现为坡地上土壤体表层小范围的滑动和微型阵性泥石流过程,导致沟道河流泥沙输移比小并产生局部严重淤积,土壤侵蚀的危害首先表现为土层进一步变薄、退化和荒芜,其次表现为泥沙游积和洪害。长江中上游地区土壤保持的基本方针应该是“保土减水”,与黄土高原“全部降水就地入渗拦蓄”的方针有所不同。     

长江流域空间经济系统的特征研究

从空间经济系统的角度来看,长江流域经济发展有三个具有内在联系的基本特征。道德是流域经济发展的空间差异性。这一特征集中体现在流域内各地区之间经济发展基础、经济发展速度、经济发展水平等同空间差异。其次是流域经济发展与自然条件和资源的空间耦合性。区域自然系统对区域经济发展有明显的作用和影响,突出地表现了上游经济发展属资源密集型、中游经济发展属劳动力密集型和资源密集型并存、下游为资金技术型。第三是流域经济     

太湖流域洪涝灾害损失模拟及预测

太湖流域是我国经济最发达的地区之一,当遭受洪涝灾害后,经济损失极为严重。本文采用地理信息系统方法,模拟了１９９１年洪涝灾害的淹没决策提供了依据。根据预测,当２０１０年在发生１９９１年型特大洪涝淹没时,灾害经济损失将可高达７７３亿元,约为１９９１年７倍,因此太湖的防洪任务极为严峻。     

Invasive species and coal bed methane development in the Powder River Basin, Wyoming

One of the fastest growing areas of natural gas production is coal bed methane (CBM) due to the large monetary returns and increased demand for energy from consumers. The Powder River Basin, Wyoming is one of the most rapidly expanding areas of CBM development with projections of the establishment of up to 50,000 wells. CBM disturbances may make the native ecosystem more susceptible to invasion by non-native species, but there are few studies that have been conducted on the environmental impacts of this type of resource extraction. To evaluate the potential effects of CBM development on native plant species distribution and patterns of non-native plant invasion, 36 modified Forest Inventory and Analysis plots (each comprised of four 168-m² subplots) were established in the Powder River Basin, Wyoming. There were 73 168-m² subplots on control sites; 42 subplots on secondary disturbances; 14 on major surface disturbances; eight on well pads; and seven on sites downslope of CBM wells water discharge points. Native plant species cover ranged from 39.5 ± 2.7% (mean ± 1 SE) in the secondary disturbance subplots to 17.7 ± 7.5% in the pad subplots. Non-native plant species cover ranged from 31.0 ± 8.4% in the discharge areas to 14.7 ± 8.9% in the pad subplots. The control subplots had significantly less non-native species richness than the combined disturbance types. The combined disturbance subplots had significantly greater soil salinity than the control sites. These results suggest that CBM development and associated disturbances may facilitate the establishment of non-native plants. Future research and management decisions should consider the accumulative landscape-scale effects of CBM development on preserving native plant diversity.     

Dams,Floodplain Land Use,and Riparian Forest Conservation in the Semiarid Upper Colorado River Basin,USA

Land and water resource development can independently eliminate riparian plant communities, including Fremont cottonwood forest (CF), a major contributor to ecosystem structure and functioning in semiarid portions of the American Southwest. We tested whether floodplain development was linked to river regulation in the Upper Colorado River Basin (UCRB) by relating the extent of five developed land-cover categories as well as CF and other natural vegetation to catchment reservoir capacity, changes in total annual and annual peak discharge, and overall level of mainstem hydrologic alteration (small, moderate, or large) in 26 fourth-order subbasins. We also asked whether CF appeared to be in jeopardy at a regional level. We classified 51% of the 57,000 ha of alluvial floodplain examined along >2600 km of mainstem rivers as CF and 36% as developed. The proportion developed was unrelated to the level of mainstem hydrologic alteration. The proportion classified as CF was also independent of the level of hydrologic alteration, a result we attribute to confounding effects from development, the presence of time lags, and contrasting effects from flow alteration in different subbasins. Most CF (68% by area) had a sparse canopy (50% canopy cover occupied <1% of the floodplain in 15 subbasins. We suggest that CF extent in the UCRB will decline markedly in the future, when the old trees on floodplains now disconnected from the river die and large areas change from CF to non-CF categories. Attention at a basinwide scale to the multiple factors affecting cottonwood patch dynamics is needed to assure conservation of these riparian forests.     

Accounting for adaptive capacity and uncertainty in assessments of species’ climate‐change vulnerability

Climate‐change vulnerability assessments (CCVAs) are valuable tools for assessing species’ vulnerability to climatic changes, yet failure to include measures of adaptive capacity and to account for sources of uncertainty may limit their effectiveness. We took a more comprehensive approach that incorporates exposure, sensitivity, and capacity to adapt to climate change. We applied our approach to anadromous steelhead trout (Oncorhynchus mykiss) and nonanadromous bull trout (Salvelinus confluentus), threatened salmonids within the Columbia River Basin (U.S.A.). We quantified exposure on the basis of scenarios of future stream temperature and flow, and we represented sensitivity and capacity to adapt to climate change with metrics of habitat quality, demographic condition, and genetic diversity. Both species were found to be highly vulnerable to climate change at low elevations and in their southernmost habitats. However, vulnerability rankings varied widely depending on the factors (climate, habitat, demographic, and genetic) included in the CCVA and often differed for the 2 species at locations where they were sympatric. Our findings illustrate that CCVA results are highly sensitive to data inputs and that spatial differences can complicate multispecies conservation. Based on our results, we suggest that CCVAs be considered within a broader conceptual and computational framework and be used to refine hypotheses, guide research, and compare plausible scenarios of species’ vulnerability to climate change.     

Distribution characteristics and source identification of polychlorinated dibenzo-p-dioxin and dibenzofurans, and dioxin-like polychlorinated biphenyls in the waters from River Kanzaki, running through Osaka urban area, Japan

This is the first to elucidate the distribution and sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs),and dioxin-like polychlorinated biphenyls in the waters from Kanzaki River,which is one of the most heavily polluted rivers in Japan.The World Health Organization (WHO)-toxic equivalent quantities (TEQs) in waters from the mainstream exceeded the Japanese environmental standard (1.0 pg-TEQ/L).The PCDD/PCDFs were dominated by highly chlorinated DFs,which predominantly contributed to the WHO-TEQs,suggesting that the main causes would be the incineration-related wastes.To find the sources,the dioxin congener concentrations in water and sediment samples from its tributary small waterways were determined.Abnormally high WHO-TEQs were detected in a water (50 pg-TEQ/L) and a sediment sample (41,000 ng-TEQ/kg dry weight) near the industrial solid waste incinerators (ISWIs).The PCDD/PCDF characteristics agreed well with those of the incinerator-related wastes as seen in the mainstream.These facts indicate that the dioxin pollution in the mainstream could be largely related to the industrial wastes from the ISWIs.Here,a TEQ apportionment method was used to understand the contribution of the pyrogenic sources to the WHO-TEQs.The average contribution ratios of the pyrogenic sources to WHO-TEQs were more than 80% for river waters from the mainstream,indicating that the elevated WHO-TEQs in the mainstream had been largely caused by the ISWIs.     

基于模糊聚类分析的矿业城市地表水环境质量评价

文章介绍了模糊聚类分析法,并运用此方法对位于阜新境内的辽河支流——柳河、绕阳河和养息牧河的地表水环境监测断面进行了聚类分析。在9个监测断面中,受污染最严重的断面位于养息牧河下游方向,此断面中,氨氮、高锰酸盐指数和化学需氧量的污染指数均严重超标。研究结果表明,辽河流域阜新段地表水水质己受到严重污染,不可以作为饮用水源地水源。聚类分析结果与实际污染情况相吻合,能客观地反映多因子共同作用下的地表水环境质量状况,这为制定辽河水环境治理方案和宏观决策提供了必要的科学依据。