基于WebGIS三峡干流水质模拟平台研究

三峡蓄水成库后仍属于典型的河道型水库,其总体水流、水质运动特性符合一维水流水质运动规律。针对三峡库区总体水流、水质运动特性,采用一维水流水质模型对三峡库区水流和水质进行了模拟。以该模型为核心,利用Web Services技术开发并在互联网上发布了模型服务,在此基础上采用成熟的WebGIS和富客户端Flex等技术构建了适用于三峡库区的干流水质模拟平台;能够实现包括各计算断面流速、流量、水位以及污染物浓度时空过程在内的三峡库区干流流速场和浓度场的数值模拟。以库区干流清溪场至十里铺断面内的江段作为模拟实例,利用该平台模拟计算江段内水流和水质状况,并以水文水质同步观测数据对模拟结果进行验证,结果表明其具有较好的模拟效果;为三峡库区污染物总体输移扩散特性研究提供了有利工具,同时也为国家和地方政府进行库区水环境决策提供了技术支持     

三峡库区汛期极端降水非均匀性特征

利用极端降水量集中度和集中期讨论三峡库区汛期极端降水量的非均匀性分布特征。结果表明: 三峡库区极端降水量空间分布表现为西南部和东北部地区相对较少,中部、东南部相对较多。库区汛期极端降水集中度和集中期的空间差异不大,集中程度总体较差,东北部和西部地区极端降水相对集中,中部相对分散。库区极端降水主要集中在6月底和7月上中旬,东北部和西部偏西地区集中期相对较晚,中部地区集中期相对较早。库区汛期极端降水量的分配状况与同期极端降水量存在较好的关系,即极端降水量越少,则极端降水量越集中、集中期越早;反之极端降水量越多,则极端降水量越分散、集中期越晚,尤其是在库区东北部地区最为显著。三峡库区蓄水后极端降水集中程度在空间上一致性较好,表现为蓄水后更为分散;极端降水量和集中期则在空间上差异显著,大致表现为蓄水后东北部极端降水增加并延迟;西南部极端降水减少并提前     

三峡工程建设前后库区城镇发展与环境变化

利用卫星遥感监测,分析三峡工程建设前后库区城镇发展类型、时空过程,揭示库区城镇变化的驱动力,探索了城镇扩展与人口城镇化关系,研究城镇环境变化特征。三峡库区城镇规模发展不均衡,库尾城市规模庞大,库中、东部区县级城市规模较小,而乡镇的比例占城镇面积24%;在过去15 a中,建城区规模扩大172%,高于全国省会城市发展水平72%;三峡库区城镇规模扩大的同时,东西城镇规模差距逐步缩小,三峡工程建设起着重要的推动作用;城镇发展以侵占了优质耕地资源为代价,耕地占城镇变化83%;城镇用地变化与人口城市化发展不平衡,城镇空间发展快于人口城镇化过程,城镇对农村人口的吸引力不及全国省会城市平均水平,在2007年城市化率低于全国水平13%,差距进一步扩大;城市空间结构发展模式受地形和土地资源的限制,城市分维数和坡度分别增加12%和104°,城市向潜山区扩展或搬迁的同时,城市空间的完整性下降     

成都大邑县西岭雪山风景名胜区环境美学评价研究

本文根据西岭雪山景区特色，将其分为三大景观区，从景观的美学价值出发，选择了１２个美学评价指标，运用层次分析法和征询评分加权法，对该风景区进行了环境美学综合评价。     

ESTIMATING MARYLAND CRITICAL AREA ACVS IMPACT ON FUTURE NONPOINT POLLUTION ALONG THE RHODE RWER ESTUARY1

ABSTRACT: This paper presents the results of an investigation of the effects of the Maryland Critical Area Act on generation of non-point source loads of phosphorus, nitrogen, and sediment to the Rhode River estuary. The Simple Method model, the Marcus and Kearney regression model, and the CREAMS model were used to estimate annual loads under: (1) present conditions, (2) maximum land use development allowable under the Act, and (3) two sets of future land use conditions that might occur if the Act were not in place. Results indicate that the Critical Area Act can reduce the present generation of nonpoint nutrient and sediment loadings 20–30 percent from the regulated area. These reductions can occur while preserving agricultural lands and allowing limited residential and urban development. The decrease in nutrient loadings is primarily dependent upon implementation and enforcement of agricultural best management practices (BMPs). The BMPs could reduce present agricultural nutrient loadings by 90 percent to a level comparable to loadings from residential areas. The estimated effectiveness of the Critical Area Act is even greater when compared to potential future nutrient loadings if development in the area remains unregulated. Unrestricted residential and urban development could increase nutrient loadings by 200 percent to 1000 percent as compared to controlled development under Critical Area Act guidelines. The Critical Area Act primarily prevents these future increases by severely limiting woodland cutting, with lesser results obtained by requiring urban BMPs.     

陕南化龙山珍稀濒危植物的保护和利用

化龙山是大巴山系在川陕境内的最高山峰,海拔２９１７．２ｍ,植物资源丰富,有野生维管植物１９７７种,隶属１８６科８１５属。化龙山是陕西省珍稀濒危植物资源最丰富的地区,共有国家保护的珍稀濒危植物２２科３０属３３种,其中属一级保护１种,二级保护１１种,三级保护２１种,属濒危２种,稀有１４各,渐危１７种,珍稀濒危植物古老成分较多,并以第三纪孑遗成分为主单少型属和中国特有属分别是１６属和１０属。这些珍稀濒危     

Visual Aesthetic Quality of Northern Ontario's Forested Shorelines

Only a few empirical studies on forest aesthetics have adopted a water-based perspective for observers and have investigated the perceived visual quality of forested shorelines. In forested environments with many lakes, such as the boreal forest in the Canadian Shield, individuals have greater exposure to forests from water-based rather than in-stand vantage points. This study employed the psychophysical research direction to explore the relationships between scenic beauty and biophysical characteristics of the forested shorelines in the boreal forests. Two model forms were tested. One model related the variation of shoreline forest aesthetic evaluations of near-vista views (140 m offshore) to a set of forest mensuration data. Tree size, tree mortality, conifer shrubs, tree density, amount of hardwood, and slope explained 60.2% of the variance in scenic beauty between the study sites. A second model was calibrated to test the relationship between an already existing ecosystem vegetation classification system and the aesthetic evaluations of the same forested shorelines. When the ecosystem classification was simplified to eight groups, the model explained 48.5% of variance. These models suggest that the psychophysical approach to studying aesthetics can be applied successfully to near-vista evaluations of scenic beauty. The finding that a forest ecosystem classification system is highly related to scenic beauty suggests that, at least in the boreal forest, managers can reasonably estimate the scenic beauty of forested shoreline environments from an ecosystem classification, with little need for intensive data on these sites.     

皖东地区大型真菌资源及其开发利用

为了合理开发皖东地区的大型真菌资源，对皖东地区大型真菌资源种类进行了调查统计分析。结果表明，该区有大型真菌4纲8目23科47属101种。分析了其资源价值，提出了相应的开发策略。     

雾灵山自然保护区的生态效应与保护对策

通过对雾灵山国家级自然保护区的调查，研究保护区的生态沿革，分析保护区的生态功能、生态作用等生态效应，针对当前所存在的草甸严重退化、动物种群密度降低、水量减少等生态问题，提出对保护区的生态环境应尽快制定环境保护规范化，建立生物多样性保护权威机构，实行社区共管，开展科学生态旅游等措施。