三峡水库入库污染负荷研究(Ⅰ)--蓄水前污染负荷现状

分析蓄水前三峡水库入库污染负荷,包括库区污染负荷,如城市生活污水、工业废水、农业面源、船舶流动污染源;主要干支流长江、嘉陵江、乌江的入库背景污染负荷,包括上游天然背景负荷和上游污染贡献负荷,为三峡水库水污染防治提供理论依据。研究表明：①进入三峡库区的污染源主要来自长江、嘉陵江、乌江上游输入的背景负荷,包括上游贡献负荷和天然背景负荷,其中：CODCr的天然背景负荷与上游污染贡献负荷较为接近,BOD5、NH3-N的上游贡献负荷略大于天然背景负荷;TP的上游贡献负荷远大于天然背景负荷。因此,“三江”上游区域的污染治理工作应为今后三峡水库水污染防治的重点;②库区内排放的主要污染物是TP、BOD5、TN、CODCr等有机污染物,其累计等标污染负荷比达到98%以上。库区内的主要污染源为农田径流,其等标污染负荷比为77.85%;其次为城市污水,其等标污染负荷比为19.45%,工业废水的等标污染负荷比只占1.62%。因此,农田面源将是今后库区污染防治的重点。     

三峡水库水质保护与渔业利用关系探讨

捕捞渔业和不投饵养鱼对水体不会造成污染,并在一定程度上具有抑制藻类生长、减缓和控制富营养化发生的功能。投饵养鱼和施肥养鱼可增加富营养化发生的几率,但通过控制网箱的数量和布局,限定养殖种类和密度,提高低污染饲料质量,采取科学的投喂方式等措施,可减少对水体的负面影响。适度发展渔业是利用三峡水库水、土地和生物资源的有效途径之一,不仅可促进库区产业发展,增加库区移民就业和收入,而且对水库水生态环境有一定的保护作用。 要做到有序利用水面资源,必须尽快制定科学的渔业发展规划,加强渔业管理指导渔业生产,使渔业生产与环境保护、移民安置和水库其他功能相协调。     

三峡库区典型消落带淹水后草本植被的自然恢复特征

消落带是影响水库生态环境安全的关键区域。利用生物调查方法,对三峡库区典型缓坡型消落带草本植被的自然恢复情况进行了初步研究。结果表明：（1）研究区植被主要为一年生和多年生草本植物,共有29种,其中空心莲子草、狗牙根、稗草、苍耳、狗尾草、鬼针草和马唐是消落带的优势种类,且空心莲子草和狗牙根是消落带成陆初期的建群种。消落带植物群落多呈斑块状集中分布,沿145～175 m高程梯度从下往上大致可分为4条植物带：空心莲子草 狗牙根带、稗草带、苍耳 马唐 狗尾草带和一年生杂草带。（2）淹水后消落带草本植物群落在没有人为干预的情况下可自然恢复,只是群落结构趋于简单,植物物种多样性显著降低。（3）植物群落的物种多样性、地上生物量和盖度均沿水位梯度带从下往上呈先增后减的抛物线状变化,即消落带下部＜消落带上部＜消落带中部。三者的变化趋势有着高度的相关性,并且都与淹水时间呈负相关。（4）沿水位梯度带植物群落的均匀度指数差异不显著,其他物种多样性指数以及地上生物量差异显著     

三峡库区土地利用变化与影响因子分析

利用1995、2000和2005年的Landsat TM遥感数据解译结果分析了三峡库区的土地利用格局，三峡库区建设用地总量上升，各类建设用地的增长率不一致，库区水面在增加；运用单一土地利用动态度分析了相关地类的变化速度和分布，各地类的动态度与变化速度存在空间上的差异；采用景观生态学的方法分析了土地利用变化的景观特征，景观的多样性在增加，而景观的破碎度有一个先减小后增加的趋势，同时景观优势度的变化不大，耕地景观的优势逐渐被多样性景观特征所替代。然后采用典型相关分析的方法，计算典型载荷，找出各典型变量在分析过程中的作用，借此分析了土地利用变化与社会经济影响因子之间的关系。     

吹扫捕集GC/MS测定水中VOCs的方法优化

针对传统吹扫捕集方法测定高沸点挥发性有机污染物回收率偏低问题,设计二次正交实验进行方法优化.结果表明,吹扫时间、吹扫速率及冷阱温度分别为19min、70ml/min和-130℃时高沸点化合物的平均回收率明显提高,检出限完全满足EPA方法要求.采用优化后的方法测定了官厅水库中VOCs的含量,VOCs的浓度范围为O.05～5.6ppb.     

三峡水库蓄水前库区水质状况研究

采用单因子评价法,对长江三峡库区1996～2001年的水质监测资料进行水质状况分析,结果表明三峡库区江段水质状况总体良好,参与评价的各项指标多年均值均符合Ⅱ类水体标准;部分水质参数测值超Ⅱ类水体标准,其中高锰酸盐指数、总铅、氨氮为库区江段的主要污染因子;汛期水质劣于非汛期水质。采用PWQTrend水质污染发展趋势分析专业软件,对长江三峡库区6年来的水质监测资料进行水质趋势分析,结果显示库区江段水质参数浓度及污染物输送率趋势均以无显著变化为主,表明库区江段总体水质状况6年来保持基本稳定。     

Two-dimensional habitat modeling of Chinese sturgeon spawning sites

Since the construction of the Gezhouba Dam in the 1980s, the number of Chinese sturgeon in the Yangtze River has been rapidly declining. The Gezhouba Dam has cutoff the migration path of these sturgeon, resulting in an overall reduction of suitable sturgeon habitat. This paper describes a habitat suitability index model that is used to evaluate the impacts of the Gezhouba Dam and Three Gorges Project on Chinese sturgeon spawning sites. Based on research concerning the reproduction characteristics of Chinese sturgeon, ten major ecological factors that influence reproduction were analyzed, including: water temperature, velocity, water depth, substrate, suspended sediment concentration, and the amount of egg predatory fish. The suitability index (SI) curves based on these ten ecological factors were obtained, and a habitat suitability function was developed. A two-dimensional mathematical model was also created to simulate and predict physical habitat situation (such as hydraulic, sediment, and substrate) of the Chinese sturgeon. By coupling the habitat suitability function and a two-dimensional mathematical model, a habitat suitability index model for Chinese sturgeon was established. The habitat suitability index model was validated by comparing measured data with predictions from the model. These comparisons showed that the computed results agreed well with the measured results, and the high calculated habitat suitability index (HSI) corresponded to high measured quantity of eggs per unit (1000 m³) discharge (CPUE_d). The calculated habitat suitability index for Chinese sturgeon also showed that the habitat suitability index was better in 1999, before the impoundment of the Three Gorges Project, compared with the habitat suitability in 2003. Simulation results of different discharges from Gezhouba Dam predicted that flow discharges between 10,000 and 30,000 m³/s were most suitable for sturgeon spawning.     

Linking the electron donation capacity to the molecular composition of soil dissolved organic matter from the Three Gorges Reservoir areas, China

Soil dissolved organic matter(DOM) plays an essential role in the Three Gorges Reservoir(TGR) as a linkage between terrestrial and aquatic systems.In particular,the reducing capacities of soil DOM influence the geochemistry of contaminants such as mercury(Hg).However,few studies have investigated the molecular information of soil DOM and its relationship with relevant geochemic al reactivities,including redox properties.We collected samples from eight sites in the TGR areas and studied the link between the molecular characteristics of DOM and their electron donation capacities(EDCs) toward Hg(II).The average kinetic rate and EDC of soil DOM in TGR areas were(0.004±0.001) hr~(-1) and(2.88±1.39) nmol e~-/mg DOM_(bulk),respectively.Results suggest that higher EDCs and relatively rapid kinetics were related to the greater electron donating components of ligninderived and perhaps pyrogenic DOM,which are the aromatic constituents that influenced the reducing capacities of DOM in the present study.Molecular details revealed that even the typical autochthonous markers are important for the EDCs of DOM as well,in contrast to what is generally assumed.More studies identifying specific DOM molecular components involved in the abiotic reduction of Hg(II) are required to further understand the relations between DOM sources and their redox roles in the environmental fate of contaminants.     

基于加权信息量和迭代自组织聚类的地质灾害易发性评价

以三峡库区忠县-方斗山地区为研究对象,首先选取坡度、坡向、坡高、岩土体类型、坡体结构、构造、水的作用、人类工程活动等8个评价因子建立地质灾害易发性评价指标体系,并对因子状态进行分级;然后,采用层次分析法计算各指标因子的权重,应用加权信息量模型进行地质灾害易发性评价;再者,利用迭代自组织聚类模型对地质灾害易发性评价结果进...     

黑龙滩水库风景区旅游容量的探讨

本文从黑龙滩风景区自然景点、游览线路、旅游开发方式、适度活动面积及空间容量计算，基础设施容量计算以及环境污染承受能力等几个方面综合计算了黑龙滩水库风景区的旅游容量。并对适度旅游容量下如何开发利用风景区旅游资源进行了探讨。