京郊观赏渔业的养殖现状与前景展望

北京市观赏鱼产业的发展趋势,正契合了都市型特色渔业的发展脚步,良好的发展机遇和社会环境,使观赏鱼产业将成为富有活力的一个新兴产业,并具有非常广阔的发展前景。     

已建水库向城市供水水价的计算

为了解决城市用水的供需矛盾,就已建水库向城市供水水价计算进行可行性分析,以期为水管部门提供参考。     

人工湿地处理农业径流研究

为了处理农业径流的污染,本研究采用水平潜流人工湿地对农业径流进行处理试验,以减轻河流污染。结果表明,进水流量2.5m3/d运行条件下,水平潜流人工湿地有较好的处理效果。潜流人工湿地CODcr、TN、NH4+-N、TP的平均去除率均分别达到49.65%,51.37 %,56.24% 和59.12%;潜流人工湿地系统的出水CODcr、TN、NH4+-N、TP平均含量分别达到Ⅱ类水质的含量,Ⅴ类水质的含量, ,Ⅱ类水质的含和Ⅳ类水质的含量。通过对人工湿地处理系统影响因素分析表明：进水流量的控制非常关键,适宜的进水流量处理效果最佳。     

Continental-scale interactions with temporary resources may explain the paradox of large populations of desert waterbirds in Australia

Arid Australia supports extraordinary numbers of waterbirds. We show that the solution to this seeming paradox lies in considering the availability of temporary wetland habitat in the context of the birds dispersal capability and fluctuations in the abundance of wetlands in time and space. For species with large dispersal capabilities, the Lake Eyre Basin of central Australia, amongst the driest regions on the continent, has the highest habitat availability for waterbirds. Analyses of landscape structure show that the wetlands of the Lake Eyre Basin are highly inter-connected and linked by broad pathways to wetter parts of south-eastern Australia. These analyses illustrate that organism traits and patch dynamics affect realised habitat availability and indicate that the processes that structure populations may operate at much larger spatial scales than those at which humans usually seek to manage the landscape.     

Changes to the landscape pattern of coastal North Carolina wetlands under the Clean Water Act, 1984–1992

Wetland management in the United States is organized through a permit process that requires a permit be filed with the U.S. Army Corps of Engineers prior to wetland alteration. A collection of these permits from 1984 through 1992 was analyzed in conjunction with classified Landsat Thematic Mapper data from 1984 and 1992 in order to quantify changes to wetland habitat in the study area in coastal North Carolina. The wetland management process in the U.S. focuses on a site-by-site review, possibly overlooking important changes to wetlands at the landscape-scale. These the two datasets were used to determine if wetland habitat loss was occurring at permit sites, but also to determine if landscape-scale wetland fragmentation and reorganization were occurring in the area surrounding each permit site under the wetland management process. The use of these two datasets attempted to span two scales: the site-specific scale often used in the management of wetlands, and the landscape-scale where effects of such management are evident. Important conclusions from the research include the following. First, while several sources imply that coastal wetlands are disproportionately protected as a result of the widespread recognition of their habitat value, estuarine wetlands were altered much more frequently in the study area than their inland counterparts. Second, despite federal level efforts that require compensatory mitigation when wetland habitat is lost, such mitigation was required in only three percent of permits, ensuring wetland loss. Third, correlation between estimates of wetland loss from the Permit Record and from the remotely sensed record was minimal, highlighting the problems inherent to wetland delineation and implying alterations to habitat not evidenced in the permit record. Finally, landscape-scale changes of loss, fragmentation and habitat reorganization have occurred in estuarine emergent wetland habitat in areas adjacent to several permit sites, implying unanticipated additional impacts to permitted actions. Wetland loss at the permit site occurred with additional fragmentation in 80 percent of the sites examined. The results highlight the lack of agreement between management and landscape-scale wetland structure, function and change, and imply the importance of examining the spatial context of permit sites in the permit review and evaluation procedure.     

Analysis of landscape patterns in coastal wetlands of Galveston Bay,Texas (USA)

High productivity and accessibility have made coastal wetlands attractive sites for human settlements. This study analyzed the patterns of wetland landscapes in Galveston Bay, Texas, USA. The first objective of the study was to describe the relationships between the fractal dimension of wetland boundaries and those factors which affect the wetland landscapes (e.g., land use, type of vegetation, size, location, and level of human disturbance). The second objective was to construct a historical database to contrast wetland areas which had experienced different levels of disturbance between 1956 and 1989. The fractal dimension, a measure of how much of the geographical space is filled by boundaries, was measured by the perimeter-area method. The fractal dimension of wetlands was significantly affected by land use, type of vegetation, size, and level of anthropogenic disturbance. In addition, increasing the size of buffers around roads did not significantly affect the fractal dimension of wetlands. Landscape indices, such as fractal dimension, dominance, and diversity, were used to characterize spatial heterogeneity in the historical database. Lake Stephenson, an area of low anthropogenic disturbance, experienced no changes in wetland composition and abundance over time. Anahuac, an area of medium disturbance, experienced changes in both wetland composition and abundance. Texas City, an area of high disturbance, experienced a change in wetland composition. These differences can be associated with the type and level of disturbance present; however, more evidence is needed to determine whether certain landscape patterns have stable, intrinsic properties which allow persistence in the face of disturbance. These results will be informative to resource managers determining how wetlands can be managed as natural resources and nature reserves.     

人工湿地去污机理研究进展

人工湿地污水处理系统具有较高的净化效率和相对较低的基建投资和处理成本，在许多国家已被广泛应用于生活污水的处理，通过工艺创新，人工湿地污水处理系统有向工业污水、农业废水等特殊污水处理方向发展的趋势，简要论述了人工湿地的研究现状，预测其研究与应用发展的趋势，探讨了处理机理及性能，分析了现行的工艺设计及存在的主要问题。     

一类简化的竹编水泥沼气池力学模型分析

针对目前在滇南一带开发推广的竹编水泥沼气池，在实地测试和实验室测试研究的基础上，建立一类简化的三次超静定力学模型，并采用力法对赘余力进行严格的数学，力学分析与计算，构造与实际结构接近的理论模型，针对壁厚3,5cm的情形进行数值计算，计算与实测结果基本一致，说明所讨论的模型及力学算法分析是正确的，计算程度是可靠的。     

不同基质垂直流人工湿地对城市污水的净化效果

选取石英砂、煤灰渣和高炉渣作为介质，再按适当的比例配以有机质和土壤组成人工土填料处理柱，进行了不同基质垂直流人工湿地对城市污水的净化效果研究。为期1a多的运行试验结果表明，煤灰渣基质对化粪池出水中COD、BOD，和TP的去除率分别达到71％～88％、80％～89％和70％～85％。高炉渣基质对化粪池出水中COD和BOD，的去除率分别为47％～57％和70％～77％，但对总磷的去除率高达83％～90％。石英砂基质虽然对化粪池出水中COD、BOD5和TP的去除率分别为36％～49％、65％～75％和40％～55％，但其导水能力最好，水力负荷最高。     

新建组合填料潜流湿地脱氮除磷研究

以城市污水ANOXIC—OXIC工艺出水为处理对象，在中试规模上研究了新建组合填料潜流湿地的脱氮除磷效能。结果表明，当COD面积负荷率、TN面积负荷率、TP面积负荷率、HRT（水力停留时间）分别为8．7～22．1g／（m^2·d）、7．29～24．28g／（m^·-d）、0．94—1．84g/（m^2·d）、0．48—0．59d时，①湿地启动阶段，COD去除率为30．3％、面积负荷去除率为6．63g／（m^2·d）、反应动力学常数为0．23m／d；SS去除率为45．5％；氨态氮、亚硝态氮和硝态氮的去除率分别为9．3％、40．0％和25．0％；TN去除率为14．9％、面积负荷去除率3．63g／（m^2·-d）、反应动力学常数为0．10m／d；TP去除率为92．4％、面积负荷去除率为0．93g／（m^2·-d），反应动力学常数为O．94m／d。②稳态运行阶段，COD去除率为33．9％，面积负荷去除率为2．98g／（／m^2·d），反应动力学常数为0．24m／d；SS去除率为50．0％；氨氮、亚硝氮和硝氮的去除率分别为50．2％、41．9％和24．7％；TN去除率为29．9％，面积负荷去除率为2．19g／（m^2·d），反应动力学常数为0．18m／d。TP去除率为90．5％、面积负荷去除率为0．89g,／（m^2·d）、反应动力学常数为0．86m／d。③随TN面积负荷增加，TN面积负荷去除率和TN动力学常数均随之线性增加；随TP面积负荷增加，TP面积负荷去除率随之线性增加，而反应动力学常数呈幂函数增加。