996 resultados para China Lake


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China Lake is located in Kennebec County, Maine. Since 1983 the lake has suffered from yearly algal blooms as a result of the addition of excess nutrients. The nutrient load was amplified by erosion within the watershed. Erosion varies widely depending on a number of factors, including the slope of the land, the type of soil, and the way the land is being used. Certain land use types have a high potential to add nutrients to the environment, while others may help absorb excess nutrients and prevent erosion and runoff into the lake. A comprehensive examination of the China Lake watershed was completed using GIS to calculate the erosion potential for the entire area, taking into account past and present land use patterns. This information will help the towns around the lake to make informed decisions about future development and land management.

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We compared the nutrient dynamics of three lakes that have been heavily influenced by point and non-point source pollution and other human activities. The lakes, located in Japan (Lake Kasumigaura), People's Republic of China (Lake Donghu), and the USA (Lake Okeechobee), all are relatively large(>30 km(2)), very shallow (<4 m mean depth), and eutrophic. In all three lakes we found strong interactions among the sediments, water column, and human activities. Important processes affecting nutrient dynamics included nitrogen fixation, light limitation due to resuspended sediments, and intense grazing on algae by cultured fish. As a result of these complex interactions, simple empirical models developed to predict in-lake responses of total phosphorus and algal biomass to external nutrient loads must be used with caution. While published models may provide 'good' results, in terms of model output matching actual data, this may not be due to accurate representation of lake processes in the models. The variable nutrient dynamics that we observed among the three study lakes appears to be typical for shallow lake systems. This indicates that a greater reliance on lake-specific research may be required for effective management, and a lesser role of inter-lake generalization than is possible for deeper, dimictic lake systems. Furthermore, accurate predictions of management impacts in shallow eutrophic lakes may require the use of relatively complex deterministic modeling tools. (C) 2000 Elsevier Science Ltd. All rights reserved.

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Comparative studies on macrozoobenthos were done in 2 shallow mesotrophic lakes in the middle basins of the Yangtze River, China: Lake Biandantang where macrophytes were abundant, and Lake Houhu where macrophytes were scarce Samples were taken monthly at 4 stations in each lake from April 1997 to March 1999, and a total of 67 and 31 tara of macrozoobenthos were recorded in Lake Biandantang and Lake Houhu, respectively. Both annual mean density and biomass of macrozoobenthos were higher in Lake Biandantang than in Lake Houhu: 780 vs 532 indivials/m(2) and 37.1 vs 25.9 g wet mass/m(2), respectively. Abundance of functional feeding groups followed the order: scraper > collector > predator > shredder in Lake Biandantang, and collector > predator > scraper > shredder in Lake Houhu. Only 1 density peak occurred from winter to early spring in Lake Houhu; however, in Lake Biandantang, there were 2 peaks, the winter peak and spring peak. K-dominance curves and Shannon-Wiener, Simpson, and Margelef indices indicated that macrozoobenthos were more diverse in Lake Biandantang than in Lake Houhu Our study suggests that, in shallow lakes, submerged macrophytes are essential for the maintenance of biodiversity of macrozoobenthos mainly because the macrophytes increase habit heterogeneity and availability of suitable food, and may also decrease predation by fish on the macrozoobenthos.

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Ecological studies on benthic nematodes were conducted in two small, shallow lakes in the middle Yangtze basin, China; Lake Houhu, where the main source of primary production is phytoplankton and Lake Biandantang where it is predominantly macrophytic in origin. Monthly sampling was carried out from April 1996 to March 1997. A total of 36 species of nematodes was found in Lake Houhu and 51 species in Lake Biandantang. The dominant trophic groups of nematodes were algophages in Lake Houhu and bacteriophages associated with omniphages and phytophages in Lake Biandantang. Community analyses based on K-dominance curves, Shannon-Wiener and Simpson diversity indices, demonstrate that the benthic nematodes are more diverse in Lake Biandantang than in Lake Houhu. The results suggest that the abundance of submerged vegetation is essential for maintenance of habitat heterogeneity and biodiversity of nematodes in shallow lakes.

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Mode of access: Internet.

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"NAVWEPS report 7770. NOTS TP 2749."

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This article examines a cultural and creative industries park project – the White Horse Lake Ecocreative City on land outside the urban centre of Hangzhou, China, which uses an imaginary rural lifestyle as its key attraction. By analysing government policies and development plans, and through interviews with initiators, managers and creative practitioners, the article first assesses the geographical position, that is, the impact of locality with regard to both hard and soft infrastructure of the project; it then examines the synergies and tensions embedded in the strategic goals, that is, to build the right city for ‘four comforts’ (siyi, 四宜) – for residence, for business, for travel and for culture. The article concludes that Chinese-style cultural conversion remains locked in a top-down ideological framework, one that rural residents and the new ‘creative class’ are expected to respect.

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Historic landscapes today are changing gradually or abruptly, and the abrupt changes have caused the loss of much historic information. How to identify and protect the significant evidence of dynamic landscapes is a question that must be answered by each cultural community. This paper establishes a decipherment process – an operational guide for landscape assessment in China. This is a methodology using European methods integrated with traditional Chinese ways of landscape appreciation, providing an effective approach to translate the cultural landscape framework into the conservation inventory. Using Slender West Lake as a case study, the decipherment process has expanded the existing landscape investigation theory using the factor of artistic conception to integrate intangible values into the assessment process. It has also established a unit-based method to classify and represent historic landscapes.

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An account is given of the current situation regarding the lake fisheries and fish culture practices in China. The modern lake fisheries take advantage of the 3-D spaces of lakes to fully develop the resources. Currently, the fisheries concentrate on the following 3 aspects: bringing the water body into full play; various types of aquaculture enclosures; and selective measures in resources protection, stocking and aquaculture.