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101.
在总结广东省耕地资源特征的基础上,分析预测了2010年广东人口的发展趋势和消费水平,广东耕地资源的现实生产力、潜在生产力,以及2010年耕地的发展规模和粮食生产力。分析得出结论:2010年广东人口突破8300万人的可能性较大;届时人均消费水平将有较大的提高;广东粮食自给率为70%时,将会出现耕地承载力严重超载。本文最后提出了提高耕地资源的人口承载力的对策。  相似文献   
102.
以长江经济带国土空间开发利用问题为研究对象,采用统计分析等方法,系统分析了长江经济带国土开发利用面临的资源环境限制性约束趋紧、国土空间结构性矛盾突出、开发利用效率不高、空间功能下降等问题。提出了优化长江经济带发展国土开发利用,必须从中华民族长远利益考虑,以构建国土空间集聚开发格局和分类保护格局的国土空间蓝图为目标,以承载力为基础优化国土空间开发格局,以分类保护和综合整治增强国土功能,以节约集约提升国土利用效益,以区域统筹协调区域土地利用,实现建设集约高效、生态良好、协调发展的国土构想。  相似文献   
103.
根据DPSIR模型构建了城市土地资源中生态环境承载力的指标体系,该体系的创新之处在于通过结构化的指标设计将生态环境与人口、经济、社会发展和管理等其他要素纳入统一分析框架,充分考察了各要素之间的密切关联。在实证分析方面,以北京市为例,对其2011—2014年土地资源中生态环境承载力的相关指标变动趋势情况进行分析。结果表明:人口增长与经济增长两大驱动力指标持续上升,对土地资源带来的压力持续存在且逐年增大;城市建设用地的压力不断增大,居住用地造成的压力最为显著;从反应指标和状态指标看,北京市在努力加强城市绿化和生态保护工作,但影响指标目前尚无显著改善,大气污染和水资源短缺等情况仍不容乐观。最后,针对如何评价和提升城市土地资源中生态环境的承载力提出了政策建议。  相似文献   
104.
从惠州市土地资源及其利用现状入手,分析其在土地资源利用上存在的耕地面积锐减、土地资源承载力下降、耕地土壤肥力下降、水土流失严重以及土壤和农作物被污染等问题,提出相应的土地资源利用和保护措施。  相似文献   
105.
城市河流水质常规评价技术研究   总被引:11,自引:0,他引:11  
运用综合水质标识指数法,对我国河流水质评价面临的关键技术问题,包括水质评价方法、水质评价项目,水质级别评价,水环境功能区达标评价、水质定性评价、河流及水系整体水质比较、水质随时间和空间变化等作了明确界定,并介绍了在上海河流水质评价中的应用。  相似文献   
106.
Abstract

Kingston Harbour has been experiencing increased levels of organic pollution since initial ecological assessments in 1971. to develop a new baseline of eutrophication in the Harbour 20 years later, and determine the most appropriate indices to be used in the continued monitoring the area, the water quality of Kingston Harbour was reassessed between December 1992 and 1993, by contemporaneous sampling of traditional water column parameters and planktonic communities at 28 stations within the Harbour. Indices used for water quality assessment were temperature, salinity, light penetration, dissolved oxygen, BOD and nutrients (nitrates-N, phosphate-P and ammonia-N). Results indicated that the planktonic community provided the most reliable index of increased eutrophication and changes in water quality. While physical variables indicated little change in Harbour waters and chemical variables indicated significant but erratic changes, the planktonic community displayed the classic characteristics of eutrophication. Phytoplankton biomass (a maximum of 148 mg m?3 chlorophyll a) was 5 to 10 times greater than in 1971 while zooplankton abundances (maximum of 80,000 animals m?3) were 4 times greater. in both cases the community composition had altered and there were fewer taxa than previously found.  相似文献   
107.
Differential Pulse Anodic Stripping Voltammetry (DPASV) was employed to measure Apparent Copper Complexing Capacity (Lt) and Stability Constants (Ks) of related cupric complexes of cell exudates of the phytoplanktonic alga Dunaliella salina. Three natural seawater samples collected 0.1, 2, 5 miles off the Tyrrhenian coast were used as culture medium. The measurements were carried out 1h and 7 days after the inoculum. Furthermore, on one culture the medium was passed through C18‐SEP‐PAK cartridges in order to separate the cell exudates. The results show that Dunaliella salina influences the value of Lt but does not affect the value of Ks . The C18SEP‐PAK retain only 50% of the ligands produced by the cells and capable of complexing copper.  相似文献   
108.
In this study a double model algorithm is developed for the simulation of the vertical profiles of monthly values of absolute humidity. The thrust of the algorithm is that is depends on the use of ground measurements for humidity and is based upon the use of two model relations for altitudes above and below 1 Km respectively. Monthly absolute humidity profiles as estimated using the specially constructed double model algorithm compare well with those calculated with the use of radiosonde data for the time period 1980–1990 (Helliniko station, Southern Greece). In particular the model estimation is very satisfactory at altitudes above the Planetary Boundary Layer and rather satisfying at altitudes below 1 Km. This implies that the model algorithm may be useful in supporting climatological studies in areas where lack of relevant information on the vertical distribution of water vapour is recognised.  相似文献   
109.
The total organic halogen (TOX) pollution in the highly polluted Ayase River system was investigated. Using the concentration of coexisting linear undecylbenzenesulfonate and the difference in the flowing water volume between summer and winter, the fractions of domestic and agricultural wastewaters in the whole water column were calculated and the variety of the TOX sources in the river was estimated. The river carried about 100 kgCl of TOX materials in one day; about 50 kgCl of the materials was from residential area in the basin. The contribution of agricultural drainage from paddy field was not negligible in summer. Highly contribution of industrial wastewater was observed in a tributary Furuayase River basin while the amount of TOX loaded in the area was widely varied; 0–105 kgCl of the materials was discharged as industrial wastewater.  相似文献   
110.
Bioaccumulation and biological effects of pollution were assessed in mussels (Mytilus galloprovincialis) caged for one month at three sites in the Oiartzun estuary (south-eastern Bay of Biscay, Spain) with the aim of evaluating their usefulness within the investigative monitoring defined in the European Union Water Framework Directive (WFD). The highest concentrations of organic contaminants determined in mussels' tissue were detected towards the inner part of the estuary but no gradient pattern was found for metal bioaccumulation. Population fitness responses measured as condition index, stress on stress and gonad index were similar in all caged mussels and did not follow the organic pollution gradient. However, biomarkers determined at tissue, cell and protein level (histopathology, micronuclei frequency, malondialdehyde levels and vitellogenin-like protein levels) revealed a higher stress syndrome at the inner part of the estuary showing signs of genotoxicity, oxidative stress and endocrine disruption. Overall, the integrated chemical–biological approach in connection with mussel caging technique proved to be a useful tool to assess environmental pollution, allowing a better understanding of the cause–effect relationship within the investigative monitoring defined in the WFD.  相似文献   
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