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971.
我国大部分城市污水的95%未经处理排放入水体,城市地区的水质有继续恶化的趋势,甚至许多城镇的下水管网尚不完善.随着城市化和工业化的发展,城市污水将继续增加.我国在污水处理中投资不足和水污染规模大这一不相适应的矛盾将会在相当长的一个时期内存在.解决我国水污染的根本原则是供求最大的费用—有效性.未来水污染防治的政策要点是:1.集中力量于源头削减污染产生量;2.建立按总量控制的流域级水污染防治的方法和示范工程;3.在投资和管理体制上建立以城市污水集中处理的市场经济刺激机制.  相似文献   
972.
本文将晚白垩世王氏组的沉积相划分为五类:湖盆陡岸浊积扇相,洪积扇沉积相、滨—浅湖前缘斜坡相、次深湖相、湖湾相。并详细研究了微相特征。王氏组沉积特征所反映的沂沐断裂带的活动特点是:先为徐缓的脉动,而后是陡然激烈的断陷,故造成了补偿性沉积与超补偿性沉积的叠置。王氏组砂岩平均化学成分表明:马站盆地具孤后盆地性质。  相似文献   
973.
我国淡水湖泊资源开发探讨——以东平湖为例   总被引:2,自引:0,他引:2  
本文阐述了我国淡水湖泊具有调节河川径流、发电、灌溉、航运等功能。并以东平湖为例,系统论述了它们的资源特征(自然环境、理化特征、鱼类生境、旅游环境),及其利用开发现状,并分级分析了它们各自的生态环境、生态系统特点。指出了我国淡水湖泊存在的主要问题:入湖水源不足,工业废污水的污染,水工建筑物阻隔河湖通道,滞洪淤积等,导致了水域生态环境恶化,溯河入湖物种绝灭,湖体湮废等。最后提出了设计湖体水生资源得以开发的流域水资源调节控制规划;加强流域水土保持;有计划地进行湖底清淤;疏竣河湖接口通道,添建鱼道;编制利于水生动、植物生境的水利工程运营方案,设计高效静水资源开发方案等整治对策。  相似文献   
974.
贾宝全 《灾害学》1995,10(1):46-50
吐鲁番盆地的生态灾害具有种类多、危害面广、危害程度深等特征,并严重制约着该区绿洲经济的持续稳定发展。本文分析了每种生态灾害发生的原因、危害程度及地区分布,并提出了生态灾害调控的基本原则;综合整体性、区域分异性、持续性.最后探讨了该地生态灾害调控的一些具体措施。  相似文献   
975.
我国华北平原分布有大小不等、形状各异的地下热水矿床;赋存于石灰岩地层形成的地质构造凸起部位的地下热水富水性好,井产水量大,自喷能力强,水质好,矿化度低,温度高,具有较高的开发利用价值。华北平原地下热水的热源与第三纪侵入的火成岩无关。地下热水的补给来源是山区大气降水渗入地下经过较大的构造断裂带和碳酸盐岩地层岩溶溶洞、断裂裂隙深循环以后形成的。地下热水的温度主要取决于水循环的深度。  相似文献   
976.
ABSTRACT: Along a drainage network, there is a systematic variation of average flow parameters (width, depth, and velocity) at flows having the same flow duration. Hydraulic geometry equations mathematically express this interdependent relationship of stream-flow characteristics for a basin for annual flow durations varying from 10 to 90 percent. However, the equations proposed so far have had rather poor predictive performance for low flows. An independent investigation of the variation of discharge with drainage area and annual flow duration demonstrates a consistent relationship between these parameters. The relationship for the high to median-flow range differs, however, from that for the median— to low-flow range. The proposed equations provide a better predictive performance for low flows than previous formulations and a versatile means of estimating flow parameters for streams throughout a basin. The improved basin hydraulic geometry equations have a wide range of applications in areas such as stream habitat assessment, water quality modeling, channel design, and stream restoration projects.  相似文献   
977.
根据果梅对环境条件的要求,通过对其分布地区的气侯特征和生态表现的调查分析,本文提出以年均温和1月均温为果梅生态适宜性划分的依据.根据四川盆地的气候特点.提出了果梅栽培的最适区、适宜区和次适宜区.本文对四川盆地发展果海生产.提高经济效益,改善生态环境具有一定的指导意义.  相似文献   
978.
ABSTRACT: Geographic Information Systems (GIS) have been successfully integrated with distributed parameter, single-event, water quality models such as AGNPS (AGricultural NonPoint Source) and ANSWERS (Areal Nonpoint Source Watershed Environmental Response Simulation). These linkages proved to be an effective way to collect, manipulate, visualize, and analyze the input and output date of water quality models. However, for continuous-time, basin large-scale water quality models, collecting and manipulating the input data are more time-consuming and cumbersome due to the method of disaggregation (subdivisions are based on topographic boundaries). SWAT (Soil and Water Assessment Tool), a basin-scale water quality model, was integrated with a GIS to extract input data for modeling a basin. This paper discusses the detailed development of the integration of the SWAT water quality model with GRASS (Geographic Resources Analysis Support System) GIS, along with an application and advantages. The integrated system was applied to simulated a 114 sq. km upper portion of the Seco Creek Basin by subdividing it into 37 subbasins. The average monthly predicted streamflw is in agreement with measured monthly streamflw values.  相似文献   
979.
ABSTRACT: To manage the first flush of storm runoff in urbanized areas, a diversion box and detention basin system has been proposed for a new storm sewer system or for retrofitting an existing system. A software package for a personal computer has been developed to facilitate the analysis and design of the system. Hydrographs and pollutographs are generated at the inlet and outlet of the diversion box and the detention basin. The peak outflow and peak pollutant concentrations are compared with the allowable outflow and pollutant concentration for urban stormwater quantity and quality management. The model is developed for both analysis and design purposes.  相似文献   
980.
This paper discusses the development and use of the first version of the WFD Explorer (WFDE), a decision support system (DSS) for the implementation of the Water Framework Directive in the Netherlands. The paper's aim is to increase our understanding of the development process of DSSs and the impact the development process has on the perceived validity and usefulness of the DSS. In other words, whether the DSS is seen as representing reality correctly and as fit for purpose and user-friendly. Contrary to the expectations, the WFDE was not used much. Tensions in the development process over the intended users, the level of analysis, the level of ambition and the type of expertise to be included have contributed to doubts over its usefulness and validity. These tensions reflect general tensions in river basin management: different actors will prefer different approaches, and none of these is objectively the best. Whereas guidelines for the development of DSSs can increase awareness of these tensions, resolving these tensions is beyond the power of the developers to control. Guidelines have their use, but also their limitations, simply because they are general and circumstances differ from case to case.  相似文献   
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