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911.
Based on the theories of landscape ecology,landscape eco-environment in the coutrol watershed by reser-voir of Erlong Mountain in Heilogjiang Province was analyzed and assessed by using GIS technique and statistical model of Principal Component Analysis and Spatial Cluster Analysis.It is found that 100.08km^2(36%) of the total area is in the state of kilter,85.73km^2(31%) of the total area is in the state of general,and 47.26km^2(17%) and 15.48km^2(16%) is in the relatively poor state and ideal state.According to landscape ecological structure,there are three land-scape function areas being planned and designed.1) Agricultural landscape function area:its developmental direction is tour agriculture and high-benefit agriculture.2)Eco-environment protected function area:the direction of development and utilization of this region is to develop vigorously forest for soil and water conservation ,and try to increase the rate of vegetation cover.3)Forest landscape function area:rational cut and utilization of forest resources,space optimization disposal of category of forest ,foster of forest and protection of wildwood will become the main development directions for this region.This study trys to provide scientific foundation for ecological restoration of the whole valley and its sustain-able development. 相似文献
912.
传统人事管理向现代人力资源管理转变 ,从人力资源规划、开发到人力资源的流动管理 ,是一项现代化的系统工程 ,它需要在实践中不断完善、不断改进 相似文献
913.
泡沫潜孔锤在水文水井钻探中的应用前景 总被引:3,自引:1,他引:2
介绍了泡沫潜孔锤的结构及工作原理,阐述了其优点及在水井钻探中的应用前景。 相似文献
914.
915.
在分析中国第二住宅发展的动力机制的基础上,系统地研究中国第二住宅发展的特征、与国外的差异及其成因,探讨第二住宅发展所引发的一系列社会经济效应,并展望其规划特征,以求对城郊规划、乡村规划及发展战略的制定、城乡土地利用协调方案的研制等工作有所裨益. 相似文献
916.
等时叠加波动方程叠前正演 总被引:6,自引:3,他引:6
非零炮检距地震正演模拟在复杂区叠前地震资料处理和解释中有着重要意义。通常使用射线追踪法和全程波动方程法来实现这一模拟。通过提出等时叠加原理和数学检波器表达式,形成了非零炮检距地震正演的新一类方法——单程波动方程法。该方法与射线追踪法相比能保持波的动力学特征,正演结果与实际地震记录相似性好。并且在计算过程中,人工干预的程度低,操作简便。与全程波动方程法相比,该方法计算效率高,且不产生直达波、多次波等干扰,信噪比高,与目的层相对应的一次波突出,波型识别难度不大。因此,单程波动方程法特别适合于复杂油气藏反射地震资料的正、反演研究。 相似文献
917.
三峡工程三期、四期蓄水后,库岸稳定性将会发生变化。为确定蓄水后对兴山段库岸稳定性的影响,文章在对兴山段库岸地质勘查的基础上,确定了兴山地区区域和库岸地质、水文条件特征。对各个库岸分段选取典型剖面,采用广义楔形体法对剖面的稳定性进行计算及评价。计算结果显示,库岸虽然在自然状态下基本稳定,但安全储备不高。随着蓄水的进行,其稳定性将进一步降低,造成一定的危害。根据兴山段库岸特点,提出几点简单的库岸防护建议。 相似文献
918.
919.
Lagrangian Stochastic Models For Turbulent Dispersion In The Atmospheric Boundary Layer 总被引:5,自引:1,他引:4
A one-particle three-dimensional stochastic Lagrangian model fortransport of particles in a horizontally-homogeneous atmosphericsurface layer with arbitrary one-point probability density functionof Eulerian velocity fluctuations is suggested. A uniquely definedLagrangian stochastic model in the class of well-mixed models isconstructed from physically plausible assumptions. These assumptionsare: (i) in the neutrally stratified horizontally homogeneous surface layer, the vertical motion is mainly controlled by eddies whose size is of order of the current height; and (ii), the streamwise drift term is independent of the crosswind velocity. Numerical simulations for neutral stratification have shown a good agreement of our model with the well-known Thomson's model, with Flesch and Wilson's model, and with experimental measurements as well. However there is a discrepancy of these results with the results obtained by Reynolds' model. 相似文献
920.
Mapping landslide susceptibility in Travis County, Texas, USA 总被引:4,自引:0,他引:4
A geographic information system (GIS) was used to construct a landslide hazard map for Travis County, Texas. The County is experiencing rapid growth, and development has encroached into unstable terrain that is vulnerable to landslides. Four layers of data were superimposed to create the landslide hazard map. Slope was given the most emphasis, followed by geology, vegetation, and proximity to faults. The final map shows areas of low, medium, and high landslide susceptibility. Areas of high susceptibility occupy stream and reservoir banks, rock escarpments, and agricultural land. The landslide hazard map can be a useful geologic criterion for land use planning. Planners can use the map to allocate appropriate land uses to unstable terrain, and to identify existing structures at risk from landslide activity. The methods presented in this paper can be adapted to other counties in the U.S. and elsewhere. Results of this study suggest that geographic information systems can effectively compile and overlay several data layers relevant to landslide hazards. 相似文献