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591.
城市土地地质经济评价是根据城市建设中存在着土地利用与地质环境不协调的矛盾,以及制定土地价格时忽略地质环境因素而提出的新概念。文章论述了该评价的基本思路、类型、指标体系、模型和方法.并以厦门海沧开发区土地利用适宜性地质经济评价为例,简述了该评价理论和方法的重大实践意义。  相似文献   
592.
ABSTRACT: The concept of a space-time tradeoff is extended to the hydrologic data sets of competing rainfall-runoff modeling techniques. Examples are given by comparing the performance of a regression model and a quasi-physically based model using data from an experimental catchment and data synthetically generated. Space-time tradeoffs are demonstrated within the data sets of the two modeling techniques, but not across the competing hydrologic data sets.  相似文献   
593.
: The danger to the environment associated with the injection of liquid industrial wastes into a deep, confined, subsurface rock formation may arise from the transport of the waste laterally or vertically in the formation. The pattern of lateral transport, which can take place as a result of convection as well as dispersion and diffusion, can be determined by an approximate analytical solution to the mass transport equation. Vertical transport may take place through both natural fractures and fractures created by hydrostatic stresses generated around the well during injection. To determine the stresses, we used the finite element method to get a numerical solution of the flow equation. We applied a solution of the flow equation to calculate the stress buildup and decay for the Jones & Laughlin Steel Corporation's injection well near Hennepin in Putnam County, Illinois. According to our computations, the stress buildup due to injection is about 0.16 pounds per square inch per foot - psi - (0.362 Newton per square centimeter per meter), which, added to normal pressure, makes an estimated total stress of 0.60 psi/ft (1.36 Newton/cm2/m). That pressure is insufficient to cause fracturing of the Cambrian Eau Claire aquitard, the confining bed for the disposal zone.  相似文献   
594.
The Hawaii Environmental Simulation Laboratory (HESL) was a three year experiment in improving governmental decision making by developing better research methodologies for use by public decision making bodies and community organizations. Funded through the University of Hawaii by the Ford Foundation (FF) and the National Science Foundation (NSF), HESL conducted its researchinteractively with the intended users of its products. This paper sets the HESL experiment in the context of recent trends in applying better methodology to environmental decision making and involving citizens in these decisions. It describes the HESL effort, and then draws conclusions about both the effectiveness of the experiment and the way it was conducted, providing information that may be useful in guiding university groups, public agencies, and community organizations pursuing similar objectives.  相似文献   
595.
This paper reviews analytical procedures for deducing from annual streamflow data information required for water resources systems planning. The procedure relies on two techniques to determine the extent that cycles exist in annual time series data. The first is to observe how the time series behaves around the mean annual flow. If it tends not to move across the mean frequently, it is concluded that a cyclical nature exists. The second technique is to observe the time path of accumulated departures from the mean annual flow. The validity of both techniques is questioned. The first because it uses mean flow as “normal” or the flow that the time series should fluctuate around. The second because the accumulated departure from the mean time series will be autocor-related even when the individual annual or seasonal flow observations are uncorrected. Alternative analytical techniques, which find no cycles, are presented.  相似文献   
596.
ABSTRACT: Techniques for predicting the hydrologic effects of grazing schemes have heretofore been unavailable. The available literature on grazing intensity influences on infiltration rates is used as a basis for a model of infiltration behavior in response to grazing systems. Background, development, cautions, and an example are given.  相似文献   
597.
The interrelationship of society and environment is addressed here through the study of a remote fishing village of 750 people. An interdisciplinary study evaluated demographic, economic, and social aspects of the community, and simulation modeling was used to integrate these societal characteristics with environmental factors.The population of the village had grown gradually until the 1960's, when a decline began. Out-migration correlated with declining fish harvests and with increased communications with urban centers. Fishing had provided the greatest economic opportunity, followed by logging. A survey was conducted to investigate the costs and revenues of village fishermen. Diversification characterized the local fleet, and analysis showed that rates of return on investment in the current year were equal between vessel types.The variable levels and rate parameters of the demographic, economic, and social components of the model were specified through static and time series data. Sensitivity analysis to assess the effects of uncertainty, and validation tests against known historical changes were also conducted. Forecast scenarios identified the development options under several levels of fish abundance and investment. The weight given to ecological versus economic resource management registered disproportionate effects due to the interaction between investment and migration rates and resource stochasticity. This finding argues against a golden mean rule for evaluating policy trade-offs and argues for the importance of using a dynamic, socio-ecological perspective in designing development policies for rural communities.  相似文献   
598.
西方灾害经济学模型述评   总被引:6,自引:0,他引:6  
张显东  梅广清 《灾害学》1999,14(1):91-96
对西方灾害经济学研究应用的模型技术进行了概略的综述,包括投入产出和线性规划相结合的模型、投入产出和生产函数相结合的模型、一般均衡模型、系统动力学模型以及社会核算矩阵模型五种,并对这些模型的优缺点进行了简要的评析.  相似文献   
599.
ABSTRACT: The individual hydrologic components are assumed to be normally distributed for each month and linear regression equations are estimated for predicting the value of the individual monthly hydrologic components. It is shown that some of the hydrologic components for downwind (in this case downstream) lakes are dependent upon hydrologic events for the upwind lakes. This is particularly so for precipitation in the downwind lake basins which appears to be dependent upon evaporation values for upwind lakes.  相似文献   
600.
Recent progress in operations research has refined stochastic programming with recourse sufficiently to significantly increase its potential for use in water resource planning. To demonstrate its strengths and weaknesses this paper considers an irrigation planning problem and illustrates how more and more refined variants of this problem are successively cast into stochastic programming with recourse forms. The result is an outline of the state of the art with method limitations and demands on model formulation clearly indicated.  相似文献   
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