SHORT-TERM FORECASTING OF SNOWMELT RUNOFF USING ARMAX MODELS1

ABSTRACT: Time series models of the ARMAX class were investigated for use in forecasting daily riverflow resulting from combined snowmelt/rainfall. The Snowmelt Runoff Model (Martinec-Rango Model) is shown to have a form similar to the ARMAX model. The advantage of the ARMAX approach is that analytical model identification and parameter estimation techniques are available. In addition, previous forecast errors can be included to improve forecasts and confidence limits can be estimated for the forecasts. Diagnostic checks are available to determine if the model is performing properly. Finally, Kalman filtering can be used to allow the model parameters to vary continuously to reflect changing basin runoff conditions. The above advantages result in improved flow forecasts with fewer model parameters.     

自然灾害综合区划的基本类别及定量方法

依据区域灾害系统论原理,提出了以灾害强度、灾害势、抗灾力和灾度４个状态参量描述的区域自然灾害系统状态,建议以之为基础,将自然灾害综合区划分为灾害强度区划、灾害势区划、抗灾力区划和灾度我划４个基本类别、并结合自然灾害综合区划定量方法的讨论,以实例说明了上述基本类别类别划分的可行性。     

九寨沟景区旅游环境容量研究

本文从不同的视角对九寨沟景区现状条件下的旅游生态环境容量、旅游空间容量、旅游服务设施容量和旅游社会环境容量进行了定量分析，获得了九寨沟景区现状条件下最大旅游环境容量和最佳旅游环境容量值；诊断出九寨沟旅游生态环境容量充分满足游客需求，但服务设施的不足限制了大量游人的进入。     

考虑火场环境实时作用下的人群疏散仿真研究

在现行的性能化防火设计中,通常将火灾发展与人员疏散两个过程分开考虑,从而忽略了火场环境对人员疏散过程的实时作用。该方法与实际情况有很大差异。笔者借助火灾模拟程序CFAST和人员疏散仿真软件buildingEXODUS,以某地铁车站为例,进行了火场环境实时作用下的人群疏散仿真研究。结果表明,火场环境会降低人群的判断和活动能力,延长疏散时间并产生其他的不利后果。因此,在防火设计中考虑火场环境对人群疏散的实时影响是十分必要的。     

民航安全风险定量评价模型研究

在对民航风险评价的现状和常用的定量风险评价方法进行分析的基础上,建立民航安全风险定量评价模型。在计算风险的可能性时,不仅考虑了风险的历史发生概率,而且利用风险发生概率影响因素所发生的变化对风险的历史发生概率进行修正,从而得出在当前情况下风险的发生概率,并且首次提出指数型权重的概念;在计算风险的后果时,考虑风险的直接损失和间接损失,并通过计算多种可能后果的期望的形式,综合考虑多种可能的后果情况;通过上述的可能性和严重性从而达到对安全风险进行定量评价的目的。最后,给出了一个算例,其结果表明该模型具有很强的实用性。     

COMPARISON OF ALTERNATIVE ENGINEERING DESIGNS1

ABSTRACT: Procedures are presented for comparing and evaluating alternative engineering designs for a particular water resources project. By using certain aspects of fuzzy set theory, it is possible to introduce both quantitative and qualitative considerations into the decisionmaking process. In addition, the viewpoints of the various interest groups involved with the water resources development can be realistically incorporated by the evaluation techniques for the alternative designs. Methods are given for eliminating undesirable alternatives and thereby obtaining a reduced set of possible feasible solutions to the problem. Because of the flexibility of the evaluation methods, the viable alternatives should not only satisfy economical, technical. environmental and other types of constraints, but these possible solutions should be politically feasible as well. A method is formulated for checking the sensitivity of the feasible results with respect to the factors that are considered in the analysis.     

森林碳汇资源开发潜力定量评价与研究——以黑龙江省为例

森林碳汇资源是开展森林碳汇贸易的基础。森林碳汇潜力的定量评价,将为森林碳汇贸易提供可靠的依据。在对森林碳汇资源开发潜力的定量方法进行深入研究的基础上,以黑龙江省为案例进行潜力评价,明确了黑龙江省具有巨大的森林碳汇增量潜力,提出了进一步发展森林碳汇贸易及构建森林碳汇交易市场的可行性。     

城市基础设施与社会经济协调发展的定量评价方法与应用

研究了城市基础设施与社会经济协调发展的定量评价方法 ,提出衡量协调发展的定量指标及计算方法 ,并依据此方法对郑州市基础设施与社会经济协调发展状况进行评价。     

可持续发展实验区灾害风险定量估算方法研究

作者将探索性数据分析方法引入区域灾害风险的定量估算，系统地建立了区域灾害风险的定量估算方法。计算实例表明，文中给出的方法可便捷地用于可持续发展实验区灾害风险评估。