雪崩危险度评价的类型、特征和方法

在提出“积雪单元”概念的基础上,将雪崩危险度评价分为区域雪崩危险度评价和点位雪崩危险度评价。从发生学角度,论证、筛选出发生危险度评价的4个主导因素,即气候、积雪厚度、坡度和植被类型与覆盖度,并提出了明确的指标体系。详细论证了两类评价各自的特征、操作性评价程序和方法。区域雪崩危险度评价是在划分积雪单元的基础上,评定各单元的等级高低并进行制图;点位雪崩危险度评价则涉及到雪崩发生点位和可能的承灾点位,分为发生危险度评价和到达危险度评价,可根据已有的统计资料来预测其概率。     

Environmental indices in irrigation management

Irrigation management calls for objective criteria capable of representing the economy, reliability, and productivity of irrigation systems. These criteria must be compatible with long-term sustainability and conservation goals. The criteria representing the above goals are the economic effect of management on yield reduction, economic effect, and reliability referring to plant growth and operation of the network. In this study environmental indices are introduced to express the above criteria in quantitative terms. The inclusion of these indices at the farm and network level create a multicriteria framework for decision-making based on composite programming. An experimental study was conducted during the irrigation periods of 1989 and 1990 in Chania, Greece, concerning water delivered to 40 experimental plots, soil moisture content at the rootzone, and irrigation system operational failures. The data collected in real time were used for the calculation of the corresponding environmental indices. The variation in time and space is high and resulted in up to 62% of yield loss and low system performance (up to 7% of system temporal reliability). The study indicated that environmental indices could be incorporated to select alternatives and also to develop policies on water delivery. The final decision involves a trade-off analysis between cost of application and desired system performance. Measures of both primary objectives can be obtained using environmental indices that represent system operation aggregation at its basic levels (on farm and network).     

Evaluating Nonpoint Pollution Policy Using a Tightly Coupled Spatial Decision Support System

Policy makers often must rely on the cumulative impact of independent actions taken by local landowners to achieve environmental goals. The connection between policy, regulation, and local action, however, is often not well understood and, thus, the impact of proposed policies may be difficult to predict. In this study we evaluate the effectiveness of alternative policy scenarios for agricultural set aside programs (e.g., the conservation reserve program administered by the United States Department of Agriculture) in reducing nonpoint pollution. Two alternative policy scenarios are developed and analyzed; one based on the erodibility index (detachment), the other sediment yield (transport). An estimate of the cumulative impact of associated land use change on nonpoint pollution is made using the AGNPS distributed parameter watershed model. This work is completed within the Cypress Creek watershed in southern Illinois. An analysis of the resulting data suggests that the most efficacious regulatory strategy for achieving nonpoint water pollution goals depends, in part, on place-specific land use patterns. This conclusion provides a solid argument for place-based regulatory strategies.     

A Multimethodological Approach for the Sustainable Management of Perifluvial Wetlands of the Po River (Italy)

/ Marginal aquatic systems (wetlands) of the Po River (Italy) have become the target of a renewed interest because of their value for recreation, natural reserves, and deposits of sand. To preserve these sites, wise management must be the objective of local administrations. In this paper a strategy for the sustainable use of 11 wetlands is presented. It uses simple economic analysis and multiple criteria techniques and provides suggestions to promote sustainability in terms of conservation of natural resources, economic self-sufficiency, and minimization of potential conflicts about the use of the wetlands. In the understanding that sustainability is framed in a long-term perspective, stability analysis is also considered and performed by means of loop analysis, a qualitative technique. Conditions for stability are then discussed about management opportunities.     

Land Evaluation in a Salt-Affected Irrigated District Using an Index of Productive Potential

2 semiarid irrigated area with salt-affected soils. The available soil map is at 1:100,000 scale and its mapping units are used for the land evaluation with the FAO framework. These data are then elaborated using the index value method. This procedure gives a map of land evaluation units and a table that rates the productive potential of these units for six crops: alfalfa, barley, maize, rice, sunflower, and wheat.     

岷江流域地表水水质的模糊综合评价

岷江是长江上游的一个重要支流，其水质安全对维持成都平原正常的生产生活起着至关重要的作用。采用模糊综合评价的方法，对岷江流域14个地表水监测断面的水质状况进行了综合评价。结果表明：在14个监测断面中，处于清洁和未污染程度的断面占50％，主要位于岷江流域的上游和下游，其水质状况较好；处于重污染的断面占29％，主要位于岷江流域的中游，水质状况较差。因此，需要加强流域综合治理尤其是对岷江中游的治理，以确保岷江流域的水质安全。     

乡村旅游与社区经济互动持续发展评估研究——以安徽省黟县西递为例

在实地调查和与专家访谈的基础上设计函调问卷,通过对函调问卷的综合分析,构建模糊评价模型,对西递旅游与社区经济互动持续发展水平做出评判。结果表明,西递旅游与社区经济处在基本可持续发展阶段,但也存在着一些制约旅游与社区经济互动持续发展的因素。在此基础上,提出促进西递旅游与社区经济互动持续发展的建议和措施。     

安徽沿江开发区发展现状评价研究

在学习并借鉴国内有关开发（园）区评价方法的基础上，选择经济总量、经济效率、基础设施和产业质量4方面共计12个指标评估开发区的发展状况，并在评估的基础上把安徽沿江15个开发区划分为重点拓展型开发区、优化提升类开发区、积极培育类开发区，最后针对不同类型的开发区分别提出发展建议。     

湖北省区域可持续发展能力综合评价

从区域可持续发展的观点出发，根据湖北省具体区域特征，通过构建湖北省区域可持续发展指标体系和评估方法，得出湖北省12个地市人口、资源、环境、经济和社会5个系统的可持续发展指数以及区域综合可持续发展指数。从总体上看，湖北省区域可持续发展水平处于偏低水平，其中武汉市是唯一具有强可持续发展能力的城市，但优势地位不明显；其它城市可持续发展5个系统均存在发展不平衡状况，且城市特色不突出。     

改进的灰色关联分析在滑坡危险性评价中的应用——以广东省滑坡危险性评价为例

利用改进的灰色关联分析方法,采用“中心化”无量纲的处理方法,对广东滑坡灾害危险性的影响因素进行灰色关联度分析。通过地形地貌条件、地层岩性特征、地质构造特征、岩土体结构特性、水文地质条件、植被覆盖率、降雨分布、地震、人类经济工程活动等9个评价因素与滑坡危险性的关联度计算,得出各影响因素与滑坡危险性评价的关系,具有一定的客观性、科学性和合理性。