Trends and issues in land and water resources management: Setting the agenda for change

The classical model of a paradigm shift is used to explore changes that are occurring in public lands and water resources management. Recent policy developments suggest that the traditional paradigm, which is characterized by sustained yield, is in the process of being invalidated. While no new paradigm has been fully accepted, the emerging paradigm does appear to be based on two principles: ecosystem management and collaborative decision making. Implementation of these two principles is likely to require extensive revision of traditional management practices and institutions. Failure to address these issues could result in adoption of the rhetoric of change without any lasting shift in management practices or professional attitudes.     

Collective action and the traditional village

This article considers the dispute between moral economy and rational peasant theories of agrarian societies in application to problems of collective action. The moral-economy theory holds that traditional peasant society is organized cooperatively through shared moral values and communal institutions; while the rational-peasant theory maintains that peasant society shows the mark of rational individual calculation, leading to free-rider problems that undermine successful collective action. This article offers an abstract model of a traditional village and assesses the applicability of recent qualifications of the collective action argument to this model. It will emerge that the social characteristics of the traditional village embody features that facilitate collective action by rational peasants.     

“暖冬”对农业生产及农业灾害的影响

本文分析了江苏省近几十年来、特别是８０年代以来冬季气温的变化特征，根据农业灾害发生的条件，讨论了“暖冬”对农业生产及农业灾害的影响，为农业生产部门和防灾抗灾部门决策提供科学依据．     

Land-cover change in upper Barataria Basin estuary,Louisiana, 1972-1992: increases in Wetland area

The Barataria Basin, Louisiana, USA, is an extensive wetland and coastal estuary system of great economic and intrinsic value. Although high rates of wetland loss along the coastal margin of the Barataria Basin have been well documented, little information exists on whether freshwater wetlands in the upper basin have changed. Our objectives were to quantify land-cover change in the upper basin over 20 years from 1972–1992 and to determine land-cover transition rates among land-cover types. Using 80-m resolution Landsat MSS data from the North American Landscape Characterization (NALC) data archive, we classified images from three time steps (1972, 1985, 1992) into six land-cover types: agriculture, urban, bottomland hardwood forest, swamp forest, freshwater marsh, and open water. Significant changes in land cover occurred within the upper Barataria Basin over the study period. Urban land increased from 8% to 17% of the total upper basin area, primarily due to conversions from agricultural land, and to a lesser degree, bottomland forest. Swamp forest increased from 30% to 41%, associated with conversions from bottomland hardwood forest and freshwater marsh. Overall, bottomland forest decreased 38% and total wetland area increased 21%. Within the upper Barataria, increases in total wetland area may be due to land subsidence. Based on our results, if present trends in the reduction of bottomland forest land cover were to continue, the upper Barataria Basin may have no bottomland hardwood forests left by the year 2025, as it is subjected to multiple stressors both in the higher elevations (from urbanization) and lower elevations (most likely from land subsidence). These results suggest that changes in the upper freshwater portions of coastal estuaries can be large and quite different from patterns observed in the more saline coastal margins.     

Modeling the spatial dynamics of regional land use: the CLUE-S model

Land-use change models are important tools for integrated environmental management. Through scenario analysis they can help to identify near-future critical locations in the face of environmental change. A dynamic, spatially explicit, land-use change model is presented for the regional scale: CLUE-S. The model is specifically developed for the analysis of land use in small regions (e.g., a watershed or province) at a fine spatial resolution. The model structure is based on systems theory to allow the integrated analysis of land-use change in relation to socio-economic and biophysical driving factors. The model explicitly addresses the hierarchical organization of land use systems, spatial connectivity between locations and stability. Stability is incorporated by a set of variables that define the relative elasticity of the actual land-use type to conversion. The user can specify these settings based on expert knowledge or survey data. Two applications of the model in the Philippines and Malaysia are used to illustrate the functioning of the model and its validation.     

National policies for biosphere greenhouse gas management: issues and opportunities

Biosphere greenhouse gas (GHG) management consists of preserving and enhancing terrestrial carbon pools and producing biomass as a fossil fuel substitute. The discussion of this topic has focused primarily on carbon-accounting and project-level issues, particularly relating to carbon sequestration as a source of emissions credits under the Kyoto Protocol. While international consensus on these matters is needed, this paper argues that an important domestic policy agenda also deserves attention. National policies for biosphere GHG management are necessary to bring about large-scale changes in land-use, forestry, and agricultural practices and can address some of the technical and policy issues that have proven to be particularly problematic from carbon-accounting and project-level perspectives. These policies should minimize land-use and resource-management conflicts, account for collateral benefits, and ensure institutional compatibility with existing resource-management regimes. Issues relating to project permanence, leakage, and transaction costs should also be addressed. A range of policy instruments should be used and biosphere GHG management should be one component of an integrated approach to environmental and resource management. Countries promoting biosphere GHG management as an important element of their climate change strategies should be developing these domestic policies to complement international negotiations and to demonstrate that carbon sequestration and biomass production can make an effective contribution to the stabilization of atmospheric GHG concentrations.     

Advancement of renewables in Bangladesh and Thailand: Policy intervention and institutional settings

This article reviews and analyses the advancement of renewable sources of energy in Bangladesh and Thailand in terms of policy intervention and institutional settings. Since renewable forms of energy emit far smaller amounts of greenhouse gas compared with fossil fuels, their use should mitigate climate change impacts while contributing to the provision of energy services. The article turns first to a review of energy–environment trends and the potential for renewables in these two nations. It then discusses strategies for the advancement of renewables. It is argued that further significant efforts can be made towards the advancement of renewables in Bangladesh and Thailand. These two nations could also learn from the experience in industrialized nations and other developing nations with regard to requisite policy instruments and processes. A number of barriers remain to the advancement of renewables, especially in terms of policy arrangements, institutional settings, financing mechanisms and technologies. Resources, cooperation and learning are required in order to overcome such barriers and to foster the development of necessary policy measures. Implementation of the clean development mechanism (CDM) under the Kyoto Protocol, and replication and adaptation of effective strategies from other settings are possible avenues for this.     

ASSESSMENT OF POSSIBLE IMPACTS OF CLIMATE CHANGE IN AN URBAN CATCHMENT1

ABSTRACT: Stationarity of rainfall statistical parameters is a fundamental assumption in hydraulic infrastructure design that may not be valid in an era of changing climate. This study develops a framework for examining the potential impacts of future increases in short duration rainfall intensity on urban infrastructure and natural ecosystems of small watersheds and demonstrates this approach for the Mission/Wagg Creek watershed in British Columbia, Canada. Nonstationarities in rainfall records are first analyzed with linear regression analysis, and the detected trends are extrapolated to build potential future rainfall scenarios. The Storm Water Management Model (SWMM) is used to analyze the effects of increased rainfall intensity on design peak flows and to assess future drainage infrastructure capacity according to the derived scenarios. While the framework provided herein may be modified for cases in which more complex distributions for rainfall intensity are needed and more sophisticated stormwater management models are available, linear regressions and SWMM are commonly used in practice and are applicable for the Mission/Wagg Creek watershed. Potential future impacts on stream health are assessed using methods based on equivalent total impervious area. In terms of impacts on the drainage infrastructure, the results of this study indicate that increases in short duration rainfall intensity may be expected in the future but that they would not create severe impacts in the Mission/Wagg Creek system. The equivalent levels of imperviousness, however, suggest that the impacts on stream health could be far more damaging.     

低温湿式空气氧化法处理废碱液的研究

对采用低温湿式空气氧化法处理炼油和乙烯废碱液进行了研究。考察了停留时间对废碱液中硫化物的氧化、氧化产物的形态、COD和酚去除率的影响，反应温度对废碱液中污染物氧化反应的影响。试验结果表明，废碱液的脱臭效果很好，S^2-的氧化产物以S2O3^2-和SO4^2-2种形式共存；酚、COD的去除率及S^2-的氧化反应停留时间影响小，受反应温度影响明显；废碱液的S^2-的酚浓度相当时，COD去除率一 般低于40％， 废碱液的S^2-浓度远大于酚浓度时，废碱液的COD去除率为40％－70％；废碱液中酚的质量浓度大于20000mg/L时才有回收价值。     

彭州市环境空气质量变化趋势及规律分析

“九五”期间 ,彭州市环境空气监测主要因子有二氧化硫、二氧化氮、总悬浮颗粒物、降尘和降水。市区空气中主要污染物排序依次为降尘、总悬浮颗粒物、二氧化硫、二氧化氮。其季节变化规律一般为第一季度 >第二季度 >第四季度 >第三季度。主要污染物年变化依次为降尘、总悬浮颗粒物、二氧化硫、二氧化氮 ,在“九五”期间除降尘量出现缓慢下降趋势外 ,其余 3项均不明显。