The role of spatial scale in sustainable development

The role of spatial scale in sustainable development is assessed by dividing the world into multiple spatial units at different levels on a socio-political spatial scale. The basic patterns of sustainable development do not appear to be evident at all spatial levels, owing to the absence of some capital stocks and the conversion processes linking them, but environmental economics theory can be generalized to explain phenomena at various levels. Capital conversion processes influencing the sustainability of development of spatial units are constrained by processes at different levels, e.g. those imposing environmental conditions on development or affecting availability of investment capital. The autonomy of individual spatial units is also compromised by capital transfers to and from other units at the same level, so it is proposed that the sustainability of development of a particular unit should be estimated using net, rather than gross capital trends. Because of uneven development the same degree of sustainability should not be expected at the same time for all spatial units at the same spatial level.     

中国耕地变化模式的资源经济学分析

本研究旨在引入灰色系统关联分析法和高等计量经济学建模思想,结合经济学和土地学等相关学科知识,从资源经济学的角度揭示我国耕地动态变化过程,促进我国耕地可持续利用理论的完善与发展。结果表明:①在中、短时间尺度内社会经济发展因子对耕地变化起着重要的影响作用,主驱动因子有GDP、人均GDP、城市化水平和国家宏观政策;②耕地面积与GDP、城市化水平呈负相关,与人均GDP呈正相关;③我国耕地制度安排存在缺陷,是造成我国城市化蔓延占耕地的最直接原因;④我国应不断完善土地制度安排,同时,应不断促进社会经济发展技术水平的提高和加强政府导向,转变经济发展方式,从而减少社会经济发展对耕地的非科学侵占。     

MODELING WATER UTILITY FINANCIAL PERFORMANCE1

ABSTRACT: The purpose of this paper is to present a theory and model for assessing the financial health of public water systems. Using financial information from 25 water utilities in Georgia, the paper seeks to identify the causal relationships between the financial performance of a water utility and its fiscal position. The need for a theoretical understanding of water utility financial health is the result of the increasingly stringent performance requirements under the Safe Drinking Water Act (SDWA). The issue has become particularly important for small water systems that will be exposed to significant financial demands. A set of financial ratios were developed and tested in a model that was based on liquid asset theory. The model contained five variables designed to account for the size of liquid assets, current debt, cash-flow, and the level of expenses. The variables fit the need of water utilities: to provide an adequate level of operation and maintenance to meet current and future system needs as well as SDWA standards.     

Some of the Nineteenth Century Origins of the Sustainability Concept

Interpreting and applying the concept of sustainable development is increasingly viewed as being the way to promulgate just and practicable economic, environmental and social policy. It is thus important that there be increased public and political awareness concerning the origins of economic theory, and its early relationship to sustainability concepts. While the term 'sustainable development' was popularised by the World Commission on Environment and Development report Our Common Future in 1987, it is generally recognised that notions of sustainability were promoted in `limits to growth' and 'green' discourses in the early 1970s (Meadows et al.: 1974, The Limits to Growth: A Report for the Club of Rome, Potomac Associates and Pan Books, London and Sydney). However, there is little acknowledgement of the way in which nineteenth century intellectuals, from a range of disciplines, conceptualised the importance of balancing economic, social and environmental sustainability in their quest for justice and the conservation of nature.There was a considerable exchange of ideas on `political economy' and nature across Europe, and later the Americas, from the middle of the eighteenth century. This discourse reached its intellectual peak in the nineteenth century. During that era there was a proliferation of literature that was aimed at improving the human condition and recognising humanity's dependence upon nature. In Europe and the USA the participants in the debate included Cantillon, Quesnay, Condorcet, Galiani, Von Hayek, Marx and George. Due to the breadth of this influential body of work, we focus here on the British Victorian thinkers such as Darwin, Malthus, Martineau and Mill. These thinkers influenced each other in developing their theories and ideas in science, politics, economics and philosophy, and were influenced in turn by an earlier generation of intellectuals, such as Adam Smith. For the Victorian thinkers, conserving nature while trying to improve the distribution of wealth was a not a paradox, but a moral duty, and for them Smith's `rational' pursuit of self-interest could only be followed if it did not interfere with 'the rules of justice'. We argue that the manner in which these thinkers conceptualised their theories and ideas represents the nineteenth century origins of sustainability concepts.     

ECONOMIC EVALUATION OF WATERSHED PROJECTS - AN OVERVIEW METHODOLOGY AND APPLICATION1

ABSTRACT: Deforestation and intensive land use on a global scale has resulted in watershed deterioration and threatened municipal and irrigation reservoirs. Watershed rehabilitation programs must allocate funds to priority projects. A tool for decisionmakers is presented which provides a four-step overview economic analysis by the integration of physical and biological considerations. The overview tool is applied to a current proposed watershed project in Morocco.     

AGRICULTURAL POLLUTION CONTROL: IMPLICATIONS FROM THE RURAL CLEAN WATER PROGRAM1

ABSTRACT: The Rural Clean Water Program has provided a unique opportunity to study the economics of agricultural nonpoint source pollution control. Several implications for improving the economic efficiency of future agricultural nonpoint source pollution control programs can be drawn from the results. First, individual projects should be targeted towards water bodies that have water quality problems causing economic damages. Considerable variation can exist among areas in the magnitude of economic damages, which may not be proportional to physical impacts. Second, the relative costs and effectiveness of the practices selected to reduce the delivery of pollutants can vary dramatically from one location to another. Early identification and emphasis on cost-effective BMPs can substantially reduce project costs and may make a project economically justifiable that would not otherwise be so. Finally, some projects that do not hive potential economic benefits from water quality improvements exceeding government cost may have on-farm benefits from reduced costs and increased long-term yields that are sufficient to make total benefits (water quality and on-farm) exceed costs.     

RUNOFF IMPOUNDMENT FOR SUPPLEMENTAL IRRIGATION IN TEXAS1

ABSTRACT: The current increase in the demand for water by municipal, industrial, and other users is likely to result in approximately one-third less water being available for agricultural use in Texas by the year 2000. As water supplies diminish, the rainfall excess needs to be used more efficiently. Large amounts of runoff occur in the eastern part of Texas that could be collected in small impoundments and utilized for crop production. Farmers in water-surplus basins or subbasins can apply for a permit to divert surface water into small on-farm impoundments to be used for supplemental irrigation. The costs for runoff collection and two supplemental irrigations, which amount to a total of 4 in./yr., are estimated to be approximately $60/acre/year. Depending upon the crop produced, the estimated increase in gross income from supplemental irrigation ranges from about $80 to more than $100 per acre annually.     

SOIL CONSERVATION PRACTICES AND WATER QUALITY: IS EROSION CONTROL THE ANSWER?1

ABSTRACT: This paper is a computer simulation analysis of an agricultural nonpoint pollution problem. Computer modeling is a universally applicable tool that can be used for establishing the linkages between and the quality of agricultural runoff in both surface and subsurface flow. The tradeoffs between the costs of soil conservation practices and water quality are reported, and the economic implications of such tradeoffs are discussed. Soil and nutrient losses resulting from crop production practices are analyzed using a field-scale computer simulation model (CREAMS). No-till planting, reduced tillage, and sod waterway systems are more cost effective than other practices for controlling soil and nutrient runoff losses. Nitrate leaching losses are increased slightly by most soil conservation practices. Terrace systems and permanent vegetative cover impose the greatest societal cost for water quality protection. Public cost sharing and tax incentives encourage farmers to adopt expensive structural practices, and policies are needed to get cost-effective practices implemented on critical acreage. Extensive treatment of land is necessary for agricultural best management practices (BMPs) to significantly improve water quality in areas that are intensively farmed.     

A RATIONALE FOR THE REGIONALIZATION OF PUBLIC WATER SYSTEMS1

ABSTRACT. A rationale is set forth for requiring and/or encouraging the consolidation or regionalization of all systems beneath certain population size levels based on the small water systems’ capability to produce an adequate supply of safe drinking water at a reasonable cost to customers. Estimates for basic costs of water service including personnel, other operation and maintenance and capital are made and a range of water rates is suggested based on reasonableness and acceptability to customers. Guidelines are then drawn for a moderate rate of $10.00 per month and an upper limit rate of $15.00 per month to show the sizes at which public water systems might be expected to achieve fiscal viability. Finally, recommendations are made to State and Federal governmental agencies concerning possible legislation, plans and programs to achieve better public water service through the regionalization or consolidation of small public water systems.     

ON THE CENTRALIZATION OF WASTEWATER TREATMENT FACILITIES1

ABSTRACT. Two factors affecting the centralization of wastewater treatment facilities were investigated; the cost of collection and treatment systems and the performance of treatment plants. Based on computer-generated minimum cost designs, wastewater collection networks were found to be characterized by diseconomies of scale of magnitude similar to the reported economies of scale for wastewater treatment works. The combined costs of collection and treatment are U-shaped functions from which the least cost size of collection and treatment systems were found for particular values of population density. Examination of the day-to-day performance of five metropoitan-area waste-water treatment plants revealed that, for time series shorter than one month, the day-to-day variation in effluent quality was random, although the variation in quantity discharged was distinctly non-random. The performances of all five plants on any given day showed little correlation. This suggests that the decentralization of treatment facilities can produce benefits both through the reduction in quantities of waste discharged at a given point and through in-stream averaging of the varying performances of several treatment plants. Since the cost function of collection and treatment combined is generally flat in the region of the minimum-cost size, little penalty is invoked to gain the potential benefits of treatment plant decentralization.