Application of Sample Selection Model in Estimating Response Functions for Nitrate Percolation

The Seymour aquifer region of Texas has been identified as containing elevated levels of nitrate in ground water. Various state and federal agencies are currently studying policy options for the region by gathering more site-specific information. However, because of lack of sufficient information, cause and effect relationships between water quality and agricultural practices have not been well established for the region. Some recently available biophysical simulation models have impressive capabilities in generating large amounts of data on environmental pollution resulting from agricultural production practices. In this study, the data generated by a biophysical simulation model were used to estimate the nitrate percolation response functions for the Seymour aquifer region. Interestingly, nitrate percolation values obtained from simulation models often comprise acensoredsample because the non-zero percolation values are only observed under certain climatic events and input levels. It has been shown in the econometric literature that the use of Ordinary Least Squares (OLS) on censored sample data produces biased and inconsistent parameter estimates. Thus, a sample selection model was used in this study to estimate the response functions for nitrate percolation. The study provides some insight into the relationship between nitrate percolation and agricultural production practices. In particular, the study demonstrates the potential of selected design standards in minimizing agricultural nonpoint-source (NPS) pollution for the study area.     

OPTIMAL PROFITS UNDER ENVIRONMENTAL CONSTRAINTS: IMPLICATIONS OF NUTRIENT AND SEDIMENT STANDARDS1

To reduce nonpoint source pollution from nutrient, chemical, and sediment runoff, a number of environmental policy standards have been proposed. Such standards could be used to reduce nonpoint source pollution from nutrient, chemical, and sediment runoff to impaired water bodies. State governments can use voluntary approaches to meet nonpoint source pollution reduction goals. However, the practices that lower net returns will not be voluntarily adopted by farmers. Crop rotations and tillage practices may help producers to comply with the environmental standards while minimizing losses in farm profits. This study compares runoff from crop rotation practices and conventional continuous row cropping systems in Mississippi. The results are compared for different tillage systems in order to examine robustness of results. Nutrient runoff and sediment runoff are simulated using the Erosion Productivity Impact Calculator (EPIC). Sensitivity analysis of the sediment and nitrate reductions at 15 percent, 25 percent, and 35 percent are conducted. Under these scenarios, net returns are optimized under environmental constraints, and the marginal cost of sediment reduction ranges from US$1.61 to US$9.63 per ton depending on soil conditions, while the corresponding nitrate and phosphorus reductions costs range from US$1.21 to US$7.08 per kg and from US$0.09 to US$31.91, respectively. The empirical results from this study indicate that a nitrate reduction policy is relatively less costly than a sediment reduction policy. The results also demonstrate the importance of geophysical conditions and policy costs, which vary across regions.     

省域水环境保护政策实施效果评价的指标体系构建与实证研究

本文以湖北省"十二五"环境规划的水环境保护指标为主要依据,采用压力—状态—响应(PSR)模型,从污染排放强度、水质改善效果、水资源利用和污染减排效率三个维度出发,建立湖北省"十二五"水环境保护政策评价指标体系,对政策的实施效果进行量化评估。结果表明:湖北省"十二五"期间水环境保护政策实施效果呈逐年上升趋势,从二级指标来看,政策实施在污染排放强度以及水资源利用和污染减排效率两方面均取得较好的成效,但在水质改善方面效果不明显甚至有所下降。建议湖北省在"十三五"期间以至接下来更长的一段时期内,首先要重点加强省内各局部区域的水环境承载能力评估,并依据评估结果对现有的产业布局进行有效的调整;其次应进一步强化环境监测和管理力度,以减少可能的非法排污。本文构建的指标体系对进一步促进省域水环境保护政策实施效果评价的规范化、合理化不无借鉴意义。     

我国水资源管理的经济政策耦合效果仿真研究

水资源管理的经济政策效果模拟是从政策理论到政策实践的关键步骤，让决策者感知政策效果的方向和影响程度，才能更好地促进政策实践转化。本研究引入系统动力学方法，构建水资源经济政策耦合机制下水资源系统动力学（SD）模型，将我国划分为三种类型区域（干旱地区、丰水地区和过渡地区），进行三类四种水资源管理经济政策（水资源有偿使用，水价政策和水权政策；水污染收费，排污收费政策；水生态保护，水生态保护补偿政策）的耦合仿真实证研究。以我国水资源管理政策设计为目标，进行不同水管理政策耦合的生态经济效果仿真和效果定量评价，结果发现：干旱地区有偿使用的经济政策是目前经济水平下效果最好的；过渡地区有偿使用结合污水排放收费政策效果是最好的；而丰水地区必须同时实施水资源有偿使用和水污染收费两类经济政策。     

ASSESSING THE ECONOMIC BENEFITS OF GROUND WATER FOR ENVIRONMENTAL POLICY DECISIONS1

ABSTRACT: The full range of environmental and economic services of ground water need to be accounted for in policy decisions. Non-recognition of these services imputes a lower value for the ground water resource in establishing policies. We describe a conceptual framework for identifying and measuring the economic value of groundwater. The valuation framework links changes in physical characteristics of ground water to services provided by ground water and the economic effects of changes in ground water services. In addition to the framework, we develop a general protocol to follow for assessing the benefits of ground water policies. Application of the protocol will aid in establishing structure and consistency across policy assessments and improve the accuracy and completeness of benefit estimates, avoid double-counting problems, and eliminate duplication of ground water valuation efforts.     

Geographic information systems: a tool for strategic ground water quality management

Geographically‐related information is needed for several elements of an integrated ground water quality management programme, including ground water monitoring planning, prioritization of pollution sources, usage of permits and inspections for source control, and planning and completion of remedial actions. Geographic Information Systems (GISs) can be used to support these elements along with delineating wellhead protection areas (WHPAs), prioritizing existing contaminant sources and evaluating proposed changes in land usage in such areas. Eight case studies of the use of GISs in wellhead protection programmes are summarized, including examples from Rhode Island, Mississippi, New Jersey, New York, Pennsylvania, Kansas, Massachusetts and Texas. Six additional examples are mentioned relative to the use of GISs for evaluating ground water pollution potential, facilitating data analysis for environmental restoration of a large area with numerous waste sites, evaluating trends in ground water nitrate contamination, establishing a national database for ground water vulnerability to agricultural chemicals, simulating water table altitudes from stream and drainage basin locations, and selecting radioactive waste dump sites. The applicability of GISs and their associated advantages in wellhead protection and other ground water management studies are demonstrated via the case studies. The GIS technology provides a unique opportunity for analysing and visualizing spatial data. Contaminant and source prioritization within WHPAs is needed for both extant conditions and in the evaluation of proposed land use changes. The coupling of a GIS with contaminant/source prioritization would provide a strategic tool which could be used to plan targeted ground water monitoring programmes, to identify appropriate management or mitigation measures, minimize introduction of contaminants from existing sources into the subsurface environment, and to evaluate the potential of proposed land use activities for causing ground water contamination. GISs can be useful in providing current information for policy makers, planners and managers engaged in ground water quality decision making.     

THE STRUCTURE AND PRACTICE OF WATER QUALITY TRADING MARKETS1

ABSTRACT: The use of transferable discharge permits in water pollution, what we will call water quality trading (WQT), is rapidly growing in the U.S. This paper reviews the current status of WQT nationally and discusses the structures of the markets that have been formed. Four main structures are observed in such markets: exchanges, bilateral negotiations, clearinghouses, and sole source offsets. The goals of a WQT program are environmental quality and cost effectiveness. In designing a WQT market, policy makers are constrained by legal restrictions and the physical characteristics of the pollution problem. The choices that must be made include how trading will be authorized, monitored and enforced. How these questions are answered will help determine both the extent to which these goals are achieved, and the market structures that can arise. After discussing the characteristics of different market structures, we evaluate how this framework applies in the case of California's Grassland Drainage Area Tradable Loads Program.     

MANAGING GROUND WATER QUALITY IN RELATION TO AGRICULTURAL ACTiVITIES1

ABSTRACT: Ground water quality is an environmental issue of national concern. Agricultural activities, because they involve large land areas, often are cited as a major contributor of ground water contaminants. It appears that some degree of ground water contamination from agricultural land use is inevitable, especially where precipitation exceeds evapotranspiration. For this reason, and because agriculture differs significantly from point sources of pollution, farmers, policymakers, and scientists need alternative management strategies by which to protect ground water. Mathematical models coupled to geographic information systems to form expert systems can be important management tools for both policymakers and agricultural producers. An expert system can provide farmers, researchers, and environmental managers with information by which to better manage agricultural production systems to minimize ground water contamination. Significant research is necessary to perfect such a system, necessitating interim ground water management strategies that include not only a strong research program, but educational and public policy components as well.     

EFFECT OF WATER QUALITY STANDARDS ON FARM INCOME,RISK, AND NPS POLLUTION1

ABSTRACT: Enforceable standards play a crucial role in the design and implementation of most water quality policies. The impacts of these standards on farm income and nonpoint source (NPS) pollution can provide valuable information to develop economic policies that can improve water quality with minimal loss in income and minimal risk. This study uses an integration of nonlinear programming and a simulation model to assess the impacts of enforceable standards at technology and farm boundary levels. The results indicate that the type of pollutant regulated, enforcement type, and the level of standard had a significant impact on farm income and water quality. Choice of farm boundary standards over technology standards is dependent on the impact of the policy on other NPS pollutants, in addition to the reduction of nitrate and phosphorus pollutants. Enforcing farm boundary standards on nitrates had desirable effects on subsurface and percolate nitrogen and variance in income. Technology standards were uncertain in their effects because of the restriction on the choice of technologies available to farmers. A comparative policy analysis considering incentives, multiple impacts, transaction costs of implementation, and regional consideration is important to an effective policy design.     

REUSE OF POWER PLANT COOLING WATER FOR IRRIGATION1

ABSTRACT: Current water quality policies in California require disposal of saline blowdown waters from power plants in sealed evaporation ponds to avoid degradation of ground waters. This policy highlights the conflict between increased energy demands, increasing scarcity of water, and environmental priorities. Saline blowdown waters can be used for the irrigation of salt tolerant crops, albeit with some reduction in yields. The results of experiments intended to specify these yield reductions are reported. If such irrigation is carefully managed, the soil profile can be used to store residual salts and ground water degradation will be avoided, provided that irrigation ceases before the salts are leached to the ground water. An analysis of discharge below a carefully managed irrigation project shows that the downward movement of salts below the root zone is no worse than with conventional methods of disposal. Thus, irrigation reuse with blowdown water is shown to be a viable means of saline water disposal while maintaining existing standards of ground water quality protection. Further analysis demonstrates the economic feasibility of such irrigation reuse by showing that it is significantly less costly than the evaporation pond alternative.     

AN ECONOMIC OVERVIEW OF HAWAII'S WATER INSTITUTIONS1

ABSTRACT: The problem of allocating scarce water resources among competing uses and users over time in Hawaii is addressed within the context of analytical institutional economics. The nature of this problem has been, in recent years, highly complicated by important institutional changes that control operating decisions for water supply and water pollution. Whereas the imbalance in governmental initiatives regarding changes in the system of water rights (predominantly state) and environmental laws (predominantly federal) are based on U.S. constitutional provisions, the more fundamental roots of the crucial legal doctrines involved have been traced back to the common property concept. This suggests that the more promising opportunities for meeting the water policy challenges of the state are to be found in the historical common property system (ahupua'a) of Hawaii.     

STRUCTURAL EQUATION MODELING OF DYNAMICS OF NITRATE CONTAMINATION IN GROUND WATER1

ABSTRACT: Most research on the temporal aspect of nitrate pollution in water resources has focused on surface water. Comprehensive studies on the dynamics of nitrate in ground water are lacking, especially on a drainage basin scale and for relatively long periods of time. In this study, structural equation modeling is applied in investigating the influences of climate, hydrology, and nitrogen management in agricultural production on nitrate concentration in the Big Spring Basin, Iowa, over a 10-year period. The study shows that for given hydrogeological settings, nitrogen management practices and climate are the two most important factors that affect nitrate dynamics. The long-term trend of nitrate is closely related to the nitrogen input primarily determined by management practices. The potential effects of nitrogen management, however, are contingent on the variations of climate. The improvements in water quality (reduced nitrate concentration and loads) in relation to improved nitrogen management are often overshadowed by the impact of climate, especially in extremely dry or wet years. The variations of climate and hydrology have much greater impacts on the nitrate dynamics than the changes in nitrogen input. This study reveals significant seasonal variation in the relations between nitrate concentration and influencing factors, which is also closely related to the seasonal variation in climate. Assessment of management practices and resultant water quality should consider the impact of short- and long-term climate dynamics.     

THE COSTS OF CONFLICTING ENVIRONMENTAL POLICY: A CASE STUDY IN MILWAUKEE1

ABSTRACT: The history of the Milwaukee water pollution abatement program is examined as a case study to investigate the costs of conflicting environmental policy. The recent U.S. Supreme Court decision concerning the Milwaukee case is described as a milestone in U.S. water pollution abatement policy which will help preclude the type of environmental policy conflict which has been found to be so costly to Milwaukee. The implications to U.S. water pollution abatement policy of the 13-year history of conflict in Milwaukee are presented.     

我国环境污染第三方治理机制改革路线图

第三方治理是促进环境污染治理市场化、专业化、产业化的有效模式,也是我国生态文明制度建设创新的重要内容。我国环境污染第三方治理还处于探索阶段,存在内涵不清晰、理论架构未建立、关键问题待突破、政策路径不明确等问题,系统设计我国环境污染第三方治理改革路线图是当前迫切的现实需求。本文在对第三方治理内涵的解析和界定的基础上,提出基于多中心公共经济论、市场经济利益最大化原理、规模经济及委托-代理理论的理论架构,综合分析第三方治理的理论依据及作用机制。从国家和地方两个层面梳理我国环境污染第三方治理的政策演进情况,并立足于我国环境公用设施建设和企业工业污染治理领域第三方治理的发展现状,剖析成效及问题,提出构建法律法规和标准体系、环境监管体系、经济政策支持体系、市场价格体系和企业诚信评价体系的政策机制改革框架及实施路径。     

WATER AND WATER RIGHTS TRANSFERS: A NEW POLICY FOR NEBRASKA1

ABSTRACT: Nebraska has abundant supplies of high quality surface and ground water. The U.S. Supreme Court decision in 1982, declaring ground water to be an article of commerce, is widely perceived as giving neighboring states easier access to Nebraska water. Some neighboring states, particularly Colorado and Wyoming, are in water short situations. Additionally, current legal restrictions on certain types of transfers within the State could be inhibiting the “highest and best use” of Nebraska's water. Thus, in 1987 the Nebraska Legislature called for the development of a new water policy for Nebraska that would promote the economically efficient use of water, yet protect the environment as well as the rights of individuals (for example, third parties) and the public. Through an interagency study employing an extensive public involvement process, a policy to be recommended to the Legislature in 1989 emerged. The policy revises the basic definition of water rights and transfers and eliminates most of the inconsistencies in the water allocation system by treating most types of water resources, most types of water users, and most locations of use similarly in the permitting process. (The principal exception is the individual irrigator using ground water on the overlying land where overlying land is one government surveyed section; such use is not defined to be a transfer nor is a permit required.) An impact assessment would be required of most new water uses except on site uses of ground water. Compensation measures could be specified as a condition of the permit where appropriate. The permit would be issued only if the benefits of the proposed transfer clearly outweigh adverse effects that could not be avoided or effectively compensated. The policy allows for the sale or lease of “salvaged” water. It calls for the State to facilitate transfers by acting as a clearinghouse for potential buyers and sellers, and it allows the State to sponsor water projects. An annual fee to be paid by many water users, in order to provide a fund for compensation and for state sponsored water projects, was proposed. However, it met with extensive opposition. Thus, the policy recommends only that the Legislature examine potential funding programs and equitable user fees.     

MANAGING CRISIS: THE EFFECTIVENESS OF LOCAL DISTRICTS FOR CONTROL OF GROUND WATER MINING1

: This article examines the willingness and capacity of local districts to control ground water mining of the Ogallala Aquifer in the High Plains. The questions of willingness and capacity were approached through extensive field interviews and a survey of all district board members and managers. The analysis focuses on the policy alternatives board members and managers perceive and how they evaluate these alternatives. Methodologically, the study utilized factor analysis of responses rating the desirability of various policy alternatives to ascertain what alternatives were perceived by the sample. Then the sample's preferences for each of the identified factors were calculated. The results demonstrate that the sample of those who must regulate if ground water mining is to be controlled at the substate level are not oriented to regulatory policies and therefore lack the willingness to deal with ground water mining.     

The use of indicators in environmental policy appraisal: lessons from the design and evolution of water security policy measures

Drawing up environmental policy options is a complex activity which involves defining and weighing the merits and risks of various alternative courses of action governments could pursue. In its modern version, this task typically involves formal policy analysis or ‘policy appraisal’, that is, policy work specifically undertaken to generate and evaluate policy options in order to address problems or issues on a policy agenda. Indicators play a powerful but under-investigated role in this process. To shed light on this issue, the paper conducts a case study of the design and evolution of policy indicators in water security policy formulation, examining both their utilization and impact. The paper documents the origins of water security policy indicators; assesses their relevance and influence in policy formulation and identifies the reasons for the emergence of certain preferred indices, despite their having several well-known limitations. In particular, the discussion flags the significance of the political advantages surrounding their ease of use and interpretation, rather than their technical merits, as a key factor affecting the continued utilization and influence of specific indicators in environmental policy and planning.     

PROMOTING GROUND WATER POLLUTION PREVENTION IN SMALL BUSINESSES1

ABSTRACT: Although they have not been the focus of major regulations, small businesses can contribute pollutants to ground water through routine practices. Because strict regulation of millions of micro firms is not likely, water resource professionals face a challenge of how to reach small business operators with effective pollution prevention messages. The purpose of this study was to examine the factors that influence a small business operator to adopt measures that reduce potential ground water pollution. We looked at how information delivery, internal business characteristics, and external relationships are associated with voluntary preventive measures. Mail surveys from small businesses in New Jersey municipalities and interviews with business owners provided data about business characteristics and current pollution prevention activities. Findings suggested that businesses doing the most to prevent ground water pollution were generally more connected to external organizations and had more financial and technical resources. The study also discovered that small business owners fear government involvement in their affairs. The study concludes with recommendations to encourage more voluntary adoption of prevention measures by businesses. These center on separating assistance programs from enforcement and involving industry peer groups in an effort to make information available in a non-threatening manner.     

Nitrate Vulnerable Zones and Nitrate Sensitive Areas: A Policy and Technical Analysis of Groundwater Source Protection in England and Wales

The Nitrate Sensitive Area (NSA) scheme and the more recent Nitrate Vulnerable Zone (NVZ) scheme are responses by the British Government to the growing demands of European legislation on water quality. Both are designed to check nitrate contamination from agriculture at source, with 'polluting' activities being changed or prohibited in areas forming the catchment of waters where the 1980 European Commission (EC) limit of 50 mg/l nitrate (N) is exceeded, or is likely to be exceeded. The NVZ scheme provides protection to surface and ground water,whereas the NSA scheme relates directly to the latter. Furthermore, action programmes to reduce nitrate pollution within NVZs are mandatory and uncompensated, whilst the more strict but voluntary measures of the NSA scheme are compensated. This paper sets out to critically analyse the NVZ scheme, with reference to the NSA scheme and further makes recommendations for an improved nitrate pollution land use control policy in relation to ground water protection. The study area is Minster NVZ on the Isle of Thanet in north east Kent.     

Environmental and resource sustainability of Chinese cities: A review of issues,policies, practices and effects

This paper synthesizes the English literature on current issues, policies and practices, and their effects on environmental and resource sustainability in China's ongoing urbanization. Aspects of urban sustainability reviewed include air, water, solid waste, energy efficiency, transportation and land use. It shows that Chinese cities have been and probably will continue to be struggling with issues such as air pollution, scarcity of clean water, solid waste and greenhouse gas emissions. But there are many opportunities for improvement. It suggests shortages of existing policies and major gaps in knowledge and practice, which can be helpful to policy makers, planners and researchers in China and other developing countries.