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41.
The Grose River is contained almost entirely within a World Heritage Area. While sewage pollution in the area has been addressed, pollution at damaging levels continues from a disused coal mine, closed in 1997. Despite some surface rehabilitation, no action has occurred to remediate zinc polluted waters emanating from the mine. We examine the historical regulation and management of the Australian Commonwealth and New South Wales governments and highlight gaps in both regulatory systems. We conclude that there is an urgent need to improve regulation of water pollution, mining and management of the environment in highly valued world heritage areas.  相似文献   
42.
This article analyses adoption of farm‐based irrigation water saving techniques, based on a cross‐sectional data set of 357 farmers in the Guanzhong Plain, China. Approximately 83% of the farmers use at least one farm‐based water‐saving technique. However, the traditional, inefficient techniques border and furrow irrigation are still prevalent whereas the use of advanced, more efficient techniques is still rather rare. We develop and estimate an adoption model consisting of two stages: awareness of water scarcity and intensity of adoption. We find that awareness of water scarcity and financial status enhance adoption of more advanced techniques whereas access to better community‐based irrigation infrastructure discourages it. We furthermore find both community‐based irrigation infrastructure and farm‐based irrigation water‐saving techniques have mitigating effects on production risk. From the results it follows that adoption can be stimulated via financial support and via extension aimed at enhancing awareness of water scarcity.  相似文献   
43.
南水北调西线工程是对我国大自然最大的改造工程,有三大挑战性的问题:对自然规律的挑战、对生态地质环境的挑战、对社会协调发展的挑战.对自然的改造和索取不是无止境的,南水北调西线工程不能搞"只争朝夕",而应"慎之又慎",要形成应对三大挑战的战略规划.水资源开发利用应换一种思维,实现三个跨越:告别改造、征服自然的幻想,实现顺应和尊重自然的跨越;从单一水利部门的规划决策向公共规划论证体系的跨越;从追求单纯的截流调水到追求国家安全,人与社会自然环境协调发展的跨越.  相似文献   
44.
Irrigation water productivity in Cambodian rice systems   总被引:1,自引:0,他引:1  
Knowledge of the marginal productivity of water is crucial for decisions about its allocation between uses, which is particularly important in the context of increasing competition for water. Using primary, plot‐level panel data, this article estimates the marginal productivity of water from supplementary irrigation in lowland rice systems in Cambodia, taking into account farmer and plot heterogeneity as well as self‐selection of supplementary irrigation. Our estimates indicate a range of elasticities for rice output with respect to water inputs of between 0.057 and 0.069 for wet season production, substantially lower than previous estimates based on either aggregate or trial data. We discuss the policy implications of these results, in particular with respect to the utility of demand management policies and the challenges they pose to the decentralization of water management to Farmer Water Users Groups.  相似文献   
45.
分析南水北调供水实行两部制水价制度的必要性,并对其三种基本模式进行分析,建议南水北调供水实行按基本水量缴纳基本水费与计量水价相结合模式的两部制水价制度。  相似文献   
46.
Land and water resource issues typically fall under separate governance systems. For example, agricultural policy regulates land-cover change while water departments regulate water quality. However, land-use changes can directly affect water resources. Water flow regulation is a key service which is affected by changes in land-cover but its dynamics are poorly understood by most policy makers and land management organisations. We simulated and quantified the effects of plant invasions on land-cover, hydrological soil characteristics and catchment responsiveness on flow regulation using a hydrological model. The case study was located in the indigenous fynbos shrublands in South Africa. Fynbos requires fire to regenerate, has moderate biomass, occurs mostly in areas with a potential to erode and is prone to invasion by woody plant species, particularly trees. Invasions can affect flow regulation by changing community structure and function and increasing fuel loads. The greater fuel load increases fire intensity and severity which, in turn, changes the hydrological responses of catchments. Few studies have assessed the effects of invasion on hydrological responses but studies on plantations have recorded significant increases in soil water repellence following fire, resulting in increased overland flow similar to impacts of fires in invaded areas. Simulation of clear-felling of pines and different degrees of water repellency increased both the responsiveness of the catchment to rainfall and extreme rainfall events. The simulated fire effects were consistent with other studies of hydrological responses to fire. Our study indicates that invasions of pines and acacias in the study area could substantially increase the risk of flood damage even from moderate rainfall events, and highlights the importance of maintaining flow regulation capacity. New policy approaches are required which take account of the linkages and interactions between land-use choices, water resources and ecosystem services, and address them when considering governance arrangements.  相似文献   
47.
The main objective of the European Water Framework Directive (WFD) is the achievement of a good ecological and chemical status of the water environment (water bodies). This status corresponds to the limit value of Germany's Working Group of the Federal States on Water Problems Issues (LAWA) for water quality class II (3 mg/l total nitrogen). The rivers in the intensively cropped Upper Ems River basin (northwestern Germany) show total nitrogen concentrations in excess of 5–10 mg/l. Hence, the objective of our study was to find a land use and land management scenario that would reduce the total nitrogen concentration to meet the WFD requirements for good ecological and chemical status. We developed consecutive land use and management scenarios on the basis of policy instruments such as the support of agro-environmental measures by Common Agricultural Policy and regional landscape development programs. The model simulations were done by using the Soil and Water Assessment Tool (SWAT). Results of SWAT scenario calculations showed that drastic measures, which are unrealistic from a socio-economic point of view, would be needed to achieve the water quality target in the basin (reduction of arable land from 77.2% to 46% [13% organic farming], increase of pasture from 4% to 15%, afforestation from 10% to 21%, increase of protected wetlands from 0% to 9%, etc.). The example shows additionally that the achievement of the WFD targets is only possible with a consideration of regional landscape and land use distinctions. A related problem yet to be addressed is the general lack of measured water quality data with which to calibrate and validate water quality models such as SWAT. This adds considerable uncertainty to already complicated and uncertainty situations. Thus, improved strategies for water quality monitoring, and data accessibility must be established.  相似文献   
48.
实施乡村振兴战略以来,各级政府对农村水利的投入不断增加,然而"政府管不到、集体管不好、市场管不了"的现象仍然存在,跨村水利管护机制缺失、基层治水规则与秩序失范问题亟待解决。本文以福建永春县吾峰镇农田水利设施管护改革为例,分析基层村镇场域中治水规则的建立与变革,从边界、身份、选择等7项规则入手剖析其对基层治水有效性的作用机制。研究发现,治水规则深刻影响了吾峰镇水利管护的行动情境:边界规则突破了原有以行政边界划定的资源治理边界,并鼓励企业等新行动主体进入;身份规则、选择规则明晰了管护主体的合约关系,确定了权责监督机制;偿付规则实现了良好的激励作用;信息规则推进了基层治水的公开、透明化运营;聚合规则创新了基层民主的可实现形式;范围规则通过试点选择创造了政策空间。在7项基层治水规则的共同作用下,吾峰镇农田水利设施管护改革摆脱了管护主体缺失困境和跨域治水合作困境,实现了治水行为的规范有序和管护绩效的稳步快速提升,促进了农村基层治水能力的现代化建设。  相似文献   
49.
通过对油站和污水站的化学成分分析,找出了电脱水器跳闸的原因:由于污水中的一些成分导致腐蚀,腐蚀产生的硫化铁和铁颗粒,随着油水混合液在管线中运移,在电脱水器上越积越厚,致使电脱水器上导电率增高,电脱水器跳闸。提出了改善注入水水质,减缓腐蚀的有利措施。  相似文献   
50.
Estimation of ecosystem service values is a hot area of research in ecological conservation and economics. However, the costs of these outputs are largely unknown. In this paper, we estimated the opportunity cost of water allocated to afforestation projects through mathematical modeling based on statistical data for all of China to provide support for restoration planning based on a fuller consideration of the true costs. To guide future ecological conservation and environmental policy development, we illustrate a neglected concept (ecosystem service costs) and use this concept to compare the ecological services provided by ecological restoration based on afforestation with those of restoration based on the conservation of natural vegetation using data obtained since 1949 in China. The results showed that afforestation and natural vegetation create annual costs related to use of the available water resources equal to 4800 and 3700 RMB ha−1, respectively, representing a water opportunity cost of 1100 RMB ha−1 for afforestation. This illustrates the rule that “there is no free lunch” for any service, including ecosystem services. Therefore, to support the development of more effective and sustainable environmental restoration policy, it will be necessary to evaluate the associated opportunity costs.  相似文献   
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