Integrated water resources management and water users' associations in the arid region of northwest China: a case study of farmers' perceptions.

Water scarcity is a critical policy issue in the arid regions of northwest China. The local government has widely adopted integrated water resources management (IWRM), but lacks support from farmers and farm communities. We undertook a case study in the Minqin oasis of northwest China to examine farmers' responses to IWRM and understand why farmer water users' associations (WUAs) are not functioning effectively at the community level. Results of quantitative and qualitative surveys of 392 farmers in 27 administrative villages showed that over 70% of farmers disapprove of the IWRM market-based reforms. In particular, the failure of farmer WUAs can be attributed to overlapping organizational structures between the WUAs and the villagers' committees; mismatches between the organizational scale of the WUAs and practical irrigation management by the farmers themselves; marginalization of rural women in water decision-making processes; and the inflexibility of IWRM implementation. An important policy implication from this study is that rebuilding farmer WUAs is key to overcoming the difficulties of IWRM. The current water governance structure, which is dominated by administrative systems, must be thoroughly reviewed to break the vicious cycle of tension and distrust between farmers and the government.

The role of desalinisation to address aquifer overdraft in SE Spain.

Aquifer overdraft is a major environmental and water management problem in Southeast Spain. In some areas, availability of desalinised seawater resources is being expanding, which provides an opportunity to address this problem at a lower social and economic cost. We analyse the economic impact of using several instruments to address the problem of non-renewable groundwater pumping in the aquifers of the Guadalentín basin: an environmental tax on groundwater use, the buyback of groundwater rights and the subsidization of desalinised resources. Their impact is assessed using a mathematical programming model that maximises the farm net margin resulting from the use of the available water resources for irrigation in the area. Our results show that, in the current situation of water availability, all the alternatives have significant economic impacts. Moreover, the first two alternatives would be unfeasible from a political point of view. The existence of abundant, though expensive, desalinised water resources in the foreseen future would reduce, but not eliminate, the negative economic impact of such instruments. Furthermore, water demand is so high in this area that even strongly subsidising desalinised water in exchange for reducing the use of groundwater would not allow to eliminate aquifer overdraft.

A new bankruptcy method for conflict resolution in water resources allocation.

Growing competition over water resources has caused political disputes among stakeholders and has brought conflict resolution in the focus of negotiation processes. In these cases, bankruptcy rules for redistributing an asset when it is not sufficient to meet all claims could be applied. In this paper, we develop a new bankruptcy rule for water resources problems that considers agents' contribution to the total resources as well as their claims, which is in accordance with the UN Watercourses Convention (1997), as important factors for reallocation. Using the Euphrates River and a hypothetical case from the literature as examples, the new rule is compared with four alternative rules. The results show that the novel solution is potentially more powerful to help solving conflicts over river sharing problems.

Assessment of the risks for human health of adenoviruses, hepatitis A virus, rotaviruses and enteroviruses in the Buffalo River and three source water dams in the Eastern Cape.

Buffalo River is an important water resource in the Eastern Cape Province of South Africa. The potential risks of infection constituted by exposure to human enteric viruses in the Buffalo River and three source water dams along its course were assessed using mean values and static quantitative microbial risk assessment (QMRA). The daily risks of infection determined by the exponential model [for human adenovirus (HAdV) and enterovirus (EnV)] and the beta-Poisson model (for hepatitis A virus (HAV) and rotavirus (RoV)) varied with sites and exposure scenario. The estimated daily risks of infection values at the sites where the respective viruses were detected, ranged from 7.31 × 10(-3) to 1 (for HAdV), 4.23 × 10(-2) to 6.54 × 10(-1) (RoV), 2.32 × 10(-4) to 1.73 × 10(-1) (HAV) and 1.32 × 10(-4) to 5.70 × 10(-2) (EnV). The yearly risks of infection in individuals exposed to the river/dam water via drinking, recreational, domestic or irrigational activities were unacceptably high, exceeding the acceptable risk of 0.01% (10(-4) infection/person/year), and the guideline value used as by several nations for drinking water. The risks of illness and death from infection ranged from 6.58 × 10(-5) to 5.0 × 10(-1) and 6.58 × 10(-9) to 5.0 × 10(-5), respectively. The threats here are heightened by the high mortality rates for HAV, and its endemicity in South Africa. Therefore, we conclude that the Buffalo River and its source water dams are a public health hazard. The QMRA presented here is the first of its kinds in the Eastern Cape Province and provides the building block for a quantitatively oriented local guideline for water quality management in the Province.

Financial and environmental modelling of water hardness--implications for utilising harvested rainwater in washing machines.

A study was conducted to determine the financial and environmental effects of water quality on rainwater harvesting systems. The potential for replacing tap water used in washing machines with rainwater was studied, and then analysis presented in this paper is valid for applications that include washing machines where tap water hardness may be important. A wide range of weather conditions, such as rainfall (284-1,794 mm/year); water hardness (14-315 mg/L CaCO3); tap water prices (0.85-2.65 Euros/m(3)) in different Spanish urban areas (from individual buildings to whole neighbourhoods); and other scenarios (including materials and water storage capacity) were analysed. Rainfall was essential for rainwater harvesting, but the tap water prices and the water hardness were the main factors for consideration in the financial and the environmental analyses, respectively. The local tap water hardness and prices can cause greater financial and environmental impacts than the type of material used for the water storage tank or the volume of the tank. The use of rainwater as a substitute for hard water in washing machines favours financial analysis. Although tap water hardness significantly affects the financial analysis, the greatest effect was found in the environmental analysis. When hard tap water needed to be replaced, it was found that a water price of 1 Euro/m(3) could render the use of rainwater financially feasible when using large-scale rainwater harvesting systems. When the water hardness was greater than 300 mg/L CaCO3, a financial analysis revealed that an net present value greater than 270 Euros/dwelling could be obtained at the neighbourhood scale, and there could be a reduction in the Global Warming Potential (100 years) ranging between 35 and 101 kg CO2 eq./dwelling/year.

A solution to the water resources crisis in wetlands: development of a scenario-based modeling approach with uncertain features.

A scenario-based interval two-phase fuzzy programming (SITF) method was developed for water resources planning in a wetland ecosystem. The SITF approach incorporates two-phase fuzzy programming, interval mathematical programming, and scenario analysis within a general framework. It can tackle fuzzy and interval uncertainties in terms of cost coefficients, resources availabilities, water demands, hydrological conditions and other parameters within a multi-source supply and multi-sector consumption context. The SITF method has the advantage in effectively improving the membership degrees of the system objective and all fuzzy constraints, so that both higher satisfactory grade of the objective and more efficient utilization of system resources can be guaranteed. Under the systematic consideration of water demands by the ecosystem, the SITF method was successfully applied to Baiyangdian Lake, which is the largest wetland in North China. Multi-source supplies (including the inter-basin water sources of Yuecheng Reservoir and Yellow River), and multiple water users (including agricultural, industrial and domestic sectors) were taken into account. The results indicated that, the SITF approach would generate useful solutions to identify long-term water allocation and transfer schemes under multiple economic, environmental, ecological, and system-security targets. It can address a comparative analysis for the system satisfactory degrees of decisions under various policy scenarios. Moreover, it is of significance to quantify the relationship between hydrological change and human activities, such that a scheme on ecologically sustainable water supply to Baiyangdian Lake can be achieved.

The effect of groundwater allocation on economic welfare loss.

Water scarcity has become a constraint for regional economic development in many cities and regions. Water rationing serves as one instrument to constrain water consumption to persuade users to save water and to moderate their consumption. When the supply of water is unable to satisfy demand, a loss of welfare for the water users will usually occur. This paper conducts an empirical case study on a Chicago suburban county, McHenry County, to evaluate effective water allocation strategies under possible water scarcity scenarios, by specifically taking into consideration of the economic welfare loss under water rationing. It points out the inefficiency of equal rationing and tests a more effective optimal rationing regime which could significantly lower the overall welfare loss for McHenry County. Instead of a conventional watershed-based approach that would provide little advantage for an area that mostly relies on groundwater, this study adopts regional planning/political boundaries as its spatial analytical units. The outcomes suggest that municipality-level water resources management models, powered under economic welfare objective functions, are both possible and practical. The planning strategy drawn under such optimization models suggests a variety of promising approaches to manage groundwater resources at county scales.