Considering Aquacultural Externality in Coastal Land Allocation Decisions in India

Commercial aquaculture in India has come under attack for having caused negative agricultural and environmental impacts. This paper formulates an interactive model of non-renewable and renewable resources to characterize land allocations between aquaculture and agriculture in ecologically and economically sustainable fashion. Through an empirical application, various economic and policy circumstances that affect the optimal land allocation mix are evaluated. The aquaculture industry must address two economic effects: off-site negative effects on renewable food and other coastal resources, and on-site self-pollution of shrimp ponds. Current regulatory and land-use policies are inadequate to address these effects.     

Drainwater Management for Salinity Mitigation in Irrigated Agriculture

Salinity and drainage management options include source control, reuse, and evaporation ponds. This article identifies efficient strategies to maintain hydrologic balance in closed drainage basins and evaluates their impact on regional agricultural profits. Theoretical analysis suggests that economic efficiency requires acknowledgment of the nonseparability between water use and land value. Empirically, our solution involves a modest amount of source control, a substantial amount of reuse, and the elimination of evaporation ponds often associated with large environmental damages, while maintaining grower income. Various policy instruments and options are introduced and discussed, including a system of drainwater charges, marketable permits, and land retirement.     

聚合磷硫酸铁的中试

通过研究聚合磷硫酸铁的合成过程及其性能特征，找出理想的合成路线，并探索其实现工业化的可能性。     

长江河口淡水资源开发的一个新思路--建设大型河口边滩水库:没冒沙水库

长江水量充沛,而上海对其利用不够充分,目前还是水质型缺水城市,经过调查研究,我们提出建设没冒沙水库,进一步开发长江口的淡水资源的设想,没冒沙水库受到外海盐水入侵的影响,但季节性(洪季)的淡水资源较充足,淡水出现机率达到76．98％～82．94％,而枯季也有时段性的淡水资源存在,机率为35％～42％。没冒沙水库地处浦尔新区,能为浦东新区的开发就近提供大节的生态、生活用水,它将成为上海市水源的重要组成部分。     

A science-driven market-based instrument for determining the cost of environmental services: A comparison of two catchments in Australia

An auction-based approach (or MBI for “market-based instrument”) was used to purchase environmental services from landowners and to establish a long-term economic resource (forest plantations) in two catchments in the state of Victoria (Australia). The policy goal of the MBI was to encourage the conversion of cleared land to forest plantations. It was desired to achieve this while also reducing the amount of land affected by dryland salinity with minimum impact on water available for irrigation. Operationally, interested landowners identified areas on which they would be willing to establish forest plantations, and stated the amount of money they would require from the government to undertake plantation establishment; this constituted a landowner bid. The proposed planting area associated with each bid was processed through a quantitative hydrological model to estimate off-site impacts on dryland salinity and the change in water yield resulting from the conversion of individual non-forested areas to forest plantations. Landowner bids were then accepted or not based on the economic trade-offs among dollars requested by a landowner, reduction in water yield, and decrease in dryland salinity. To enable a comparison of costs, the MBI was independently trialled in two catchments. For both, the cost to government of a hectare of plantation and/or a hectare of salinity benefit was calculated a number of ways. Assuming the existence of a calibrated hydrological model, costs associated with distributing money via such an MBI were publicity, fieldwork, processing the bids through the model, probity, legal, and administration. In the Gippsland catchment, the total cost to establish forest plantations was $5340 per ha whereas it was $1635 per ha in the Corangamite catchment. No salinity benefit was obtained in Gippsland, but in Corangamite, if considered in isolation of the economic forest plantation benefit, the cost per hectare of salinity benefit was $5020.Operational aspects of the MBI are presented and discussed and a comparison is made to the expected costs of a conventional, non-science driven approach to landowner incentives.     

高价阳离子与矿化度之间的协同效应实验研究

采用天然岩心的动态模拟试验,系统地分析了油气田开发过程中水敏性地层的矿化度和酸碱度对黏土矿物膨胀、分散和运移的影响;研究了由此引起的地层孔隙堵塞规律中高价阳离子浓度与矿化度之间的关系,得到了一些十分重要的新认识,为进一步研究黏土矿物膨胀、分散、运移微观动力学机理提供了重要依据.     

Historical regulation of Victoria's water sector: A case of government failure?*

This paper analyses the role of government failure in Victoria's water sector between 1905 and 1984 as evidenced in the rise of in-stream salinity. It will be shown that high levels of salinity can, in part, be attributed to regulatory failure for two reasons. First, the method of water allocation, a compulsory minimum charge with the marginal cost of water being zero, encouraged over watering, resulting in increased water tables via groundwater recharge. Second, the government did not provide adequate finance for construction of appropriate removal of saline drainage water, and thereby allowed increasing in-stream salinity.     

The evolution of aquatic agricultural systems in Southwest Bangladesh in response to salinity and other drivers of change

Aquatic agricultural systems (AAS) in coastal Southwest Bangladesh have evolved in response to a number of stimuli and constraints including improving market access, technological change, and salinization. Farming systems in the region are highly dynamic, and are characterized by the integration of varying combinations of freshwater prawns, rice, fish, vegetables, and brackish water shrimp. This paper examines the developmental history, productivity, and profitability of three distinct AAS: a low-salinity freshwater prawn-dominated system; an intermediate-salinity-mixed prawn and shrimp system, and a high-salinity shrimp-dominated system. Productivity, cropping intensity, and profitability are found to be highest in the diversified low- and intermediate-salinity systems, and lower in the high-salinity system, where cultivation of rice and vegetables is no longer possible. The paper concludes that more diverse integrated systems reduce risk and vulnerability for farming households. Salinization is found to be a double-edged sword – proving a stimulus to diversification at low levels, but reducing agro-biodiversity at higher salt concentrations. While the adaptation strategies in all systems have been successful in maintaining or improving most, though not all, system functions due to high levels of social resilience, support for effective community-based adaptation strategies will enable continued transformation and adaptation to future drivers of change.     

Mathematical optimisation of drainage and economic land use for target water and salt yields*

Land managers in upper catchments are being asked to make expensive changes in land use, such as by planting trees, to attain environmental service targets, including reduced salt loads in rivers, to meet needs of downstream towns, farms and natural habitats. End‐of‐valley targets for salt loads have sometimes been set without a quantitative model of cause and effect regarding impacts on water yields, economic efficiency or distribution of costs and benefits among stakeholders. This paper presents a method for calculating a ‘menu’ of technically feasible options for changes from current to future mean water yields and salt loads from upstream catchments having local groundwater flow systems, and the land‐use changes to attain each of these options at minimum cost. It sets the economic stage for upstream landholders to negotiate with downstream parties future water‐yield and salt‐load targets, on the basis of what it will cost to supply these ecosystem services.     

Water use and salinity in the Murray–Darling Basin: A state-contingent model*

The supply of water for irrigation is subject to climatic and policy uncertainty. The object of the present paper is to show how the linear and non-linear programming models commonly used in modelling problems such as those arising in the Murray–Darling Basin may be adapted to incorporate a state-contingent representation of uncertainty. Estimates showing the potential value of improved water use are also derived.