共查询到20条相似文献，搜索用时 62 毫秒
1.
Tradable water rights systems are becoming an important way to achieve distributive efficiency for water resources. However, it is not easy for countries or regions to establish water markets due to the existence of various barriers. In early 2002, the Ministry of Water Resources (MWR) of China initiated an experimental project—Building Water-saving Society in Zhangye City. This project was the first of its kind in China. The aim of the project was to establish a new water use rights (WUR) system with tradable water quotas and to reallocate water resources reasonably and efficiently through market-based instruments. This paper presents the research done on the system and water markets. It has been found that that the system is hard to implement well and that WUR trading is not popular. The barriers to implementing a WUR system are social and administrative in nature. WUR trading faces management, legal, administrative, and fiscal barriers. We discuss why these barriers exist and we provide policy recommendations to overcome them. 相似文献
2.
《Agricultural Systems》1999,59(1):79-98
This paper addresses issues surrounding measurement of the potential productivity gains from new livestock technologies and the returns to international livestock research. The approach, applicable to many livestock production constraints and technologies, uses geographic information systems (GIS) to spatially link a biophysical herd simulation model with an economic surplus model. The particular problem examined is trypanosomosis in cattle in Africa, and the potential research product is a multi-component vaccine. The results indicate that the potential benefits of improved trypanosomosis control, in terms of meat and milk productivity alone, are $700 million per year in Africa. The disease now costs livestock producers and consumers an estimated $1340 million annually, without including indirect livestock benefits such as manure and traction. Given an adoption period of 12 years, a maximum adoption rate of 30%, a discount rate of 5%, and a 30% probability of the research being successful within 10 years, the net present value of the vaccine research is estimated to be at least $288 million, with an internal rate of return of 33%, and a benefit/cost ratio of 34:1. © 相似文献
3.
Much of inland Australia has been in perpetual drought since 1997 except during 2010 when above average rainfall occurred. It has been the worst drought since 1788 when European settlement began. Water scarcity poses a serious threat to the sustainability of the irrigated agriculture in major irrigation systems across the Murray-Darling Basin (MDB). There is a need for water-saving measures and a structured approach to assess water loss in earthen supply channels. This paper presents such an approach to assess and reduce seepage losses for improving irrigation efficiencies. Main elements of this approach are the following: field measurements, hydrologic modelling, potential options for seepage reduction, economic analysis and financing water-saving investments. Using data from two irrigation systems in the southern MDB, a case is made for reducing seepage water losses in irrigation supply channels in a cost-effective manner using low-cost technologies. Increasing the level of security for investments in water-saving programs provides incentives to key stakeholders to achieve water-saving targets. Considering the value of water recovered from reducing seepage loss at irrigation system level, this study demonstrates how reducing just one component (seepage) from the total water losses in irrigation systems can help improve water supplies as well as the environmental flows. Potential options for financing infrastructure improvement for saving irrigation water are proposed and discussed. 相似文献
4.
Dairy systems in southern Australia rely on grazed feed from pasture to supply between 50% and 70% of total herd feed requirements on an annual basis. However, the dominant pasture type in the region, which is based on perennial ryegrass (Lolium perenne), commonly results in feed deficits in summer which must be filled with supplements purchased off-farm, and feed surpluses in spring which must be conserved. Both of these strictures impose costs on farm businesses. It is likely, therefore, that additional grazeable feed available to dairy herds in southern Australia may have different economic value when interactions between season, stocking rate, calving date, and locality are taken into account. The analysis reported in this paper aimed to estimate, using the farm systems simulation model UDDER, the effect of these interactions on the efficiency with which extra feed can be converted to extra milk production, and therefore the possible gross economic value of the additional feed.‘Base’ farm simulations for ‘average’ and ‘top 10%’ farms (ranked according to farm profitability) in two localities (Terang: average annual rainfall 796 mm, 8 month growing season; and Ellinbank: average annual rainfall 1085 mm, 9-10 month growing season) were created to mimic the physical production and profitability of these farms as seen in regional farm benchmark datasets. These simulations were then altered to add the equivalent of 10% of the total annual herbage accumulation used in the Base simulation either on a pro-rata basis all year round, or in autumn only, in winter only, in spring only, or in summer only. The additional feed amounted to 620 and 780 kg DM/ha for Terang average and top 10% farms respectively, and 735 and 905 kg DM/ha for Ellinbank average and top 10% farms respectively. The management policies used in the Base simulations were then adjusted to harvest as much of the extra feed as possible, either by direct grazing or through silage conservation, while keeping the key system state indicators of cow condition score and average farm pasture cover within the limits known to result in long-term sustainable production.The efficiency with which extra feed was utilised was greatest in summer in all scenarios (80-100% of the extra feed supplied was harvested, all by direct grazing). This translated into consistently high gross economic returns of between $0.26 and $0.34 per kg DM of extra feed added to the model. Utilisation efficiency was lower in all other seasons and/or required marked increases in silage conservation, both of which resulted in lower gross economic returns per kg DM of additional feed. The impact of interactions between locality, season, stocking rate (higher in top 10% farm simulations than average farm simulations) and calving date (earlier at Terang than at Ellinbank) were clearly captured in the model. These interactions have very large effects on the profitability of growing extra feed at different times of the year. Agronomic research for the southern Australia dairy industry should focus on low-cost ways for supplying additional grazeable feed in summer, since current forage species options for this time of year are limited. 相似文献
5.
The Southeast U.S. receives an average of 1300 mm annual rainfall, however poor seasonal distribution of rainfall often limits production. Irrigation is used during the growing season to supplement rainfall to sustain profitable crop production. Increased water capture would improve water use efficiency and reduce irrigation requirements. Furrow diking has been proposed as a cost effective management practice that is designed to create a series of storage basins in the furrow between crop rows to catch and retain rainfall and irrigation water. Furrow diking has received much attention in arid and semi-arid regions with mixed results, yet has not been adapted for cotton production in the Southeast U.S. Our objectives were to evaluate the agronomic response and economic feasibility of producing cotton with and without furrow diking in conventional tillage over a range of irrigation rates including no irrigation. Studies were conducted at two research sites each year from 2005 to 2007. Irrigation scheduling was based on Irrigator Pro for Cotton software. The use of furrow diking in these studies periodically reduced water consumption and improved yield and net returns. In 2006 and 2007, when irrigation scheduling was based on soil water status, an average of 76 mm ha−1 of irrigation water was saved by furrow diking, producing similar cotton yield and net returns. Furrow diking improved cotton yield an average of 171 kg ha−1 and net return by $245 ha−1 over multiple irrigation rates, in 1 of 3 years. We conclude that furrow diking has the capability to reduce irrigation requirements and the costs associated with irrigation when rainfall is periodic and drought is not severe. 相似文献
6.
Shahbaz Khan Tariq Rana Munir A. Hanjra John Zirilli 《Agricultural Water Management》2009,96(3):493-503
Agricultural water markets can facilitate adjustments to water scarcity and competition and enhance economic efficiency, but markets cannot automatically balance efficiency, equity and environmental sustainability goals. The consequences of water trading on soil salinity in irrigation areas are not yet fully understood, but recognized as an issue that needs to be analysed. This paper explores the nexus between water trading and groundwater-induced soil salinity in a selected irrigated area in the Murray-Darling Basin. Results show that minimum irrigation intensities must be met to flush salts out of the root zone especially in shallow water table/high salinity impact areas. Such minimum irrigation intensities are helpful but not necessarily in deep water table/low salinity impact areas. Should water markets lead to permanent water transfers out of mature irrigation areas, minimum irrigation intensity needs might not be met in high salinity impact areas, causing substantial negative impacts on resource quality and agricultural productivity. Water trading that adds to salinity cannot be economically viable in the long run. The tradeoffs between water trading and environmental and equity goals need to be determined. This work contributes to the wider debate on Australian water policy aimed at achieving water security through water trading in the Murray-Darling Basin. 相似文献
7.
This paper examines the changing profile of water traders (both allocation and entitlement traders) in the Goulburn-Murray Irrigation District in Australia, and examines the efficiency of the water allocation and entitlement markets from 1998-99 to 2003-06. The results suggest that the profile of traders in the early and mature stages of the water allocation market differ greatly. In addition, the profile of allocation traders is significantly dissimilar from that of water entitlement traders at all stages of water market development. The decision to buy or sell water allocations was more likely to be associated with a farmer's socioeconomic characteristics and the type of farm, while the decision to buy or sell water entitlements was more likely to be associated with the extent of existing farm infrastructure and farm productivity. Finally, there was strong evidence to suggest that trading in the water allocation market has become more efficient over time, though there is no evidence to suggest the same for the water entitlement market. 相似文献
8.
We analyse supply, demand, and welfare measures in markets where the temporary trading of water rights is reasonably active and liquid on a weekly basis. We identify four important characteristics of water trading within the Watermove program: (1) demand is highly responsive to price changes, supporting evidence that farmers’ participation is driven by the advantages water markets provide in reducing seasonal risk; (2) some efficiency enhancing trades are prevented from taking place due to physical limitations of the delivery system, thereby reducing the ability of the market to move toward equilibrium. In addition, these limitations also created price premiums in some zones; (3) variations in the types of products traded are explained by differences in the administrative charges for trading and current drought conditions; and (4) relatively large gains have been made thus far, suggesting that water markets will expand and generate additional increases in consumer and producer surplus in the future. 相似文献
9.
Temporary water trading is an established and growing phenomenon in the Australian irrigation sector. However, decision support and planning tools that incorporate economic and biophysical factors associated with temporary water trading are lacking. In this paper the integration of an economic trading model with a hydrologic water allocation model is discussed. The integrated model is used to estimate the impacts of temporary water trading and physical water transfers. The model can incorporate economic and biophysical drivers of water trading. The economic model incorporates the key trade drivers of commodity prices, seasonal water allocations and irrigation deliveries. The hydrologic model is based on the Resource Allocation Model (REALM) framework, which facilitates hydrologic network simulation modelling. It incorporates water delivery system properties and operating rules for the main irrigation and urban centres in a study area.The proposed integration method has been applied to a case study area in northern Victoria, Australia. Simulations were conducted for wet and dry spells, a range of commodity prices and different irrigation distribution system configurations. Some example analyses of scenarios incorporating water trading were undertaken. From these analyses potential bottlenecks to trade that constrain the economic benefits from temporary water trading were identified. Furthermore, it was found that in certain areas of the system, trading can make impacts of long drought spells worse for water users, e.g. irrigators. Thus, the integrated model can be used to quantify short-term and long-term third party impacts arising from temporary water trading. These findings also highlight the need to link “paper trades” (estimated by economic models) to physical water transfers (estimated by biophysical models). 相似文献
10.
Using economic incentives and regulations to reduce seawater intrusion in the Batinah coastal area of Oman 总被引：1，自引：0，他引：1
Slim Zekri 《Agricultural Water Management》2008,95(3):243-252
Excessive groundwater abstraction is a major problem in Oman, primarily in the Batinah coastal area where it results in seawater intrusion. The Government began to address the problem in the 1990s by encouraging the use of more efficient irrigation systems, replacing date palms with winter vegetable crops and using treated wastewater for municipal irrigation. However, 15 years later, seawater intrusion in the Batinah aquifers is still advancing at an alarming pace. This paper analyses the relative merits of strategies to control groundwater pumping based on water quotas, electricity quotas and electricity pricing. A cost benefit approach is used to evaluate the feasibility of three strategies over a period of 25 years and to compare them to the “business as usual” option. Results show that the net present loss to the community when no active policy is implemented amounts to (−$288) million. Imposing water quotas on tubewells would give a net present benefit of $153 million. However, such quotas would give the lowest present benefit and create inequity among farmers. Other possible approaches would be to control the pumping of groundwater from all wells - tubewells and dug wells - by enforcing energy quotas and by increasing the price of electricity used to pump water. The net present benefits would be greater and the costs to farmers would be more fairly spread. The results of cost-benefit analysis show that enforcing an electricity quota, coupled with removal of the subsidy on the electricity price, is the easiest and most equitable solution to implement. 相似文献
11.
This paper combines an agricultural production decision support tool, GrassGro, with economic risk efficiency theory to examine several cattle feeding options that include various grazing systems for three climatic environments in Saskatchewan, Canada. Historical weather data were used to simulate a distribution of forage and cattle production data for each of several grazing systems during a 21-year period, 1978–1998. Price variability was included by varying year 2000 prices using historical price margin changes between the buying and selling weights of cattle. The risk efficiency analysis was completed using the Mean Standard Deviation (MSD) framework, and stochastic dominance principles.
Results of the study suggested that feeding systems, which included grazing, were economically competitive with traditional feedlot feeding systems and grain farming. Finishing cattle on pasture with the addition of a barley supplement was an attractive option, especially when high pasture productivity can be achieved. In all locations, more intense systems that included pasture fertilization and provision of an energy supplement, improved production and risk efficiency. Although the average net returns of all these feeding simulations were negative, the returns of traditional grain crops were even more negative. It is these negative returns in grain operations that lead to the incentive for producers to diversify into cattle production. Despite the negative net returns, the cash flow (range −$15.59 to $407.54 ha−1) was mostly positive in all three locations. 相似文献
12.
《Agricultural Water Management》1997,33(1):1-18
The net volumetric (m3) irrigation water requirements for the main crop categories currently irrigated in England and Wales have been calculated and mapped within a geographic information system (GIS). The procedure developed by Knox et al. (1996, Agric. Water Manage., 31: 1–15) for maincrop potatoes (Solanum tuberosum) was extended to cater for the other crops currently irrigated. The annual irrigation needs (mm) for the eight major irrigated crop categories, grown on three contrasting soil types at 11 representative weather stations, were determined using a daily water balance irrigation scheduling model. The results were correlated with existing national datasets of climate, current land use, soils and irrigation practice, to generate volumetric (m3) irrigation water requirement maps at 2 km resolution.The total net volumetric irrigation water requirements for a UK ‘design’ dry year (defined as the requirement with a 20% probability of exceedance) are estimated to be 140 × 106 m3 for the eight main crop categories currently irrigated and the 1994 cropping pattern. Previous theoretical dry year demand estimates, using scheduling models and large agroclimatic areas, were 109 × 106 m3 and 222 × 106 m3. The irrigation demand for other crops grown in the open would typically add another 4%.The procedure has been validated nationally, by comparing the calculated dry year demand for 1990 against government irrigation survey returns for 1990, for each crop category, and regionally against National Rivers Authority (NRA) abstraction records for 1990, for each NRA Region. The estimates obtained agree well with the reported distribution between crops and between regions.The most recent actual ‘dry’ year for which comparative data are available is 1990. It is estimated that the dry year requirements for the 1990 land use would have been 148 × 106 m3. Although farmer demand, actual abstractions and crop requirements are not necessarily the same, irrigation survey returns to the Government indicated that 134 × 106 m3 were actually applied, and the NRA estimated from meter returns that 138 × 106 m3 were abstracted. It is noted, however, that some abstraction restrictions were in force, the scope of the data is slightly different and all figures contain inaccuracies. Potential applications for improving irrigation demand management and water conservation at regional and catchment levels are discussed with reference to two contrasting regions. 相似文献
13.
Fiona Barker-Reid Grant A. Harper Andrew J. Hamilton 《Irrigation and Drainage Systems》2010,24(1-2):79-94
Water scarcity in Australia has become a significant challenge for all water users and water reuse is now a critical component of Melbourne’s response to this water crisis, particularly for food production. While most vegetable production occurs in a large-scale commercial environment, there is a significant proportion produced in backyards. With the introduction of severe water restrictions, commercial vegetable production now relies heavily on high quality Class A reclaimed water, while households have turned to the use of greywater. While there are many benefits of wastewater reuse, there are also many potential risks to plant, environmental and human health. A quantitative microbial risk assessment of the two systems was conducted to evaluate the human health risks associated with both large-scale and backyard reuse of water for vegetable irrigation. This preliminary model suggests that for irrigation with typical greywater, the annual infection probability for enteric viruses is >10?4, even after a two week period of no irrigation with greywater. The human annual enteric virus risk from Class A reclaimed water was much lower. 相似文献
14.
Mexico passed a new water law in 1992 that shifted from state-managed water policy to a regulated market-oriented policy with tradable water rights. Water trading will initially be closely supervised by government agencies, but the law includes a number of provisions that will allow liberalization of water markets as water users become more involved in operation and management of water and gain experience in water trading. Incentives for the Mexican water policy reforms include the growing economic value of increasingly scarce water; the rising budgetary costs from highly subsidized capital development and operations and maintenance for irrigation and water supply systems; and general liberalization of the Mexican economy, which has raised the cost of maintaining relatively inflexible water allocation systems that cannot respond to changing incentives. 相似文献
15.
《Agricultural Systems》2005,83(2):223-224
The objective of this paper is to examine the impacts of terminating rice [Oryza sativa] irrigation earlier than usual. One straightforward result of this would be the associated cost savings (≈$10 ha−1 per irrigation or more with deep wells) without placing a value on the water itself. However, another option exists for some farms. An assumption is that the typical farm will be constrained from irrigating all of the soybean [Glycine max (L.) Merr] crop due to constraints in any or all of water supply, pumping capacity, and labor availability. In these cases, a portion of the land in soybean production would be non-irrigated for the first part of the growing season. This study explores the possibility of transferring irrigation water to the soybean crop after the needs of the rice crop are met. If rice and soybean planting dates are planned optimally, this partial irrigation can lead to substantial soybean yield improvements and therefore a more profitable rice/soybean production system. On average, across a 41 year period, net revenue gains from partially irrigating the soybean crop were consistently positive, ranging from $41 to $458 ha−1. While these numbers are interesting, the reader is cautioned that the results are based on simulation models and therefore the marginal analysis results are more realistic. On clayey and silt loam soils at Keiser and Stuttgart, respectively, the change in returns for moving from the least to the most water saving rice irrigation strategy was $190 and $99 ha−1, respectively. In addition, for any given year, financial losses are typically restricted to the irrigation setup costs of $17 ha−1. The irrigation termination strategies therefore show high economic potential with little risk of loss. 相似文献
16.
D. S. Intrigliolo L. Bonet P. A. Nortes H. Puerto E. Nicolas J. Bartual 《Irrigation Science》2013,31(5):959-970
The effects of sustained and regulated deficit irrigation (SDI and RDI) on “Mollar de Elche” pomegranate tree performance were investigated in a field trial conducted over three consecutive seasons. In the RDI regimes, severe water restrictions were applied during one of three phases: flowering and fruit set, fruit growth, or the final phase of fruit growth and ripening. In another approach, SDI was applied by watering trees at 50 % of the estimated crop water needs (ETc) during the entire season. Results showed that even after three consecutive seasons of water restrictions, similar yield levels were obtained in SDI and Control trees watered at 100 % ETc. This was because a 22 % reduction in average fresh fruit weight recorded in the SDI treatment was compensated by an increase in 28 % in the quantity of fruit collected per tree. This was most likely due to a reduction in the fall of the reproductive organs. However, the SDI strategy led to a reduction in 28 % in the yield value when fruits are sold for fresh fruit markets. Water restrictions applied only during flowering and fruit set also resulted in an increase in the quantity of fruit collected per tree, with only a slight reduction in fruit weight and without affecting the yield value. On the other hand, severe water restrictions applied during the summer (i.e., mid-phase of fruit growth) led to 24 % water savings with only a 7 % reduction in fruit weight. Fruit cracking was very low in all treatments and seasons (2–6 % over the total quantity fruit collected per tree). Only the RDI regime with restrictions during the summer increased cracking in one out of the three seasons. It is concluded that RDI can be used as a measure to cope with water scarcity and high water prices. Among all the RDI explored, the one with restrictions applied early in the season (during flowering and fruit set) was the most convenient strategy. 相似文献
17.
P. Heilman R.W. MaloneL. Ma J.L. HatfieldL.R. Ahuja K.P. BoyleR.S. Kanwar 《Agricultural Systems》2012,106(1):59-71
A 45% reduction in riverine total nitrogen flux from the 1980-1996 time period is needed to meet water quality goals in the Mississippi Basin and Gulf of Mexico. This paper addresses the goal of reducing nitrogen in the Mississippi River through three objectives. First, the paper outlines an approach to the site-specific quantification of management effects on nitrogen loading from tile drained agriculture using a simulation model and expert review. Second, information about the net returns to farmers is integrated with the nitrogen loading information to assess the incentives to adopt alternative management systems. Third, the results are presented in a decision support framework that compares the rankings of management systems based on observed and simulated values for net returns and nitrogen loading. The specific question addressed is how information about the physical and biological processes at Iowa State University’s Northeast Research Farm near Nashua, Iowa, could be applied over a large area to help farmers select management systems to reduce nitrogen loading in tile drained areas. Previous research has documented the parameterization and calibration of the RZWQM model at Nashua to simulate 35 management system effects on corn and soybean yields and N loading in tileflow from 1990 to 2003. As most management systems were studied for a 6 year period and in some cases weather had substantial impacts, a set of 30 alternative management systems were also simulated using a common 1974-2003 input climate dataset. To integrate an understanding of the economics of N management, we calculated net returns for all management systems using the DevTreks social budgeting tool. We ranked the 35 observed systems in the Facilitator decision support tool using N loading and net returns and found that rankings from simulated results were very similar to those from the observed results from both an onsite and offsite perspective. We analyzed the effects of tillage, crop rotation, cover crops, and N application method, timing, and amount for the 30 long term simulations on net returns and N loading. The primary contribution of this paper is an approach to creating a quality assured database of management effects on nitrogen loading and net returns for tile drained agriculture in the Mississippi Basin. Such a database would systematically extend data from intensively monitored agricultural fields to the larger area those fields represent. 相似文献
18.
Environmental and economic impacts of reducing total phosphorous runoff in an agricultural watershed
Hector German Rodriguez Jennie Popp Edward Gbur Indrajeet Chaubey 《Agricultural Systems》2011,104(8):623-633
The economy of northwest Arkansas relies greatly upon livestock and poultry production. The supply of production by-products is increasingly coming under scrutiny as an important source of water pollution in the region. This study uses stochastic dominance techniques to evaluate, environmentally and economically, a range of ten best management practice scenarios to lessen water pollution in the Lincoln Lake watershed. The goal is to generate rankings that could be useful for supporting producers’ and watershed managers’ selection of management practices to reduce total phosphorous losses in runoff. Specifically, this study compares scenarios in terms of net return risk reduction for bermudagrass hay producers.The results showed that environmental and economic rankings differ from each other. Although all scenarios analyzed were effective in reducing total phosphorous losses when compared to a baseline, six of them also decreased net returns. This suggests that including some best management practices may lead to increased net return risk. However, some scenarios were identified that may increase net returns, reduce total phosphorous losses and do not differ considerably from producers’ current management practices.The previous results suggested that the joint environmental-economic impact was important when considering scenarios and that producers’ risk attitudes and best management practices’ economic impacts should be accounted for when selecting scenarios. Producers and watershed managers can weigh trade-offs between total phosphorous losses reduction and net returns variability when making water conservation decisions. 相似文献
19.
《Agricultural Water Management》2005,72(3):161-175
Water markets can improve water use efficiency through the transfer of water to users who can obtain the highest marginal return from using it. Existing water markets are implemented among farmers or between farmers and urban water companies or hydropower companies. Several studies have shown that farmers may benefit from trading water mainly in countries where water scarcity is increasing and new water supply projects are either very costly or not possible because of environmental concerns. This paper estimates the potential benefits and losses of implementing water market among farmers and between farmers and urban water company in Tunisia. We used linear programming to examine four separate farm models and an aggregate model. The method is applied to an irrigation area of 4500 ha in Northern Tunisia. Results indicate that water trading among farmers would be quite limited and would have a minor impact on farmers’ income. In contrast, the market among farmers and the urban water company offers higher volumes of water trades to urban users and helps increase farmers’ profitability by up to 7.9%. The sale of water to the urban company is accompanied by a decrease in occasional labor by as much as 34.8% and a decrease of up to 17.6% in farmers’ expenditures for inputs and machinery. Additionally, results obtained in this paper show that inter-year storage of irrigation water may be more advantageous than selling water to the urban utility. Whether farmers would opt to sell water or inter-temporarily store it would depend on the establishment of water rights and the empowerment of farmers. 相似文献
20.
Improved pasture technology for beef production provides the potential for significant increases in food production in many agriculturally underdeveloped regions of the world. However, if extension officers and farmers are to accept new pasture technology they must be convinced that it is superior to the traditional system, not only in terms of expected return but also in terms of its relative riskiness.This paper describes a simulation model developed to assess the risks and returns from establishing improved pasture in an extensive beef breeding enterprise. Particular attention has been given to modelling the effect of stocking rate policy as this is a major management factor that will affect both the returns and risks associated with pasture improvement.Use of the model is illustrated for an enterprise in northeastern New South Wales, Australia, where much of the beef industry has been tradionally based on poor native pastures. 相似文献