A NEW APPROACH FOR ESTIMATING IRRIGATION CONVEYANCE LOSSES AND THEIR ECONOMIC EVALUATION1

ABSTRACT: In this paper a new methodology for estimating conveyance efficiency within irrigation systems is presented. Based on statistical analysis of daily water releases from the source of supply and deliveries to the farmers in an irrigation district in Mexico, a linear model is obtained for estimating conveyance efficiency and two component factors. One of these factors points out the relative importance of the operational losses (i.e., losses due to water management), and the second shows the importance of the fixed losses which can be attributed to the average flow through the canal network without variations. In the last part of this paper, an analysis of the expected benefits and costs accruing from system improvement permits derivation of a decision rule which may be used for analyzing the economic feasibility of lining in-place canals.     

DEMAND PROJECTIONS CONSIDERING CONSERVATION1

ABSTRACT: Prediction of future water demands depends on the degree to which conservation effects can be anticipated. A model developed for the Corps of Engineers shows that choosing a numerical conservation target to be achieved is more meaningful and yields more predictable results than price or price elasticity manipulations. The method developed and then applied to the Kaneohe Bay region of Oahu considers the following determinants of demand: geographic distribution of the users, indoor and outdoor requirements, time - by year and month of the year, precipitation, historical unit usage rates, gross and irrigable acreage of land uses, price for water, elasticity of demand with respect to price, source of the water supply (local private supplies vs. agency supplies), and the percentage conservation savings anticipated in each future period in indoor and outdoor uses of water in each of 40 possible land uses. While developed for use in Hawaii, the model is applicable generally.     

中国与东盟水产品资源贸易价格波动——以冻鲭鱼出口价格为例

东盟是我国第三大水产品出口地,掌握对东盟水产品出口价格波动规律,以预测未来水产品出口价格波动趋势,为拓展水产品贸易潜力、有效进行渔业资源配置、促进水产品信息体系的建立提供依据和支撑。冻鲭鱼是我国重要的水产品出口品种,而东盟又是我国冻鲭鱼的最大出口地。以冻鲭鱼为例,利用2012—2017年我国对东盟以及东盟主要国家冻鲭鱼出口的月度价格数据,采用ARCH族模型和H-P滤波法研究其出口价格的聚簇性、非对称性和构成价格波动的四种因素。结果表明：（1）冻鲭鱼出口价格具有聚簇性,可以进行价格预测,市场价格上涨或下跌对其影响力基本相同;（2）价格呈现明显的季节性波动和周期性,可分为3或4个周期,2014—2015年之前的价格波动幅度大于之后期间内的波动幅度;（3）价格波动由四种因素构成,各因素对冻鲭鱼出口价格波动的贡献率差别较大。     

基于模糊数学的排污权交易基准价测算模型及其应用

为了解决排污权交易基准价的制定这一排污权交易制度设计的关键问题,在对影响排污权价值的因素进行理论分析的基础上,利用模糊数学理论建立了包含人均国民生产总值、环境容量、污染物排放绩效3个影响因素的排污权价值模糊数学评价模型,结合污染物削减成本构建了排污权交易基准价测算模型.利用该套模型,建立了重庆市COD和氨氮排污权价值评价体系,计算得到重庆市人均国民生产总值、污染物环境排放量、工业污染物排放绩效等影响因素对排污权价值的权重分别为0.540、0.163和0.297,COD和氨氮排污权价值的模糊综合评价结果向量分别为（0,0.715,0.285,0,0）和（0,0.865,0.135,0,0）;根据重庆市废水COD和氨氮削减成本,测算了重庆市废水COD和氨氮的排污权交易基准价格分别为5 900和16 000元/t,处于全国排污权交易试点省市确定的基准价的中上水平.该套模型将排污权基准价测算过程中具有模糊性、不确定性的影响因素进行了定量表达,使测算结果更符合客观实际,并且具有实用价值,但在排污权价值影响因素的筛选及其量化等方面有待进一步研究.      

济南市城区水资源价值模糊综合评价

水资源具有价值和价格，价格杠杆是解决水问题的重要手段。以济南市城区为例，分析了影响水资源价值的主要因素，运用模糊数学方法对水资源价值进行了评价，并计算出了济南市城区的水资源价值。     

我国水资源管理现状及对策

从建立水资源管理体系、水资源管理法规等方面介绍了我国水资源管理的现状，指出我国的水资源管理存在水平落后、市场化程度低、体制和政策上存在弊端以及忽视节水方针的实施等问题，提出了，通过倡导新的生态经济管理思想、建立国家统一的水资源管理体系、以市场为导向进行水资源管理、建设节水型社会和采用先进技术等解决问题的办法。     

A MUNICIPAL WATER SUPPLY INVESTMENT PROBLEM IN RHODE ISLAND1

ABSTRACT: The traditional “requirements” approach to water system planning presumes perfectly inelastic demand and arbitrarily selects a fixed water requirement per capita per day as a planning target. Economists have often pointed out that such a policy leads to over-investment in water supply facilities; a superior approach would maximize some measure of net benefits incorporating price-sensitive demand. Using a dynamic programming model to depict an investment problem in Rhode Island, we find that ambiguities about how to incorporate price-sensitive demand into a decision framework may make such an approach as arbitrary as the requirements approach. Water conservation responses may be a function of other social parameters than water price; if so, variations in these social parameters should be regarded as economic alternatives to water supply investments.     

EFFECT OF PRICE ON THE RESIDENTIAL DEMAND FOR WATER WITHIN AN AGENCY1

ABSTRACT: This paper develops a model that can be used to forecast the residential elasticity of demand for water within a district. Long-term water conservation programs and revenue and cost decisions hinge crucially on a determination of this elasticity. This study then pools cross-sectional (census) and time series data to generate elasticity forecasts for the Oakland urban area.     

Carbon forestry economic mitigation potential in India,by land classification

Carbon forestry mitigation potential estimates at the global-level are limited by the absence or simplicity of national-level estimates, and similarly national-level estimates are limited by absence of regional-level estimates. The present study aims to estimate the mitigation potential for a large diverse country such as India, based on the GTAP global land classification system of agro-ecological zones (AEZs), as well the Indian AEZ system. The study also estimates the implications of carbon price incentive (US$50 and $100) on mitigation potential in the short-, medium- and long-term, since afforestation and reforestation (A & R) is constrained by lack of investment and financial incentives. The mitigation potential for short and long rotation plantations and natural regeneration was estimated using the GCOMAP global forest model for two land area scenarios. One scenario included only wastelands (29 Mha), and the second enhanced area scenario, included wastelands plus long fallow and marginal croplands (54 Mha). Under the $100 carbon price case, significant additional area (3.6 Mha under the wasteland scenario and 6.4 Mha under the enhanced area scenario) and carbon mitigation is gained in the short-term (2025) compared to the baseline when using the GTAP land classification system. The area brought under A & R increases by 85–100% for the $100 carbon price compared to $50 carbon price in the short-term, indicating the effectiveness of higher carbon price incentives, especially in the short-term. A comparison of estimates of mitigation potential using GTAP and Indian AEZ land classification systems showed that in the short-term, 35% additional C-stock gain is achieved in the $100 carbon price case in the enhanced area scenario of the Indian AEZ system. This difference highlights the role of the land classification system adopted in estimation of aggregate mitigation potential estimates, particularly in the short-term. Uncertainty involved in the estimates of national-level mitigation potential needs to be reduced, by generating reliable estimates of carbon stock gain and losses, and cost and benefit data, for land use sector mitigation options at a scale disaggregated enough to be relevant for national mitigation planning.     

土地利用线性规划结果的影子价格计算与敏感性分析

在土地利用规划中,对线性规划结果进行影子价格计算可以确定其结果在最优状况时,放宽某个约束条件(a_ijx_i=b_i)对目标函数（S）产生的附加贡献值。而敏感性分析解决了在线性规划仍保持最优解情况下,所允许的因市场条件和生产过程的改变导致的资源限制且（b_i）和利益系数（c_i）的可行变化范围。通过以上计算和分析,使静态的线性规划模型向动态模型方向迈进了一步。为其在一定空间和时间上推广应用开拓了余地。