基于边际成本的跨流域调水水量交易价格研究——以南水北调中线一期工程为例

目前,中国跨流域调水用户间的水量交易价格多采用平均成本法予以定价,这样容易带来成本费用重复计入以及资源配置效率不高的问题。为解决上述问题,在边际成本相关理论的基础上,结合水利工程供水成本费用的发生机理以及水量交易特性,构建了基于边际成本理论的跨流域调水工程受益省市间的水量交易价格模型,并提出了模型各项参数的确定方法。以南水北调中线一期工程沿线的河北省和北京市水量交易为研究对象,针对不同的工程条件,用构建的模型测算了水量交易价格。结果表明:(1)在完全利用现有工程——南水北调干线北京段从总干渠河北段调水入京的情况下,交易水价为1.18元/m;(2)在通过新建固安支线向北京市调水的情况下,交易水价为1.40~1.45元/m;(3)工程可变成本是边际成本的主要组成部分,加压工程方案交易价格普遍要高于自流工程方案的水交易价格。

高质量发展模式下内蒙古河套灌区的可交易水量

黄河流域必须推进水资源节约集约利用,推动流域高质量发展。水权交易是运用市场机制实现水资源优化配置,促进水资源高效流转的有效手段。可交易水量是水权交易的基础要件之一,如何在高质量发展模式下科学测算可交易水量,是保障转让方水资源安全,促进水权交易顺利实现的关键。文章提出高质量发展模式下水权交易中可交易水量的测算方法,为灌区开展水权交易,测算可交易水量提供理论依据。首先,充分考虑水权交易对转让方用水安全的影响,界定可交易水量是转让方在保障自身生产、生活、生态等用水的前提下,在水权交易中可转让的水量。其次,依据中国水权交易政策分析得出可交易水量来源于节水潜力,国内水权交易实践显示农业节水潜力是当前及未来可交易水量的主要来源。再次,遵循高质量发展模式下保障粮食安全、实现水资源节约集约利用的原则,提出农业节水潜力的估测方法。最后,分析可交易水量的影响因素,确定调整系数,提出农业节水潜力中能够转化为可交易水量的测算方法。将该方法应用于国家高质量发展战略的施力地区以及中国水权交易的典范——内蒙古河套灌区,得出2021—2025年内蒙古河套灌区农业节水潜力分别为11.0713亿m^(3)、11.5496亿m^(3)、12.0486亿m^(3)、12.5692亿m^(3)、13.1123亿m^(3)。依据内蒙古河套灌区可交易水量影响因素分析以及内蒙古水权交易政策规定,取可交易水量调整系数为2/3,计算得出内蒙古河套灌区2021—2025年可交易水量为7.381亿m^(3)、7.700亿m^(3)、8.032亿m^(3)、8.379亿m^(3)、8.742亿m^(3),为内蒙古河套灌区乃至黄河流域测算可交易水量提供借鉴。

基于最严格水资源管理制度的县域水权交易决策模型研究

针对单纯依靠行政手段配置水资源的不足,提出市场环境下水资源再次优化配置的水权交易意愿分析。通过构建水权交易决策模型,引入复杂适应系统理论,简化并分析了用水主体的行为。采用经济学方程对水权交易行为进行了选择并作出交易决策,分析了研究区潜在水权交易水量。结果表明,决策行为受用水主体经济效益最大化的约束,受节水成本和交易后所获收益的影响。研究成果为区域水权市场构建和区域水市场可交易水量的确定提供了依据。

Water, CO_2 and Energy Exchange at Vegetation-air Interface

[Objective] The aim was to analyze water and heat fluxes, CO2 fluxes and energy balance in wheat ecosystem in Luancheng County of Hebei Province. [Method] Based on data of water and heat flux, and CO2 fluxes, routine meteorological and biomass data in Luancheng in 2008, water and heat fluxes, CO2 fluxes and energy balance in wheat ecosystem were explored. [Result] The results showed that latent and sensible heat and CO2 fluxes were of obvious daily and seasonal changes; latent and sensible heat fluxes shaped an inverted U in daily change, and CO2 fluxes were of a U-shape; daily flux peak differed significantly. Furthermore, the change of latent heat, sensible heat and CO2 fluxes were closely related to environ- mental factors. Detailedly, the three were sensitive to light intensity and net radiation, and correlation coefficients were 0.92, 0.66, 0.65 and 0.90, 0.69, 0.74, respectively. Besides, the fluxes, sensitive to temperature, proved better in sunny day, especially for latent flux which is more sensitive to water in soils after precipitation. In addition, closure degree of energy balance in wheat fields was 0.91 and non-closure, caused by measurement error and neglection of heat storage, was observed, too. What＇s more. closure degree differed in months and time periods within a day. [Conclusion] The research concluded water and heat fluxes, CO2 fluxes, transport mechanisms and concerning factors, providing scientific reference for revealing mechanism of evapo- ration and heat dissipation of canopy, relationship between photosynthesis and water use efficiencyand energy distribution mechanism.

Distribution of Dissolved Inorganic Carbon (DIC) and Its Related Parameters in Seawater of the North Yellow Sea and off the Qingdao Coast in October, 2007

Data on the distribution of dissolved inorganic carbon (DIC) were obtained from two cruises in the North Yellow Sea (NYS) and off the Qingdao Coast (QC) in October, 2007. Carbonate parameters were calculated. The concentrations of DIC are from 1.896-2.229 mmolL-1 in the NYS and from 1.939-2.032 mmolL-1 off the QC. In the southwest of the NYS, DIC in the upper layers decreases from the north of the SP (Shandong Peninsula) shelf to the center of the NYS; whereas in the lower layers DIC increases from the north of the SP shelf to the center of the NYS and South Yellow Sea. In the northeast of the NYS, DIC in all layers in- creases from the YR (Yalu River) estuary to the centre of the NYS. The distribution of DIC in NYS can be used as an indicator of Yellow Sea Cold Water Mass (YSCWM). Air-sea CO2 fluxes were calculated using three models and the results suggest that both the NYS and the QC waters are potential sources of atmospheric CO2 in October.

Variations of Terrestrial Water Storage in the Yangtze River Basin under Climate Change Scenarios

In this study, the water balance-based Precipitation-Evapotranspiration-Runoff (PER) method combined with the land surface model Variable Infiltration Capacity (VIC) was used to estimate the spatiotemporal variations of terrestrial water storage (TWS) for two periods, 1982-2005 (baseline) and 2071-2100, under future climate scenarios A2 and B2 in the Yangtze River basin. The results show that the estimated TWS during the baseline period and under the two future climate scenarios have similar seasonal amplitudes of 60-70 mm. The higher values of TWS appear in June during the baseline period and under the B2 scenario, whereas the TWS under A2 shows two peaks in response to the related precipitation pattern. It also shows that the TWS is recharged from February to June during the baseline period, but it is replenished from March to June under the A2 and B2 scenarios. An analysis of the standard derivation of seasonal and interannual TWS time series under the three scenarios demonstrates that the seasonal TWS of the southeastern part of the Yangtze River basin varies remarkably and that the southeastern and central parts of the basin have higher variations in interannual TWS. With respect to the first mode of the Empirical Orthogonal Function (EOF), the inverse-phase change in seasonal TWS mainly appears across the Guizhou-Sichuan-Shaanxi belt, and the entire basin generally represents a synchronous change in interannual TWS. As a whole, the TWS under A2 presents a larger seasonal variation whereas that under B2 displays a greater interannual variation. These results imply that climate change could trigger severe disasters in the southeastern and central parts of the basin.

Limits of Level 3 Fair Value Measurement： Based on Conceptual Framework

The IASB stated that in the review of the conceptual framework, if measurement uncertainty is very high, a measurement basis different from fair value may provide more appropriate information. Level 3 fair value measurements are inappropriate for areas （called ＂Level 4＂ by the author） in which models are not formulated and that have material uncertainty in measurement. The purpose of this paper is to elucidate ＂measurement uncertainty＂, which impacts ＂faithful representation＂ in fair value measurement, from the perspective of ＂verifiability＂. To do so, it will employ a conceptual examination of the limits of Level 3 fair value measurement based on IFRS 13 （Fair Value Measurement）. While taking into consideration recent discussions on reviewing conceptual framework, the author will reorganize the conceptual categories of verifiability （i.e., clarification of the ＂reasonable verifiability＂ categories） to underpin the fact that material uncertainties in measurement have obstructed constructing faithful representation. In addition, the author will discuss the problem that the dichotomy of direct and indirect found in IASB is not accurate enough to fully understand the concept of verifiability. In this context, the author will also suggest that the concept of verifiability, reorganized through ＂reasonable verifiability＂, can satisfy the requirements for constructing faithful representation.

水权交易中的水价估算

水权交易是实现水资源有效配置的手段,而交易水价的估算又是进行水权交易的重要依据。选定反映水资源稀缺程度和经济发展水平的水资源影子价格作为水资源价值量化手段,提出在水权交易中的水资源影子价格递减效应、递增效应等概念,分析了水权交易中水资源影子价格对交易水量的递减(买方)、递增(卖方)效应,以及对时间的递增效应等对交易水价的影响,并据此推导了水权交易的水价估算方法以及最佳交易水量的确定方法。通过中国甘肃省与宁夏回族自治区之间进行的水权交易实例计算,阐述了具体实现方法。