中国多层次水资源税体系构建研究

水资源税费改革是我国生态文明建设的重要措施。首先,本文从水资源税的基础理论出发,认为水资源税的征收依据出于受益原则、公平原则、补偿原则和效率原则。在此基础上,分析论证水资源税的多重内涵。其次,以此为依据,制定多层水资源税体系:第一层是资源地租;第二层是稀缺价值;第三层是经济调节。对于水资源相对丰富的区域,可以只收取第一层的水资源税;对于水资源相对稀缺的地区,则收取第一层和第二层的水资源税;对于水资源严重稀缺,并对经济和环境造成巨大影响的区域,要收取三个层次的水资源税。再次,利用数量经济模型给出每个层次水资源税的计算方法,分别利用基于投入产出模型结构分解分析计算的农业节水成本表征资源地租;利用可计算一般均衡模型计算水资源稀缺机制;利用影子价格表征经济调节税。最后采用山西省煤炭行业的水资源税改革为例进行研究,并提出了三阶段水资源税征收方案。

深长隧道涌水量预测影响因素评价分析

隧道涌水不但与施工条件和隧道特征有关,而且受到水文地质条件的影响,对影响隧道涌水的主要因素的遴选和分析是准确进行隧道涌水量预测的前提。对我国深长隧道地质与水文地质条件进行详细分析,采用层次分析法建立深长隧道涌水量影响因素评价模型,定量确定了各因素的权重。研究结果表明:地层岩性、岩层富水性、地下水类型、地质构造、地形地貌和年均降水量是影响深长隧道涌水量的关键因素。本文分析结果为深长隧道涌水量预测分析提供了科学依据。

Seasonal Dynamics of Nitrogen and Phosphorus in Water and Sediment of A Multi-level Ditch System in Sanjiang Plain,Northeast China

The multi-level ditch system developed in the Sanjiang Plain,Northeast China has sped up water drainage process hence transferred more pollutants from farmlands into the rivers of this region.Understanding the seasonal dynamics of nitrogen (N) and phosphorus (P) transportation in the ditch system and the role of different ditch size is thus crucial for water pollution control of the rivers in the Sanjiang Plain.In this study,an investigation was conducted in the Nongjiang watershed of the Sanjiang Plain to study the nutrient variation and the correlation between water and sediments in the ditch system in terms of ditch level.Water and sediments samples were collected in each ditch level in growing season at regular intervals (once per month),and TN,NO 3--N,NH 4+-N,TP,and PO 4 3--P were analyzed.The results show that nutrient contents in water were higher in June and July,especially in July,the contents of TN and TP were 3.21mg/L and 0.84mg/L in field ditch,4.04mg/L and 1.06mg/L in lateral ditch,2.46mg/L and 0.70mg/L in branch ditch,1.92mg/L and 0.63mg/L in main ditch,respectively.In August and September,the nutrient contents in the water were relatively lower.The peak value of nutrient in ditch water had been moving from the field ditch to the main ditch over time,showing a remarkable impact of ditch system on river water environment.The nutrient transfer in ditch sediments could only be found in rainfall season.Nutrient contents in ditch sediment had effect on that in ditch water,but nutrients in ditch water and sediments had different origination.Ditch management in terms of the key fac-tors is hence very important for protecting river water environment.

Evaluation and optimization of secondary water supply system renovation

Due to pollution in second water supply system (SWSS),nine renovation alternative plans were proposed and com-prehensive evaluations of different plan based on Analytical Hierarchy Process (AHP) were presented in this paper. Comparisons of advantages and disadvantages among the plans of SWSS renovations provided solid foundation for selecting the most appro-priate plan for engineering projects. In addition,a mathematical model of the optimal combination of renovation plans has been set up and software Lingo was used to solve the model. As a case study,the paper analyzed 15 buildings in Tianjin City. After simulation of the SWSS renovation system,an optimal scheme was obtained,the result of which indicates that 10 out of those 15 buildings need be renovated in priority. The renovation plans selected for each building are the ones ranked higher in the com-prehensive analysis. The analysis revealed that the optimal scheme,compared with two other randomly calculated ones,increased the percentage of service population by 19.6% and 13.6% respectively,which significantly improved social and economical benefits.

Effects of soil moisture and soil depth on nitrogen mineralization process under Mongolian pine plantations in Zhanggutai sandy land, P. R. China

The rates of soil N mineralization at soil depths of 0-15, 15-30, 30-45 and45-60 cm and moisture regimes were measured at three sand-fixation plantations of Pinus sylvestrisvar. mongolica by laboratory aerobic incubation method. The results showed that average rates ofsoil net N-mineralization across soil depth varied from 1.06 to 7.52 mg · kg^(-1)·month^(-1) atsoil depths from 0 to 60 cm. Statistical analyses indicated that the effects of different soildepths, moistures and their interactions on net N-mineralization rates were significant (P < 0.05).The net N-mineralization rates significantly decreased with increasing soil depths and at depth 0-15cm accounted for 60.52% of that at depth of 0-60 cm. There was no difference in soil netN-mineralization rates between half and fully-saturated water treatments, however these rates weresubstantially higher than that without water treatment (P < 0.05). The factors influencing Nmineralization process have to be studied further in these semiarid pine ecosystems.

Study on the Multi-dimension Evaluation Index System of Agricultural Water Resources in Liaoning Province

[Objective] This study aimed to establish the multi-dimensional evaluation index system of agricultural water resources in Liaoning Province. [Method] Delphi method in conjunction with AHP method was adopted to establish the multi-dimensional evaluation index system of agricultural water resources in Liaoning Province, and all the indexes in each hierarchy were ranked overall according to their weights. [Result] There were three hierarchies in this index system, totally including 21 indexes, among which water resource exploitation and utilization rate, sewage treatment rate and utilization of available water resources were the three crucial factors influencing the sustainable development. [Conclusion] This evaluation index system can reflect the true sustainable situation of the agricultural water resources in Liaoning Province.

Ocean Mixing with Lead-Dependent Subgrid Scale Brine Rejection Parameterization in a Climate Model

Sea ice thickness is highly spatially variable and can cause uneven ocean heat and salt flux on subgrid scales in climate models.Previous studies have demonstrated improvements in ocean mixing simulation using parameterization schemes that distribute brine rejection directly in the upper ocean mixed layer.In this study,idealized ocean model experiments were conducted to examine modeled ocean mixing errors as a function of the lead fraction in a climate model grid.When the lead is resolved by the grid,the added salt at the sea surface will sink to the base of the mixed layer and then spread horizontally.When averaged at a climate-model grid size,this vertical distribution of added salt is lead-fraction dependent.When the lead is unresolved,the model errors were systematic leading to greater surface salinity and deeper mixed-layer depth(MLD).An empirical function was developed to revise the added-salt-related parameter n from being fixed to lead-fraction dependent.Application of this new scheme in a climate model showed significant improvement in modeled wintertime salinity and MLD as compared to series of CTD data sets in 1997/1998 and 2006/2007.The results showed the most evident improvement in modeled MLD in the Arctic Basin,similar to that using a fixed n=5,as recommended by the previous Arctic regional model study,in which the parameter n obtained is close to 5 due to the small lead fraction in the Arctic Basin in winter.

Anion Content in Surface and Subsurface Water Flows in Grassland

Grassland devoted about 90% of agricultural Irish land. Anion retention capacity of most agriculture soils is less than cation retention capacity, therefore chemical analyzed for anion （NO3 （nitrate）, CI- （chloride）, SO42 （sulphate） and HPO4 （biphosphate）） in different water flow types （overland flow, interflow and vertical flow or drainage） samples. In this work, simple equipment was used to operationally distinguish between overland flow and interflow while vertical flow collected in different depths using soil water sampler equipments. Episodes of overland flow and interflow occurred even though the site is located in the lowest rainfall in Ireland and on well-drained soil. Samples of different origin showed marked differences in their anion contents, while HPO4 concentrations were almost equal to zero in all water flow types, nitrate where relatively high in overland and interflow samples and was very high in drainage samples. No sampling was carried out below the root zone but it must be assumed that the high concentrations measured in drainage samples would constitute a threat to groundwater resources. When overland flow and interflow did occur, NO3 concentrations were usually close to or in excess of the maximum admissible concentrations for drinking water and it will be constituted a threat to inland surface water bodies.

Risk assessment study on bridge foundation in deep overlying stratum

Based on the analysis about the hydrogeological conditions and engineering geological conditions, this paper makes analysis on the possible risks of the deep overlying stratum foundation and establishes the risk evaluation index system during the foundation operating period. Such methods as analytic hierarchy process （AHP） , Delphi method and fuzzy comprehensive evaluation method are adopted to make the quantitative analysis on the risk factors and establish the risk judgment model. According to the actual engineering of Taizhou Bridge, the paper evaluates the risk of the foundation during the operating period at the condition of deep overlying stratum. The evaluation results can provide the reference for the risk management of the bridge foundation durin~ the ooerating period.

Clustered trajectories anonymity in wireless sensor networks

This paper proposes a clustered trajectories anonymity scheme （CTA） that enhances the kano nymity scheme to provide the intended level of source location privacy in mobile event monitoring when a global attacker is assumed. CTA applies isomorphic property of rotation to create traces of the fake sources distributions which are similar to those of the real sources. Thus anonymity of each trajectory and that of the clustered is achieved. In addition, location kdiversity is achieved by dis tributing fake sources around the base station. To reduce the time delay, tree rooted at the base sta tion is constructed to overlap part of the beacon interval of the nodes in the hierarchy. Both the ana lytical analysis and the simulation results prove that proved energy overhead and time delay. our scheme provides perfect anonymity with improved energy overhead and time delay.

Use of Multi-criteria Decision Analysis Methods for Water Supply Problems： A Framework for Improved Rainwater Harvesting

Several conflicting objectives are considered in decision-making. MCDA （multi-criteria decision analysis） methods are developed to facilitate better decision making by decision-makers. Water supply problems are complex problems with multiple decision making and criteria. Hence, the use of multi-criteria decision analysis is very appropriate for solving these problems. Multi-criteria decision analysis can be divided into three main groups： value measurement models, goals, aspiration and reference level models and outranking models. The methods listed have been applied to water supply problems, especially in the evaluation of alternative water supply strategies. Each method has its advantages and limitations. A good alternative for concluding a better-suited method for water supply problems is to apply more than one method, either in combination to make use of the strengths of both methods, or in parallel to obtain a broader decision basis for the decision maker. Previous studies of MCDA in water supply planning have usually considered water supply networks with only one water service delivery. Advanced water supply sources with multiple water service delivery systems have been neglected. This is an on-going study in which analytical hierarchical multi-criteria decision analysis methods are proposed for solving water supply problems and a framework for improved rainwater harvesting systems will be developed.

高中化学课堂分层教学探析

一、问题的提出十几年的中学化学教学过程中,发现很多学生反映化学是难学的学科。经过对200名学生问卷调查显示,52.4%的学生认为化学难学,其中24.5%的学生因化学难学而"失去学习化学的兴趣",12.8%的学生因化学难学而产生"厌学",这一结果令人感觉沉重。

“井冈卫士”铸忠诚——武警江西省总队护卫赣鄱服务人民纪实

江西是中国革命的摇篮,人民军队的摇篮,共和国的摇篮。成长在红土地上的武警江西省总队,有着光荣的历史,既有参加过解放江西、湘赣战役、剿匪肃特、抗美援朝和围捕"二王"、98抗洪、08抗击雨雪冰冻、2010年抗击历史特大洪涝灾害创造十万群众大转移奇迹的英雄集体,也有受到毛主席、江主席、胡主席等党和国家领导人亲切接见的光荣部队和官兵。近年来,总队在武警党委和江西省委、省政府的正确领导下,坚持用党关于新形势下国防和军队建设思想,特别是习主席建设一支听党指挥、能打胜仗、作风优良的现代化武装警察部队的指示要求统揽部队建设,着眼战斗力标准牵引遂行多样化任务能力,着眼全面过硬提升基层建设层次水平,着眼践行苏区干部好作风加强党委班子建设,部队全面建设有新跃升。

Application of a Full Hierarchical Bayesian Model in Assessing Streamflow Response to a Climate Change Scenario at the Coweeta Basin, NC, USA

We have applied a full hierarchical Baysian （HB） model to simulate streamffow at the Coweeta Basin that drains western North Carolina, USA under a doubled CO2 climate scenario. The full HB model coherently assimilated multiple data sources and accounted for uncertainties from data, parameters and model structures. Full predictive distributions for streamflow from the Bayesian analysis indicate not only increasing drought, with substantial decrease in fall and summer flows, and soil moisture content, but also increase in the frequency of flood events when they were fit with Generalized Extreme Value （GEV） distribution and Generalized Pareto Distribution （GPD） under this doubled CO2 climate scenario compared to the current climate scenario. Full predictive distributions based on the hierarchical Bayesian model, compared to deterministic point estimates, is capable of providing richer information to facilitate development of adaptation strategy to changing climate for a sustainable water resource management.