中国城市生活用水效率及收入、价格弹性评估

为有效引导中国城市提高生活用水效率,借鉴标杆管理思路,根据正态分布统计学特征,构建城市生活用水效率的标杆体系,对中国城市生活用水效率进行了系统性评估,并通过构建双对数模型,对水量、水价两项生活用水重要影响因子的影响弹性进行了定量化分析评估。结果表明,中国城市人均日生活用水量稳中有降,主要得益于生活用水效率较低的城市和水资源禀赋较高的城市生活水效提升;各城市间的人均日生活用水量差异显著,但这种差异呈现缩小趋势;收入弹性基本稳定,人均可支配收入增长10%,人均生活用水量增长7%左右,而价格弹性不断变小,从2009年的-0.484逐年下降至2013年的-0.187,意味着城市水价微调对于生活用水的影响越来越小,为更好发挥水价机制在水资源配置方面的作用,需要推动水价政策变革。

Benefit evaluation of the Three-Gorges Reservoir migration by an assessment index model based on analytic hierarchy process

An assessment index model was established to evaulate the benefit of the Three-Gorges Reservoir migration through the analytical hierarchy process. Totally 43 indicators were selected to assess the impact of migration on the economic, social and ecological environmental aspects of the migration communities, with the data of the indicators of the years 1992, 1998, 2002 which represented the period of premigration, the end of the first phase migration and the end of the second phase migration, respectively. The evaluation matrix is sufficiently consistent, with a consistency ratio CR equal to 0.086 3. The assessment turned out a benefit value for the economic subsystem in the year 2004 larger than triple the value in the year 1992, indicating a remarkable economic growth in the Reservoir area. The constantly increasing value for the social subsystem reflects the stable social situations. There is a slight decline in the assessment outcome of the ecological subsystem for the year 1998, which implies enviromental conservation was given insufficient importance during that period. On the whole, the implementation of the migration project is favorable to the Reservoir region, as confirmed by the stably increasing overall evaluation value from 42.22% in 1992 to 68.81% in 2002. However, there is still much room to improve from the status quo to the target criteria.

Exposure Level, Toxicity Effects and Health Risk Assessment of Organophosphorus Flame Retardants in Water Environment

Organophosphorus flame retardants(OPFRs) are gradually replacing brominated flame retardants(BFRs), which are widely used in the world. The increasing output of OPFRs and the increasing detection of OPFRs in environmental media have attracted wide attention of scholars at home and abroad. OPFRs are generally semi-volatile, easy to enter the environment and accumulate in organisms,causing potential hazards to the environment and human health. In this paper, the pollution status and toxic effects of OPFRs in aquatic environment were introduced,and the research progress of human health risk caused by them was summarized.The existing problems were pointed out, and the future research was prospected. In the future, the analytical methods of various environmental and biological media should be improved, and comprehensive and in-depth environmental investigation and ecological and health risk assessment should be carried out. Attention should be paid to the effects of combined pollution on organisms and the study of biological acceptability.

Remote Sensing for Assessing Water Management and Irrigation Performance in the Arid Environment of the Gezira Scheme, Sudan

The effective and efficient management of agricultural water use is crucial to enhance agricultural production to meet the demand of a rapidly growing population. The performance assessment studies are successfully used to describe the irrigation problems and provide remedial measures. In this study, the performance assessment of the twin main canals of the Gezira Scheme were examined and evaluated using a set of performance indicators. The analysis was made using 3 Landsat and 8 Modis data of 2001-2002, and results showed that the seasonal average values of water productivity, relative water supply, overall consumed ratio, depleted fraction and relative evapotranspiration were respectively 0.47, 0.72, 1.41, 0.75 and 0.57 kg·m^-3 for Gezira main canal, whereas the values for Managil main canal were 0.43, 0.54, 1.68, 0.71 and 0.50 kg·m^-3, respectively. The monthly average values of crop water deficit for Gezira and Managil were respectively 71 and 78 mm-month^-1. Considering the spatial variation in some indicators, the irrigation uniformity is deemed as poor according to Molden and Gates （1990）. The analysis also showed that the gap between water demand and supply during winter season was glaringly high （46%）.

Analysis of Irrigation Systems Employing Comparative Performance Indicators： A Benchmark Study for National Irrigation and Communal Irrigation Systems in Cagayan River Basin

Comparative performance analysis of four irrigation schemes within Cagayan River Basin was assessed using comparative performance indicators between the years 2008 and 2012. The objectives were to establish benchmarks for both productivity and performance of irrigation schemes along the valley and to inquire whether small schemes function better than large schemes. The performance evaluation study of the systems composed of three general performance indicators, based on three domains-（1） system operation performance; （2） agricultural productivity and economics; （3） financial performance. Each indicator was assessed based on the prescribed descriptors used by the International Water Management Institute （IWMI） and Food and Agriculture Organization （FAO）. Analysis showed an overall system performance efficiency of 59%, 55%, 47% and 36% for Magat River Integrated Irrigation System （MARI1S）, Lucban, Garab and Divisoria Communal Irrigation Systems （CIS）, respectively. In terms of annual productivity performance, Lucban CIS dominates the three other systems with 0.35 kg/m3, which was classified as moderately performing system, while the rest were classified with low productivity index. Financial sustainability of the systems were extremely poor with cost recovery ratio of 0, 0.33, 0.41 and 0.49 for Divisoria, Garab, Lucban and MARIIS, respectively, which were exceptionally below the standard value of at least one. Also, analysis of the indicators revealed that on average, large schemes performed similarly to small-scale schemes, but small schemes were more variable, particularly in input-use efficiency. The benchmarking study will provide strategic information to policy makers of agricultural and irrigation agencies on the existing weaknesses of irrigation systems in the country and determine in a more quantifiable terms levels of potential improvement and intervention targets.

Hybrid assessment of pre-blasting weakening to horizontal section top coal caving (HSTCC) in steep and thick seams

Horizontal section top-coal(HSTCC)caving offers a powerful method to efficiently excavate rude coal in steep and thick seams,and pre-blasting weakening has a profound effect on pursuing great production,high efficiency and good benefit under particular conditions like a small-scale working face with large-scale sectional caving height.+564-level HSTCC working face in B3–6coal seams of Jiangou Colliery in Urumqi was taken as study case for in situ industrial experiment.Total thickness of seams in the study case is about 50.0 m and average angel here is over 83°.In the industrial experiments,at first we adopted continuous charge machine and emulsion matrix explosive to substitute for traditional blasting schemes for specific geological settings in the study case.Hybrid analyses and assessments with blasting crack propagation analysis,abutment pressure monitoring prediction and economical benefit assessment were attributed to be able to attest pre-blasting weakening effects practically.Meanwhile crack propagation analysis after pre-blasting weakening showed that in all triple monitoring bore holes rock masses of top-coal would be fallen into three stages from the bottom up:fracture zone,plastic zone and elastic zone generally,and fracture toughness respectively in correspondent zones was calculated by the analytical formula:0.5616–0.8806,0.6403–0.9541 and0.7535–1.1900 MPa m1/2after pre-blasting weakening.Pressure monitoring prediction and economical benefit assessment also indicated that it was necessary to introduce the pre-blasting weakening with predominant blasting scheme from both views.For excavation in extremely steep and thick coal seams,relevant results would be a useful tool to study the mechanism of pre-blasting weakening both qualitatively and quantitatively.

Design of an Index System for Deep Groundwater Management Efficiency Evaluation: A Case Study in Tianjin City, China

An effective evaluation system can provide specific and practical suggestions to the deep groundwater management. But such kind of evaluation system has not been proposed in China. In this study, an evaluation index system is specifically developed to evaluate deep groundwater management efficiency. It is composed of three first-level indicators(law enforcement capability, management ability, and management effectiveness) and eleven second-level indicators. The second-level indicators include seven mandatory indicators and four optional indicators. Piecewise linear function is used to normalize the quantitative indicators, and expert scoring method and questionnaire survey method are used to normalize the qualitative indicators. Then a comprehensive indicator weighting evaluation method is used to evaluate the first-level indicators and the target topic. A case study is carried out to evaluate deep groundwater management efficiency in Tianjin City. According to the evaluation score in each period, the management efficiency of every district in Tianjin City gradually improved. The overall evaluation score in the early deep groundwater extraction period is 0.12. After a series of deep groundwater protection efforts, this score reached to 0.61 in 2007, and met the regulation criteria. The evaluation results also showed that the further groundwater management efforts in Tianjin City should be focused on building a dynamic database to collect comprehensive deep well-log data; and on a reasonable design and distribution of the groundwater monitoring network. It demonstrated that the index system is suitable to locate the deficiencies of current groundwater management systems and to guide further improvements. It can then be used to protect deep groundwater.

An Assessment of Ingestion Dose due to the Intake of ^210Po and ^210Pb through Drinking Water of Eloor, Ernakulam District, Kerala, India

The present study aims at measuring the activity concentrations of ^210Po and ^210Pb in the potable water of Eloor, a major industrial belt in the Ernakulam district of Kerala, India with an aim of evaluating resultant ingestion dose to critical population. The industrial units located in Eloor discharge their treated effluents into the river Periyar and the surrounding environs. The two major industries of interest with respect to NORMs are the fertilizer plant, processing rock phosphate and the monazite processing plant, which had been in operation for the last 50 years. For sampling, Eloor region was divided into four zones and a total of 55 water samples from different locations were collected and analysed as per standard analytical procedure manual of BARC. The ^210Po concentration ranged between 0.3 to 4.7 mBq.L^-1 and ^210Pb ranged from 0.6 to 4.3 mBq.L^-1. All values are well below the limit of 0.1 Bq.Ll recommended by World Health Organization. Statistical analysis shows a good co-relation between ^210Po and ^210Pb in the water samples analyzed and the mean activity concentration is found to be relatively high in the western region of Eloor compared to other regions. The annual effective dose equivalent to man from ^210Po and ^210Pb through drinking water intake were estimated and found to be 1.13 μSv.y^-1 and 0.99 μSv.y^-1 respectively, which is well below the reference level of committed effective dose （100 μSv.y^-1） recommended by WHO.

Modelling of Chillers for Energy Performance Assessment of HVAC Systems

The reliable assessment of the annual energy demand has become necessary in view of building energy performance certification. Accurate models must be used to simulate the behaviour of HVAC （heating, ventilation and air conditioning） components in real operation, usually characterized by a wide variation of building loads. In this context, this paper deals with the development and validation of an algorithm aimed at the assessment of part load performance of various kinds of controls for vapour compresion based heat pumps and chillers, in particular referring to on-off, inverter-driven and multi-stage vapour compression. The reliability of this algorithm in the calculation of seasonal performances is checked against monitoring of heat pumps and chillers operating under real conditions.