Evaluating Water Withdrawals for Regional Water Management Under a Data-driven Framework

With an increase in population and economic development,water withdrawals are close to or even exceed the amount of water available in many regions of the world.Modelling water withdrawals could help water planners improve the efficiency of water use,water resources allocation,and management in order to alleviate water crises.However,minimal information has been obtained on how water withdrawals have changed over space and time,especially on a regional or local scale.This research proposes a data-driven framework to help estimate county-level distribution of water withdrawals.Using this framework,spatial statistical methods are used to estimate water withdrawals for agricultural,industrial,and domestic purposes in the Huaihe River watershed in China for the period 1978–2018.Total water withdrawals were found to have more than doubled,from 292.55×10^(8)m^(3) in 1978 to 642.93×10^(8)m^(3) in 2009,and decreased to 602.63×10^(8)m^(3) in 2018.Agricultural water increased from 208.17×10^(8)m^(3) in 1978 to 435.80×10^(8)m^(3) in 2009 and decreased to 360.84×10^(8)m^(3) in 2018.Industrial and domestic water usage constantly increased throughout the 1978–2018 period.In 1978,industrial and domestic demands were 20.35×10^(8)m^(3) and 60.04×10^(8)m^(3),respectively,and up until 2018,the figures were 105.58×10^(8)m^(3) and 136.20×10^(8)m^(3).From a spatial distribution perspective,Moran’s I statistical results show that the total water withdrawal has significant spatial autocorrelation during 1978–2018.The overall trend was a gradual increase in 1978–2010 with withdrawal beginning to decline in 2010–2018.The results of Getis-Ord G_(i)^(*)statistical calculations showed spatially contiguous clusters of total water withdrawal in the Huaihe River watershed during1978–2010,and the spatial agglomeration weakened from 2010 to 2018.This study provides a data-driven framework for assessing water withdrawals to enable a deeper understanding of competing water use among economic sectors as well as water withdrawal modelled with proper data resource and method.

Spatial Patterns of Irrigation Water Withdrawals in China and Implications for Water Saving

By considering numerical features, spatial variation, and spatial association, the spatial patterns of China's irrigation water withdrawals in 2001 and 2010 were explored at the regional, provincial, and prefectural scales. In addition, an overlay analysis was used to develop specific water-saving guidance for areas under different levels of water stress and with different degrees of irrigation water withdrawals. It was found that at the regional scale, irrigation water withdrawals were highest in the Middle-Lower Yangtze River region in both years, while at the provincial scale, the largest irrigation water withdrawals occurred in Xinjiang. During 2001–2010, the total of irrigation water withdrawals decreased; however, in the Northeast region, especially in Heilongjiang Province, it experienced a dramatic increase. The spatial variation was largest at the prefectural scale, with an apparent effect. The spatial association was globally negative at the provincial scale, and Xinjiang was the only significant high-low outlier. In contrast, the association displayed a significant positive relationship at the prefectural scale, and several clusters and outliers were detected. Finally, it was found that the water stress in the northern part of China worsened and water-saving irrigation techniques urgently need to be applied in the Northeast region, the Huang-Huai-Hai Plain region, and Gansu-Xinjiang region. This study verified that a multi-scale and aspect analysis of the spatial patterns of irrigation water withdrawals were essential and provided water-saving advice for different areas.

Optimizing selective withdrawal strategies to mitigate hypoxia under water-level reduction in Germany’s largest drinking water reservoir

Water-level reduction frequently occurs in deep reservoirs,but its effect on dissolved oxygen concentration is not well understood.In this study we used a well-established water qual-itymodel to illustrate effects of water level dynamics on oxygen concentration in Rappbode Reservoir,Germany.We then systematically elucidated the potential of selectivewithdrawal to control hypoxia under changing water levels.Our results documented a gradual decrease of hypolimnetic oxygen concentration under decreasing water level,and hypoxia occurred when the initial level was lower than 410 m a.s.l(71 m relative to the reservoir bottom).We also suggested that changes of hypoxic region,under increasing hypolimnetic withdrawal discharge,followed a unimodal trajectory with themaximum hypoxic area projected under the discharge between 3 m^(3)/sec and 4 m^(3)/sec.Besides,our results illustrated the extent of hypoxia was most effectively inhibited if the withdrawal strategy was applied at the end of stratification with the outlet elevation at the deepest part of the reservoir.Moreover,hy-poxia can be totally avoided under a hybrid elevation withdrawal strategy using surface withdrawal during early and mid stratification,and deep withdrawal at the end of strat-ification.We further confirmed the decisive role of thermal structure in the formation of hypoxia under water-level reduction and withdrawal strategies.We believe the conclusions from this study can be applied to many deep waters in the temperate zone,and the results should guide stakeholders to mitigate negative impacts of hypoxia on aquatic ecosystems.

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.

基于多维度输入的水厂日取水量卷积长短期记忆网络预测

鉴于传统的单维输入卷积长短期记忆网络(CNN-LSTM)的预测精度依赖于历史数据的规律性,构建了基于多维度输入的卷积长短期记忆网络预测模型,其中采用皮尔逊相关分析来识别数据内部特征或外界环境因子相关性,在此基础上构建模型输入,并应用于两个自来水厂日取水量预测。结果表明,相较于传统单维度输入预测模型,构建的基于数据内部特征或外部环境因子的多维度输入CNN-LSTM预测导致A水厂取水量的平均绝对百分比误差分别降低了32%、17%;B水厂的平均绝对百分比误差分别降低了47%、12%,表明基于数据内部特征的多维度输入模型更高。其余评价指标也呈现类似变化;且增大水厂取水量有助于提高模型的预测精度。该模型输入分析方法可为提高预测模型精度提供有效范例。

溪洛渡水库分层取水对向家坝库区水温的影响分析

为了探究上游溪洛渡水库分层取水对下游向家坝库区水温的影响,基于历史水文数据,分析向家坝建库对河道水温的影响,结合率定好的CE-QUAL-W2模型,设置溪洛渡水库分层取水与不分层取水两种计算工况,分析2019年溪洛渡水库分层取水对下游向家坝库区水温变化过程的影响。结果表明,向家坝水库蓄水后使坝下河道水温达到18℃的时间滞后50 d,向家坝坝下河道水温受支流水温影响较大;2019年上游溪洛渡水库分层取水在4~5月最高可使下游向家坝库区表层水温升高1.0℃,其影响沿程逐渐减弱,至绥江县城完全消失;分层取水使下游向家坝库区4~5月水温结构明显改变,4~5月下泄水温明显提高,最大可提高0.48℃。研究结果可提高对叠梁门分层取水效果的认识,并为后续生态调度提供科学依据。

京杭大运河全线贯通补水对地下水回补的影响

基于2022—2023年京杭大运河(小运河、卫运河、南运河、北运河、通惠河)全线贯通补水期间沿线419眼浅井和173眼深井地下水位监测数据,分析实施生态补水后河道的入渗水量以及河道沿线和灌溉水源置换区的地下水位变化。结果表明:相较小运河、北运河和通惠河等衬砌河道,卫运河和南运河渗透性较好,地下水回补效果更为显著;贯通补水后大运河河道周边0~10 km范围内浅层地下水位较去年同期回升0.48 m,3—5月春灌期取水过程中大运河沿线地下水位下降幅度减少了0.19 m,表明生态补水对地下水位恢复具有积极作用;河道周边地下水位对生态补水过程的响应有滞后,表现为距离河道越近,水位下降幅度越小;水源置换能够有效缓解因灌溉取水导致的水位下降,卫运河和南运河段农灌受水区深、浅层地下水位较去年同期分别回升3.17 m和0.27 m。重点对入渗性强、灌溉需水量高的河段持续实施生态补水,保证河道水量,能够更为有效地促进地下水水位回升。

综采工作面双回撤通道围岩控制技术研究

为保证某矿21102工作面双回撤通道稳定,实现综采设备安全高效回撤,提出锚网索支护+末采临近双排高强立柱的支护方式,通过计算,高强立柱的承载力需大于6.4 MPa。共设计全部采用直径φ1 m的高强立柱、混合采用直径φ1 m和φ0.8 m的高强立柱、全部采用直径φ0.8 m的高强立柱3种支护方案。通过计算,决定施工2排直径φ1 m的高强立柱、间排距1.8 m×1.2 m,采用“三花”布置方式。高强立柱采用新型ZKD型高水速凝充填材料,强度达到15 MPa,在立柱对应的锚索上固定玻璃钢锚杆一体浇筑,将HDPE树脂套管固定在顶板上同时采用约束钢带箍筋可防止高强立柱歪斜变形。实践表明,末采期间回撤通道采用锚网索+高强支柱的支护方式,能够抵御末采期间超前支撑应力和动压影响,回采过程中未见大规模的片帮、冒顶或顶板破碎情况,取得了良好的支护效果。

葡萄酒厂水资源论证分析

开展规划水资源论证是落实最严格的水资源管理制度,协调经济社会发展与水资源承载能力的重要手段。根据葡萄酒厂所处区域情况,分析项目取水的必要性,分析、论证项目取、退水方案的合理性,用水合理性及节水分析,取、退水影响分析等,为项目区确定了合理的取用水量。

取用水领域信用体系建设的思考与建议

将社会信用引入取用水管理,通过信用的优劣评价,对从事水资源开发、保护、利用、节约活动的单位和个人在依法取用水、履行取用水义务方面形成约束力,是规范取用水秩序的创新手段和强化水资源刚性约束的重要内容。结合当前取用水管理需求和实际,分析了取用水领域信用体系建设的必要性和重要意义,梳理有关领域信用体系建设经验与取用水领域信用体系建设探索情况,阐述取用水领域信用体系内涵,并从推动实施取用水领域信用评价、加强严重失信主体信用管理、开展信用日常监督管理、推进取用水领域信用体系信息化建设和加强宣传营造良好氛围等方面提出建议,为进一步推进我国取用水领域信用体系建设提供参考。

2×660 MW机组煤电一体化工程水资源论证分析

目前,国家关于煤电路一体化项目和大型空冷机组建设中,对于项目水源配置方案要求符合当地水资源条件、水资源规划和管理等多方面要求。文章以某2×660 MW机组煤电一体化项目为例,进行了深入的水资源论证研究。对项目的取用水合理性进行了专项分析并得出结论:项目取水方案及水源可靠、项目的退水方案可行,并给出了取水和退水影响消减措施。该项目水资源论证工作的实施,对水资源的规划、管理、保护及建设项目的安全生产具有重要意义。

水利建设项目安全生产费用的思考

水利建设项目安全生产费用的计取在前期工作阶段、建设实施阶段有不同的要求,对应不同的计算方式。安全生产费用使用方面主要存在问题包括未在招投标文件中单列安全生产费用项目报价、工程承包合同中未约定安全生产费用有关内容、施工企业内部制度不健全且管理不规范、未按规定范围安排使用等。针对这些问题,提出了加强招投标工作中安全生产费用管理、施工企业加强内部管理等对策建议。

Characteristics of the Correlation between Regional Water Vapor Transport along with the Convective Action and Variation of the Pacific Subtropical High in 1998

This paper explores the impact of the convective action over the low-latitude region, the water vapor transport around the West Pacific subtropical high (WPSH), and its convective action on the seasonal northward jump and southward withdrawal of the WPSH in summer by using the daily data set of NCEP and TBB for 1998. The research shows that in summer, the WPSH moves northward when the convection over the low-latitude tropical region intensifies and the subsidence region of the meridional vertically vertical circulation in meridional direction circulation over the region of 110?150癊 moves northward. Furthermore, as revealed by diagnostic analysis, the subtropical high moves northward after the obvious weakening of the longitudinal water vapor transport over the region around the subtropical high, but withdraws southward a pentad after the reduction of the latitudinal water vapor transport over the tropical West Pacific region. The research results show that the northward jump and southward withdrawal of the WPSH are closely related to the release of the convective latent heat at low latitudes and the water vapor transport at boundaries around WPSH and its convective action. The numerical simulation further validates the above-mentioned correlation between the variation of the action of the subtropical high and the preceding water vapor transport along with the convection characteristics.

Multi-level Flocculation Structures of Fresh Cement Paste by Confocal Laser Scanning Microscope

Under saturation dosage of all kinds of SP, the free water amount was examined by centrifuge. The distribution of solution and flocculation microstructures in fresh cement paste was observed in three- dimensional space by confocal laser scanning microscope（CLSM）. Results indicate that SP can increase the free water amount by destroying the flocculated cement particle structure and different free water amount is released by different kinds of SP. The changes of the size of flocculation structures and the dispersion of solution were obviously detected with confocal laser scanning microscope： the size of flocculation structures was smaller and more dispersed in fresh cement paste with polycarboxylate superplasticizer, but the size of flocculation structures was bigger and cannot be dispersed uniformly in fresh cement paste with others SP. The multi- level flocculation structures theoretical model of fresh cement paste was then set up. The theory indicates that different kinds of SP with different dispersion strength will open the flocculation structures at different levels, which in turn present different water reducing rate.

长江流域饮用水水源地名录管理的思考和建议

《长江保护法》规定了长江流域饮用水水源地名录管理的制度内容,也确认了水行政主管部门水源地保护的法定职责。为深入落实《长江保护法》要求,在全面分析长江流域饮用水水源地管理现状的基础上,分析了长江流域饮用水水源地名录管理形势要求,提出了加强长江流域饮用水水源地名录管理的工作思路和建议。研究成果可强化《长江保护法》饮用水水源地保护制度落实,为加强流域饮用水水源地管理提供决策依据,对建立以水源地名录管理为基础的水源地保护体系、复苏河湖生态环境具有深远的指导意义。

糯扎渡水电站不同调度下下泄低温水改善效果研究

【目的】大型水库下泄低温水影响及相应的减缓措施效果受到水库运行、取水方式等因素的影响,各因素之间彼此联系、相互作用。明晰水库运行方式对下泄水温的影响及其对叠梁门分层取水改善效果,可为大型水库的叠梁门分层取水效果评估及优化调度提供参考。【方法】以糯扎渡水电站为研究对象,建立糯扎渡立面二维水温数学模型,探讨水库运行方式对下泄水温及叠梁门分层取水效果的影响。【结果】结果显示:(1)水库修建后下泄水体存在明显的冬季高温水、夏季低温水现象,单独运行时,10月—次年2月水温较天然水温平均偏高2.0℃,4—6月偏低2.9℃。(2)与单独运行相比,糯扎渡水电站在梯级联合运行下的下泄水体升温效应更强,10月—次年2月水温平均升高2.5℃,3—8月水温平均升高1.4℃。(3)使用叠梁门后,4—8月下泄水温较单层取水时平均提高1.9℃,水温达到18℃的时间平均提前78 d。【结论】结果表明:澜沧江下游梯级联合运行对高温水产生叠加影响,对低温水表现出削弱影响;叠梁门抬高了取水流动层位置,对下泄水温有较好的改善作用,其改善效果与淹没水深、运行时段有明显的关系。

Total control-based unified allocation model for allowable basin water withdrawal and sewage discharge

In this paper,a new model with a total amount control target of allowable water withdrawal based on initial water right is built for the implementation of initial water right allocation scheme as well as unified allocation for allowable water withdrawal and sewage discharge.The model couples the water allocation simulation model and the computational model of permissible pol-lution bearing capacity.In view of the model complexity,a new technology which synthesizes system simulation,iterative reservoir turns and intelligent computation is proposed to improve the operability of allocation scheme and computational efficiency.Taking the Beijiang River Basin in the Pearl River Basin as an example,the study explains the model establishment,solution and application,and draws an optimized operation graph of large-scale reservoirs.The study also obtains a long-term operation strategy of river basin water resources system,the allocation schemes of allowable water withdrawal and sewage discharge in a typical year and the flow hydrographs of trans-boundary sections.The validity of the model and the allocation rationality are analyzed as well.

Demand-driven water withdrawals by Chinese industry： a multi-regional input-output analysis

With ever increasing water demands and the continuous intensification of water scarcity arising from China＇s industrialization, the country is struggling to harmonize its industrial development and water supply. This paper presents a systems analysis of water with- drawals by Chinese industry and investigates demand- driven industrial water uses embodied in final demand and interregional trade based on a multi-regional input-output model. In 2007, the Electric Power, Steam, and Hot Water Production and Supply sector ranks first in direct industrial water withdrawal （DWW）, and Construction has the largest embodied industrial water use （EWU）. Investment, consumption, and exports contribute to 34.6%, 33.3%, and 30.6% of the national total EWU, respectively. Specifically, 58.0%, 51.1%, 48.6%, 43.3%, and 37.5% of the regional EWUs respectively in Guangdong, Shanghai, Zhejiang, Jiangsu, and Fujian are attributed to international exports. The total interregional import/export of embodied water is equivalent to about 40% of the national total DWW, of which 55.5% is associated with the DWWs of Electric Power, Steam, and Hot Water Production and Supply. Jiangsu is the biggest interregional exporter and deficit receiver of embodied water, in contrast to Guangdong as the biggest interregional importer and surplus receiver. Without implementing effective water- saving measures and adjusting industrial structures, the regional imbalance between water availability and water demand tends to intensify considering the water impact of domestic trade of industrial products. Steps taken to improve water use efficiency in production, and to enhance embodied water saving in consumption are both of great significance for supporting China＇s water policies.

丙烯腈装置流化床反应器化学清洗方法与实践

介绍了某26万t/a丙烯腈装置流化床反应器撤热水系统的化学清洗方法及现场实际操作的过程。丙烯腈装置反应器的撤热水系统划分为N个象限,其每个象限由数根支管组成,且反应器内部结构为U型的纵向盘管。U型纵向盘管的结构特点决定了其内部极易存在污垢、锈蚀产物的沉积。针对该种情况,选用带有络合功能的复合清洗剂进行化学清洗,并且在清洗设备选型、不同清洗阶段的清洗系统划分等方面进行设计优化,可确保清洗后装置在启用前达到理想的清洁状态。

Synergetic pathways of water-energy-carbon in ecologically vulnerable regions aiming for carbon neutrality:a case study of Shaanxi,China

Synergetic energy-water-carbon pathways are key issues to be tackled under carbon-neutral target and high-quality development worldwide,especially in ecologically vulnerable regions(EVRs).In this study,to explore the synergistic pathways in an EVR,a water-energy-carbon assessment(WECA)model was built,and the synergistic effects of water-energy-carbon were comprehensively and quantitatively analyzed under various scenarios of regional transition.Shaanxi Province was chosen as the representative EVR,and Lower challenge(LEC)and Greater challenge(GER)scenarios of zerocarbon transition were set considering the technological maturity and regional energy characteristics.The results showed that there were limited effects under the zero-carbon transition of the entire region on reducing water withdrawals and improving the water quality.In the LEC scenario,the energy demand and CO_(2) emissions of Shaanxi in 2060 will decrease by 70.9%and 99.4%,respectively,whereas the water withdrawal and freshwater aquatic ecotoxicity potential(FAETP)will only decrease by 8.9%and 1.6%,respectively.This could be attributed to the stronger demand for electricity in the energy demand sector caused by industrial transition measures.The GER scenario showed significant growth in water withdrawals(16.0%)and FAETP(36.0%)because of additional biomass demand.To promote the synergetic development of regional transition,EVRs should urgently promote zero-carbon technologies(especially solar and wind power technologies)between 2020 and 2060 and dry cooling technology for power generation before 2030.In particular,a cautious attitude toward the biomass energy with carbon capture and storage technology in EVRs is strongly recommended.