In order to explore the impact of hydrological variation and external diversion of water supply on power generation and ecology of hydropower stations, taking the downstream water-reducing reach of Guanting Reservoir as an example, based on the calculation of ecological flow under hydrological variation, the ecological assurance degree of the water-reducing reach is defined. A multi-objective optimal operation model for reservoir power generation and ecological guarantee degree is established, and the non-dominated sorting genetic algorithm（NSGA-II） is used to solve multiple scenarios. The results show that the inflow runoff of Guanting Reservoir changed in 1971 and 1983 respectively, and the power generation and average ecological assurance degree decreased significantly after the hydrological variation. The multi-objective relationship between hydropower generation and ecology is significant, and the reduction of 37.4% in power generation can increase 67.8% in ecological benefits. The power generation and the average ecological guarantee degree are significantly improved after the recharge of the external water source, especially in the dry year, which increased by 56.9% and 40.3% respectively.

Considering the two key indicators of per capita GDP and per capita energy consumption, this study comprehensively analyzed the environmental Kuznets curve（EKC） of the total water consumption and different industrial water consumptions in China from 1997 to 2020, and the multiple tests, including augmented Dickey-Fuller test, t-test, and Breusch-Godfrey test, were used to optimize the parameters of the EKC model. Then, the supply side and demand side of water resources were further analyzed. Results indicate that EKCs of total water consumption, industrial water consumption, and agricultural water consumption show inverted “N” shape, and the total water consumption, industrial water consumption, and agricultural water consumption exhibit declining trends; EKC of tertiary industrial water consumption exhibits a linear growth trend, and the tertiary industrial water consumption has not reached the declining stage yet; tertiary industrial water consumption is the main growing point of water consumption in future, and reduction of groundwater extraction should be emphasized.

受2305号台风"杜苏芮"带来的强降雨影响,海河流域发生"23·7"流域性特大洪水.台风"杜苏芮"登陆后,北京市水务局密切跟踪云团行进路径,加密与气象部门会商,依据气象部门降雨预报结果,利用"北京模型"开展流域洪水、城市内涝、山洪灾害的预报,及时研判洪水总量和洪峰等关键要素,超前发布预警.在洪水发生发展过程中,以流域为单元,统筹上下游、左右岸、干支流,采用预泄、拦洪、蓄滞等综合调度措施并动态调整,最大程度发挥了防洪工程体系综合防洪减灾效益,有序调度洪水,减轻洪涝灾害损失.灾后全面恢复重建阶段,结合卫星遥感影像解译、现场调查等手段,开展洪水反演、移置分析等总结复盘、系统评估灾情工作,为补齐工程体系、监测预报等能力短板,健全规划标准体系,有序开展灾后重建提供技术支撑.

国家"十四五"规划纲要明确提出"构建智慧水利体系,以流域为单元提升水情测报和智能调度能力",水利部提出要加快构建具有"四预"(预报、预警、预演、预案)功能的智慧水利体系.

Aiming at the inconsistency between the results of precipitation water resources assessment and annual scale water resources assessment, a new evaluation method of precipitation water resource is proposed in this paper by splitting the runoff components such as antecedent precipitation recession and annual scale base flow, in order to realize the refined evaluation of precipitation water resources. The analysis results in the typical basin of Chaobai River show that the method has good adaptability, significantly improve the pertinence and accuracy of the assessment results of precipitation water resources, and fulfills the needs of water resources assessment with multiple temporal and spatial scale coordination.

Urban flooding is a global water disaster resulting from the expansion of urban impervious surfaces and the strengthening of extreme precipitation events, especially in China. Nonetheless, few studies have focused on the spatial distributions of urban flooding characteristics and their variations in the context of climate change. In this study, eight critical metrics (i.e., maximum flooding volume, total overloaded manholes with different flooding volumes or durations, total flooding volume, mean and maximum flooding durations, maximum inundation area, and depth) are adopted to characterize the urban flood events. The impacts of climate change on these metrics are assessed for two periods, the 2030s (2020–2049) and 2070s (2060–2089), and compared with those in the baseline period (1976–2005). The Future Science City Park in Beijing, China, is selected as our study area. The results show that all four flood events are well simulated, with both efficiency coefficients and correlation coefficients being over 0.8. The number of overloaded manholes and the total flooding volume are projected to increase 19.3%–44.8% and 171%–716% under 20‐year rainfall events due to climate change in the two future periods. The spatial distribution of overloaded manholes with different increased flooding volumes is projected to expand to almost the whole area from the region with lowland and limited drainage capacity. Furthermore, the maximum inundation area and depth are projected to increase obviously. This study will be helpful for designing and improving the drainage system, controlling urban flooding, and adapting to climate change.

从海绵城市建设前的背景监测、海绵设施监测、场地尺度监测、排水分区监测及城市监测等5个不同尺度综述了海绵城市监测所用到的技术与方案,包括监测点布设原则、监测内容、监测频率及监测设备选型等,提出了目前监测面临的困难.研究成果可以为国内海绵城市监测方案的制定提供借鉴.

为判断顺义区节水所处阶段、指导未来节水方向,在SDA的使用中不引入投入产出表,从产业用水和家庭用水两方面,采用两极分解法分解顺义区2010～2019年的用水情况,并得到顺义区用水驱动因素变化情况.结果表明,两极分解法比初始分解法得出的结果稳定性更高,可解决SDA分解路径不唯一的问题;顺义区产业节水主要驱动力已由结构调整逐渐转向技术提升,结构效应节水潜力较小,产业节水应继续侧重行业用水效率提升.农村人均家庭用水量增长较快,未来需加强农村节水意识、节水器具的普及.

开展精准化临近期降水预报是开展实时洪涝预测预警的基础.传统的临近期降水预报一般基于气候模式进行数值预报,计算时间较长、空间分辨率低,预报精度仅为15％～20％,难以满足洪涝灾害预测预警需求.为快速、高精度、高空间分辨率预报降水过程,本研究提出了一种基于气象雷达反演和云图外推法的临近期降雨预报方法.主要包括:(1)采用金字塔光流法(Pyramid Lucas Kanade Optical Flow,简称LK光流法)进行云的运动矢量计算,根据运动矢量计算云团的运移位置;(2)提出基于回波强度和梯度特征的云层类型自动识别方法;(3)利用回波反射率与降水强度间的关系进行临近期降水量的反演及预报;(4)对预报结果进行落区精度评估和量级精度评估.2019-2020年四场降水实验研究结果表明:该方法可以实现0～1 h近实时1km高空间分辨率预测,而且预测期内的降水落区预测精度较高,平均精度可达60％;对落区内雨量站的量级精度进行对比分析得出四场降水的偏差 BIAS 分别为 0.23 mm、3.56 mm、-7.12 mm、-5.15 mm,均方根误差 RMSE 分别为 5.09 mm、8.45 mm、21.23 mm、14.63 mm,四场降水的相对误差绝对值均值为37.21％.预测精度均随时间增加呈下降趋势,下降程度与降水系统特征密切相关.总体来说,该方法对大范围高强度的降水预测精度较高,可为实时洪涝过程模拟分析提供重要支撑.

Combined sewer overflow pollution has gradually become the limiting factor for the further improvement of river water quality during rain events. Setting up a comprehensive regulation method based on synchronous monitoring is essential for combined sewer overflow management. However, current studies mainly focus on single monitoring and lack a correlation between control objectives and control effects. This study establishes a new aspect of a comprehensive regulation and control method based on overflow characteristic analysis, a calculation model, and control target determination. Through synchronous monitoring of the pipe network, the sewage treatment plant, and the river course in the Liangshui River basin of China, rainfall thresholds of outlets in a combined pipe network, pre-treatment overflow, and simple-treatment overflow were 14, 9, and 16 mm, respectively, and the overflow volume was positively correlated with the rainfall. The COD (chemical oxygen demand) concentration from the pre-treatment overflow was much higher than that from the combined pipe network, and the EMC (event mean concentration) in heavy rain was higher than in rainstorms. The shortest time exceeding the water quality by overflow pollution was 1 h, and the longest time was more than 7 days. Overflow load proportions of the three links were 43.4%, 32.8%, and 23.8%, accounting for 66.3% of the total pollutant load of the river, and the best scheme of input–output ratio was to regulate the first three outlets of overflow load. Our results provide comprehensive guidance and a systematic approach for the monitoring and control of combined sewer overflow.

大规模的跨区域生态水量调度,在恢复长期断流河道生态水量需求的同时,也打破了流域原有的水文循环规律.为识别生态补水对河道径流的影响,本文开展了永定河流域年径流历史序列时空变化及生态补水前后对比分析.结果表明:流域年径流量呈显著性减少趋势,且在1983年存在变点;变点年后年径流量大幅度减少,且日径流量历时曲线显示变异后低流量的分布历时增加,年内日径流量的差异变大;开展大规模生态补水工作以后,官厅水库年人库流量较之前多年平均有明显提高,年内逐月流量过程恢复明显的双峰过程,生态流量满足率显著提高,生态补水对现状条件下河道径流起到了积极作用.

考虑用水效率提升对不同时期用水定额的影响,核算了 1988-2019年北京市水足迹变化过程,利用信息熵方法对比分析了实体水和水足迹用水结构的演变特征.结果表明:北京市实体水开发利用情势不断优化,呈现农业和工业用水量快速下降、生活和生态用水量显著增加的变化规律,形成了以生活用水保障为主、生态用水需求提升为辅的用水格局;北京市水足迹不断上升,商品贸易带来的虚拟水净输入极大缓解了北京市用水压力,但提高了北京市对虚拟水净输入的依赖程度,2015-2019年农业和工业虚拟水净输入在其水足迹中的占比都超过60％,水资源系统常年处于严重超载状态;实体水系统信息熵呈先增后减的态势,生活与生态用水已逐渐成为占绝对优势的用水类型,水足迹系统前期为熵增过程,随后趋于稳定,用水结构较为均衡.

南水北调水源密云-怀柔-顺义(密怀顺)潮白河地下水回补工程,是密怀顺地下水源地可持续利用和河道生态恢复的重要保障.基于密怀顺回补河道区长期地下水水质监测数据,综合运用水质评价、统计学方法,分析了不同回补时期的地下水水化学变化特征;同时,采用水文地球化学模拟软件(PHREEQC)分析核心回补路线——小中河调水路线回补影响下的潮白河段地下水水文地球化学变化,结合聚类分析方法探究了地下水水化学变化成因.结果表明:①回补区地表水、地下水整体水质良好,南水北调水源及本地地下水水化学类型主要为HCO3-Ca-Mg型.补水以来,地下水水质整体得到改善,补水区域地下水中的Na+、Cl?明显降低.②根据水化学模拟,2017年底,小中河调水回补河道附近的地下水中南水与本地地下水混合比例变为1:10,但经过2018—2019年的回补,河道附近地下水中南水占主导地位,回补后所采集的地下水样中水化学成分基本与南水趋于一致.③根据水岩作用模拟,影响回补区地下水水质的主要因素为南水-当地地下水混合作用、矿物溶解及阳离子交换作用.研究显示,南水回补改善了地下水水质,并通过混合与水岩相互作用影响地下水水化学演化.

Land subsidence induced by groundwater level decline has spatiotemporal variations. Taking the Interferometric Synthetic Aperture Radar (InSAR) results and the groundwater subsidence data acquired by the monitoring stations as the source material, this paper aims to reveal the spatiotemporal heterogeneity of groundwater-land subsidence in Beijing plain by using the Wind Rose Map (WRM) method and the Change Point Analysis (CPA) method. The WRM results show that the amount and variation in subsidence differs in different directions. This method detected the formation of new subsidence centers and the slowdown of land subsidence in 2008. The CPA results show that obvious changes are detected in subsidence development at the Wangsiying (WSY), Tianzhu (TZ) and Wangjing (WJ) stations. However, there is a relatively stable trend of groundwater decline and land subsidence at the Tianzhu (TZ) station. The stages of land subsidence development show a significant response to groundwater. Moreover, changes in land subsidence also show delayed response behind the changes in groundwater level. The time-lag could be affected by the variation in amplitude of the groundwater level.

城市下垫面对径流过程的调控特征及其空间差异是城市化水文效应关注的热点.现有研究受基础资料和模型发展等制约,城市复杂下垫面影响下降雨-径流过程模拟和径流过程特征指标变化机制辨识仍需加强.本文采用时变增益水文非线性产流模型耦合排水管网水动力模型,实现了对城市多种下垫面类型和汇流方式下降雨-径流过程的耦合模拟.在此基础上,以不同下垫面和排水管网等条件的四座城市（北京、深圳、武汉和重庆）典型小区为例,通过相似性检验和秩次分析等探索了下垫面对径流过程特征指标（径流系数、年径流总量控制率、洪水时间尺度及峰现时间延迟等）的影响、空间差异及关键影响因子,并量化其贡献.结果表明:耦合模型对各小区场次径流过程的模拟效果明显优于国内外使用广泛的暴雨洪水管理模型（SWMM）. 60%场次（12/20）的综合模拟精度提高了4～86%;特别是对模型偏差的改善效果最好,其次为效率系数.除径流系数外,各地块年径流总量控制率、标准化洪水时间尺度和峰现时间延迟占比存在显著的空间差异,其差异性指数分别为0.43、0.22和0.16（p＜0.05）.显著性影响因子包括排水管网系统的管道长度（r=0.51）和下垫面类型中林地（r=0.56）、海绵措施（r=0.52）、草地（r=0.48）和不透水地表（r=0.46）面积占比;其中排水管网和下垫面类型的贡献率分别为4.27%和37.83%.下垫面类型对径流过程的调控占主导,其中北京以草地调蓄为主,表现为延迟和削减洪峰,对径流总量有一定削减作用;深圳调控并不显著,表现为以不透水地表产生的尖瘦型径流过程;武汉以林地调蓄为主,表现为削减径流总量和延迟洪峰;重庆以水域调蓄为主,表现为削减径流总量和洪峰流量.本文可为拓展城市化径流效应研究、海绵城市建设效果评估等提供理论和技术支持,也为中国城市水文模型的发展提供参考借鉴.

喹诺酮类抗生素(QNs)作为一种合成类抗菌药物,被广泛用于治疗人类和动物的感染性疾病.基于已有文献资料,分析我国水环境中喹诺酮类抗生素赋存现状,并运用风险熵法评估QNs的生态风险.结果表明:水环境中喹诺酮类抗生素环丙沙星(CIP)、氧氟沙星(OFL)质量浓度相对较高;东部地区喹诺酮类抗生素污染现状相对较严重,多种喹诺酮类抗生素质量浓度超过1μg/L;中部地区喹诺酮类抗生素质量浓度差异性相对较小;西部地区喹诺酮类抗生素污染较少,但OFL质量浓度相对较高;东北地区CIP和OFL质量浓度相对较高,OFL的质量浓度超过1μg/L;地下水中OFL质量浓度超过1μg/L,较大部分地表水中的高;同一采样区域的同种抗生素在丰水期与枯水期的质量浓度基本处于同一数量级;水环境中CIP和OFL的生态风险较诺氟沙星(NOR)、恩诺沙星(ENR)的高.

基于"危险性-暴露性.脆弱性"的内涝风险评估框架,采用层次分析法构建了北京城市副中心内涝风险评估体系,运用模型模拟法、GIS空间分析法等多种方法获取评估指标值,对研究区进行了 10、20、50 a 一遇降雨情景下的内涝风险评估.研究结果表明:1)副中心现状排涝能力基本满足10 a 一遇降雨,距离规划50 a 一遇的排涝标准有较大差距;2)中高风险区主要集中在北运河以西、通惠河以南的原通州老城区,运潮减河以北、小中河以东的区域,以及京秦铁路沿线路段的下凹桥区;3)积水危险性与内涝风险度结果并不吻合,内涝风险度评价结果更为科学,也更具指导性.建议对高风险区采取"一点一策"的方式制定应急预案,提升副中心洪涝预报预警能力.

The regulation and spatial differences of urban runoffs are of great concern in contemporary hydrological research. However, owing to a shortage of basic data sources and restrictions on urban hydrological simulation functions, simulating and investigating the regulation mechanism behind rainfall-runoff processes remain significantly challenging. In this study, the Time Variant Gain Model (TVGM), a hydrological nonlinear system model, was extrapolated to the hydrodynamic model of an urban drainage network system by integrating it with the widely used Stormwater Management Model (SWMM) to adequately simulate urban runoff events while considering various underlying surfaces and runoff routing modes, such as surface, drainage network and river runoff, in urban regions (i.e., TVGM-SWMM). Moreover, runoff events were characterized using the following four runoff regime metrics: runoff coefficient, capture ratio of annual runoff volume, standardized flood timescale, and the ratio of occurrence time differences between flow and rainfall peak to event duration (peak flow delay time). The characteristics and spatial differences of urban runoff regulations were investigated, and the key impact factors and their relative contributions were identified using multivariate statistical analyses. Four communities were selected as our study areas, consisting of communities from Beijing, Shenzhen, Wuhan, and Chongqing. Our results showed that the TVGM-SWMM performed considerably better than SWMM alone. The comprehensive simulation accuracy of 60% of the events (12/20) improved by 486%, with the bias improving the most, followed by the efficiency coefficient. Barring the runoff coefficient, significant spatial differences were identified at the patch scale for the runoff regime metrics, with differences of 0.43, 0.22, and 0.16 (p<0.05). The key impact factors were the pipe length (r=0.51) in the drainage network system and the forest area ratios (r=0.56), sponge measures (r=0.52), grassland (r=0.48), and impervious surface (r=0.46) in the underlying surfaces. The contributions of the drainage network system and the underlying surfaces were 4.27% and 37.83%, respectively. Regulation in the Beijing community, dominated by grassland regulation, delayed and reduced the peak flow and total runoff volume. In the Shenzhen community, sharp and thin runoff events were mainly generated by impervious surfaces and were not adequately regulated. Forest regulation was the dominant regulation type in the Wuhan community, which reduced the total runoff volume and delayed the peak flow. Waterbody regulation was the primary regulation type in the Chongqing community, which reduced the total runoff volume and peak flow. This study aims to introduce a comprehensive theoretical and technical assessment of the hydrological effects of urbanization and the performance of sponge city construction and provide a reference for urban hydrological model improvements in China.

低影响开发(LID)是海绵城市建设的重要技术之一,常用的LID设施又称典型海绵设施.为了对典型海绵设施的降雨、入渗、径流、蒸发过程进行长期监测分析,丰富典型海绵设施水文过程与污染物迁移转化过程的研究内容,加深对海绵设施的水量、水质转化全过程的了解,在北京市西郊雨洪调蓄工程园区建立了一个典型海绵设施水文过程综合监测实验场.该实验场的研究对象包括透水铺装、生物滞留设施和绿色屋顶.主要介绍该实验场典型海绵设施的结构设计、水循环过程以及污染物削减过程监测系统构建等,可为类似研究提供参考.

Entropy indexes are widely used to measure the complexity of precipitation and its spatiotemporal variability, due to their advantages in quantifying the complex and nonlinear interactions of climate variables. However, different entropy indexes may provide different outcomes on the complexity of precipitation, thus causing difficulties in the assessment of actual complexity. In this study, we identified and chose the optimal entropy index from six entropy indexes based on the reliability and stability of entropy values, to assess the complexity of precipitation. The six entropy indexes considered are: information entropy (IE), fuzzy entropy (FE), approximate entropy (AE), sample entropy (SE), wavelet entropy (WE), and permutation entropy (PE). We implemented the approach on the monthly precipitation data observed over the period 1968–2017 at 58 meteorological stations in Beijing, China. The results indicated that the SE index was the optimal index with the best reliability and stability and, thus, was used to examine the complexity of the 58 monthly precipitation series in Beijing. The results also suggested that the complexity of precipitation can be viewed in terms of four sub-regions in Beijing. The precipitation in the ‘Northern Mountain Area’, with high complexity, was more affected by the interactions between the terrain and climate variability, compared with that in the ‘Southern Mountain Area’ with low complexity. The precipitation in the ‘Central Urban Area’ was more significantly impacted by the extensive urbanization than that in the ‘Northeast Suburban Area’, causing higher complexity in the former. At temporal scale, the complexity of precipitation in the ‘Southern Mountain Area’ exhibited the largest increasing rate due to the highest impacts of climate variability, followed by the ‘Central Urban Area’ with a moderate increasing rate of complexity of precipitation due to the impacts of human activities. However, the complexity of precipitation in the ‘Northern Mountain Area’ and ‘Northeast Suburban Area’ exhibited small changes due to relatively weak sensitivity to climate variability and human activities.