Benchmarking Fluvial Dynamics for Process‐Based River Restoration: the Upper Rhine River (1816–2014)

Multi‐temporal analysis of river‐floodplain processes is a key tool for the identification of reference conditions or benchmarks and for the evaluation of deviations or deficits as a basis for process‐based river restoration in large modified rivers. This study developed a methodology for benchmarking fluvial processes at river segment level, focusing on those interrelations between morphodynamics (aggradation, erosion, channel shift) and vegetation succession (initial, colonization, transition) that condition habitat structure. Habitat maps of the free‐flowing Upper Rhine River downstream from Iffezheim dam (France–Germany border) were intersected with a geographic information system‐based approach. Patches showing trajectories of anthropization, changeless, progression and regression allowed for the identification of natural and human‐induced processes over almost 200 years. Before channelization, the riverine system was characterized by a shifting habitat mosaic with natural heterogeneity, high degree of surface water connectivity and equilibrium between progression and regression processes. On the other hand, the following 175 years of human interventions led to severe biogeomorphologic deficits evidenced by loss of natural processes and habitat heterogeneity, hydrological disconnection between the river and its floodplain and imbalance of progression versus regression dynamics. The main driving forces of change are found in hydromorphological impacts (channelization, regulation and hydropower plant construction). Regression processes are now almost absent and have to be the objective of process‐based river restoration measures for the studied river‐floodplain system. A sustainable view on water management and river restoration should aim at a more resilient riverine system by balancing the recovery of natural processes with societal needs. Copyright © 2016 John Wiley & Sons, Ltd.     

溪源泄洪洞出口处闽江设计水位分析研究

溪源泄洪洞出口位于闽江之上,为分析泄洪洞出口处的设计水位,采用设计流量和水位流量关系推求法及实测水位资料推求法两种方法对工程设计水位进行计算,经过合理性分析,工程所在地近年水位变化剧烈,采用设计流量和水位流量关系推求法更符合现状情况,为工程建设提供可靠的设计成果。     

滇池环湖截污干渠错峰技术模拟与分析

为了实现滇池流域截污效果的最大化,基于前期建立的东岸排水管网SWMM模型,结合该区域1995-2016年间降雨资料,研究环湖截污干渠的错峰调蓄技术。根据雨水干渠液位高度执行不同控制模式:当水位低于6.76 m时执行典型污染物浓度阈值控制模式;当水位高于6.76 m时执行典型污染物阈值控制的同时执行液位-污染物通量控制模式。采用SS和TN作为干渠截流的典型污染物控制指标,其控制浓度阈值分别取12和5 mg/L。模拟重现期为0.5~1 a降雨时SS、TN浓度-负荷通量调蓄方案下干渠负荷收集情况,结果表明两种调蓄方案均能有效提高雨水干渠的负荷收集率,提高污水干渠出口浓度,降低雨水径流对污水厂的高水量和低浓度冲击负荷。随着重现期增大,干渠对污染物的高效和最大化收集效果越明显。但是TN调控下污染负荷收集效果优于SS,因此选择TN作为干渠截流的最优典型污染物控制指标。     

半封闭连通管式差压传感器在桥梁挠度测量中的应用

挠度是评价桥梁结构安全性的重要指标。根据桥梁结构特点,选用半封闭连通管式差压传感器进行实际工程应用。论述了传感器的基本原理,介绍了实际的半封闭连通管式差压传感器及其系统的构成,并将该传感系统应用于荆岳长江公路大桥通车鉴定试验的静载挠度测量中,测量结果表明:半封闭连通管式差压传感器的测量数据能够有效地反映桥梁结构状态变化,且具有较高的测量效率和准确度。     

生物流化床预处理黄浦江原水中试研究

对采用悬浮填料的生物流化床原水预处理技术进行了探讨。分析了自然挂膜条件下的工艺启动过程。在8个工况条件下，流化床对污染物的去除效果。中试运行表明；在温度适谊，停留时间为60min，填料填充率为50%条件下，氨氮平均去除效率达到77.6%。氨氮的比表面去除负荷与温度线性相关。相关系数为0.911;CODMn平均去除率为6.5%。中试装置在温度10.6℃条件下，重启动需要4d，即对污染物有较好的去除效果；由于填料的完全流化，池体内溶解氧传质效率高，出水接近饱和溶解氧；进出水浊度变化不大。填料和池体本身不会积泥，不需反冲洗。     

黄河水水质配方实验及其应用

该文通过水质调查和大量实验数据，对循环水改为黄河水质运行的配方进行了筛选，并提出了自然ｐＨ全有机配方的概念，通过监测数据，对黄河水配方运行情况进行了总结，该配方投用后，不但能节约地下水资源，而且经济效益显著。     

长江经济带水-能源-粮食系统耦合时空动态特征研究

水、能源和粮食为可持续发展的基础性资源,如何从时空角度全面评价长江经济带水-能源-粮食系统的耦合协调发展是促进区域资源可持续发展的重要前提。以水、能源、粮食以及共生单元水能、水粮和能粮系统为单元,构建水-能源-粮食系统耦合协调评价指标体系,采用熵值法对各系统指标赋权,运用耦合协调度模型和空间自相关分析对2010—2019年长江经济带的水-能源-粮食系统协调发展和时空动态特征进行定量研究。结果表明：2010—2019年长江经济带水-能源-粮食系统综合评价指数整体呈缓慢增长趋势,其中水系统对水-能源-粮食系统综合评价指数贡献最大,年均贡献占比为21.57%;能源系统贡献最小,占比为11.95%; 2010—2019年长江经济带水-能源-粮食系统耦合协调水平呈先升后降趋势,其中四川省上升幅度为5.05%,重庆市下降幅度为2.83%,且存在显著的空间异质性,上游地区明显高于中下游地区。其中能源资源是水-能源-粮食系统耦合协调发展的短板;长江经济带水-能源-粮食系统耦合协调度表现出显著空间关联性,高-高集聚区集中在长江上游地区,下游地区主要以低-低集聚区为主。长江经济带内各省市应因地制宜地完善资源管理机制,推动长江经济带资源可持续发展。     

A modified NRCS-CN method for eliminating abrupt runoff changes induced by the categorical antecedent moisture conditions

The popular Natural Resources Conservation Service Curve Number (NRCS-CN) (earlier known as Soil Conservation Service Curve Number (SCS-CN) method of rainfall-runoff modeling has often faced the criticism of exhibiting quantum jumps in runoff computations because of the sudden jumps appearing in CN-values derived from NEH-4 tables for three antecedent moisture conditions (AMC), viz., AMC-I, AMC-II, and AMC-III valid for dry, normal, and wet conditions, respectively. The variability of antecedent soil moisture within an AMC category is responsible for the abrupt jump and other deficiencies in the CN method for runoff estimation. This paper suggests a novel procedure to account for the antecedent moisture (M), preventing quantum jumps and eliminating deficiencies in determination of CN and, in turn, estimation of direct runoff. Its validity was verified utilizing the observed rainfall (P)-runoff (Q) events from 36 US watersheds, four sub-catchments of the Godavari basin, and small agricultural plots at Roorkee, India. The performance of the proposed model (M5) for runoff prediction was compared with the existing NRCS-CN (M1), Mishra and Singh (2002) (M2), Singh et al. (2015) (M3), and Verma et al. (2021) (M4) model using various performance indices. Using the CNs derived from observed events, model M5 was seen to have performed better than M1-M4 in terms of Nash Sutcliffe Efficiency (NSE), Root Mean Square Error (RMSE), and Percent Bias (PBIAS) for the data of US watersheds, and CN-P correlation improved as the coefficient of determination (R²) enhanced. Similarly, using the RS & GIS-based CNs on natural watersheds of the Godavari basin and considering AMC-I, the performance of M5 was again better than M1-M4 in terms of RMSE, Mean Bias Error (mBIAS), Mean Absolute Error (MAE), and Normalized-Nash Sutcliffe Efficiency (NNSE). Interestingly, there existed a significant (p < 0.05) relationship between the in-situ water content (w) measured for the experimental plots of Roorkee and the model input variable antecedent moisture (M), offering a physical touch to the conceptual model.     

塔里木河干流人工与天然绿洲转化及适宜比例研究

利用1990,2000,2010年3期Landsat TM/ETM遥感影像,基于RS/GIS技术,分别提取土地利用/覆被类型信息,分析1990~2010年塔里木河流域人工绿洲和天然绿洲的变化规律及其比例,探讨该区人工绿洲和天然绿洲的适宜配比。研究结果表明:(1)1990~2010年,研究区域人工绿洲呈不断扩张,天然绿洲面积不断缩小,人工绿洲替代天然绿洲的趋势。(2)1990~2010年,人工与天然绿洲总面积几乎无差异,面积变化主要是人工绿洲与天然绿洲之间的相互转换。具体表现为:天然草地、林地等向人工绿洲中的耕地、建筑用地转化;同时植被长势衰退:高覆盖草地向中、低覆盖草地转化,中覆盖草地向低覆盖草地转化,灌木林地逐渐退化为草地,低覆盖草地向沙漠转化。(3)人工与天然绿洲面积比例在近20 a呈增加的趋势,在1990,2000,2010年,人工与天然绿洲面积比值分别是1∶9,2∶8,3∶7。     

河工模型量测控制系统设计与应用——以赣江下游尾闾整治工程为例

赣江下游尾闾综合整治工程物理模型建于室外,且模拟河流多级分叉,对整个模型测控系统运行的可靠性以及室外的防雷性能提出了更高的要求。在分析现场情况的基础上,提出了一套较为先进的模型量测控制系统总体设计方案,控制系统由平水塔供水系统、流量控制系统、水位与流速测量系统、尾门控制系统、防雷接地系统、地形测量系统等量测子系统组成。简要介绍了各测量子系统工作原理,设计方案及实际应用情况,系统应用现代网络技术及高性能自动化测量仪器,可实现模型试验中各种参数的实时采集、控制和数据处理。试验结果表明,该测控系统可满足模型试验的测控需求。