Measurement of the flood discharge of a small-sized river using an existing digital video recording system

In this study, a closed-circuit television (CCTV) system, installed for surveillance purposes, is utilized to measure the flow rate during a flood. The procedure to determine both the angle and scale-factor of the camera is described. Then, image analysis techniques, namely the direct visual measurement method, Large-Scale PIV (LSPIV) and Space-Time Image Velocimetry (STIV), are applied to the video images recorded by the CCTV camera. The results of these methods and the conventional float measurement are compared. In addition, the accuracy of the respective methods is discussed. A set of low-quality video images of a flood during a thunderstorm that occurred under the dark ambient conditions (midnight) is analyzed using three image-based methods. The transition of the flow rate during the event is successfully estimated.     

Roughness coefficient and its uncertainty in gravel-bed river

Manning's roughness coefficient was estimated for a gravel-bed river reach using field measurements of water level and discharge,and the applicability of various methods used for estimation of the roughness coefficient was evaluated.Results show that the roughness coefficient tends to decrease with increasing discharge and water depth,and over a certain range it appears to remain constant.Comparison of roughness coefficients calculated by field measurement data with those estimated by other methods shows that,although the field-measured values provide approximate roughness coefficients for relatively large discharge,there seems to be rather high uncertainty due to the difference in resultant values.For this reason,uncertainty related to the roughness coefficient was analyzed in terms of change in computed variables.On average,a 20%increase of the roughness coefficient causes a 7% increase in the water depth and an 8% decrease in velocity,but there may be about a 15% increase in the water depth and an equivalent decrease in velocity for certain cross-sections in the study reach.Finally,the validity of estimated roughness coefficient based on field measurements was examined.A 10% error in discharge measurement may lead to more than 10% uncertainty in roughness coefficient estimation,but corresponding uncertainty in computed water depth and velocity is reduced to approximately 5%.Conversely,the necessity for roughness coefficient estimation by field measurement is confirmed.     

China’s ‘old’ and ‘new’ Mekong River politics: the Lancang-Mekong Cooperation from a comparative benefit-sharing perspective

This article analyzes China’s Mekong River politics before and after the establishment of the Lancang-Mekong Cooperation (LMC) from a comparative benefit-sharing perspective. China’s pre-LMC approach focused too much on the creation of economic benefits from and beyond the river while neglecting ecological benefits to the river. Moreover, despite the problems this ‘old’ approach caused for China and its downstream neighbours, China’s current LMC strategy seems to essentially replicate its former approach. While sustainable water resources management is identified as a priority area, actual cooperation and benefit sharing in this field remain insufficient.     

韩江流域规划环境影响评价优化调整研究

该文对广东省韩江流域综合规划进行环境影响评价,从规划布局、实施时序、开发方式、生态保护与社会经济等角度开展优化调整方案,研究结果表明:规划新建的14个梯级中8个梯级取消建设,5个梯级近期开发,1个梯级进一步优化论证后开发;采砂控制区划将10个采砂区列为禁采区.     

夏县河道治理对策

就夏县河道治理对策展开论述,描述了夏县河道的基本情况,分析了河道历史灾情,对河道现状和存在的问题加以论述,针对性地提出河道的治理措施.     

Utilization of geothermal systems in South-East Hungary

Thermal wells have been used in Hungary for over 140 years. As thermal water production has increased during the past decades, the pressure drawdown has increased in the geothermal systems of the Pannonian basin, showing that their sustainable management is lacking. The Hódmez?vásárhely, Szeged, and Szentes case histories are presented, including the very first indications of stabilization and recharge of the Pannonian thermal aquifers, as a result of reduction of thermal water production. Sustainable production and overall resource management of geothermal systems in SE-Hungary can only be achieved by injection.     

截流钢筋笼的稳定性及其计算方法

对实践中常用到的正六面体钢筋笼的稳定性从质量、形状以及有无垫底材料等方面进行了试验研究及工程实例验证。首次拟合提出了考虑其形状因素、河床糙度因素的正六面体钢筋笼止动流速和起动流速的计算公式,经试验验证具有较高的计算精度和实用性。此外,对四面体钢筋笼的稳定性也进行了试验研究,研究表明:四面体钢筋笼用于截流抛投这类止动问题的工程时,其止动稳定性明显优于相同质量的正六面体钢筋笼;而对于护底等起动问题的工程,两者起动稳定性差别不大。     

单根辐射管集水模型的研究

本文通过对影响单根辐射管集水因素的分析,探讨了集取河床渗透水的单根辐射管集水模型,并用模拟试验确定了模型参数。结果表明:模拟试验值、工程实例实测值与集水模型计算值具有一致性。     

淮北平原旱涝综合治理优化模型

本文针对淮北平原水旱灾害交错发生的特点,研究流域旱涝综合治理优化模型。根据水资源大系统优化理论,建立了“分解-聚合”谱系递阶结构模型,对流域内沟、闸、井等工程设施的合理布局和规模进行优化,并为联合运用地表水和地下水提供优化控制方案。文中还以汾泉河流域为实例,采用“DDDP-BSDP”套用的优化方法进行求解,验证了所建优化模型及其解法的有效性。