A customised approach to determining the geomorphic effectiveness of small flood events in a regulated river

The construction of dams significantly alters flow and sediment regimes with subsequent deleterious effects on the morphological and ecological character of rivers. Effective experimental floods can ameliorate the downstream geomorphic impacts of dams. The traditional view is that large floods are required to perform effective geomorphic work, and the geomorphic outcomes of small floods are often overlooked. Many river restoration frameworks do not consider small floods. Yet, there is evidence that the hydrological characteristics that ameliorate specific geomorphic impacts in a river are unique to each river, and a customised approach to setting the right mix of floods (including small experimental floods) is needed. In this study, we modify an existing flood effectiveness model developed for large floods, for determining the geomorphic effectiveness of small floods in a highly regulated Australian river. Two flood classes were added to the model (medium peak stream power and moderate total energy expenditure), and the flood power characteristics were rescaled to reflect the relative difference in the magnitude of the small floods and the magnitude of the geomorphic work performed. Using a step‐wise approach, this customised model determined the geomorphic effectiveness of small floods. The best flood for ameliorating the geomorphic impacts of flow regulation had medium to long duration (10 to 51 days), high peak unit stream power (77 to 123 Wm^?2) and moderate to large total energy expenditure (78,600 to 342,320 × 10³ J). This approach to determining flood effectiveness for small floods is applicable to other geomorphically impacted river channels downstream of dams and can be used to inform experimental flood releases for geomorphic outcomes.     

Polybrominated Diphenyl Ethers in Surface Sediment from Songhua River Basin, Northeast of China

Sixty sediment samples were collected from the main Songhua River in three years. Twelve polybrominated diphenyl ether ( PBDE) congeners ( BDE17, 28, 47, 66, 99, 100, 153, 154, 138, 183, and BDE?209) w...     

抓住机遇迎接挑战 为保护美丽长江再谱新篇

当前长江流域水资源保护面临难得的机遇,如何推进长江水生态文明建设,打造水清地绿天蓝的生态廊道是长江水资源保护工作的重大课题。通过对长江水资源保护问题的梳理,规划了今后一段时期的总体构想,从规划体系、水功能区监管、水生态保护、应急管理和监测监控等5个方面探讨了下一步的工作重点;提出了长江干流、主要支流、三峡、丹江口和长江口以及重点湖泊的保护措施;通过健全法规体系、创新管理机制、强化能力建设等,以逐步提升长江水资源保护能力、健全长江水资源保护管理体系,为保护美丽长江再谱新篇。     

桃汛试验对万家寨水库冲淤影响分析

通过对桃汛试验前后两个时段对比分析,认为桃汛试验没有增加万家寨库区淤积;库区淤积形态有所调整,淤积三角洲向坝前推进,库尾段平均河底高程没有抬升.     

1950—2010年黄河径流情势变化特点

对1950—2010年黄河径流地区分布不均匀、断流和连续枯水段历时较长等特点进行了分析,阐述了天气变化、植被变化、水利工程对径流的调节、工农业及生活用水等影响黄河径流变化的因素,提出了相关建议:①长期推行节水和水土保持建设;②建立流域机构统一管理与省(区)水行政主管部门分级管理相结合的黄河水资源管理体系;③积极推进补水工程建设;④建立污染物入河总量控制、排污入河许可等水资源保护制度,提升对污染物输移扩散的预测预报水平与能力。     

2010年长江流域暴雨洪水初步分析

分析2010年长江流域暴雨洪水,有利于更全面认识长江流域暴雨洪水特性,可为今后更好开展长江流域防汛水情保障工程。从主汛期长江流域暴雨及气候特征、干支流主要洪水过程及洪水特性等方面,进行了初步的总结和分析。2010年长江主汛期洪水发生范围广、持续时间长且局部地区洪水量级大,通过与三峡水库蓄水前后几次大的历史洪水分析对比,初步认为,2010年长江流域主汛期出现的洪水为长江上中游区域性较大洪水。     

广东韩江松源河省界界面水质变化及环境管理策略

根据2007、2008年7次调查的实测资料,分析了松源河及多宝水库的水质变化过程,并讨论了影响水质恶化的原因;根据水质变化特点,提出了水质保洁及科学管理的策略,为梅州的绿色崛起、“以人为本”的和谐社会服务.     

Gamma-ray remote sensing of aeolian salt sources in the Murray-Darling Basin, Australia

This paper presents a new technique for mapping regional salt sources that has major implications for salinity management in southeastern Australia. This was achieved by analyzing a regional mosaic of airborne gamma-ray emission derivatives and verified by existing airborne electromagnetic and drilling data. A significant correlation was found between aeolian (windblown) materials, upland salts and gamma-ray signatures. This is consistent with the conceptual model that much of the salt in the upland areas of the Murray-Darling Basin is sourced from deposited aeolian materials that have been derived from deflationary events in salt-bearing landscapes in the western arid part of the basin. From gamma-ray emissions, and based on an observed relationship with borehole salinity, concentrated aeolian salt source deposits contained about 0.7% potassium and 10 ppm thorium. Using this signature on normalized data, an Euclidean distance algorithm provided mapping and information relating to salt-mobility pathways over a wide region. The resulting gamma-ray salt source model (GSM) facilitates focussed management of salinity infiltration zones in catchments across the basin.     

论溪落渡水电站的战略地位

溪落渡水电站是金沙江上最大的一座巨型电站,装机容量1200~1500万kW,除发电外兼有防洪、拦沙、改善下游航运等综合利用效益。通过对金沙江水电基地在我国经济建设中的地位和作用;溪落渡水电站在金沙江水电基地开发中的地位和作用、在“西电东送(包括南送)”中的地位和作用以及在长江上游水电基地中的地位和作用等论述,希望引起有关领导和决策部门的重视,加快溪落水电站前期工作的进程和促进金沙江水电基地的开发。     

Measuring the economic benefits of the Youngsan River Restoration Project in Kwangju,Korea, using contingent valuation

This study examines the economic benefits of a river restoration project in the Youngsan River, Kwangju, Korea, using a contingent valuation method. It employs a spike model to address the high proportion of zero responses. The results indicate that a household's annual mean willingness to pay is KRW3410 in Kwangju and KRW1744 in other regions. The resulting benefit-cost ratio is 2.29, indicating that the project would be socially profitable, and that households appear willing to support it financially.