THE RED RIVER FLOOD CONTROL SYSTEM AND RECENT FLOOD EVENTS1

ABSTRACT: The 1950 flood disaster in the Red River Valley, Manitoba, and particularly in Winnipeg made all levels of government aware of the need for control measures. The principal elements of the system which was implemented were two large excavated diversion channels, a storage reservoir, and ring dykes around several small communities. In terms of cost and size, the flood control system is the largest in Canada and despite Federal contributions amounting to nearly 60 percent of the final cost, it represented a considerable fiscal burden for the comparatively small population of Manitoba. Between the opening of the Red River Floodway in 1968 and 1979, a series of exceptional spring peak flows on the Red and Assiniboine Rivers demonstrated the benefits of such a system to a degree which could not have been anticipated at the time the projects were being considered. Furthermore, maximum spring discharges from 1913 to 1978 show a clear rising trend, indicating that the flood hazard is becoming even more severe than was initially assumed; if this trend continues, future benefits will continue to exceed expectations. The overall effectiveness of the hazard reduction program in the Red River Valley, however, has suffered from continued development in unprotected areas. Recent federal-provincial agreements have been reached which will substantially reduce this problem and place greater emphasis on improving the non-structural components of an overall flood hazard reduction program.     

SUMMER FLOODING AT CHICAGO AND POSSIBLE RELATIONSHIPS TO URBAN-INCREASED HEAVY RAINFALL1

ABSTRACT: : Studies of two measures of flooding in the Chicago metropolitan area reveal a wide range of floods with the magnitude related to recurrence interval expressions of rain intensity. Minor type floods (in basements and underpasses) usually result from localized heavy rains (≤ 3-hour duration) with return intervals of 1 to 2 years, and more major floods result from rains with return intervals of 2 to 5 years (or more). Urban-factors help lead to increases in warm season rain events in Chicago with 1- to 4-year return intervals. These apparently help lead to 10 to 100 percent more flooding events in Chicago than expected. The range of increase varies depending on locale and type of flood, but the increases in storms should be accounted for in drainage designs.     

FLOODPLAIN MANAGEMENT NEEDS PECULIAR TO ARID CLIMATES1

ABSTRACT: Many practices followed uniformly nationwide in the federal flood control and floodplain management programs are inappropriate or even counter productive in the arid Utah climate. An analysis of the 130-year Utah flood history, the structural and nonstructural flood programs in the state, and local perceptions obtained by field visits and interviews in 35 Utah communities revealed a number of such inefficiencies. Since flood flows dissipate quickly when they emerge from mountain watersheds onto desert lowlands, risks are concentrated near the apex of alluvial fans, include hazard from mud as well as water flow, and are compounded by canal interception of flood waters. Because of variation in the area flooded from one event to the next, floodplain mapping has tended to show risks too high in mapped areas and too low outside. Traditional channelization carries floods downstream past where they would dissipate naturally. The federal government needs to become more active in developing better flood hazard delineation and structural and nonstructural designs for arid areas. State government can help by providing a forum where communities can exchange experiences, reviewing structural designs prepared by local government, and providing local communities with technical expertise for dealing with federal agencies.     

浙江三门湾沉积记录:U k37表层海水温度和浮游植物群落变化与El Ni?o/La Ni?a的关联

应用三门湾沉积柱样中长链烯酮不饱和指数(U k37)与表层海水温度SST的关系重建历史上的El Ni?o/La Ni?a事件;利用3种浮游植物标志物菜子甾醇(brassicasterol)、甲藻甾醇(dinosterol)和长链烯酮C37(alkenones)来恢复单一种硅藻Diatom、甲藻Dinoflagellates和颗石藻Emiliania huxleyi变化.研究结果表明:(1)U k37估算温度在15.19~17.61℃波动,与当地秋季海水实测温度接近.U k37估算的温度清晰地再现了全球变暖的趋势,且其波动可能与El Ni?o/La Ni?a震荡有关.(2)浮游植物标志物总含量变化范围为710.7~6998.5 ng·g-1,180年以来呈总体上升趋势.沉积记录中硅藻相对比例最高、甲藻次之,硅藻/甲藻比值在2.1~7.2波动,表现出近岸浮游植物对海洋环境变化的敏感性.(3)El Ni?o/La Ni?a事件可影响到浮游植物细胞丰度以及群落结构变化,在El Ni?o盛期,浮游植物细胞丰度剧增,而浮游植物种类数及群集多样性程度明显减少.另外,浮游植物细胞丰度的季节性规律不明显,El Ni?o事件可能是影响三门湾海域浮游植物生产力的主要因素.     

Living with disasters: social capital for disaster governance

This paper explores how social networks and bonds within and across organisations shape disaster operations and strategies. Local government disaster training exercises serve as a window through which to view these relations, and ‘social capital’ is used as an analytic for making sense of the human relations at the core of disaster management operations. These elements help to expose and substantiate the often intangible relations that compose the culture that exists, and that is shaped by preparations for disasters. The study reveals how this social capital has been generated through personal interactions, which are shared among disaster managers across different organisations and across ‘levels’ within those organisations. Recognition of these ‘group resources’ has significant implications for disaster management in which conducive social relations have become paramount. The paper concludes that socio‐cultural relations, as well as a people‐centred approach to preparations, appear to be effective means of readying for, and ultimately responding to, disasters.     

Media coverage of the ‘UK flooding crisis’: a social panorama

A disaster referred to by the press as the ‘UK flooding crisis’ occurred between December 2015 and January 2016. This study employed three different levels of analysis to identify a multidimensional perspective adopted in the disaster reporting of the British Broadcasting Corporation (BBC). These levels revealed details about the social actors and their interactions. The set of news exposed diverse viewpoints on the crisis, from loss and damage to distinct affected subgroups to the various social engagement actions of aid and the multiplicity of technical response measures. The conclusions highlight considerable social amplitude in the BBC's coverage; however, owing to the reductionist approach of this media communicator, the field of action involving different social actors was not very clear in the content of the news, particularly with regard to cohesion, conflict/obstruction, and concernthe concept of crisis in its essence. In addition, the paper suggests new questions for future reports. 1     

The Oder – a river that floods: the problem of environmental adaptation in literary texts

This article discusses inter and post-war works of fiction written by Polish and German-speaking authors with biographical connections to Oder River regions. The literary texts provide insights into the vulnerability to and resilience constructions of floods, which are related to such cultural factors as migrant histories and traditions, regional beliefs and religion, and the political background of changing frontiers in 1919 and 1945 that affected residents of this cross-border area.

The capacity to cope with the flooding Oder, especially after the major flood in 1997, intertwines with the problematic Polish-German relationship, including Silesia. For Polish communities, whose environmental cultures have been distorted by wars, resettlement and communism, vulnerability and resilience perceptions lack representations of the tangible river. It is culturally bounded in the stigmatising image of the Oder as the border of division, revived after 1945 and exposed by the Polish communist party in the so-called ‘Polonisation’ of the ‘Recovered Territories’. Fiction detects the problem of overworking the difficult past in response to the Oder’s hazardous nature. Writers representing an emotional attachment to the river and an aquacritical approach express the need to learn about the river’s lively nature, both in cooperating and sharing space, which is called the environmental adaptation.     

International NGOs and the role of network centrality in humanitarian aid operations: a case study of coordination during the 2000 Mozambique floods

In February 2000, Mozambique suffered its worst flooding in almost 50 years: 699 people died and hundreds of thousands were displaced. Over 49 countries and 30 international non-governmental organisations provided humanitarian assistance. Coordination of disaster assistance is critical for effective humanitarian aid operations, but limited attention has been directed toward evaluating the system-wide structure of inter-organisational coordination during humanitarian operations. Network analysis methods were used to examine the structure of inter-organisational relations among 65 non-governmental organisations (NGOs) involved in the flood operations in Mozambique. Centrality scores were used to estimate NGO-specific potential for aid coordination and tested against NGO beneficiary numbers. The average number of relief- and recovery-period beneficiaries was significantly greater for NGOs with high relative to low centrality scores (p < 0.05). This report addresses the significance of these findings in the context of the Mozambican 2000 floods and the type of data required to evaluate system-wide coordination.     

A HYDROCLIMATIC APPLICATION STRATEGY FOR THE POISSON PARTIAL DURATION MODEL1

ABSTRACT: A strategy for formulating and testing the Poisson partial duration extreme value model is presented. The procedure is demonstrated using recorded Streamflow series from a humid subtropical region of the southern United States. The observed data series are partitioned by climatic causes and tested for both the Poisson assumption and the validity of the exponential as marginal distributions. Several statistical tests are utilized in making these determinations. Some important aspects of the model as applied to humid climates are demonstrated. It was found that a majority of Streamflow series could be represented by the model and that significant differences do exist between the arrival structures of floods resulting from different climatic mechanisms. However, these differences generally do not exist in the distribution of the flood magnitudes. In addition, it is possible that model validity is restricted by drainage basin size.     

How to get there? Assessing motorists’ flash flood risk perception on daily itineraries

Flash floods are characterized by their suddenness, fast and violent movement, rarity, small scale but high level of damage. They are particularly difficult to forecast accurately and there is little lead time for warning. This makes motorists especially vulnerable. Assuming that these flash flood hazard specificities may be the significant factors leading to difficulties for drivers to perceive danger, we used cognitive mapping combined with GIS data processing to assess motorists’ flash flood risk perception on their daily itineraries. The analysis of 200 mental maps collected allows planners to have maps highlighting dangerous areas where risk perception is weak and to identify reasons for this.