Sea-level rise and flooding in coastal riverine flood plains

Abstract

This work presents a method for calculating the contributions of sea-level rise and urban growth to flood risk in coastal flood plains. The method consists of hydraulic/hydrological, urban growth and flood-damage quantification modules. The hydraulic/hydrological module estimates peak annual flows to generate flood stages impacted by sea-level rise within flood plains. A model for urban growth predicts patterns of urbanization within flood plains over the period 2010–2050. The flood-damage quantification module merges flood maps and urbanization predictions to calculate the expected annual flood damage (EAFD) for given scenarios of sea-level rise. The method is illustrated with an application to the Tijuana River of southern California, USA, and northwestern Mexico, where the EAFD is predicted to increase by over US$100 million because of sea-level rise of 0.25–1.0 m and urban growth by the year 2050. It is shown that urbanization plays a principal role in increasing the EAFD in the study area for the range of sea-level rise considered.

Editor Z.W. Kundzewicz

Citation Garcia, E.S. and Loáiciga, H.A., 2013. Sea-level rise and flooding in coastal riverine flood plains. Hydrological Sciences Journal, 59 (1), 204–220.     

Hydrological study of the potential effects of the melting of Nevado del Ruiz glacier on urban growth zones in Manizales,Colombia

ABSTRACT

This paper presents the results of a hydrological study aimed at characterizing flood-prone areas in the urban growth zone in the city of Manizales based on the potential effects of melting of the Nevado del Ruiz glacier, in Caldas, Colombia. These results constitute a basis for decision making regarding possible urban growth zones in Andean areas that face risks from volcanic eruptions producing lahars and floods caused by glacier melt. Conservative estimates of extreme flows in the Chinchiná River in the urban growth area of El Rosario can be obtained by considering the effects of rain triggered by airborne particulate material following a volcanic explosion combined with the effects of glacier melt. The effects of global warming on tropical glaciers contribute to their retreat, leading to their disappearance. Therefore, the worst scenario would take place if these events occurred in the short term as glacier volume decreases with time.

Editor Z.W. Kundzewicz; Associate editor not assigned     

Hydrological response characteristics of Mediterranean catchments at different time scales: a meta-analysis

ABSTRACT

This work examines 140 hydrological studies conducted in the Mediterranean region. It identifies key characteristics of the hydrological responses of Mediterranean catchments at various time scales and compares different methods and modelling approaches used for individual-catchment studies. The study area is divided into the northwestern (NWM), eastern (EM) and southern (SM) Mediterranean. The analysis indicates regional discrepancies in which the NWM shows the most extreme rainfall regime. A tendency for reduced water resources driven by both anthropogenic and climatic pressures and a more extreme rainfall regime are also noticeable. Catchments show very heterogeneous responses over time and space, resulting in limitations in hydrological modelling and large uncertainties in predictions. However, few models have been developed to address these issues. Additional studies are necessary to improve the knowledge of Mediterranean hydrological features and to account for regional specificities.

Editor D. Koutsoyiannis Associate editor A. Efstratiadis     

An approach for the determination of precipitation input for worst-case flood modelling

ABSTRACT

There is a lack of suitable methods for creating precipitation scenarios that can be used to realistically estimate peak discharges with very low probabilities. On the one hand, existing methods are methodically questionable when it comes to physical system boundaries. On the other hand, the spatio-temporal representativeness of precipitation patterns as system input is limited. In response, this paper proposes a method of deriving spatio-temporal precipitation patterns and presents a step towards making methodically correct estimations of infrequent floods by using a worst-case approach. A Monte Carlo approach allows for the generation of a wide range of different spatio-temporal distributions of an extreme precipitation event that can be tested with a rainfall–runoff model that generates a hydrograph for each of these distributions. Out of these numerous hydrographs and their corresponding peak discharges, the physically plausible spatio-temporal distributions that lead to the highest peak discharges are identified and can eventually be used for further investigations.

Editor A. Castellarin; Associate editor E. Volpi     

Reach-scale suspended sediment balance downstream from dams in a large Mediterranean river

Abstract

This paper presents a reach-scale sediment balance of a large impounded Mediterranean river (the lower Ebro, 1998–2008). Multi-temporal sediment storage and the influence of floods and tributaries on the sediment load were examined using continuous discharge and turbidity records. The mean annual suspended sediment load at the reach outlet (Xerta) is 0.12?×?10⁶ t, corroborating previous results. Suspended sediment concentrations were low (SSC_mean?=?13 mg L^-1), attaining a maximum of 274 mg L^-1. Erosion processes (channel-scour, bank erosion) are dominant, and net export of sediment occurs over the long term. Unexpectedly, ephemeral tributaries were found to contribute significantly: sediment delivered during torrential events attained 5% of the Ebro annual load, and was even larger than that in flushing flows. Overall, most of the suspended sediment load is transported by floods (up to 65% in some years). The results constitute basic information to underpin current management actions aiming to achieve the sustainability of the riverine and deltaic system.

Editor D. Koutsoyiannis; Associate editor D. Hughes

Citation Tena, A., Batalla, R.J. and Vericat, D., 2012. Reach-scale suspended sediment balance downstream from dams in a large Mediterranean river. Hydrological Sciences Journal, 57 (5), 831–849.     

Remote sensing applications to hydrology: future impact

Abstract

The case is made that the hydrological sciences are data limited and that future progress in understanding hydrological processes is hampered by the lack of adequate data. The future applications of remote sensing to hydrology should provide new types of data that enable hydrologists to address the previously unsolved questions.     

Reassessment of flood frequency using historical information for the River Ouse at York,UK (1200–2000)

Abstract

The reassessment of flood risk at York, UK, is pertinent in light of major flooding in November 2000, and heightened concerns of a perceived increase in flooding nationally. Systematic flood level readings from 1877 and a wealth of documentary records dating back as far as 1263 AD give the City of York a long and rich history of flood records. This extended flood record provides an opportunity to reassess estimates of flood frequency over a time scale not normally possible within flood frequency analysis. This paper re-evaluates flood frequency at York, considering the strengths and weaknesses in estimates resulting from four contrasting methods of analysis and their corresponding data: (a) single-site analysis of gauged annual maxima; (b) pooled analysis of multi-site gauged annual maxima; (c) combined analysis of systematic annual maxima augmented with historical peaks, and (d) analysis of only the very largest peaks using a Generalized Pareto Distribution. Use of the historical information was found to yield risk estimates which were lower and considered to be more credible than those achieved using gauged records alone.

Citation Macdonald, N. & Black, A. R. (2010) Reassessment of flood frequency using historical information for the River Ouse at York, UK (1200–2000). Hydrol. Sci. J. 55(7), 1152–1162.     

Use of artificial flood events to demonstrate the invalidity of simple mixing models / Utilisation de crues artificielles pour prouver l'invalidité des modèles de mélange simple

Abstract

The whole of a basin responds to a precipitate on event. The resulting flood wave introduces a complex pattern of interrelated processes which occur in the vegetation, soil, bedrock, human facilities, channel and in the different parts of the basin. The main advantage of field experiments is that it becomes possible to exclude several governing factors or sources and to control others by the experimental design. In a small brook near Trier (Germany), artificial flood events are created. In-channel transport processes of sediment are investigated without taking into account the interference of soil erosion and runoff. It is demonstrated that kinematic waves-describing the translation of flow with limited hydraulic dispersion or diffusion-also occur in small basins. The kinematic waves-travelling only a few hundred meters-have a large impact on the relationship between the hydrograph and dissolved or particle-bound substances. Consequently, classifications and simple mixing models between those components are impeded.     

构建城市地表产流和汇流模型探讨

本文基于空间离散化理论与方法和DEM技术,将城市地表划分成一系列网格单元,从水平方向和垂直方向研究城市地表空间位置和综合因素的空间离散化描述、表达以及参数模型化处理机制,创新构建出一个特定的以DEM空间离散化解析函数式表达的、综合顾及城市地表地形特征、下垫面物质形态和人工建筑物等因素的地表产流和汇流模型,实施城市地表产流和汇流的路径以及水流累积量的分析计算。     

Modest Maps的Flash网络地图发布与应用

本文分析了Adobe Flash技术在网络地图发布前端技术上的优势和应用现状,选择开源Flash地图组件Modest Maps作为开发工具,在其上添加了一些组件模块,以"5.12地震信息显示"为示例,实现了基于Modest Maps的Falsh网络地图发布和简单的空间分析.