scholarly journals Coupled modelling of subsurface water flux for an integrated flood risk management

2009 ◽  
Vol 9 (4) ◽  
pp. 1277-1290 ◽  
Author(s):  
T. Sommer ◽  
C. Karpf ◽  
N. Ettrich ◽  
D. Haase ◽  
T. Weichel ◽  
...  
Keyword(s):  
Flood Risk ◽  
Data Exchange ◽  
Subsurface Water ◽  
Flood Event ◽  
Causal Process ◽  
Water Fluxes ◽  
Sewerage System ◽  
Flood Water ◽  
Coupled Modelling ◽  
Groundwater Levels

Abstract. Flood events cause significant damage not only on the surface but also underground. Infiltration of surface water into soil, flooding through the urban sewer system and, in consequence, rising groundwater are the main causes of subsurface damage. The modelling of flooding events is an important part of flood risk assessment. The processes of subsurface discharge of infiltrated water necessitate coupled modelling tools of both, surface and subsurface water fluxes. Therefore, codes for surface flooding, for discharge in the sewerage system and for groundwater flow were coupled with each other. A coupling software was used to amalgamate the individual programs in terms of mapping between the different model geometries, time synchronization and data exchange. The coupling of the models was realized on two scales in the Saxon capital of Dresden (Germany). As a result of the coupled modelling it could be shown that surface flooding dominates processes of any flood event. Compared to flood simulations without coupled modelling no substantial changes of the surface inundation area could be determined. Regarding sewerage, the comparison between the influx of groundwater into sewerage and the loading due to infiltration by flood water showed infiltration of surface flood water to be the main reason for sewerage overloading. Concurrent rainfalls can intensify the problem. The infiltration of the sewerage system by rising groundwater contributes only marginally to the loading of the sewerage and the distribution of water by sewerage has only local impacts on groundwater rise. However, the localization of risk areas due to rising groundwater requires the consideration of all components of the subsurface water fluxes. The coupled modelling has shown that high groundwater levels are the result of a multi-causal process that occurs before and during the flood event.

scholarly journals Monitoring water fluxes in rice plots under three different cultivation methods

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Enrico Antonio Chiaradia ◽  
Daniele Ferrari ◽  
Gian Battista Bischetti ◽  
Arianna Facchi ◽  
Olfa Gharsallah ◽  
...  
Keyword(s):  
Management Practices ◽  
Water Cycle ◽  
Considerable Effect ◽  
Level Gauge ◽  
Total Production ◽  
Water Fluxes ◽  
Wireless Data ◽  
Data Logger ◽  
Groundwater Levels ◽  
The North

Italy is the leading producer of rice in Europe with over half of total production, almost totally concentrated in a large traditional paddy rice area between the Lombardy and Piedmont regions, in the north-western part of the country. In this area irrigation of rice has been traditionally carried out by flooding. The introduction of new combined irrigation and agronomic management practices (dry seeding followed by field flooding and in a full aerobic cultivation with intermittent irrigations), aiming to reduce the water consumption, can determine considerable effect on the landscape and the water cycle. With the aim to study in depth the water fluxes during the whole crop season, three experimental plots at the Ente Nazionale Risi-Rice Research Centre’s Experimental Station of Castello d’Agogna (PV) were instrumented. In each plot the following instruments have been installed: 1) a long throated flume and a double shaped (V-notch and rectangular) thin plate for superficial inputs and outputs, 3) a set of piezometers for groundwater levels, 4) one stage level gauge in each submerged field, 5) four tensiometers and moisture sensors clusters, 6) one eddy covariance station for vapour fluxes estimation. Most of the instruments were equipped with electrical sensors connected by cables to a wireless data logger that, in turn, send the data to a PC placed within ENR offices and web-connected by a LAN. In this way, besides the automatic download of data, it was possible to remotely control the devices, to quickly fix troubles, and to better plan the field trips. The management of the whole framework was done by a specifically developed software. In this paper the whole system, which presents some degree of innovation, is described in detail.

scholarly journals Successful Small-Scale Household Relocation after a Millennial Flood Event in Simbach, Germany 2016

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 156 ◽  
Author(s):  
Barbara Mayr ◽  
Thomas Thaler ◽  
Johannes Hübl
Keyword(s):  
Risk Management ◽  
Flood Risk ◽  
Planning Process ◽  
Flood Risk Management ◽  
Flood Event ◽  
Small Scale ◽  
Successful Implementation ◽  
Adaptive Planning ◽  
Extreme Flood ◽  
Household Relocation

International and national laws promote stakeholder collaboration and the inclusion of the community in flood risk management (FRM). Currently, relocation as a mitigation strategy against river floods in Central Europe is rarely applied. FRM needs sufficient preparation and engagement for successful implementation of household relocation. This case study deals with the extreme flood event in June 2016 at the Simbach torrent in Bavaria (Germany). The focus lies on the planning process of structural flood defense measures and the small-scale relocation of 11 households. The adaptive planning process started right after the damaging event and was executed in collaboration with authorities and stakeholders of various levels and disciplines while at the same time including the local citizens. Residents were informed early, and personal communication, as well as trust in actors, enhanced the acceptance of decisions. Although technical knowledge was shared and concerns discussed, resident participation in the planning process was restricted. However, the given pre-conditions were found beneficial. In addition, a compensation payment contributed to a successful process. Thus, the study illustrates a positive image of the implementation of the alleviation scheme. Furthermore, preliminary planning activities and precautionary behavior (e.g., natural hazard insurance) were noted as significant factors to enable effective integrated flood risk management (IFRM).

scholarly journals Sand box experiments to evaluate the influence of subsurface temperature probe design on temperature based water flux calculation

2011 ◽  
Vol 15 (11) ◽  
pp. 3495-3510 ◽  
Author(s):  
M. Munz ◽  
S. E. Oswald ◽  
C. Schmidt
Keyword(s):  
Water Flux ◽  
Subsurface Water ◽  
Pass Band ◽  
Time Lags ◽  
Water Fluxes ◽  
Amplitude Ratios ◽  
Flux Calculation ◽  
Temperature Probe ◽  
Sand Box ◽  
Flow Velocities

Abstract. Quantification of subsurface water fluxes based on the one dimensional solution to the heat transport equation depends on the accuracy of measured subsurface temperatures. The influence of temperature probe setup on the accuracy of vertical water flux calculation was systematically evaluated in this experimental study. Four temperature probe setups were installed into a sand box experiment to measure temporal highly resolved vertical temperature profiles under controlled water fluxes in the range of ±1.3 m d−1. Pass band filtering provided amplitude differences and phase shifts of the diurnal temperature signal varying with depth depending on water flux. Amplitude ratios of setups directly installed into the saturated sediment significantly varied with sand box hydraulic gradients. Amplitude ratios provided an accurate basis for the analytical calculation of water flow velocities, which matched measured flow velocities. Calculated flow velocities were sensitive to thermal properties of saturated sediment and to temperature sensor spacing, but insensitive to thermal dispersivity equal to solute dispersivity. Amplitude ratios of temperature probe setups indirectly installed into piezometer pipes were influenced by thermal exchange processes within the pipes and significantly varied with water flux direction only. Temperature time lags of small sensor distances of all setups were found to be insensitive to vertical water flux.

scholarly journals Compound flood modelling framework for rainfall-groundwater interactions

2021 ◽  
Author(s):  
Francisco Peña ◽  
Fernando Nardi ◽  
Assefa Melesse ◽  
Jayantha Obeysekera ◽  
Fabio Castelli ◽  
...  
Keyword(s):  
Water Table ◽  
Flood Risk ◽  
Numerical Models ◽  
Absorption Capacity ◽  
Subsurface Water ◽  
Climate Projections ◽  
Exchange Flow ◽  
Storm Events ◽  
Modelling Framework ◽  
Water Tables

Abstract. Compound floods are an active area of research where the complex interaction between pluvial, fluvial, coastal or groundwater flooding are analyzed. A number of studies have simulated the compound flooding impacts of precipitation, river discharge and storm surge variables with different numerical models and linking techniques. However, groundwater flooding is often neglected in flood risk assessments due to its sporadic frequency - as most regions have water tables sufficiently low that do not exacerbate flooding conditions -, isolated impacts and considerably less severity in respect to other types of flooding. This paper presents a physically-based, loosely-coupled modelling framework using FLO-2D and MODFLOW-2005 that is capable to simulate surface-subsurface water interactions to represent compound flooding events in North Miami. FLO-2D, responsible of the surface hydrology and infiltration processes, transfers the infiltration volume as recharge to MODFLOW-2005 until the soil absorption capacity is exceeded, while MODFLOW-2005 return exchange flow to the surface when groundwater heads are higher than the surface depth. The model calibration is based on three short-lived storm events that as individual processes represent minimum flooding conditions but in combination with pre-existing high-water table levels results in widespread flooding across the study area. Understanding groundwater flood risk is of particular interest to low-elevation coastal karst environments as the sudden emergence of the water table at ground surface can result in social disruption, adverse effects to essential services and damage infrastructure. Results are validated using FEMA’s severe repetitive loss (SRL) property records and crowdsourced data. Further research should assess the exacerbated impacts of high tides and sea level rise on water tables under current and future climate projections.

scholarly journals Pasts and Presents of Urban Socio-Hydrogeology: Groundwater Levels in Berlin, 1870–2020

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2261
Author(s):  
Theresa Frommen ◽  
Timothy Moss
Keyword(s):  
Groundwater Management ◽  
Urban Groundwater ◽  
Research Process ◽  
Subsurface Water ◽  
Water History ◽  
Groundwater Levels ◽  
Scant Attention ◽  
History Of ◽  
Historical Methods

Although it is self-evident that today’s groundwater issues have a history that frames both problems and responses, these histories have received scant attention in the socio-hydrogeological literature to date. This paper aims to enrich the field of socio-hydrogeology with a novel, historical perspective on groundwater management whilst simultaneously demonstrating the value to water history of engaging with groundwater. This is achieved by applying hydrogeological, socio-hydrogeological, and historical methods in an interdisciplinary and collaborative research process while analysing a case study of urban groundwater management over a 150-year period. In the German capital Berlin, local aquifers have always been central to its water supply and, being close to the surface, have made for intricate interactions between urban development and groundwater levels. The paper describes oscillations in groundwater levels across Berlin’s turbulent history and the meanings attached to them. It demonstrates the value to socio-hydrogeology of viewing the history of groundwater through a socio-material lens and to urban history of paying greater attention to subsurface water resources. The invisibility and inscrutability associated with groundwater should not discourage attention, but rather incite curiosity into this underexplored realm of the subterranean city, inspiring scholars and practitioners well beyond the confines of hydrogeology.

scholarly journals Big and small: menisci in soil pores affect water pressures, dynamics of groundwater levels, and catchment-scale average matric potentials

2010 ◽  
Vol 7 (5) ◽  
pp. 6491-6523
Author(s):  
G. H. de Rooij
Keyword(s):  
Soil Water ◽  
Large Scale ◽  
Soil Surface ◽  
Subsurface Water ◽  
Vertical Position ◽  
Pore Scale ◽  
Catchment Scale ◽  
Matric Potential ◽  
Groundwater Levels ◽  
Interface Curvature

Abstract. Soil water is confined behind the menisci of its water-air interface. Catchment-scale fluxes (groundwater recharge, evaporation, transpiration, precipitation, etc.) affect the matric potential, and thereby the interface curvature and the configuration of the phases. In turn, these affect the fluxes (except precipitation), creating feedbacks between pore-scale and catchment-scale processes. Tracking pore-scale processes beyond the Darcy scale is not feasible. Instead, for a simplified system based on the classical Darcy's Law and Laplace-Young Law we i) clarify how menisci transfer pressure from the atmosphere to the soil water, ii) examine large-scale phenomena arising from pore-scale processes, and iii) analyze the relationship between average meniscus curvature and average matric potential. In stagnant water, changing the gravitational potential or the curvature of the air-water interface changes the pressure throughout the water. Adding small amounts of water can thus profoundly affect water pressures in a much larger volume. The pressure-regulating effect of the interface curvature showcases the meniscus as a pressure port that transfers the atmospheric pressure to the water with an offset directly proportional to its curvature. This property causes an extremely rapid rise of phreatic levels in soils once the capillary fringe extends to the soil surface and the menisci flatten. For large bodies of subsurface water, the curvature and vertical position of any meniscus quantify the uniform hydraulic potential under hydrostatic equilibrium. During unit-gradient flow, the matric potential corresponding to the mean curvature of the menisci should provide a good approximation of the intrinsic phase average of the matric potential.

High-Resolution Simulation of Hydraulic Structures in a Typhoon Induced Urban Flood Event

2020 ◽  
Author(s):  
Yunsong Cui ◽  
Qiuhua Liang ◽  
Gang Wang ◽  
Jian Zeng ◽  
Jinchun Hu
Keyword(s):  
High Resolution ◽  
Flood Risk ◽  
Flood Event ◽  
Hydraulic Structures ◽  
Urban Flood ◽  
Flood Modelling ◽  
Flood Model ◽  
Fully Coupled ◽  
Urban Flood Modelling ◽  
Urban Flood Risk

<p>Due to climate change and rapid urbanization, urban flooding has become one of the major natural hazards threatening the safety of people and their properties and affecting the overall sustainability of cities across the globe, especially developing countries such as China. Flood modelling has now provided an indispensable tool to support urban flood risk assessment and management, and inform the planning of cities that are more resilient to flooding.</p><p>Hydraulic structures, e.g. regulation gates and pumping stations, play an important role in urban flood risk management. However, direct simulation of these hydraulic structures is not a current practice in 2D urban flood modelling. This work presents and applies a robust numerical approach to directly simulate the effects of hydraulic structures in a 2D high-resolution urban flood model. An additional computational module is developed and fully coupled to a GPU-accelerated finite volume shock-capturing urban flood model to directly simulate the highly transient flood waves through hydraulic structures. The improved flood model is applied to  reproduce a flood event induced by Typhoon “Lekima” in 2019 in Yuhuan, Zhejiang Province, China. At 3m resolution, the model is able to simulate the complete process of the flood event in nearly 3.5 times faster than real time, demonstrating the efficiency and robustness of the new fully coupled model for high-resolution food modelling in cities. Further simulations are performed to systemically investigate the effect of hydraulic structures and different operational regulations on flood dynamics and associated risks, demonstrating the importance of directly considering hydraulic structures and their operations in 2D high-resolution urban flood modelling.</p><p></p>

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