Geomorphic and hydrologic consequences of vegetation destruction, Sudbury, Ontario

1976 ◽  
Vol 13 (10) ◽  
pp. 1358-1373 ◽  
Author(s):  
Andrew J. Pearce
Keyword(s):  
Flood Control ◽  
Overland Flow ◽  
Drainage Basin ◽  
Weighted Average ◽  
Design Parameters ◽  
Snowmelt Runoff ◽  
Control Structures ◽  
Denudation Rates ◽  
Complete Destruction ◽  
Erosion Pins

Near-complete destruction of vegetation over 125 km2 near Sudbury, Ontario has increased denudation rates by two orders of magnitude and caused substantial changes in hydrologic regime. Denudation by channeled and unchanneled flow, measured with erosion pins on small plots (2–1000 m2) and a small drainage basin (0.09 km2), averaged 6000 m3/km2 (maximum 24 700 m3/km2) during summer and fall in 1971 and 1972. Maximum denudation occurred during late August to October. Snowmelt runoff in 1972 yielded 1000 m3/km2 of sediment. The weighted average denudation rate, including rates of bedrock disintegration (60–170 m3/km2/y; mean 120 m3/km2/y) is 3700 m3/km2/y.Runoff coefficients average 0.88 for events with return periods between 2 and 10 years; 25% of the May–October rainfall runs off as Hortonian overland flow. Estimated sedimentation rates for three flood-control structures indicate 25% storage depletion over a 50 year period; the return period of floods then able to be retained is reduced to 50 years, compared to the design parameters of 100 year 6 h rainfall (smaller structures) and 100–200 year 12 h rainfall, 6 h P.M.P. (largest structure).

scholarly journals Numerical analysis of coupled hydrosystems based on an object-oriented compartment approach

2008 ◽  
Vol 10 (3) ◽  
pp. 227-244 ◽  
Author(s):  
Olaf Kolditz ◽  
Jens-Olaf Delfs ◽  
Claudius Bürger ◽  
Martin Beinhorn ◽  
Chan-Hee Park
Keyword(s):  
Numerical Solution ◽  
Land Surface ◽  
Overland Flow ◽  
Drainage Basin ◽  
Spatial Scales ◽  
Shallow Water Equation ◽  
Object Oriented ◽  
Richards Equation ◽  
Saturated Flow ◽  
Flow Processes

In this paper we present an object-oriented concept for numerical simulation of multi-field problems for coupled hydrosystem analysis. Individual (flow) processes modelled by a particular partial differential equation, i.e. overland flow by the shallow water equation, variably saturated flow by the Richards equation and saturated flow by the groundwater flow equation, are identified with their corresponding hydrologic compartments such as land surface, vadose zone and aquifers, respectively. The object-oriented framework of the compartment approach allows an uncomplicated coupling of these existing flow models. After a brief outline of the underlying mathematical models we focus on the numerical modelling and coupling of overland flow, variably saturated and groundwater flows via exchange flux terms. As each process object is associated with its own spatial discretisation mesh, temporal time-stepping scheme and appropriate numerical solution procedure. Flow processes in hydrosystems are coupled via their compartment (or process domain) boundaries without giving up the computational necessities and optimisations for the numerical solution of each individual process. However, the coupling requires a bridging of different temporal and spatial scales, which is solved here by the integration of fluxes (spatially and temporally). In closing we present three application examples: a benchmark test for overland flow on an infiltrating surface and two case studies – at the Borden site in Canada and the Beerze–Reusel drainage basin in the Netherlands.

scholarly journals Assessment of the community vulnerability to extreme spring floods: the case of the Amga River, central Yakutia, Siberia

2020 ◽  
Author(s):  
N. I. Tananaev ◽  
V. A. Efremova ◽  
T. N. Gavrilyeva ◽  
O. T. Parfenova
Keyword(s):  
Rural Areas ◽  
Flood Control ◽  
Management Practices ◽  
Snow Water Equivalent ◽  
Risk Mitigation ◽  
Control Structures ◽  
Ice Jam ◽  
Central Yakutia ◽  
Urban Settlements ◽  
Water Stage

Abstract Spring floods in Siberia annually affect local communities. Major urban settlements in the region implemented flood control structures, so rural areas take a heavy beating. In 2018, spring floods severely hit multiple communities in central Yakutia, exposing deficient flood prevention and risk management practices. Notably, Amga village, an important local center, was severely inundated. Hydrological analysis shows that the 2018 flood had a 50-yr return period, and was caused by an ice jam in a nearby channel bend where mid-channel sand bars impede ice movement during breakup. The cold spells of late April and early May in the middle section of the river promote ice-jam development, causing extreme water stage rise. Highest water stage is unrelated to either winter snow water equivalent or early May rainfall. Estimated tangible direct damage to the Amga community equals 5.1B ($81.5M) in 2018 prices, but only 0.13B ($2.1M), or 2.5% of this total, was reclaimed. A questionnaire survey revealed that most residents report important deterioration of drinking water quality and health after flooding. Residents respond positively to risk mitigation actions, implemented by the local and regional authorities, except ice dusting and cutting, and report minor activity of official sources in spreading information on flood progress.

scholarly journals Flood Risk Zoning by Using 2D Hydrodynamic Modeling: A Case Study in Jinan City

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Tao Cheng ◽  
Zongxue Xu ◽  
Siyang Hong ◽  
Sulin Song
Keyword(s):  
Flood Risk ◽  
Flood Control ◽  
Overland Flow ◽  
The South ◽  
Rapid Urbanization ◽  
Risk Zoning ◽  
The North ◽  
Hourly Rainfall ◽  
Infoworks Icm ◽  
Jinan City

Climate change and rapid urbanization have aggravated the rainstorm flood in Jinan City during the past decades. Jinan City is higher in the south and lower in the north with a steep slope inclined from the south to the north. This results in high-velocity overland flow and deep waterlogging, which poses a tremendous threat to pedestrians and vehicles. Therefore, it is vital to investigate the rainstorm flood and further perform flood risk zoning. This study is carried out in the “Sponge City Construction” pilot area of Jinan City, where the InfoWorks ICM 2D hydrodynamic model is utilized for simulating historical and designed rainfall events. The model is validated with observations, and the causes for errors are analyzed. The simulated water depth and flow velocity are recorded for flood risk zoning. The result shows that the InfoWorks ICM 2D model performed well. The flood risk zoning result shows that rainfalls with larger recurrence intervals generate larger areas of moderate to extreme risk. Meanwhile, the zoning results for the two historical rainfalls show that flood with a higher maximum hourly rainfall intensity is more serious. This study will provide scientific support for the flood control and disaster reduction in Jinan City.

scholarly journals Determination of potential retention of the Fryšávka River basin

2010 ◽  
Vol 58 (5) ◽  
pp. 263-270 ◽  
Author(s):  
Tomáš Mašíček ◽  
František Toman
Keyword(s):  
River Basin ◽  
Flood Control ◽  
Water Retention ◽  
Curve Number ◽  
Control Measures ◽  
Design Parameters ◽  
Software Products ◽  
Software Applications ◽  
Integrated Software

Hydrological models provide design parameters for the design of flood control measures. Runoff from the river basin is primarily determined by the amount of rainfall and water retention of the river basin. The Fryšávka River basin was chosen to determine the potential water retention of the river basin. Before the determination of potential retention preparatory work was carried out: description of the current state of land cover based on a detailed field survey, the representation of hydrological soil groups in the basin found in BPEJ (Bonitované půdně ekologické jednotky – Valuated land–ecological units) maps, delimitation of basin parts by the digital vector layer ZABAGED altimetry (Základní báze geografických dat – Fundamental base of geographic data) – 3D contour and evaluation of basin parts by the runoff curve numbers (CN). The processing of background data was performed by the program ArcGIS 9.2 of ArcView software products using a set of integrated software applications ArcMap, ArcCatalog and ArcToolbox. To assess the potential retention, as part of the hydrologic cha­ra­cte­ri­stics of the Fryšávka River basin, the curve number method, a modification of the deterministic episode model DesQ–MAXQ, was used. The average numbers of runoff curves and the data about potential retention of river basin parts are presented in the form of map outputs.

scholarly journals Urban Flood Event and Associated Damage in the Benue Valley, Nigeria

2021 ◽  
Author(s):  
Temi Ologunorisa ◽  
Obioma Ogbuokiri ◽  
Adebayo Oluwole Eludoyin
Keyword(s):  
Flood Control ◽  
Overland Flow ◽  
Standardized Precipitation Index ◽  
Flood Damage ◽  
Geographical Information ◽  
Flood Event ◽  
Discharge Data ◽  
Precipitation Concentration Index ◽  
Infiltration Excess ◽  
The Impact

Abstract Flooding events in the Lower Benue valley of Nigeria are often associated with huge damage to properties and loss of life in the adjoining communities. Specific objective of this study is to evaluate the impact of 2017 flood event as typical of the study area. Method used was an integrated environmental approach that combines analysis of rainfall and discharge data with social surveys, remote sensing and geographical information system. Standardized Precipitation Index (SPI), Precipitation Concentration Index (PCI) as well as flood damage curves were analysed with landuse/cover change and soil data to establish the nature of the flood and its impacts. Result showed that the flood in the study area is essentially saturation overland flow, which is more associated with saturation-excess than infiltration excess flow, and that the flood events are recurrent and predictable. 85% of the affected residents are however poor, earning an equivalent of US $4.3 daily, and live in non-reinforced concrete masonry (64%) and wooden buildings (24%). Many of the affected communities lived within flood plain and most buildings were structurally deficient. Victims received no compensation, and the properties were generally uninsured. The study recommends extensive flood control policy for the area and similar flood-prone communities.

scholarly journals Remote sensing and monitoring of earthen flood-control structures

2017 ◽  
Author(s):  
Joseph Dunbar ◽  
Gustavo Galan-Comas ◽  
Lucas Walshire ◽  
Ronald Wahl ◽  
Donald Yule ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Flood Control ◽  
Control Structures

scholarly journals Model Sophistication in Relation to Scales in Snowmelt Runoff Modeling

2000 ◽  
Vol 31 (4-5) ◽  
pp. 267-286 ◽  
Author(s):  
Lars Bengtsson ◽  
Vijay P. Singh
Keyword(s):  
Stream Flow ◽  
Overland Flow ◽  
River Basins ◽  
Rainfall Runoff ◽  
Snowmelt Runoff ◽  
Degree Day ◽  
Groundwater Origin ◽  
Runoff Modeling ◽  
Snow Model ◽  
Runoff Model

Snowmelt induced runoff from river basins is usually successfully simulated using a simple degree-day approach and conceptual rainfall-runoff models. Fluctuations within the day can not be described by such crude approaches. In the present paper, it is investigated which degree of sophistication is required in snow models and runoff models to resolve the basin runoff from basins of different character, and also how snow models and runoff models must adapt to each other. Models of different degree of sophistication are tested on basins ranging from 6,000 km2 down to less than 1 km2. It is found that for large basins it is sufficient to use a very simple runoff module and a degree day approach, but that the snow model has to be distributed related to land cover and topography. Also for small forested basins, where most of the stream flow is of groundwater origin, the degree-day method combined with a conceptual runoff model reproduces the snowmelt induced runoff well. Where overland flow takes place, a high resolution snow model is required for resolving the runoff fluctuations at the basin outlet.

scholarly journals Socio-hydrology: conceptualising human-flood interactions

2013 ◽  
Vol 10 (4) ◽  
pp. 4515-4536 ◽  
Author(s):  
G. Di Baldassarre ◽  
A. Viglione ◽  
G. Carr ◽  
L. Kuil ◽  
J. L. Salinas ◽  
...  
Keyword(s):  
Flood Control ◽  
Technological Development ◽  
River System ◽  
High Water ◽  
Social Processes ◽  
Individual Characteristics ◽  
Water Levels ◽  
Control Structures ◽  
Flooding Events

Abstract. Over history, humankind has tended to settle near streams because of the role of rivers as transportation corridors and the fertility of riparian areas. However, human settlements in floodplains have been threatened by the risk of flooding. Possible responses have been to resettle away and/or modify the river system by building flood control structures. This has led to a complex web of interactions and feedback mechanisms between hydrological and social processes in settled floodplains. This paper is an attempt to conceptualise these interplays for hypothetical human-flood systems. We develop a simple, dynamic model to represent the interactions and feedback loops between hydrological and social processes. The model is then used to explore the dynamics of the human-flood system and the effect of changing individual characteristics, including external forcing such as technological development. The results show that the conceptual model is able to reproduce reciprocal effects between floods and people as well as the emergence of typical patterns. For instance, when levees are built or raised to protect floodplain areas, their presence not only reduces the frequency of flooding, but also exacerbates high water levels. Then, because of this exacerbation, higher flood protection levels are required by the society. As a result, more and more flooding events are avoided, but rare and catastrophic events take place.

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