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16. The GCTE validation of soil erosion models for global change

Author

Favis-Mortlock, David T., Quinton, John N., and Dickinson, W. Trevor

Subjects
Mathematical models -- Evaluation -- Research, Soil erosion -- Research, Environmental issues, Evaluation, Research
Abstract

Take a hammer! It may be used (or misused) to bang in nails and tacks, as a crowbar or lever, and for many other things. Now imagine that you are [...]

Published
1996

17. Feast or famine? Rainfall in Burkina Faso

Author

Crawford, Thomas and Favis-Mortlock, David

Subjects
Rain and rainfall -- Research
Abstract

The British are familiar with the rhyme 'rain, rain go to Spain, never show your face again'. For farmers in west Africa, the amount and timing of rainfall is a […]

Published
2004

24. Coastal Modelling Environment version 1.0: a framework for integrating landform-specific component models in order to simulate decadal to centennial morphological changes on complex coasts

Author

Payo, Andrés, primary, Favis-Mortlock, David, additional, Dickson, Mark, additional, Hall, Jim W., additional, Hurst, Martin D., additional, Walkden, Mike J. A., additional, Townend, Ian, additional, Ives, Matthew C., additional, Nicholls, Robert J., additional, and Ellis, Michael A., additional

Published
2017
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26. ‘Local gradient’ and between‐site variability of erosion rate on badlands in the Karoo, South Africa.

Author

Favis‐Mortlock, David, Boardman, John, Foster, Ian, and Greenwood, Philip

Subjects
SOIL erosion, BADLANDS, CLINOMETER, CHANNEL flow, CHANNELS (Hydraulic engineering)
Abstract

Abstract: Site‐average values of local gradient, defined as the steepest slope angle measured at a point, are a powerful predictor of long‐term rates of soil loss as measured by erosion pins on the non‐channel floor portions of ten badland study sites in the Karoo area of South Africa. Local gradient may be easily measured using a smartphone clinometer. The successful use of local gradient here is in strong contrast to the previous failure of other site‐specific attributes, including other measures of gradient and relief, to explain between‐site variation in erosion rate on these study sites. Each measurement of local gradient may be thought of as a sample of the site's microtopography. Microrelief is a strong determinant of the emergent patterns of inter‐channel overland flow, and hence of the patterns of inter‐channel erosion by flow. Local gradient changes most rapidly during the initial stages of channel incision. When channels are established, local gradient changes more slowly leading to almost‐parallel retreat of channel sidewalls. A sensitivity analysis suggests that measurements of local gradient are not all equal with regard to prediction of long‐term erosion rate. A greater share of predictive power is contributed by measurements made on very steep or vertical channel side wall areas, and a lesser share is contributed by measurements made on interfluves. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2018
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28. Measurement and modelling of high resolution flow-velocity data under simulated rainfall on a low-slope sandy soil

Author

Tatard, Lucile, Planchon, Olivier, Wainwright, John, Nord, Guillaume, Favis-Mortlock, David, Silvera, Norbert, Ribolzi, Olivier, Esteves, Michel, Hua Huang, Chi, Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Sols, usages des terres, dégradation, réhabilitation (SOLUTIONS), Sheffield Centre for International Drylands Research, Department of Geography, Laboratoire d'étude des transferts en hydrologie et environnement (LTHE), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), of Geography, Queen's University Belfast, Belfast, UK., ECU, NSERL, (NSERL), USDA, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Laboratoire Central des Ponts et Chaussées (LCPC)-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Queen's University [Belfast] (QUB), Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
erosion models, interrill, rill, water erosion, [SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study, simulation, Senegal
Abstract

International audience; The study presented here is focussed on the question of the hydraulic nature of the threshold that allows a rill to start. A rainfall-simulation experiment was carried out to produce high-resolution flow-velocity data. The experiment employed a 10 m  4 m experimental plot with a 1 % slope, which had been previously eroded and had a small rill formed in the middle. The experiment consisted of a 2 h 15'-long rainfall at a constant intensity of 69 mm h-1. Surface elevation was measured before rainfall at a horizontal resolution of 2.5 cm across, and 5 cm along the slope direction. During rainfall, flow velocities were measured at 68 locations on the plot with the Salt Velocity Gauge technology, an automated, miniaturized device based on the inverse modelling of the propagation of a salt plume. The experiment led to the collection of flow-velocity measurements which are novel in three ways: (i) the small size of the measured section, which was only 10-cm long and 1-cm wide, (ii) the wide range of measured flow velocities, which ranged from 0.006 m s-1 to 0.27 m s-1 and, (iii) the large number of measured locations. The flow-velocity field was simulated with three models: PSEM_2D solves the Saint-Venant equations in 2D, MAHLERAN uses a 1D kinematic wave in the slope direction coupled with a 2D flow-routing algorithm, and Rillgrow2, which involves an empirical runoff algorithm that is close in principle to the diffusion-wave equation in 2D. The Darcy-Weisbach friction factor (ff) and the infiltration parameters were calibrated in all cases to investigate the capabilities of the different models to reproduce flow hydraulics compatible with the onset of rilling. In a first set of numerical experiments, ff was set uniform, and calibration used only the hydrograph. The comparison of simulated and observed flow-velocity field showed that PSEM_2D was the most satisfying model, at the cost of longer computational time. MAHLERAN gave surprisingly good results with regards to the simplicity of the model and its low computational needs. However, all models largely underestimated the highest velocity values, located in the rill. Furthermore, none of the models was able to simulate the Reynolds (Re) and Froude (Fr) numbers. The next numerical experiment was done with PSEM_2D. Non-uniform ff values were calibrated by fitting the simulated flow-velocity field to the observed one. The latter simulation produced realistic simulations of Re and Fr. The hydraulic conditions at the transition from interrill flow to rill flow are discussed. The results support the theory that supercritical flows are a necessary condition for a rill to emerge from a smooth surface.

Published
2008

29. CoastalME version 1.0: a Coastal Modelling Environment for simulating decadal to centennial morphological changes.

Author

Payo, Andrés, Favis-Mortlock, David, Dickson, Mark, Hall, Jim W., Hurst, Martin, Walkden, Mike J. A., Townend, Ian, Ives, Matthew C., Nicholls, Robert J., and Ellis, Michael A.

Subjects
*COASTAL zone management, *LANDFORMS, *SUSTAINABLE development, *CLIMATE change, *COMPUTER simulation
Abstract

Modelling coastal morphological changes at decadal to centennial time scales is required to support sustainable coastal management world-wide. One approach involves coupling of landform-specific components (e.g. cliff, beach, dunes, estuaries, etc.) that have been independently developed. An alternative, and novel approach explored in this paper is to capture the essential characteristics of the landform-specific models using a common spatial representation within an appropriate software-environment. In the proposed Coastal Modelling Environment (CoastalME), change in coastal morphology is formulated by means of dynamically linked raster and geometrical objects. A grid of raster cells provides the data structure for representing quasi-3D spatial heterogeneity and sediment conservation. Other geometrical objects (lines, areas and volumes) that are consistent with, and derived from, the raster structure represent a library of coastal elements (e.g. shoreline, beach profiles and estuary volumes) as required by different landform-specific models. As a proof-of-concept, we illustrate the potential capabilities of CoastalME by integrating a cliff-beach model. We verify that CoastalME can reproduce behaviours of each individual landform-specific model. Their integration within the framework of CoastalME reveals behaviours that emerge from landforms interaction and which have not previously been captured, such as the influence of the regional bathymetry on the local alongshore sediment transport gradient. This is the first step of the framework development, which provides an alternative to directly coupling existing models. [ABSTRACT FROM AUTHOR]

Published
2016
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32. A Brave Try

Author

Favis-Mortlock, David

Published
2001

46. Feast or famine?

Author

Crawford, Thomas and Favis-Mortlock, David

Subjects
RAINFALL, RAINFALL frequencies, RUNOFF, AGRICULTURAL water supply, WEATHER, PLANTING, AGRICULTURE
Abstract

Presents a case study regarding the variability of the regional rainfall in Burkina Faso. Focus of the research on the effects of rainfall on the runoff process and agricultural practices; Geographic description; Average rainfall per annum; Difference between the wet and dry season; Weather patterns and climates; Spatial and temporal variability of rainfall; Factors limiting rainfall variability; Impact of the region's soils and semi-arid zone on runoff; Planting techniques used to maximize water absorption.

Published
2004

47. Sunflowers or sugar beet? Potential impacts of climate change on agriculture in Norfolk.

Author

Lorenzoni, Irene, Jordan, Andrew, Viner, David, Favis-Mortlock, David, and Hall, Jilly

Abstract

A case study of the Norfolk Arable Land Management Initiative, an area of intensively farmed land in East Anglia, identifies some of the potential impacts and adaptive responses to climate change during the next 50 years. [ABSTRACT FROM AUTHOR]

Published
2000

48. Coastal Modelling Environment version 1.0: a framework for integrating landform-specific component models in order to simulate decadal to centennial morphological changes on complex coasts

Author

Payo, Andrés, Favis-Mortlock, David, Dickson, Mark, Hall, Jim W., Hurst, Martin D., Walkden, Mike J. A., Townend, Ian, Ives, Matthew C., Nicholls, Robert J., and Ellis, Michael A.

Abstract

The ability to model morphological changes on complex, multi-landform, coasts during decadal to centennial time scales is essential for sustainable coastal management world-wide. One approach involves coupling of landform-specific 15 simulation models (e.g. cliffs, beaches, dunes, estuaries, etc.) that have been independently developed. An alternative, novel, approach explored in this paper is to capture the essential characteristics of the landform-specific models using a common spatial representation within an appropriate software framework. This avoid the problems that result from the model-coupling approach due to between-model differences in the conceptualisations of geometries, volumes and locations of sediment. In the proposed framework, the Coastal Modelling Environment (CoastalME), change in coastal morphology is 20 represented by means of dynamically linked raster and geometrical objects. A grid of raster cells provides the data structure for representing quasi-3D spatial heterogeneity and sediment conservation. Other geometrical objects (lines, areas and volumes) that are consistent with, and derived from, the raster structure represent a library of coastal elements (e.g. shoreline, beach profiles and estuary volumes) as required by different landform-specific models. As a proof-of-concept, we illustrate the capabilities of an initial version of CoastalME by integrating a cliff-beach model and two wave propagation 25 approaches. We verify that CoastalME can reproduce behaviours of the component landform-specific models. Additionally, the integration of these component models within the CoastalME framework reveals behaviours that emerge from the interaction of landforms, which have not previously been captured, such as the influence of the regional bathymetry on the local alongshore sediment transport gradient, the effect on coastal change on an undefended coastal segment and on sediment bypassing of coastal structures.

49. Book reviews.

Author

Favis-Mortlock, David, Viles, Heather A., Mendel, Alexandra C., Dubois, Jean-Marie M., and Dengshan Ding

Subjects
BEACH Management (Book), ZOOGEOMORPHOLOGY (Book), PHYSICAL Geography & Natural Resources in the Region of Mount Namjagbarwa (Book)
Abstract

Arnell, N. 1996: Global warming, river flows and water resources Bird, E.C.F. 1996: Beach management Butler, D.R. 1995: Zoogeomorphology: animals as geomorphic agents Derruau, M. 1996: Les formes du relief terrestre: notions de geomorphologie (7th edn) Derruau, M., editor, 1996: Composantes et concepts de la geographie physique Peng, B. and Yang, Y., editors, 1996: Physical geography and natural resources in the region of Mount Namjagbarwa Senneset, K., editor, 1996: Landslides/glissements de terrain, 3 volumes. [ABSTRACT FROM AUTHOR]

Published
1998
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50. Spatial and temporal variation in two rainfall simulators: implications for spatially explicit rainfall simulation experiments

Author

Favis-Mortlock, David T., Parsons, Anthony J., Lascelles, Bruce, and Guerra, Antonio J. T.

Subjects
SPATIO-temporal variation, METEOROLOGICAL precipitation, INSTRUMENTATION technicians, EROSION
Abstract

Rainfall simulators are widely used yet there is little evidence in the literature to show that their spatial and temporal variability has been adequately taken into account. For experiments that are concerned only with some aggregate or mean effect of simulated rain then such variations may be unimportant. However, where rainfall simulation is being used to study (and perhaps model) small-scale processes thatare themselves spatially variable (such as rill initiation) then knowledge of the simulator's inherent variability is vital. A first aim of this paper is therefore to examine this variability, and to appraise methodologies by which it may be quantified. A second aim is to evaluate the implications for spatially explicit rainfall simulation experiments. Two simulators were used, a portable drip-screen simulatorand a laboratory-based full-cone nozzle simulator. Neither produced a spatially uniform distribution of rainfall depth: both produced distributional patterns that were fairly consistent despite varying intensities and run times. Small-scale, apparently random variations weresuperimposed on these more deterministic patterns. However, despite this marked spatial variability, calculation of uniformity coefficients (1-SD/mean) resulted in high values. Thus it appears that the uniformity coefficient gives little real indication of the spatial uniformity of simulated rainfall, despite its established usage in the literature. Additionally, spatial distributions of raindrop size -and hence kinetic energy -were calculated for the full-cone nozzle simulator. These show that zones of high rainfall amount do not necessarily relate to zones of high energy reaching the surface. The presence of such variability raises a number of issues for spatially explicit rainfall simulation experiments. While there has been little work on the spatial variability of natural rainfall at field scale and smaller, itappears that the spatial heterogeneity of simulated rainfall depths obse [ABSTRACT FROM AUTHOR]

Published
2000

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