scholarly journals LABORATORY INVESTIGATION OF SHORE EROSION PROCESSES

1976 ◽  
Vol 1 (15) ◽  
pp. 87
Author(s):  
E.F. Brater ◽  
David Ponce-Campos
Keyword(s):  
Laboratory Investigation ◽  
Relative Effectiveness ◽  
Shore Protection ◽  
Test Procedures ◽  
Demonstration Program ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Protective Methods ◽  
Hydraulics Laboratory ◽  
Shore Erosion

The laboratory investigation was undertaken as part of a shore protection demonstration program sponsored by the Michigan Department of Natural Resources. Subsequently funding was also provided by the Sea Grant Program. The laboratory work is being done in the Lake Hydraulics Laboratory, a facility of the Department of Civil Engineering of the University of Michigan. The field demonstration program consists of 19 field installations at locations on Lakes Michigan, Huron and Superior. The laboratory program was planned to supplement information from the field installations by testing over a wider range of variables and to test procedures not included in the field program. This program has also proven to be useful in the demonstration of shore erosion processes to groups concerned with shore problems. Although erosion rates determined in a model cannot be converted quantitatively to nature it was reasoned that if natural shore erosion processes could be simulated and if repeatable erosion rates could be produced in the model the results could help to evaluate the relative effectiveness of many protective methods. The advantages of using a model are the much lower cost compared with field installations, the control over such variables as wave height and water level and the speed with which results can be obtained.

Retrospective on the 1970’s “Low Cost Shore Protection” program

Shore & Beach ◽  
2019 ◽  
pp. 3-12
Author(s):  
Joan Pope
Keyword(s):  
Coastal Erosion ◽  
Low Cost ◽  
Management Strategies ◽  
Public Information ◽  
Coastal Engineering ◽  
Shoreline Erosion ◽  
Shore Protection ◽  
Demonstration Program ◽  
Alternative Approaches ◽  
The U.S

In the 1970s, the U.S. Congress authorized and funded a five-year demonstration program on low-cost methods for shore protection called the “U.S. Army Engineers Shoreline Erosion Control Demonstration (Section 54) Program.” The Section 54 also known as the “Low-Cost Shore Protection” demonstration program is revisited. Demonstration and monitoring sites including the materials, devices, vegetative plantings, approaches tested, and program findings are discussed. Simply put, a major finding of the Section 54 program was that the concept of “low-cost shore protection” was a bit naïve. However, the program did lead to a wealth of public information documents and practical coastal engineering lessons that are still resonating as home owners, communities, and engineers consider alternative approaches for managing coastal erosion. The program structure and findings are applicable 40 years later as consideration is given toward the use of Natural and Nature-based Features (NNBF) for addressing coastal erosion. Evolution in thought relative to coastal erosion and shoreline enhancement activities since the 1970s has built upon many of the lessons and concepts of the Section 54 program and other real-world coastal erosion management success-failure experiences. This growth has led to a modern appreciation that those features that emulate NNBF are promising and responsible alternative coastal erosion management strategies if proper engineering standard elements of design are included in the project.

scholarly journals Analyzing Regional Geographic Challenges: The Resilience of Chinese Vineyards to Land Degradation Using a Societal and Biophysical Approach

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 227
Author(s):  
Yang Yu ◽  
Jesús Rodrigo-Comino
Keyword(s):  
Soil Erosion ◽  
Land Degradation ◽  
Environmental Concern ◽  
Point Of View ◽  
Irreversible Damage ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Lack Of Information ◽  
Scientific Hypothesis ◽  
Vineyard Soil

Land degradation, especially soil erosion, is a societal issue that affects vineyards worldwide, but there are no current investigations that inform specifically about soil erosion rates in Chinese vineyards. In this review, we analyze this problem and the need to avoid irreversible damage to soil and their use from a regional point of view. Information about soil erosion in vineyards has often failed to reach farmers, and we can affirm that to this time, soil erosion in Chinese vineyards has been more of a scientific hypothesis than an agronomic or environmental concern. Two hypotheses can be presented to justify this review: (i) there are no official and scientific investigations on vineyard soil erosion in China as the main topic, and it may be understood that stakeholders do not care about this or (ii) there is a significant lack of information and motivation among farmers, policymakers and wineries concerning the consequences of soil erosion. Therefore, this review proposes a plan to study vineyard soil erosion processes for the first time in China and develop a structured scientific proposal considering different techniques and strategies. To achieve these goals, we present a plan considering previous research on other viticultural regions. We hypothesize that the results of a project from a regional geographic point of view would provide the necessary scientific support to facilitate deriving guidelines for sustainable vineyard development in China. We concluded that after completing this review, we cannot affirm why vine plantations have not received the same attention as other crops or land uses.

A multi-decade assessment of the impact of large fire events on sediment redistribution using LAPSUS - the Águeda catchment, north-central Portugal

2021 ◽  
Author(s):  
Dante Föllmi ◽  
Jantiene Baartman ◽  
João Pedro Nunes ◽  
Akli Benali
Keyword(s):  
Soil Depth ◽  
Spatial Scales ◽  
Fire Severity ◽  
Sediment Dynamics ◽  
Land Uses ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Sediment Redistribution ◽  
Central Portugal ◽  
The Impact

<p><strong>Abstract</strong></p><p>Wildfires have become an increasing threat for Mediterranean ecosystems, due to increasing climate change induced wildfire activity and changing land management practices. Apart from the initial risk, fire can alter the soil in various ways depending on different fire severities and thus post-fire erosion processes are an important component in assessing wildfires’ negative effects. Recent post-fire erosion (modelling) studies often focus on a short time window and lack the attention for sediment dynamics at larger spatial scales. Yet, these large spatial and temporal scales are fundamental for a better understanding of catchment sediment dynamics and long-term destructive effects of multiple fires on post-fire erosion processes. In this study the landscape evolution model LAPSUS was used to simulate erosion and deposition in the 404 km<sup>2</sup> Águeda catchment in northern-central Portugal over a 41 year (1979-2020) timespan. To include variation in fire severity and its impact on the soil four burnt severity classes, represented by the difference Normalized Burn Ratio (dNBR), were parameterized. Although model calibration was difficult due to lack of spatial and temporal measured data, the results show that average post-fire net erosion rates were significantly higher in the wildfire scenarios (5.95 ton ha<sup>-1</sup> yr<sup>-1</sup>) compared to those of a non-wildfire scenario (0.58 ton ha<sup>-1</sup> yr<sup>-1</sup>). Furthermore, erosion values increased with a higher level of burnt severity and multiple fires increased the overall sediment build-up in the catchment, fostering an increase in background sediment yield. Simulated erosion patterns showed great spatial variability with large deposition and erosion rates inside streams. Due to this variability, it was difficult to identify land uses that were most sensitive for post-fire erosion, because some land-uses were located in more erosion-sensitive areas (e.g. streams, gullies) or were more affected by high burnt severity levels than others. Despite these limitations, LAPSUS performed well on addressing spatial sediment processes and has the ability to contribute to pre-fire management strategies. For instance, the percentage soil loss map (i.e. comparison of erosion and soil depth maps) could identify locations at risk.</p>

The role of erosion in the morphometry of composite volcanoes

2021 ◽  
Author(s):  
Roos van Wees ◽  
Pierre-Yves Tournigand ◽  
Daniel O’Hara ◽  
Pablo Grosse ◽  
Gabor Kereszturi ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Age Determination ◽  
Morphometric Parameters ◽  
Physical Weathering ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Digital Elevation ◽  
Shape Complexity ◽  
Geochronological Constraints ◽  
Natural Composite

<p>Volcanoes are extremely dynamic landforms. They grow by the accumulation of eruptive products and intrusions and degrade by a range of erosion processes such as superficial runoff, chemical and physical weathering, fluvial and glacial incision, and mass movements. In this study, we aim at documenting and quantifying the morphology of natural composite volcanoes using a range of morphometric indices, to better understand the factors that control erosion rates and patterns.</p><p>In addition to standard morphometric indices, including edifice ellipticity and irregularity, computed by the MORVOLC algorithm, a fractal dimension tool is developed to quantitatively report the shape complexity of stratovolcanoes. A convex hull approach is used to derive minimal erosion volumes and estimate erosion rates, considering available geochronological constraints. Morphometric parameters are derived from digital elevation models (DEMs) for a few exemplary stratovolcanoes of contrasted ages from the same volcanic region. To analyse the potential bias induced by the selected DEMs and the identification of the volcanic edifice outline, we also conduct a sensitivity analysis. The morphometric parameters are similarly extracted using the freely and globally available ALOS 30m (AW3D30), SRTM 30m (SRTMGL1), and ASTER 30m (GDEM 003), and compared to values obtained with the TanDEM-X 12m. The subjective user-drawn edifice outlines are compared to outlines generated by available algorithms, i.e. NETVOLC and MBOA, and their impact on the accuracy of morphometric indexes is quantified.  </p><p>Our results highlight that erosion increases edifice irregularity and fractal dimension. Preliminary trends between volcano fractal dimension, eroded volume, and age suggest that fractal analysis has the potential to be used as a relative age determination tool. The proposed morphometric characterisation paves the way for a comparison between natural volcanoes and controlled lab experiments reproducing the degradation of pristine volcanic cones by surface runoff to be developed later in our project.  </p>

Advances in techniques to assess soil erodibility

2021 ◽  
pp. 175-214
Author(s):  
R. J. Rickson ◽  
◽  
E. Dowdeswell Downey ◽  
G. Alegbeleye ◽  
S. E. Cooper ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Test Procedure ◽  
Aggregate Stability ◽  
Analytical Techniques ◽  
Soil Biology ◽  
Soil Erodibility ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Assessment Techniques ◽  
Soil Erosion By Water

Soil erodibility is the susceptibility of soil to the erosive forces of rainsplash, runoff and wind. It is a significant factor in determining present and future soil erosion rates. Focusing on soil erosion by water, this chapter shows that erodibility is determined by static and dynamic soil properties that control a range of sub-processes affecting soil erosion, but there is no standardised test procedure, making comparison of erodibility assessment techniques and their results challenging. Most researchers agree that aggregate stability is the best indicator of soil erodibility. Selection of techniques to measure aggregate stability need to consider the type of disruptive forces and breakdown processes to which field aggregates are subjected. New indices must incorporate spatial and temporal variabilities in erodibility; the different erosion processes operating; the impact of climate change; and the role of soil biology. New analytical techniques such as computer aided tomography show promise in considering soil erodibility as a dynamic continuum operating over 3 dimensions.

DIMENSIONAL ANALYSIS RELATIONSHIPS OF STREAMBANK EROSION RATES

2016 ◽  
Vol 78 (5-5) ◽  
Author(s):  
Azlinda Saadon ◽  
Junaidah Ariffin ◽  
Jazuri Abdullah ◽  
Norhidayati Mat Daud
Keyword(s):  
Dimensional Analysis ◽  
Physical Characteristics ◽  
Bank Failure ◽  
Erosion Process ◽  
Streambank Erosion ◽  
Fluvial Erosion ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Hydraulic Force ◽  
River Meandering

Bank erosion is commonly associated with river meandering initiation and development, through width adjustment and planform evolution. It consists of two types of erosion processes; basal erosion due to fluvial hydraulic force and bank failure under the influence of gravity. Most of the studies only focused on one factor rather than integrating both factors. Evidences of previous works have shown integration between both processes of fluvial hydraulic force and bank failure. Bank failure seldom treated as a probabilistic phenomenon without assessing the physical characteristics and the geotechnical aspects of the bank. Thus, the objective of this paper is to investigate factors governing streambank erosion process and to perform a dimensional analysis considering the physical characteristics of both processes namely fluvial erosion and mass failure and their interaction.

scholarly journals Reconstructing long-term gully dynamics in Mediterranean agricultural areas

2017 ◽  
Vol 21 (1) ◽  
pp. 235-249 ◽  
Author(s):  
Antonio Hayas ◽  
Tom Vanwalleghem ◽  
Ana Laguna ◽  
Adolfo Peña ◽  
Juan V. Giráldez
Keyword(s):  
Land Use ◽  
Temporal Resolution ◽  
Land Use Changes ◽  
Mediterranean Area ◽  
Gully Erosion ◽  
Aerial Photographs ◽  
High Temporal Resolution ◽  
Erosion Rates ◽  
Erosion Processes

Abstract. Gully erosion is an important erosive process in Mediterranean basins. However, the long-term dynamics of gully networks and the variations in sediment production in gullies are not well known. Available studies are often conducted only over a few years, while many gully networks form, grow, and change in response to environmental and land use or management changes over a long period. In order to clarify the effect of these changes, it is important to analyse the evolution of the gully network with a high temporal resolution. This study aims at analysing gully morphodynamics over a long timescale (1956–2013) in a large Mediterranean area in order to quantify gully erosion processes and their contribution to overall sediment dynamics. A gully network of 20 km2 located in southwestern Spain has been analysed using a sequence of 10 aerial photographs in the period 1956–2013. The extension of the gully network both increased and decreased in the study period. Gully drainage density varied between 1.93 km km−2 in 1956, a minimum of 1.37 km km−2 in 1980, and a maximum of 5.40 km km−2 in 2013. The main controlling factor of gully activity appeared to be rainfall. Land use changes were found to have only a secondary effect. A new Monte Carlo-based approach was proposed to reconstruct gully erosion rates from orthophotos. Gully erosion rates were found to be relatively stable between 1956 and 2009, with a mean value of 11.2 t ha−1 yr−1. In the period 2009–2011, characterized by severe winter rainfalls, this value increased significantly to 591 t ha−1 yr−1. These results show that gully erosion rates are highly variable and that a simple interpolation between the starting and ending dates greatly underestimates gully contribution during certain years, such as, for example, between 2009 and 2011. This illustrates the importance of the methodology applied using a high temporal resolution of orthophotos.

scholarly journals Estimation of soil redistribution rates due to snow cover related processes in a mountainous area (Valle d'Aosta, NW Italy)

2012 ◽  
Vol 16 (2) ◽  
pp. 517-528 ◽  
Author(s):  
E. Ceaglio ◽  
K. Meusburger ◽  
M. Freppaz ◽  
E. Zanini ◽  
C. Alewell
Keyword(s):  
Soil Erosion ◽  
Sediment Yield ◽  
Mountainous Area ◽  
Mountain Areas ◽  
Spatial And Temporal Scales ◽  
Erosion Rates ◽  
Soil Redistribution ◽  
Erosion Processes ◽  
Soil Accumulation ◽  
Snow Gliding

Abstract. Mountain areas are widely affected by soil erosion, which is generally linked to runoff processes occurring in the growing season and snowmelt period. Also processes like snow gliding and full-depth snow avalanches may be important factors that can enhance soil erosion, however the role and importance of snow movements as agents of soil redistribution are not well understood yet. The aim of this study was to provide information on the relative importance of snow related processes in comparison to runoff processes. In the study area, which is an avalanche path characterized by intense snow movements, soil redistribution rates were quantified with two methods: (i) by field measurements of sediment yield in an avalanche deposition area during 2009 and 2010 winter seasons; (ii) by caesium-137 method, which supplies the cumulative net soil loss/gain since 1986, including all the soil erosion processes. The snow related soil accumulation estimated with data from the deposit area (27.5 Mg ha−1 event−1 and 161.0 Mg ha−1 event−1) was not only higher than the yearly sediment amounts, reported in literature, due to runoff processes, but it was even more intense than the yearly total deposition rate assessed with 137Cs (12.6 Mg ha−1 yr−1). The snow related soil erosion rates estimated from the sediment yield at the avalanche deposit area (3.7 Mg ha−1 and 20.8 Mg ha−1) were greater than the erosion rates reported in literature and related to runoff processes; they were comparable to the yearly total erosion rates assessed with the 137Cs method (13.4 Mg ha−1 yr−1 and 8.8 Mg ha−1 yr−1). The 137Cs method also showed that, where the ground avalanche does not release, the erosion and deposition of soil particles from the upper part of the basin was considerable and likely related to snow gliding. Even though the comparison of both the approaches is linked to high methodological uncertainties, mainly due to the different spatial and temporal scales considered, we still can deduce, from the similarity of the erosion rates, that soil redistribution in this catchment is driven by snow movement, with a greater impact in comparison to the runoff processes occurring in the snow-free season. Nonetheless, the study highlights that soil erosion processes due to the snow movements should be considered in the assessment of soil vulnerability in mountain areas, as they significantly determine the pattern of soil redistribution.

scholarly journals Geospatial-based automated watershed modeling in Garhwal Himalaya

2010 ◽  
Vol 12 (4) ◽  
pp. 502-520 ◽  
Author(s):  
U. C. Kothyari ◽  
Raaj. Ramsankaran ◽  
D. Sathish Kumar ◽  
S. K. Ghosh ◽  
Nisha Mendiratta
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
Assessment Tool ◽  
Watershed Modeling ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Runoff Potential ◽  
Soil Erosion Rates ◽  
Modelling Methodology ◽  
User Friendly

An automated GIS tool and its computational outcomes on the spatial distribution of runoff and soil erosion are presented. The developed tool, named Automated Soil Erosion Assessment Tool (ASEAT), simulates runoff and soil erosion rates based on the concept of erosion processes suggested by Morgan–Morgan–Finney (MMF) in 1984. ASEAT is provided with a user-friendly graphical user interface (GUI) to interact with the users. The computational algorithms used are made fully automated and have been developed using the ERDAS Macro Language (EML) and Spatial Macro Language (SML). The developed modelling methodology is applied to the data of an experimental watershed of Pathri Rao in the Indian lower Himalayan region. Generated spatial distribution of runoff potential and soil erosion rates for the studied watershed using ASEAT are depicted by maps. The model-computed surface runoff potential (145.63 mm) available in the watershed seems fair when compared with the runoff depth (176.07 mm) observed at the watershed outlet. The derived estimates of soil erosion are validated, albeit qualitatively, with field observations and seem reliable for making decisions on the adoption of soil erosion conservative measures in the watershed.

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