scholarly journals Differences in the Efficiency of the Vertical Transfer of Windblown Sediment over Different Ploughed Surfaces during Wind Erosion Events

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 511
Author(s):  
Mohamed Taieb Labiadh ◽  
Gilles Bergametti ◽  
Jean Louis Rajot ◽  
Christel Bouet ◽  
Mohsen Ltifi ◽  
...  

Airborne sediment fluxes were measured in southern Tunisia on two experimental plots tilled with a moldboard and a tiller plough, respectively, during five wind erosion events of different intensities. The sediment fluxes were sampled on both plots using a mast equipped with seven sand traps positioned between ≈10 and 120 cm height. The windblown sediment fluxes in the 0–100 cm layer were about eight times higher on the plot tilled using the tiller plough compared to the plot tilled using the moldboard plough due to different efficiencies in the trapping of the saltating particles in the furrow, depending on the ridges characteristics. On both plots, sediment fluxes of larger particles were depleted in the sediment samplers compared to the proportions measured in the soil from which they were derived. When examining the sediment flux in the 30–100 cm layer, we observed that the efficiency of the vertical transfer was about twice higher on the moldboard plot than on the tiller one. This implies that a higher fraction of the sediment mobilized by wind can be transported over long distances in the case of a surface ploughed with a moldboard. This result could reduce in part the benefit of using the moldboard instead of the tiller plough regarding soil loss by wind erosion.

2011 ◽  
Vol 8 (4) ◽  
pp. 7137-7175 ◽  
Author(s):  
F. A. Buschman ◽  
A. J. F. Hoitink ◽  
S. M. de Jong ◽  
P. Hoekstra

Abstract. Forest clearing for reasons of timber production, open pit mining and the establishment of oil palm plantations generally results in excessively high sediment loads in the tropics. The increasing sediment fluxes pose a threat to coastal marine ecosystems such as coral reefs. This study presents observations of suspended sediment fluxes in the Berau river (Indonesia), which debouches into a coastal ocean that can be considered the preeminent center of coral diversity. The Berau is an example of a small river draining a mountainous, relatively pristine basin that receives abundant rainfall. Flow velocity was measured over a large part of the river width at a station under the influence of tides, using a Horizontal Acoustic Doppler Current Profiler (HADCP). Surrogate measurements of suspended sediment concentration were taken with an Optical Backscatter Sensor (OBS). Tidally averaged suspended sediment concentration increases with river discharge, implying that the tidally averaged suspended sediment flux increases non-linearly with river discharge. Averaged over the 6.5 weeks observations covered by the benchmark survey, the tidally averaged suspended sediment flux was estimated at 2 Mt y−1. Considering the wet conditions during the observation period, this figure may be considered as an upper limit of the yearly averaged flux. This flux is significantly smaller than what could have been expected from the characteristics of the catchment. The consequences of ongoing clearing of rainforest were explored using a plot scale erosion model. When rainforest, which still covered 50–60 % of the basin in 2007, is converted to production land, soil loss is expected to increase with a factor between 10 and 100. If this soil loss is transported seaward as suspended sediment, the increase in suspended sediment flux in the Berau river would impose a severe sediment stress on the global hotspot of coral reef diversity. The impact of land cover changes will largely depend on the degree in which the Berau estuary acts as a sediment trap.


1983 ◽  
Vol 26 (6) ◽  
pp. 1758-1765 ◽  
Author(s):  
George W. Cole ◽  
Leon Lyles ◽  
Lawrence J. Hagen

Land ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 974
Author(s):  
Simon Scheper ◽  
Thomas Weninger ◽  
Barbara Kitzler ◽  
Lenka Lackóová ◽  
Wim Cornelis ◽  
...  

Various large-scale risk maps show that the eastern part of Austria, in particular the Pannonian Basin, is one of the regions in Europe most vulnerable to wind erosion. However, comprehensive assessments of the severity and the extent of wind erosion risk are still lacking for this region. This study aimed to prove the results of large-scale maps by developing high-resolution maps of wind erosion risk for the target area. For this, we applied a qualitative soil erosion assessment (DIN 19706) with lower data requirements and a more data-demanding revised wind erosion equation (RWEQ) within a GIS application to evaluate the process of assessing wind erosion risk. Both models defined similar risk areas, although the assignment of severity classes differed. Most agricultural fields in the study area were classified as not at risk to wind erosion (DIN 19706), whereas the mean annual soil loss rate modeled by RWEQ was 3.7 t ha−1 yr−1. August was the month with the highest modeled soil loss (average of 0.49 t ha−1 month−1), due to a low percentage of vegetation cover and a relatively high weather factor combining wind speed and soil moisture effects. Based on the results, DIN 19706 is suitable for a general classification of wind erosion-prone areas, while RWEQ can derive additional information such as seasonal distribution and soil loss rates besides the spatial extents of wind erosion.


2021 ◽  
Author(s):  
Dongfeng Li ◽  
Xixi Lu ◽  
Ting Zhang

<p>Sediment flux in cold environments is a crucial proxy to link glacial, periglacial, and fluvial systems and highly relevant to hydropower operation, water quality, and the riverine carbon cycle. However, the long-term impacts of climate change and multiple human activities on sediment flux changes in cold environments remain insufficiently investigated due to the lack of monitoring and the complexity of the sediment cascade. Here we examine the multi-decadal changes in the in-situ observed fluvial sediment fluxes from two types of basins, namely, pristine basins and disturbed basins, in the Tibetan Plateau and its margins. The results show that the fluvial sediment fluxes in the pristine Tuotuohe headwater have substantially increased over the past three decades (i.e., a net increase of 135% from 1985–1997 to 1998–2017) due to the warming and wetting climate. We also quantify the relative impacts of air temperature and precipitation on the increases in the sediment fluxes with a novel attribution approach and finds that climate warming and intensified glacier-snow-permafrost melting is the primary cause of the increased sediment fluxes in the pristine cold environment (Tuotuohe headwater), with precipitation increase and its associated pluvial processes being the secondary driver. By contrast, the sediment fluxes in the downstream disturbed Jinsha River (southeastern margin of the Tibetan Plateau) exhibit a net increase of 42% from 1966-1984 to 1985-2010 mainly due to human activities such as deforestation and mineral extraction (contribution of 82%) and secondly because of climate change (contribution of 18%). Then the sediment fluxes dropped by 76% during the period of 2011-2015 because of the operations of six cascade reservoirs since 2010. In an expected warming and wetting climate for the region, we predict that the sediment fluxes in the pristine headwaters of the Tibetan Plateau will continue to increase throughout the 21st century, but the rising sediment fluxes from the Tibetan Plateau would be mostly trapped in its marginal reservoirs.</p><p>Overall, this work has provided the sedimentary evidence of modern climate change through robust observational sediment flux data over multiple decades. It demonstrates that sediment fluxes in pristine cold environments are more sensitive to air temperature and thermal-driven geomorphic processes than to precipitation and pluvial-driven processes. It also provides a guide to assess the relative impacts of human activities and climate change on fluvial sediment flux changes and has significant implications for water resources stakeholders to better design and manage the hydropower dams in a changing climate. Such findings may also have implications for other cold environments such as the Arctic, Antarctic, and other high mountainous basins.</p><p>Furthermore, this research is under the project of "Water and Sediment Fluxes Response to Climate Change in the Headwater Rivers of Asian Highlands" (supported by the IPCC and the Cuomo Foundation) and the project of "Sediment Load Responses to Climate Change in High Mountain Asia" (supported by the Ministry of Education of Singapore). Part of the results are also published in Li et al., 2018 Geomorphology, Li et al., 2020 Geophysical Research Letters, and Li et al., 2021 Water Resources Research.</p>


Solid Earth ◽  
2015 ◽  
Vol 6 (3) ◽  
pp. 823-837 ◽  
Author(s):  
J. Rodrigo Comino ◽  
C. Brings ◽  
T. Lassu ◽  
T. Iserloh ◽  
J. M. Senciales ◽  
...  

Abstract. Vineyards are one of the eco-geomorphological systems most conditioned by human activity in Germany. The vineyards of the Ruwer Valley (Germany) are characterized by high soil erosion rates and rill problems on steep slopes (between 23 and 26°) caused by the increasingly frequent heavy rainfall events as well as deterioration due to incorrect land use managements. The objective of this paper is to determine and to quantify the hydrological and erosive phenomena in one vineyard in Germany during different seasons and under different management conditions (before, during and after vintage). For this purpose, a combined methodology was applied. Climatic (rainfall depth distributions and return periods), pedological (soil analysis and classification), geomorphological (sediment movements and rills evolution) and biological (botanic marks on the vines) variables were used on the two experimental plots in the village of Waldrach (Trier, region of Rhineland-Palatinate). The results showed high infiltration rates (near 100 %) and subsurface flow which were detected by rainfall simulations performed at different times of the year (between September and December). The highest variations of the monitored rills (lateral and frontal movements) were noted before and during vintage, when footsteps occurred concentrated during a short period of time (between September and October). Finally, two maps of soil loss were generated, indicated by botanic marks on the graft union of the vines. 62.5 t ha−1 yr−1 soil loss was registered in the experimental plots of the new vineyards (2 years), while 3.4 t ha−1 yr−1 was recorded in the old one (35 years).


Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1124
Author(s):  
Salman A. H. Selmy ◽  
Salah H. Abd Al-Aziz ◽  
Raimundo Jiménez-Ballesta ◽  
Francisco Jesús García-Navarro ◽  
Mohamed E. Fadl

Soil erosion modeling is becoming more significant in the development and implementation of soil management and conservation policies. For a better understanding of the geographical distribution of soil erosion, spatial-based models of soil erosion are required. The current study proposed a spatial-based model that integrated geographic information systems (GIS) techniques with both the universal soil loss equation (USLE) model and the Index of Land Susceptibility to Wind Erosion (ILSWE). The proposed Spatial Soil Loss Model (SSLM) was designed to generate the potential soil erosion maps based on water erosion and wind erosion by integrating factors of the USLE and ILSWE models into the GIS environment. Hence, the main objective of this study is to predict, quantify, and assess the soil erosion hazards using the SSLM in the Dakhla Oasis as a case study. The water soil loss values were computed by overlaying the values of five factors: the rainfall factor (R-Factor), soil erodibility (K-Factor), topography (LS-Factor), crop types (C-Factor), and conservation practice (P-Factor). The severity of wind-driven soil loss was calculated by overlaying the values of five factors: climatic erosivity (CE-Factor), soil erodibility (E-Factor), soil crust (SC-Factor), vegetation cover (VC-Factor), and surface roughness (SR-Factor). The proposed model was statistically validated by comparing its outputs to the results of USLE and ILSWE models. Soil loss values based on USLE and SSLM varied from 0.26 to 3.51 t ha−1 yr−1 with an average of 1.30 t ha−1 yr−1 and from 0.26 to 3.09 t ha−1 yr−1 with a mean of 1.33 t ha−1 yr−1, respectively. As a result, and according to the assessment of both the USLE and the SSLM, one soil erosion class, the very low class (<6.7 t ha−1 yr−1), has been reported to be the prevalent erosion class in the study area. These findings indicate that the Dakhla Oasis is slightly eroded and more tolerable against water erosion factors under current management conditions. Furthermore, the study area was classified into four classes of wind erosion severity: very slight, slight, moderate, and high, representing 1.0%, 25.2%, 41.5%, and 32.3% of the total study area, respectively, based on the ILSWE model and 0.9%, 25.4%, 43.9%, and 29.9%, respectively, according to the SSLM. Consequently, the Dakhla Oasis is qualified as a promising area for sustainable agriculture when appropriate management is applied. The USLE and ILSWE model rates had a strong positive correlation (r = 0.97 and 0.98, respectively), with the SSLM rates, as well as a strong relationship based on the average linear regression (R2 = 0.94 and 0.97, respectively). The present study is an attempt to adopt a spatial-based model to compute and map the potential soil erosion. It also pointed out that designing soil erosion spatial models using available data sources and the integration of USLE and ILSWE with GIS techniques is a viable option for calculating soil loss rates. Therefore, the proposed soil erosion spatial model is fit for calculating and assessing soil loss rates under this study and is valid for use in other studies under arid regions with the same conditions.


2018 ◽  
Vol 6 (3) ◽  
pp. 611-635 ◽  
Author(s):  
Elizabeth H. Dingle ◽  
Hugh D. Sinclair ◽  
Mikaël Attal ◽  
Ángel Rodés ◽  
Vimal Singh

Abstract. Accurately quantifying sediment fluxes in large rivers draining tectonically active landscapes is complicated by the stochastic nature of sediment inputs. Cosmogenic 10Be concentrations measured in modern river sands have been used to estimate 102- to 104-year sediment fluxes in these types of catchments, where upstream drainage areas are often in excess of 10 000 km2. It is commonly assumed that within large catchments, the effects of stochastic sediment inputs are buffered such that 10Be concentrations at the catchment outlet are relatively stable in time. We present 18 new 10Be concentrations of modern river and dated Holocene terrace and floodplain deposits from the Ganga River near to the Himalayan mountain front (or outlet). We demonstrate that 10Be concentrations measured in modern Ganga River sediments display a notable degree of variability, with concentrations ranging between ∼9000 and 19 000 atoms g−1. We propose that this observed variability is driven by two factors. Firstly, by the nature of stochastic inputs of sediment (e.g. the dominant erosional process, surface production rates, depth of landsliding, degree of mixing) and, secondly, by the evacuation timescale of individual sediment deposits which buffer their impact on catchment-averaged concentrations. Despite intensification of the Indian Summer Monsoon and subsequent doubling of sediment delivery to the Bay of Bengal between ∼11 and 7 ka, we also find that Holocene sediment 10Be concentrations documented at the Ganga outlet have remained within the variability of modern river concentrations. We demonstrate that, in certain systems, sediment flux cannot be simply approximated by converting detrital concentration into mean erosion rates and multiplying by catchment area as it is possible to generate larger volumetric sediment fluxes whilst maintaining comparable average 10Be concentrations.


2017 ◽  
Vol 12 (No. 3) ◽  
pp. 144-151 ◽  
Author(s):  
M. Başaran ◽  
O. Uzun ◽  
S. Kaplan ◽  
F. Görmez ◽  
G. Erpul

Wind erosion and resultant dust emissions create significant risks for land degradation and ecosystem health in arid and semi-arid regions. In these regions, fallowing constitutes a major component of conventional agriculture. The present study was conducted to determine wind erosion quantities and agricultural activity-induced mass transport from fallow lands and to assess the correlations of mass transport with climate and soil characteristics. Experiments were conducted over the fallow lands of two adjacent agricultural enterprises (Altinova and Gözlü, Turkey). Sediment flux was measured with passive traps in wet and dry seasons (Q<sub>t</sub>WET and Q<sub>t</sub>DRY). Mass transport in wet and dry seasons was respectively measured as 11.38 and 11.40 kg/ha in Altinova and as 31.61 and 19.71 kg/ha in Gözlü. Both the differences between mass transport of the enterprises and the differences between Q<sub>t</sub>WET and Q<sub>t</sub>DRY of each enterprise were found to be significant (P &lt; 0.05). Pearson’s correlation analysis for the correlations of mass transport with soil characteristics revealed significant correlations with electrical conductivity and soil lime content (r = 0.721 and –0.635) (P &lt; 0.05). Total mass transport from the fallow lands of both enterprises throughout a 7-month period of measurement was estimated at 600 t. Based on current findings it was concluded that fallowing should be abandoned and sustainable soil and land management practices from conventional agriculture like minimum tillage or crop rotations should be introduced.  


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