scholarly journals Supplementary material to "New molecular evidence for surface and sub-surface soil erosion controls on the composition of stream DOM during storm events"

2017 ◽  
Author(s):  
Marie Denis ◽  
Laurent Jeanneau ◽  
Patrice Petitjean ◽  
Anaëlle Murzeau ◽  
Marine Liotaud ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Surface Soil ◽  
Molecular Evidence ◽  
Storm Events ◽  
Supplementary Material

scholarly journals New molecular evidence for surface and sub-surface soil erosion controls on the composition of stream DOM during storm events

2017 ◽  
Author(s):  
Marie Denis ◽  
Laurent Jeanneau ◽  
Patrice Petitjean ◽  
Anaëlle Murzeau ◽  
Marine Liotaud ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Erosion ◽  
Soil Solution ◽  
Surface Runoff ◽  
Surface Soil ◽  
Molecular Evidence ◽  
Storm Events ◽  
Soil Solutions ◽  
Chemical Segregation ◽  
Dom Composition

Abstract. Storm events are responsible for more than 60 % of the export of dissolved organic matter (DOM) from headwater catchments due to an increase in both the discharge and concentration. The latter was attributed to changing water pathways inducing the mobilization of DOM from the surface soil horizons. Recent molecular investigations have challenged this view and hypothesized (i) a contribution of an in-stream partition of organic matter (OM) between eroded particles and the dissolved fraction and (ii) the modification of the composition of soil DOM during storm events. To investigate these assumptions, soil solutions in the macropores, surface runoff and stream outlet were sampled at high frequency during three storm events in the Kervidy-Naizin catchment, part of the French critical zone observatory AgrHys. The molecular composition of the DOM was analysed by thermally assisted hydrolysis and methylation (THM) with tetramethylammonium hydroxide (TMAH) coupled to a gas chromatograph and a quadrupole mass spectrometer. These analyses highlighted a modification of the DOM composition in soil solution controlled by the water-table dynamic and pre-event hydrological conditions. These findings fits with the mechanism of colloidal and particulate destabilization in the soil macroporosity. The different behaviour observed for lignins, carbohydrates and fatty acids highlights a potential chemical segregation based on their hydrophobicity. The composition of surface runoff DOM is similar to the DOM composition in soil solution and could be generated by the same mechanism. The DOM composition in both soil solution and surface runoff corresponds to the stream DOM composition observed during storm events. On the basis of these results, modifications of the stream DOM composition during storm events seem to be due to surface and sub-surface soil erosion rather than in-stream production.

scholarly journals New molecular evidence for surface and sub-surface soil erosion controls on the composition of stream DOM during storm events

2017 ◽  
Vol 14 (22) ◽  
pp. 5039-5051 ◽  
Author(s):  
Marie Denis ◽  
Laurent Jeanneau ◽  
Patrice Petitjean ◽  
Anaëlle Murzeau ◽  
Marine Liotaud ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Erosion ◽  
Soil Solution ◽  
Surface Runoff ◽  
Surface Soil ◽  
Molecular Evidence ◽  
Storm Events ◽  
Soil Solutions ◽  
Chemical Segregation ◽  
Dom Composition

Abstract. Storm events are responsible for more than 60 % of the export of dissolved organic matter (DOM) from headwater catchments due to an increase in both the discharge and concentration. The latter was attributed to changing water pathways inducing the mobilization of DOM from the surface soil horizons. Recent molecular investigations have challenged this view and hypothesized (i) a contribution of an in-stream partition of organic matter (OM) between eroded particles and the dissolved fraction and (ii) the modification of the composition of soil DOM during storm events. To investigate these assumptions, soil solutions in the macropores, surface runoff and stream outlet were sampled at high frequency during three storm events in the Kervidy–Naizin catchment, part of the French critical zone observatory AgrHyS. The molecular composition of the DOM was analysed by thermally assisted hydrolysis and methylation (THM) with tetramethylammonium hydroxide (TMAH) coupled to a gas chromatograph and a quadrupole mass spectrometer. These analyses highlighted a modification of the DOM composition in soil solution controlled by the water-table dynamic and pre-event hydrological conditions. These findings fit with the mechanism of colloidal and particulate destabilization in the soil macroporosity. The different behaviour observed for lignins, carbohydrates and fatty acids highlights a potential chemical segregation based on their hydrophobicity. The composition of surface runoff DOM is similar to the DOM composition in soil solution and could be generated by the same mechanism. The DOM composition in both soil solution and surface runoff corresponds to the stream DOM composition observed during storm events. On the basis of these results, modifications of the stream DOM composition during storm events seem to be due to surface and sub-surface soil erosion rather than in-stream production.

scholarly journals Soil Erosion Estimates in Arid Region: A Case Study of the Koutine Catchment, Southeastern Tunisia

2021 ◽  
Vol 11 (15) ◽  
pp. 6763
Author(s):  
Mongi Ben Zaied ◽  
Seifeddine Jomaa ◽  
Mohamed Ouessar
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Scientific Evidence ◽  
Field Measurements ◽  
Spatiotemporal Variability ◽  
Soil Conditions ◽  
Storm Events ◽  
Erosion Processes ◽  
Study Results ◽  
Soil Losses

Soil erosion remains one of the principal environmental problems in arid regions. This study aims to assess and quantify the variability of soil erosion in the Koutine catchment using the RUSLE (Revised Universal Soil Loss Equation) model. The Koutine catchment is located in an arid area in southeastern Tunisia and is characterized by an annual mean precipitation of less than 200 mm. The model was used to examine the influence of topography, extreme rainstorm intensity and soil texture on soil loss. The data used for model validation were obtained from field measurements by monitoring deposited sediment in settlement basins of 25 cisterns (a traditional water harvesting and storage technique) over 4 years, from 2015 to 2018. Results showed that slope is the most controlling factor of soil loss. The average annual soil loss in monitoring sites varies between 0.01 and 12.5 t/ha/y. The storm events inducing the largest soil losses occurred in the upstream part of the Koutine catchment with a maximum value of 7.3 t/ha per event. Soil erosion is highly affected by initial and preceding soil conditions. The RUSLE model reasonably reproduced (R2 = 0.81) the spatiotemporal variability of measured soil losses in the study catchment during the observation period. This study revealed the importance of using the cisterns in the data-scarce dry areas as a substitute for the classic soil erosion monitoring fields. Besides, combining modeling of outputs and field measurements could improve our physical understanding of soil erosion processes and their controlling factors in an arid catchment. The study results are beneficial for decision-makers to evaluate the existing soil conservation and water management plans, which can be further adjusted using appropriate soil erosion mitigation options based on scientific evidence.

COMPUTER ASSISTED MAPPING OF SOIL EROSION POTENTIAL

1985 ◽  
Vol 65 (3) ◽  
pp. 411-418 ◽  
Author(s):  
T. VOLD ◽  
M. W. SONDHEIM ◽  
N. K. NAGPAL
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Surface Soil ◽  
Mineral Soil ◽  
Weighted Average ◽  
Bare Soil ◽  
Computer Assisted ◽  
Additional Information ◽  
Potential Map ◽  
Fraser Valley

Soil erosion potential maps and summary statistics can be produced from existing information with relative ease with the aid of computers. Soil maps are digitized and survey information is stored as attributes for each soil. Algorithms are then prepared which evaluate the appropriate data base attributes (e.g. texture, slope) for each interpretation. Forty surface soil erosion potential maps were produced for the Lower Fraser Valley which identify the most erosion-prone areas and indicate average potential soil losses to be expected under assumed conditions. The algorithm developed follows the universal soil loss equation. Differences across the landscape in the R, K, and S factors are taken into account whereas the L factor is considered as a constant equal to 1.0. Worst conditions of bare soil (no crop cover, i.e. C = 1.0) and no erosion control practices (i.e. P = 1.0) are assumed. The five surface soil erosion potential classes are determined by a weighted average annual soil loss value based both on the upper 20 cm of mineral soil and on the proportion of the various soils in the polygon. A unique polygon number shown on the erosion potential map provides a link to computer tables which give additional information for each individual soil within that polygon. Key words: Erosion, computer mapping, USLE

scholarly journals Reduced Tillage Impacts on Pumpkin Yield, Weed Pressure, Soil Moisture, and Soil Erosion

HortScience ◽  
2016 ◽  
Vol 51 (12) ◽  
pp. 1524-1528 ◽  
Author(s):  
Megan E. O’Rourke ◽  
Jessica Petersen
Keyword(s):  
Soil Moisture ◽  
Soil Erosion ◽  
Weed Control ◽  
Field Experiments ◽  
Production Systems ◽  
Conservation Tillage ◽  
Fruit Weight ◽  
Storm Events ◽  
No Till ◽  
Trade Offs

Conservation tillage has the potential to decrease the environmental footprint of pumpkin production, but possible trade-offs with yield are not well understood. This study experimentally tested the effects of three cultivation techniques (conventional-till, strip-till, and no-till) on pumpkin production, weed pressure, soil moisture, and soil erosion. Randomized complete block field experiments were conducted on Cucurbita pepo L. ‘Gladiator’ pumpkins in 2014 and 2015. Overall yields were higher in 2015, averaging 45.2 t·ha−1, compared with 37.4 t·ha−1 in 2014. In 2014, pumpkin yields were similar across tillage treatments. In 2015, the average fruit weight of no-till pumpkins was significantly greater than strip-till and conventional-till pumpkins, which corresponded to a marginally significant 13% and 22% yield increase, respectively (P = 0.11). Weed control was variable between years, especially in the strip-till treatment. Soil moisture was consistently highest in the no-till treatment in both years of study. Conventional-till pumpkin plots lost ≈9 times more soil than the two conservation tilled treatments during simulated storm events. The 2015 yield advantage of no-till pumpkins seems related to both high soil moisture retention and weed control. Research results suggest that no-till and strip-till pumpkin production systems yield at least as well as conventional-till systems with the advantage of reducing soil erosion during extreme rains.

scholarly journals An assessment of soil loss and natural hazards in Nepal

2000 ◽  
Vol 21 ◽  
Author(s):  
Dinesh R. Shiwakoti
Keyword(s):  
Soil Erosion ◽  
Debris Flow ◽  
Soil Loss ◽  
Surface Soil ◽  
Mass Movements ◽  
Critical Factors ◽  
Outburst Flood ◽  
Paper Briefly ◽  
Grass Roots ◽  
The Status

This paper briefly reviews the status of soil erosion in Nepal, and examines the major causes and factors leading to soil erosion and mass movements. There are the following four major mechanisms associated with soil loss: a) surface soil erosion, b) landslide and debris flow, c) earthquake, and d) glacier lake outburst flood. Effective methods for investigating, analysing, identifying, and implementing the critical factors for protecting accelerated soil loss in a planned manner are essential from the grass roots to national and international levels.

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