scholarly journals High natural erosion rates are the backdrop for enhanced anthropogenic soil erosion in the Middle Hills of Nepal

2014 ◽  
Vol 2 (2) ◽  
pp. 935-969
Author(s):  
A. J. West ◽  
M. Arnold ◽  
G. Aumaître ◽  
D. L. Bourlès ◽  
K. Keddadouche ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Agricultural Activity ◽  
Natural Background ◽  
Mass Wasting ◽  
Production Rates ◽  
Erosion Rates ◽  
Denudation Rates ◽  
Short And Long Term ◽  
The Himalaya

Abstract. Although agriculturally accelerated soil erosion is implicated in the unsustainable environmental degradation of mountain environments, such as in the Himalaya, the effects of land use can be difficult to quantify in many mountain settings because of the high and variable natural background rates of erosion. In this study, we present new long-term denudation rates, derived from cosmogenic 10Be analysis of quartz in river sediment from the Likhu Khola, a small agricultural river basin in the Middle Hills of central Nepal. Calculated long-term denudation rates, which reflect background natural erosion processes over 1000+ years prior to agricultural intensification, are similar to present-day sediment yields and to soil loss rates from terraces that are well-maintained. Similarity in short- and long-term catchment-wide erosion rates for the Likhu is consistent with data from elsewhere in the Nepal Middle Hills, but contrasts with the very large increases in short-term erosion rates seen in agricultural catchments in other steep mountain settings. Our results suggest that the large sediment fluxes exported from the Likhu and other Middle Hills rivers in the Himalaya are derived in large part from natural processes, rather than from soil erosion as a result of agricultural activity. Because of the high natural background rates, simple comparison of short- and long-term rates may not reveal unsustainable soil degradation, particularly if much of the catchment-scale erosion flux derives from mass wasting. Correcting for the mass wasting contribution in the Likhu implies minimum catchment-averaged soil production rates of ~0.25–0.35 mm yr−1. The deficit between these production rates and soil losses suggests that terraced agriculture in the Likhu may not be associated with a large systematic soil deficit, at least when terraces are well maintained, but that poorly managed terraces, forest and scrubland may lead to rapid depletion of soil resources.

scholarly journals High natural erosion rates are the backdrop for present-day soil erosion in the agricultural Middle Hills of Nepal

2015 ◽  
Vol 3 (3) ◽  
pp. 363-387 ◽  
Author(s):  
A. J. West ◽  
M. Arnold ◽  
G. AumaÎtre ◽  
D. L. Bourlès ◽  
K. Keddadouche ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Soil Loss ◽  
Mass Wasting ◽  
Catchment Scale ◽  
Erosion Rates ◽  
Denudation Rates ◽  
Soil Production ◽  
The Himalaya

Abstract. Although agriculturally accelerated soil erosion is implicated in the unsustainable environmental degradation of mountain environments, such as in the Himalaya, the effects of land use can be challenging to quantify in many mountain settings because of the high and variable natural background rates of erosion. In this study, we present new long-term denudation rates, derived from cosmogenic 10Be analysis of quartz in river sediment from the Likhu Khola, a small agricultural river basin in the Middle Hills of central Nepal. Calculated long-term denudation rates, which reflect background natural erosion processes over 1000+ years prior to agricultural intensification, are similar to present-day sediment yields and to soil loss rates from terraces that are well maintained. Similarity in short- and long-term catchment-wide erosion rates for the Likhu is consistent with data from elsewhere in the Nepal Middle Hills but contrasts with the very large increases in short-term erosion rates seen in agricultural catchments in other steep mountain settings. Our results suggest that the large sediment fluxes exported from the Likhu and other Middle Hills rivers in the Himalaya are derived in large part from natural processes, rather than from soil erosion as a result of agricultural activity. Catchment-scale erosional fluxes may be similar over short and long timescales if both are dominated by mass wasting sources such as gullies, landslides, and debris flows (e.g., as is evident in the landslide-dominated Khudi Khola of the Nepal High Himalaya, based on compiled data). As a consequence, simple comparison of catchment-scale fluxes will not necessarily pinpoint land use effects on soils where these are only a small part of the total erosion budget, unless rates of mass wasting are also considered. Estimates of the mass wasting contribution to erosion in the Likhu imply catchment-averaged soil production rates on the order of ~ 0.25–0.35 mm yr−1, though rates of mass wasting are poorly constrained. The deficit between our best estimates for soil production rates and measurements of soil loss rates supports conclusions from previous studies that terraced agriculture in the Likhu may not be associated with a large systematic soil deficit, at least when terraces are well maintained, but that poorly managed terraces, forest, and scrubland may lead to rapid depletion of soil resources.

scholarly journals Acceleration of Soil Erosion by Different Land Uses in Arid Lands above 10Be Natural Background Rates: Case Study in the Sonoran Desert, USA

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 834
Author(s):  
Ara Jeong ◽  
Ronald I. Dorn ◽  
Yeong-Bae Seong ◽  
Byung-Yong Yu
Keyword(s):  
Soil Erosion ◽  
Sonoran Desert ◽  
Land Use Changes ◽  
Arid Lands ◽  
Metropolitan Region ◽  
Natural Background ◽  
Sediment Yields ◽  
Erosion Rates ◽  
Denudation Rates ◽  
Urban Rural

Land use changes often lead to soil erosion, land degradation, and environmental deterioration. However, little is known about just how much humans accelerate erosion compared to natural background rates in non-agricultural settings, despite its importance to knowing the magnitude of soil degradation. The lack of understanding of anthropogenic acceleration is especially true for arid regions. Thus, we used 10Be catchment averaged denudation rates (CADRs) to obtain natural rates of soil erosion in and around the Phoenix metropolitan region, Arizona, United States. We then measured the acceleration of soil erosion by grazing, wildfire, and urban construction by comparing CADRs to erosion rates for the same watersheds, finding that: (i) grazing sometimes can increase sediment yields by up to 2.3–2.6x, (ii) human-set wildfires increased sediment yields by up to 9.7–10.4x, (iii) after some post-fire vegetation recovered, sediment yield was then up to 4.2–4.5x the background yield, (iv) construction increased sediment yields by up to 5.0–5.6x, and (v) the sealing of urban surfaces led to one-tenth to one-half of the background sediment yields. The acceleration of erosion at the urban–rural interface in arid lands highlights the need for sustainable management of arid-region soils.

scholarly journals Soil erosion by snow gliding – a first quantification attempt in a subalpine area in Switzerland

2014 ◽  
Vol 18 (9) ◽  
pp. 3763-3775 ◽  
Author(s):  
K. Meusburger ◽  
G. Leitinger ◽  
L. Mabit ◽  
M. H. Mueller ◽  
A. Walter ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Land Cover ◽  
Sediment Yield ◽  
Soil Loss ◽  
Water Erosion ◽  
Erosion Rates ◽  
The Difference ◽  
Snow Gliding

Abstract. Snow processes might be one important driver of soil erosion in Alpine grasslands and thus the unknown variable when erosion modelling is attempted. The aim of this study is to assess the importance of snow gliding as a soil erosion agent for four different land use/land cover types in a subalpine area in Switzerland. We used three different approaches to estimate soil erosion rates: sediment yield measurements in snow glide depositions, the fallout radionuclide 137Cs and modelling with the Revised Universal Soil Loss Equation (RUSLE). RUSLE permits the evaluation of soil loss by water erosion, the 137Cs method integrates soil loss due to all erosion agents involved, and the measurement of snow glide deposition sediment yield can be directly related to snow-glide-induced erosion. Further, cumulative snow glide distance was measured for the sites in the winter of 2009/2010 and modelled for the surrounding area and long-term average winter precipitation (1959–2010) with the spatial snow glide model (SSGM). Measured snow glide distance confirmed the presence of snow gliding and ranged from 2 to 189 cm, with lower values on the north-facing slopes. We observed a reduction of snow glide distance with increasing surface roughness of the vegetation, which is an important information with respect to conservation planning and expected and ongoing land use changes in the Alps. Snow glide erosion estimated from the snow glide depositions was highly variable with values ranging from 0.03 to 22.9 t ha−1 yr−1 in the winter of 2012/2013. For sites affected by snow glide deposition, a mean erosion rate of 8.4 t ha−1 yr−1 was found. The difference in long-term erosion rates determined with RUSLE and 137Cs confirms the constant influence of snow-glide-induced erosion, since a large difference (lower proportion of water erosion compared to total net erosion) was observed for sites with high snow glide rates and vice versa. Moreover, the difference between RUSLE and 137Cs erosion rates was related to the measured snow glide distance (R2 = 0.64; p < 0.005) and to the snow deposition sediment yields (R2 = 0.39; p = 0.13). The SSGM reproduced the relative difference of the measured snow glide values under different land uses and land cover types. The resulting map highlighted the relevance of snow gliding for large parts of the investigated area. Based on these results, we conclude that snow gliding appears to be a crucial and non-negligible process impacting soil erosion patterns and magnitude in subalpine areas with similar topographic and climatic conditions.

scholarly journals Applying the RUSLE and ISUM in the Tierra de Barros Vineyards (Extremadura, Spain) to Estimate Soil Mobilisation Rates

Land ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 93 ◽  
Author(s):  
Jesús Barrena-González ◽  
Jesús Rodrigo-Comino ◽  
Yeboah Gyasi-Agyei ◽  
Manuel Pulido Fernández ◽  
Artemi Cerdà
Keyword(s):  
Soil Erosion ◽  
Environmental Sustainability ◽  
Soil Surface ◽  
Tillage Practices ◽  
Erosion Rates ◽  
La Mancha ◽  
Soil Erosion Rates ◽  
Soil Depletion ◽  
Mapping Techniques

Spain is one of the largest wine producers in the world, with Extremadura (south-west Spain) being its second-largest producing region after Castilla La Mancha. Within Extremadura, the most traditional and productive viticulture region is the Tierra de Barros, which boasts an annual production of 3×106 litres. However, no soil erosion assessment has been undertaken in any vineyard in the region to ascertain environmental sustainability. Therefore, the Improved Stock Unearthing Method (ISUM) and the Revised Universal Soil Loss Equation (RUSLE) were applied to assess the long-term soil erosion rates. Both methods were applied using an experimental plot (2.8 m × 148.5 m) encompassing 99 paired vines in a 20-year-old vineyard under a tillage management system and on bare soils throughout the year. The ISUM and RUSLE found total soil mobilization values of 45.7 Mg ha−1 yr−1 and 17.4 Mg ha−1 yr−1, respectively, a difference of about 5 times. Mapping techniques showed that soil surface declined to an average of −6.2 cm, with maximum values of −28 cm. The highest values of soil depletion were mainly observed in the upper part and the form of linear features following the hillslope direction. On the other hand, under the vines, the soil surface level showed accumulations of up to +2.37 cm due to tillage practices. Our study demonstrated the potential of high soil erosion rates occurring in conventional vineyards managed with tillage in the inter-row areas and herbicides under the vines within the Tierra de Barros. Also, we demonstrated the elevated differences in soil mobilisation rates using the ISUM and RUSLE. Therefore, further research must be conducted in other vineyards to determine the suitability of the models for assessing soil erosion rates. Undoubtedly, soil conservation measures must be designed and applied immediately due to high erosion rates.

Assessment of long-term Holocene soil erosion rates in Polish loess areas using sedimentary archives from closed depressions

2018 ◽  
Vol 43 (5) ◽  
pp. 978-1000 ◽  
Author(s):  
Renata Kołodyńska-Gawrysiak ◽  
Jean Poesen ◽  
Leszek Gawrysiak
Keyword(s):  
Soil Erosion ◽  
Erosion Rates ◽  
Soil Erosion Rates

Early cultivation and bioturbation cause high long-term soil erosion rates in tropical forests: OSL based evidence from Ghana

CATENA ◽  
2017 ◽  
Vol 151 ◽  
pp. 130-136 ◽  
Author(s):  
Henrik Breuning-Madsen ◽  
Jeppe Ågård Kristensen ◽  
Theodore W. Awadzi ◽  
Andrew S. Murray
Keyword(s):  
Soil Erosion ◽  
Tropical Forests ◽  
Erosion Rates ◽  
Soil Erosion Rates

scholarly journals SUSTAINABLE AGRICULTURE MANAGEMENTS TO CONTROL SOIL EROSION

2021 ◽  
Author(s):  
Artemi Cerdà ◽  
Enric Terol
Keyword(s):  
Soil Erosion ◽  
Sustainable Agriculture ◽  
Spatial Scales ◽  
Low Frequency ◽  
Traditional Management ◽  
Erosion Rates ◽  
Olive Groves ◽  
Simulated Rain ◽  
The Impact

High rates of soil erosion compromise sustainable agriculture. In rainfed agricultural fields, erosion rates several orders ofmagnitude higher than the erosion rates considered tolerable have been quantified. In Mediterranean rainfed crops suchas vineyards, almonds and olive groves, and in the new sloping citrus and persimmon plantations, the rates of soil lossmake it necessary to apply measures to reduce them to avoid collapse in agricultural production. Managements such asweeds, catch crops and mulches (straw and pruning remains) are viable options to achieve sustainability. This work appliesmeasurements through plots, simulated rainfall experiments and ISUM (Improved Stock-Unearhing method) to quantifythe loss of soil at different temporal and spatial scales in fields of traditional management (herbicide or tillage) and underalternative management (mulches and plant covers). The work carried out at the experimental station for the study of soilerosion in the Sierra de Enguera and those of Montesa and Les Alcusses provide information on erosion plots undernatural rain. Experiments carried out with simulated rain in fields of olive, almond, citrus, persimmon, vineyard and fruittrees report the hydrological and erosive response under low frequency and high intensity rains. And finally, the ISUMtopographic method report the impact of long-term management, from the plantation. The results indicate that the loss ofsoil is greater (x10-1000) in soils under traditional management (tillage and herbicide) due to the fact that they remain barefor most of the year. The use of straw mulch immediately reduces soil erosion by two orders of magnitude. Also mulchesfrom chipped pruned branches remains are very efficient but require more years to reduce soil loss. Weeds and catchcrops are very efficient in controlling erosion.

scholarly journals Denudation rates derived from spatially-averaged cosmogenic nuclide analysis in Nelson/Tasman catchments, South Island, New Zealand

2021 ◽  
Author(s):  
◽  
Abby Jade Burdis
Keyword(s):  
New Zealand ◽  
Dynamic Environment ◽  
Low Frequency ◽  
Short Term ◽  
Erosion Rates ◽  
Cosmogenic Nuclide ◽  
Denudation Rates ◽  
Conventional Methods

<p>New Zealand’s tectonically and climatically dynamic environment generates erosion rates that outstrip global averages by up to ten times in some locations. In order to assess recent changes in erosion rate, and also to predict future erosion dynamics, it is important to quantify long-term, background erosion. Current research on erosion in New Zealand predominantly covers short-term (100 yrs) erosion dynamics and Myr dynamics from thermochronological proxy data. Without competent medium-term denudation data for New Zealand, it is uncertain which variables (climate, anthropogenic disturbance of the landscape, tectonic uplift, lithological, or geomorphic characteristics) exert the dominant control on denudation in New Zealand. Spatially-averaged cosmogenic nuclide analysis can effectively offer this information by providing averaged rates of denudation on millennial timescales without the biases and limitations of short-term erosion methods.  Basin-averaged denudation rates were obtained in the Nelson/Tasman region, New Zealand, from analysis of concentrations of meteoric ¹⁰Be in silt and in-situ produced ¹⁰Be in quartz. The measured denudation rates integrate over ~2750 yrs (in-situ) and ~1200 yrs (meteoric). Not only do the ¹⁰Be records produce erosion rates that are remarkably consistent with each other, but they are also independent of topographic metrics. Denudation rates range from ~112 – 298 t km⁻² yr⁻¹, with the exception of one basin which is eroding at 600 - 800 t km⁻² yr⁻¹. The homogeneity of rates and absence of a significant correlation with geomorphic or lithological characteristics could indicate that the Nelson/Tasman landscape is in (or approaching) a topographic steady state.  Millennial term (¹⁰Be-derived) denudation rates are more rapid than those inferred from other conventional methods in the same region (~50 – 200 t km⁻² yr⁻¹). This is likely the result of the significant contribution of low frequency, high magnitude erosive events to overall erosion of the region. Both in-situ and meteoric ¹⁰Be analyses have the potential to provide competent millennial term estimates of natural background rates of erosion. This will allow for the assessment of geomorphic-scale impacts such as topography, tectonics, climate, and lithology on rates of denudation for the country where many conventional methods do not. Cosmogenic nuclides offer the ability to understand the response of the landscape to these factors in order to make confident erosion predictions for the future.</p>

Evaluating the stability and evolution of a proposed post mining landform.

2021 ◽  
Author(s):  
Welivitiyage Don Dimuth Prasad Welivitiya ◽  
Garry Willgoose ◽  
Gregory Hancock
Keyword(s):  
Cross Sections ◽  
Soil Profile ◽  
Evolution Model ◽  
Short Term ◽  
Landform Evolution ◽  
Erosion Rates ◽  
Denudation Rates ◽  
Land Denudation ◽  
Profile Characteristics

&lt;p&gt;Evaluating the future stability and land denudation rates of natural or anthropogenic landforms is paramount for sustainable land use practices. Landform evolution models can be powerful tools in this endeavour.&amp;#160; In this study we used the well-established landform evolution model SIBERIA and the newly developed coupled soilscape-landform evolution model SSSPAM to simulate the evolution of a proposed post mining landform. SIBERIA uses a cellular digital elevation model to simulate annual average fluvial and diffusive erosion on landforms using annual average precipitation. However it does not simulate the soil profile evolution on the evolving landform. The new SSSPAM coupled soilscape-landform evolution model has the ability to assess the overall erosion rates of catchment scale landforms either using short term precipitation events, variable precipitation or time averaged precipitation rates. In addition, SSSPAM is able to simulate the evolution of the soil profile of the evolving landform using pedogenetic processes such as physical weathering and armouring.&lt;/p&gt;&lt;p&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; To assess the reliability of SSSPAM, model predictions at 100 and 10000 years were compared with SIBERIA predictions at the same times. During the long term (10000yr) simulation the effect of armouring and weathering on the landform evolution was also assessed. The results obtained from these different simulations were compared and contrasted. Comparison of the short term simulations revealed that SSSPAM results compare well with the simulation results of the more established SIBERIA model. Long term simulation showed that SSSPAM simulation results also compares well with SIBERIA simulations while the erosion rates predicted by both models are close to the land denudation rates measured in the field. The soil profile characteristics and channel forms simulated by SSSPAM long term simulations were examined using several landform cross-sections. This analyses revealed that SSSPAM produces deep incised channels with very low soil thickness in upper reaches of the catchment and shallow channels with relatively thick soil layers in the lower reaches of the catchment. These SSSPAM simulated channels match well with the channel forms and distribution of bedrock channels and alluvial channels observed in the field. The analysis of the catchment cross-sections also showed that SSSPAM is capable of reproducing complex subsurface soil evolution and stratification and spatial variability of soil profile characteristics typically observed in the field.&lt;/p&gt;

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