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1.
J Environ Manage ; 301: 113812, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34601350

RESUMO

Removing vegetation cover from hill-slope land increases risk for soil erosion and delivery of sediment to waterways. In New Zealand's productive landscapes, clear-fell harvesting of forestry blocks and winter forage grazing by agricultural livestock are two significant causes of vegetation removal. Bare ground exposed by these activities varies annually and seasonally in location and spatial extent. Modelling soil erosion therefore requires temporally and spatially explicit mapping of this bare ground. We have developed an automated mapping method using time-series satellite imagery, thereby enabling wide-area coverage and ease of updating. The temporal analysis identifies land use along with the period of vegetation removal. It produces results per land parcel (in vector format) for use in a Geographic Information System. We present a description of our method, national maps and statistics of bare ground extent in New Zealand's hill-country forestry and winter forage grazing land in 2018, and an assessment of accuracy. The attributes of the mapped land parcels are designed for input into a soil erosion estimation model such as the New Zealand Universal Soil Loss Equation.


Assuntos
Agricultura Florestal , Erosão do Solo , Agricultura , Conservação dos Recursos Naturais , Monitoramento Ambiental , Sistemas de Informação Geográfica , Nova Zelândia , Solo
2.
Sci Total Environ ; 802: 149665, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34450437

RESUMO

We compiled an extensive database of erosion and runoff measurements on erosion plots under natural rainfall in China. We used this database to analyse how soil loss by sheet and rill erosion and runoff in China were affected by land use, slope gradient, slope length and mean annual precipitation. Our results show that land use dominates the variation of soil loss and runoff: Soil loss and runoff rates on land covered by grass and trees are one to three orders of magnitude lower than rates on cropland. Slope gradient and slope length affect soil loss and runoff rates on cropland but there is no statistically significant effect on either soil loss or runoff on plots with a permanent vegetation cover. Runoff rates consistently increase with mean annual precipitation. The relationship between soil loss and mean annual precipitation is, on the contrary, nonlinear for all land use types, with a clear increase of soil loss with precipitation up to a mean annual precipitation of ca. 700 mm yr-1, a subsequent decline and a second rise when the mean annual precipitation exceeds ca. 1400 mm yr-1. We attribute this non-linear response to the interplay of an increasing rainfall erosivity and an increasing protection due to vegetation cover with increasing mean annual precipitation. This non-linear response implies that the effect of precipitation changes induced by climate change on the erosion risk depends on how both rainfall erosivity and vegetation cover change with changing climate. Our study provides important insights as to how soil loss and runoff in China are related to controlling factors and this will allow improving assessments of total soil erosion and runoff rates over the entire territory of China.


Assuntos
Sedimentos Geológicos , Chuva , China , Conservação dos Recursos Naturais , Monitoramento Ambiental , Solo , Erosão do Solo
3.
Environ Monit Assess ; 193(12): 836, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34802075

RESUMO

The Awash River basin is one of the most developed basins in Ethiopia, and its water resources are crucial to development. The collective impact of land cover (LC) changes has driven a difference in the hydrological components, substantially impacting the availability of water resources and demand. This review aimed (i) to examine the extent of change quantitatively and its effects; (ii) to analyze the relationship with a mean annual rainfall that would further reveal the causes and potential LC type response to hydrologic variables in the Awash River basin, Ethiopia. The results have revealed that urbanization and agricultural activities in the basin are the most trending types of LC, while the forest, shrubland, grassland, and pasture land have been decreasing significantly in the subbasins. As a result, the change in these subbasins has triggered hydrologic variations (runoff, groundwater flow, base flow, and evapotranspiration), and its impacts on downstream basins have mostly been flood and drought. In addition, farmland, urbanization, and shrubland trends showed a significant positive interaction, while forest and water bodies had a substantial and slight negative relation to mean annual rainfall, respectively. Vegetation, bareland, urbanization, and agriculture/farmland are directly responsible for the hydrologic variation. LC change significantly affected hydrologic regimes and the distribution of spatial rainfall is correlated significantly to LC change pattern. Besides, due to the lack of LC management practices, the impact continues to propagate. Hence, this review helps to portray the potential implications and extent of effects of changes in LC on the hydrological regimes. As a result, the implementation of sound water management strategies and practices in response to changing environments to resurrect water scarcity and mitigate flood and sediment are needed straightaway.


Assuntos
Erosão do Solo , Movimentos da Água , Monitoramento Ambiental , Etiópia , Hidrologia
4.
Environ Monit Assess ; 193(11): 754, 2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34713350

RESUMO

The ecosystem, biodiversity, and anthropological existence in the Chitral district are in danger due to the sediments and soil erosion stemming from the changes in the land-cover and climate. This research aims to practice the RUSLE model with the changes in the land-cover and climate in upcoming situations for 2030 and 2040 to evaluate soil erosion annually as per the spatial dissemination and the tendency of sediment yield. The multilayer perceptron (MLP), an artificial neural network (ANN), besides the Markov chain analysis was used to model upcoming land-cover. The Max Planck Institute model, which demonstrated a revised bias as well as downscaled grid size under the Representative Concentration Pathways (RCPs), was used for examining the future changes in the climate. The modeled land-cover showed that the areas that are primarily comprised of natural trees and shrubs were transformed largely to agriculture and build-up areas. The average rainfall in the future under different RCP situations was elevated compared to the rainfall through historical time. The continuous variability in the R and C factors affects the probable soil erosion rate and sediment yield. Under RCP8.5 for both future years of 2030 and 2040, the extreme erosion rate was assessed at around 500 and 550 t/ha/year. Additionally, under the different RCP scenarios in 2030 and 2040, the outcomes of sediment yield were more significant than the sediment yield through historical time. The results showed that lower regions of the Chitral district are at risk of amplified soil erosion and sediment yield presently, as shown by the historical data and in the future. The produced soil erosion maps using ArcGIS 10.2 can play a valuable role in managing sustainable development, conservation of the watershed of the Chitral River, and reducing soil loss. Effective measures to overcome these concerns and mitigate the possible effects need to be planned and practiced, particularly the decrease in the storage volume of the reservoirs situated on the river.


Assuntos
Mudança Climática , Ecossistema , Conservação dos Recursos Naturais , Monitoramento Ambiental , Solo , Erosão do Solo
5.
An Acad Bras Cienc ; 93(4): e20191120, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34586313

RESUMO

This article presents the identification of soil use potential for different agropastoral and forest scenarios, using an indicator for erosion susceptibility from the spatialized Universal Soil Loss Equation (USLE). All USLE factors were spatialized using ArcGis 10.5 software, for the case study of the Cachoeira Cinco Veados Watershed-RS. To determine the R factor, we used the Cassol et al. 2007 equation and a 33-year series of rain data from six climatic stations. For the K factor, published values for the soil classes: Entisol, Ultisol, Oxisol, Molisols were used. From the DEM, the LS factor was obtained, considering six slope classes (0-3, 3-8, 8-20, 20-45, 45-75, >75%). In addition to the actual land use situation in the watershed, nine scenarios were proposed for the C factor. The value of 0.5 was used for the evaluation of conservation practices (P factor). Considering scenarios of current use situation along with the nine other scenarios, the results showed that, by identifying the most susceptible areas in each scenario, it is possible to construct an indicator map of soil compatibilities for each use, considering sustainable limits of soil losses. Therefore, this resulting map has potential use as instrument for land use planning and zoning studies.


Assuntos
Conservação dos Recursos Naturais , Erosão do Solo , Monitoramento Ambiental , Sistemas de Informação Geográfica , Solo
6.
PLoS One ; 16(9): e0256827, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34492049

RESUMO

Sediment transport capacity (Tc) is an essential parameter in the establishment of the slope soil erosion model. Slope type is an important crucial factor affecting sediment transport capacity of overland flow, and vegetation can effectively inhibit soil loss. Two new formulae of sediment transport capacity (Tc) are proposed of brown soil slope and vegetation slope in this study and evaluate the influence of slope gradient (S) and flow discharge (Q) on sediment transport capacity of different slope types. Laboratory experiments conducted using four flow discharges (0.35, 0.45, 0.55, and 0.65 L s-1), four slope gradients (3, 6, 9, and 12°), and two kinds of underlying surface (Brown soil slope, Vegetation slope). The soil particle size range is 0.05-0.5mm. The vegetation stems were 2mm in diameter and randomly arranged. The results show that the sediment transport capacity was positively correlated with the flow discharge and slope gradient. The vegetation slope's average sediment transport capacity is 11.80% higher than the brown soil slope that same discharge and slope gradient conditions. The sensitivity of sediment transport capacity to flow discharge on brown soil slope is higher than that of slope gradient. The sensitivity of sediment transport capacity of vegetation slope to slope gradient is more heightened than flow discharge. The sediment transport capacity was well predicted by discharge and slope gradient on brown soil slope (R2 = 0.982) and vegetation slope (R2 = 0.993). This method is helpful to promote the study of the sediment transport process on overland flow.


Assuntos
Sedimentos Geológicos/análise , Erosão do Solo/prevenção & controle , Solo/normas , Movimentos da Água , China , Humanos , Chuva , Água/normas
7.
PLoS One ; 16(9): e0253768, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34499651

RESUMO

The Labyrinth in the McMurdo Dry Valleys of Antarctica is characterized by large bedrock channels emerging from beneath the margin of Wright Upper Glacier. To study the morphodynamics of large subglacial channels cut into bedrock, we develop herein a numerical model based on the classical theory of subglacial channels and recent results on bedrock abrasion by saltating bed load. Model results show that bedrock abrasion in subglacial channels with pressurized flow reaches a maximum at an intermediate distance up-ice from the glacier snout for a wide range of sediment grain sizes and sediment loads. Close to the snout, the velocity is too low and the sediment particles cannot be mobilized. Far from the snout, the flow accelerates and sediment is transported in suspension, thus limiting particle impacts at the channel bottom and reducing abrasion. This non-monotonic relationship between subglacial flow and bedrock abrasion produces concave up bottom profiles in subglacial channels and potential cross-section constrictions after channel confluences. Both landforms are present in the bedrock channels of the Labyrinth. We therefore conclude that these geomorphic features are a possible signature of bedrock abrasion, rather than glacial scour, and reflect the complex interplay between transport rate, sediment load, and transport capacity in subglacial channels.


Assuntos
Sedimentos Geológicos/análise , Camada de Gelo , Modelos Teóricos , Erosão do Solo
8.
PLoS One ; 16(9): e0253080, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34529668

RESUMO

The tropics are naturally vulnerable to watershed erosion. This region is rapidly growing (projected to be 50% of the global population by 2050) which exacerbates erosional issues by the subsequent land use change. The issue is particularly of interest on the many (~45,000) small tropical (<5,000 km2) islands, and their >115M residents, where ecotourism and sediment intolerant ecosystems such as coral reefs are the main driver of their economies. However, vulnerability to erosion and deposition is poorly quantified in these regions due to the misclassification or exclusion of small islands in coarse global analyses. We use the only vulnerability assessment method that connects watershed erosion and coastal deposition to compare locally sourced, high-resolution datasets (5 x 5 m) to satellite-collected, remotely sensed low-resolution datasets (463 x 463 m). We find that on the island scale (~52 km2) the difference in vulnerability calculated by the two methods is minor. On the watershed scale however, low-resolution datasets fail to accurately demonstrate watershed and coastal deposition vulnerability when compared to high-resolution analysis. Specifically, we find that anthropogenic development (roads and buildings) is poorly constrained at a global scale. Structures and roads are difficult to identify in heavily forested regions using satellite algorithms and the rapid, ongoing rate of development aggravates the issue. We recommend that end-users of this method obtain locally sourced anthropogenic development datasets for the best results while using low resolution datasets for the other variables. Fortunately, anthropogenic development data can be easily collected using community-based research or identified using satellite imagery by any level of user. Using high-resolution results, we identify a development trend across St. John and regions that are both high risk and possible targets for future development. Previously published modeled and measured sedimentation rates demonstrate the method is accurate when using low-resolution or high-resolution data but, anthropogenic development, watershed slope, and earthquake probability datasets should be of the highest resolution depending on the region specified.


Assuntos
Monitoramento Ambiental/instrumentação , Imagens de Satélites/métodos , Erosão do Solo , Algoritmos , Sedimentos Geológicos , Atividades Humanas , Ilhas , Dinâmica Populacional , Clima Tropical
9.
Sci Total Environ ; 800: 149513, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34392222

RESUMO

Mitigation of erosion along the riverbanks is a global challenge. Stabilisers such as cement can control erosion, but it risks the river ecology. This paper presents the erosion characteristics of riverbank soil treated with two biological stabilisers that alleviate the ecological cost. The riverbank soil of one of the largest river systems, Brahmaputra, is treated by bio-polymeric and bio-cement binders and their composite. Moreover, a novel selective bio-stimulation technique has been employed to achieve bio-mineralisation. The soil stabilisation is assessed by needle penetration tests and CaCO3 contents. The specimens were tested in a flow-controlled hydraulic flume subjected to a critical current profile ranging from 0.06 to 0.62 m/s. Soil samples treated up to four cycles of biocementation have been tested at three different slopes (30°, 45° and 53°). The eroded depth and erosion rate are evaluated with image analysis. Up to four-fold reduction in the erosion rate was observed with biocementation treatment. However, cementation beyond a threshold led to the formation of brittle chunks. A bio-composite was devised through a pre-treatment of low-viscosity biopolymer along with biocementation. The bio-composite was found to effectively mitigate the current-induced erosion with 36% lower ammonia production than the equally erosion resistant biocemented counterpart. The dual characteristics of the bio-composite were confirmed with the microstructural analysis. This study unravels the potential of biopolymer-biocement composite as a sustainable erosion mitigation strategy.


Assuntos
Erosão do Solo , Solo , Rios
10.
Sci Total Environ ; 799: 149218, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34352466

RESUMO

Shrubland is a Mediterranean biome characterized by densely growing evergreen shrubs adapted to fire events. To date, scientific research has focused on the impact of vegetation on soil erosion mainly through the control that plant biomass or plant cover exerts on sediment delivery and runoff discharge, being the individual plant species influence on hydrological and erosional processes not achieved in detail. The objective of this research is to determine: i) runoff and soil losses in a shrubland-covered rangeland at Sierra de Enguera, Spain; and ii) how four plant species affect soil and water losses. We measured soil cover, soil properties, runoff discharge and sediment yield under natural rainfall for five years (2010-2014) in a typical shrubland burnt in 1999. Four plant species were selected with 4 plots each: Ulex parviflorus Pourr., Pistacia lentiscus L., Quercus coccifera L. and Rosmarinus officinalis L. Despite that the soil properties and plant cover did not exhibit statistically significant differences among plant species, the runoff discharge was lower on Q. coccifera (4.87%, SE 0.24) and P. lentiscus (6.24%, SE 0.51) than on U. parviflorus (13.41%, SE 0.58) and R. officinalis (13.84%, SE 1.23). Sediment concentrations were, respectively, 3.91, 4.33, 4.31 and 4.88 g l-1, and the differences between R. officinalis and the other species were statistically significant. The runoff discharge determined differences in soil erosion rates among the plant species with lower rates on P. lentiscus (1.36 Mg ha-1 y-1) and Q. coccifera (1.53 Mg ha-1 y-1), than on U. parviflorus (3.17 Mg ha-1 y-1) and R. officinalis (3.85 Mg ha-1 y-1). This long term in situ study indicated that Q. coccifera and P. lentiscus are more efficient in controlling runoff discharge and soil losses than U. parviflorus and R. officinalis one decade after a fire. We discuss these results in light of the recent findings by the scientific community of the role of the canopy cover (rainfall interception), soil macropore and root system, and the water repellency that control the hydrological response of the soil (e.g. runoff generation, infiltration). The information supplied by 5 years of research is relevant for restoration and rehabilitation programs and advise that Q. coccifera and P. lentiscus are the most efficient plant species to control soil and water losses within the Mediterranean shrubland. This is an applied science approach for a better management of rangelands.


Assuntos
Erosão do Solo , Solo , Ecossistema , Plantas , Movimentos da Água
11.
Sci Total Environ ; 795: 148774, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34328923

RESUMO

Soil erosion is a potentially important source of microplastic (MP) entering aquatic ecosystems. However, little is known regarding the erosion and transport processes of MP from agricultural topsoils. The aim of this study is to analyze the erosion and transport behavior of MP during heavy rainfall events, whereas a specific focus is set to preferential MP transport and MP-soil interactions potentially leading to a more conservative transport behavior. The study is based on a series of rainfall simulations on paired-plots (4.5 m × 1.6 m) of silty loam and loamy sand located in Southern Germany. The simulations (rainfall intensity 60 mm h-1) were repeated 3 times within 1.5 years. An amount of 10 g m-2 of fine (MPf, size 53-100 µm) and 50 g m-2 of coarse (MPc, size 250-300 µm) high-density polyethylene as common polymer was added to the topsoil (<10 cm) of the plots. The experiments show a preferential erosion and transport of the MP leading to a mean enrichment ratio of 3.95 ± 3.71 (MPc) and 3.17 ± 2.58 (MPf) in the eroded sediment. There was a higher MP enrichment on the loamy sand but a higher sediment delivery on the silty loam resulting in nearly equal MP deliveries from both soil types. An increasing interaction with mineral soil particles or aggregates leads to a decreasing MP delivery over time. Within 1.5 years, up to 64% of the eroded MP particles were bound to soil particles. Overall, more of the MPc was laterally lost via soil erosion, while for the MPf the vertical transport below the plough layer was more important. In general, our study indicates that arable land susceptible to soil erosion can be a substantial MP source for aquatic ecosystems.


Assuntos
Microplásticos , Solo , Agricultura , Ecossistema , Plásticos , Erosão do Solo
12.
Sci Total Environ ; 795: 148972, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34328944

RESUMO

The Himalayan basins are characterised by severe soil erosion rates and several basins are among the largest sediment dispersal systems in the world. Unsustainable agricultural activities increase the soil erosion rates and influence the overall hydro-geomorphic regime of river basins. Consequently, the water holding capacity of soil reduces, which enhances the flood risk in the lowland regions. In addition, excessive sediment flux severely affects the reservoir capacity in the mountainous regions, thus amplifying the flood hazard in the upland regions. Here, we have analysed two large and hydro-geomorphically diverse Himalayan River basins, namely, the Ganga Basin (GBA) from source to Allahabad in northern India and the Kosi Basin (KB) draining through Nepal and north Bihar plains in eastern India. Based on RULSE and region-specific SDR modelling framework, which includes model calibration, validation and uncertainty assessment, we demonstrate that spatial variation in rainfall, hydrogeomorphic conditions, the presence of hydraulic structures, and large-scale agricultural activities influence the overall pattern of sediment production and transport in these two large river basins. Total soil erosion in GBA and KB are estimated to be ~404 × 106 t/y and ~724 × 106 t/y respectively, a large part of which comes from the mountainous regions in both basins. Sediment yield at the mountain exits of the GBA and KB are computed as 14.1 × 106 t/y and 86.4 × 106 t/y respectively, which work out to be ~5% and ~15% of total soil erosion from the respective contributing areas of the KB and GBA respectively. Similarly, sediment yields at outlets in the alluvial plains are estimated to be 32.2 × 106 t/y and 37.3 × 106 t/y in the GBA and the KB, respectively suggesting that a large part of sediments are accommodated in the alluvial plains of KB. These results have significant implications for sediment management in the Himalayan River basins.


Assuntos
Monitoramento Ambiental , Erosão do Solo , Sedimentos Geológicos , Índia , Rios , Solo
13.
Environ Sci Technol ; 55(14): 9905-9915, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34252277

RESUMO

Soil erosion and sediment deposition are relevant to multiple important ecosystem services essential for natural and human systems. The present study aims to project future soil erosion and sediment deposition in the Upper Mississippi River Basin (UMRB) using climate projections by five Global Circulation Models (GCMs) under the Representative Concentrations Pathway (RCP) 8.5 scenario. To understand the importance of freeze-thaw cycles (FTCs) for soil erosion and sediment deposition estimation with climate change, this study compared two Soil and Water Assessment Tool (SWAT) models with different representations of the FTCs, with the standard SWAT using a simple regression method and SWAT-FT employing a physically based method. Modeling results show that future climate change can pronouncedly intensify soil erosion and increase sediment deposition, and the impacts are sensitive to how FTCs are represented in the model. The standard SWAT projected an increase in soil erosion by nearly 40% by the end of the 21st century, which is much lower than the projected over 65% increase in soil erosion by SWAT-FT. For sediment deposition, the projected percent changes by the standard SWAT and SWAT-FT also deviate from each other (i.e., about 70% by the standard SWAT vs about 120% by SWAT-FT). Overall, these results demonstrate the important roles of FTCs in projecting future soil erosion and sediment deposition and underline the need to consider the effects of conservation practices on FTCs to realistically assess the effectiveness of those measures.


Assuntos
Rios , Erosão do Solo , Mudança Climática , Ecossistema , Humanos , Solo
14.
Artigo em Inglês | MEDLINE | ID: mdl-34200518

RESUMO

Large-scale vegetation restoration greatly changed the soil erosion environment in the Loess Plateau since the implementation of the "Grain for Green Project" (GGP) in 1999. Evaluating the effects of vegetation restoration on soil erosion is significant to local soil and water conservation and vegetation construction. Taking the Ansai Watershed as the case area, this study calculated the soil erosion modulus from 2000 to 2015 under the initial and current scenarios of vegetation restoration, using the Chinese Soil Loess Equation (CSLE), based on rainfall and soil data, remote sensing images and socio-economic data. The effect of vegetation restoration on soil erosion was evaluated by comparing the average annual soil erosion modulus under two scenarios among 16 years. The results showed: (1) vegetation restoration significantly changed the local land use, characterized by the conversion of farmland to grassland, arboreal land, and shrub land. From 2000 to 2015, the area of arboreal land, shrub land, and grassland increased from 19.46 km2, 19.43 km2, and 719.49 km2 to 99.26 km2, 75.97 km2, and 1084.24 km2; while the farmland area decreased from 547.90 km2 to 34.35 km2; (2) the average annual soil erosion modulus from 2000 to 2015 under the initial and current scenarios of vegetation restoration was 114.44 t/(hm²·a) and 78.42 t/(hm²·a), respectively, with an average annual reduction of 4.81 × 106 t of soil erosion amount thanks to the vegetation restoration; (3) the dominant soil erosion intensity changed from "severe and light erosion" to "moderate and light erosion", vegetation restoration greatly improved the soil erosion environment in the study area; (4) areas with increased erosion and decreased erosion were alternately distributed, accounting for 48% and 52% of the total land area, and mainly distributed in the northwest and southeast of the watershed, respectively. Irrational land use changes in local areas (such as the conversion of farmland and grassland into construction land, etc.) and the ineffective implementation of vegetation restoration are the main reasons leading to the existence of areas with increased erosion.


Assuntos
Conservação dos Recursos Naturais , Erosão do Solo , China , Solo , Árvores
15.
Environ Manage ; 68(2): 240-261, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34105015

RESUMO

This study was conducted to evaluate the effectiveness of best management practices (BMPs) to reduce soil erosion in Gumara watershed of the Abbay (Upper Blue Nile) Basin using the Soil and Water Assessment Tool (SWAT) model. The model was calibrated (1995-2002) and validated (2003-2007) using the SWAT-CUP based on observed streamflow and sediment yield data at the watershed outlet. The study evaluated four individual BMP Scenarios; namely, filter strips (FS), stone/soil bunds (SSB), grassed waterways (GW) and reforestation of croplands (RC), and three blended BMP Scenarios, which combines individual BMPS of FS and RC (FS & RC), GW and RC (GW & RC), and SSB and GW (SSB & GW). Mean annual sediment yield at the baseline conditions was estimated at 19.7 t ha-1yr-1, which was reduced by 13.7, 30.5, 16.2 and 25.9% in the FS, SSB, GW, and RC Scenarios, respectively at the watershed scale. The highest reduction efficiency of 34% was achieved through the implementations of the SSB & GW Scenario. The GW & RC, and FS & RC Scenarios reduced the baseline sediment yield by 32% and 29.9%, respectively. The study therefore concluded that the combined Scenarios mainly SSB & GW, and GW & RC can be applied to reduce the high soil erosion in the Gumera watershed, and similar agro-ecological watersheds in Ethiopia. In cases where applying the combined scenarios is not possible, the SSB Scenario can yield significant soil erosion reduction.


Assuntos
Solo , Água , Etiópia , Erosão do Solo , Qualidade da Água
16.
J Environ Manage ; 294: 112987, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34118516

RESUMO

The Saranda forest region, which is well known for its biodiversity in India, is now confronted by rapid socio-economic development, particularly the hilltop mining activities. Hilltop mining areas of this region have always been responsible for producing excessive soil erosion in the associated river basin. This erosion phenomenon becomes hazardous during the rainy season, thereby contributing to various environmental problems, and consequently, necessitating soil erosion control planning in the Saranda forest. Hence, this study aimed to estimate average annual soil erosion in the Saranda region in terms of the spatial distribution using the Geographic Information System (GIS) integrated Revised Universal Soil Loss Equation (RUSLE) model. The erosion was quantified at a spatial resolution of 10 m (pixel by pixel) using the GIS-based RUSLE inputs. This study also applies GIS integrated Analytic Hierarchy Process (AHP) model to identify the favorable zones for sediment deposition in the study area. On the basis of erosion severity, the entire study area is classified into six categories (very low to extreme). The study reveals that the Saranda forest's average annual soil erosion is 76 tons per hectare per year (t/ha/yr). Approximately 63% of the total area is categorized under very low to low erosion category, and the relevant area is mainly covered by forest land, whereas the mining region comprises less than 1% of the total study area with extremely high soil erosion (156 t/ha/yr) potential. As envisaged from the present study, the erosion-prone mining areas are located within a 1-5 km range of the adjacent Karo and Koina rivers, thereby, necessitating the erosion control strategy to avoid the possible threats. From this perspective, the study also investigates the favorable zones for sediment deposition using the GIS integrated AHP model to suggest the appropriate erosion control measures. Finally, the RUSLE and AHP models are combined on the GIS platform to identify the distressed catchment area. Moreover, 42% (41,060 ha) of the total area is disturbed due to the present mining activities, which involves 11 sub-watersheds, and their associated 50 micro-watersheds. From the context of watershed conservation, erosion control measures are also recommended. The methodology adopted in this study can be easily extended to any global mining-dominated catchment for sustainable conservation planning.


Assuntos
Sistemas de Informação Geográfica , Solo , Conservação dos Recursos Naturais , Monitoramento Ambiental , Índia , Erosão do Solo
17.
Sci Total Environ ; 793: 148466, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34175609

RESUMO

Assessment of soil loss and understanding its major drivers are essential to implement targeted management interventions. We have proposed and developed a Revised Universal Soil Loss Equation framework fully implemented in the Google Earth Engine cloud platform (RUSLE-GEE) for high spatial resolution (90 m) soil erosion assessment. Using RUSLE-GEE, we analyzed the soil loss rate for different erosion levels, land cover types, and slopes in the Blue Nile Basin. The results showed that the mean soil loss rate is 39.73, 57.98, and 6.40 t ha-1 yr-1 for the entire Blue Nile, Upper Blue Nile, and Lower Blue Nile Basins, respectively. Our results also indicated that soil protection measures should be implemented in approximately 27% of the Blue Nile Basin, as these areas face a moderate to high risk of erosion (>10 t ha-1 yr-1). In addition, downscaling the Tropical Rainfall Measuring Mission (TRMM) precipitation data from 25 km to 1 km spatial resolution significantly impacts rainfall erosivity and soil loss rate. In terms of soil erosion assessment, the study showed the rapid characterization of soil loss rates that could be used to prioritize erosion mitigation plans to support sustainable land resources and tackle land degradation in the Blue Nile Basin.


Assuntos
Conservação dos Recursos Naturais , Erosão do Solo , Monitoramento Ambiental , Sistemas de Informação Geográfica , Solo
18.
Environ Monit Assess ; 193(Suppl 1): 274, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-33988744

RESUMO

The ecosystem service (ES) approach usually addresses soil erosion as the regulating service control of erosion rates or soil retention. In addition to the assessment of this regulating ES, mitigated impacts on soil-related ES by preventing soil erosion can be assessed. This study presents a scenario-based approach for the assessment of the impact of soil erosion on soil-related ES. The assessment approach was tested in agricultural landscapes in Northern Germany, combining mapping and assessment of soil-related ES. In six scenarios, the degradation of soils due to soil erosion was simulated by the calculation of soil profile reductions. The scenarios represent two levels of impact with three time steps (+50, +100, +150 years). In the scenarios for the structural impact, the potential soil erosion rates were extrapolated into the future to generate spatially explicit information on degraded soils. In the scenarios for the mitigated impact, the actual soil erosion rates were extrapolated. Four soil-related ES were assessed for the initial state and the scenarios crop provision, water filtration, water flow regulation and fresh water provision. The comparison of the potential service supply of the four soil-related ES in the scenarios enabled the assessment of the long-term effect of the ES control of erosion rates. The mitigated reduction in the potential service supply for three of the considered ES (crop provision, water filtration, water flow regulation) is large and highlights the importance of sustainable soil management. Contrary to this, the ES fresh water provision benefits of erosion-induced soil profile reductions.


Assuntos
Ecossistema , Solo , Conservação dos Recursos Naturais , Monitoramento Ambiental , Alemanha , Erosão do Solo
19.
Isotopes Environ Health Stud ; 57(3): 316-331, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33974464

RESUMO

Cosmogenic 7Be was used to evaluate soil loss in a mountainous micro-watershed near Belo Horizonte, Southwest Brazil. Two nearby sites were selected, a reference site in a flat area and an eroded site in a hill slope. At the reference site, soil samples were collected monthly throughout the year in order to evaluate seasonal variations of 7Be inventory in soil and its relation with the precipitation regime. Additionally, rainwater was collected and the expected 7Be soil content was predicted. At the reference site, the 7Be inventory shows seasonal variations, in accordance with the rainy season, and its distribution in the soil profile shows an exponential decrease in depth (h0 = 6.9 ± 0.6 kg m-2; r2 = 0.97). At the eroded site, two soil sampling campaigns were performed in order to measure soil erosion in the watershed. The estimated net erosion was 42.2 ± 3.7 t ha-1, indicating the loss of upper 5mm of soil per year. This corresponds to soil losses in the area in the range from moderate to severe erosion.


Assuntos
Berílio/análise , Radioisótopos/análise , Erosão do Solo , Brasil , Chuva , Solo/química
20.
Environ Res ; 197: 111087, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33798514

RESUMO

Soil erosion can present a major threat to agriculture due to loss of soil, nutrients, and organic carbon. Therefore, soil erosion modelling is one of the steps used to plan suitable soil protection measures and detect erosion hotspots. A bibliometric analysis of this topic can reveal research patterns and soil erosion modelling characteristics that can help identify steps needed to enhance the research conducted in this field. Therefore, a detailed bibliometric analysis, including investigation of collaboration networks and citation patterns, should be conducted. The updated version of the Global Applications of Soil Erosion Modelling Tracker (GASEMT) database contains information about citation characteristics and publication type. Here, we investigated the impact of the number of authors, the publication type and the selected journal on the number of citations. Generalized boosted regression tree (BRT) modelling was used to evaluate the most relevant variables related to soil erosion modelling. Additionally, bibliometric networks were analysed and visualized. This study revealed that the selection of the soil erosion model has the largest impact on the number of publication citations, followed by the modelling scale and the publication's CiteScore. Some of the other GASEMT database attributes such as model calibration and validation have negligible influence on the number of citations according to the BRT model. Although it is true that studies that conduct calibration, on average, received around 30% more citations, than studies where calibration was not performed. Moreover, the bibliographic coupling and citation networks show a clear continental pattern, although the co-authorship network does not show the same characteristics. Therefore, soil erosion modellers should conduct even more comprehensive review of past studies and focus not just on the research conducted in the same country or continent. Moreover, when evaluating soil erosion models, an additional focus should be given to field measurements, model calibration, performance assessment and uncertainty of modelling results. The results of this study indicate that these GASEMT database attributes had smaller impact on the number of citations, according to the BRT model, than anticipated, which could suggest that these attributes should be given additional attention by the soil erosion modelling community. This study provides a kind of bibliographic benchmark for soil erosion modelling research papers as modellers can estimate the influence of their paper.


Assuntos
Bibliometria , Erosão do Solo , Agricultura , Publicações , Solo
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