scholarly journals Soil loss and PM10 emissions from agricultural fields in the Junggar Basin over the past six decades

2021 ◽  
pp. 00018
Author(s):  
H. Pi ◽  
N.P. Webb ◽  
J. Lei ◽  
S. Li
Keyword(s):  
Soil Loss ◽  
Junggar Basin ◽  
Agricultural Fields ◽  
The Past ◽  
Pm10 Emissions

Using 137Cs to investigate net soil erosion at two soil benchmark sites in Quebec

1993 ◽  
Vol 73 (4) ◽  
pp. 515-526 ◽  
Author(s):  
Y. Z. Cao ◽  
D. R. Coote ◽  
C. Wang ◽  
M. C. Nolin
Keyword(s):  
Soil Erosion ◽  
Key Words ◽  
Soil Conservation ◽  
Soil Loss ◽  
Soil Samples ◽  
Grid Pattern ◽  
Erosion Rates ◽  
The Past ◽  
Soil Erosion Rates ◽  
Small Grains

137Cs in the soil was used to estimate soil erosion at two National Soil Conservation Program benchmark sites in the province of Quebec (sites 15-QU and 16-QU). The 137Cs baseline in an uneroded forest area was approximately 3100 Bq m−2. The 137Cs content at site 15-QU ranged from 1072 Bq m−2 to 6389 Bq m−2, while at site 16-QU it ranged from 663 Bq m−2 to 5444 Bq m−2. Computed net erosion over the past 30 yr at site 15-QU varied from a loss of 9.65 kg m−2 yr−1 to a gain of 10.88 kg m−2 yr−1 and at site 16-QU from a loss of 6.38 kg m−2 yr−1 to a gain of 1.73 kg m−2 yr−1. The average net erosion rates were 2.43 kg m−2 yr−1 at site 15-QU and 1.29 kg m−2 yr−1 at site 16-QU. Soil samples collected on a grid pattern indicated that 90% and 83% of the area at sites 15-QU and 16-QU, respectively, was subjected to net soil loss. A comparison of total 137Cs movement from eroded areas to depositional areas showed that 24.2% of 137Cs was lost from site 15-QU, while about 17.6% of 137Cs was lost from site 16-QU. Mapping of 137Cs content and calculated soil loss and deposition showed that soil erosion was closely related to topography.Under similar slope conditions, the soil erosion rates were 27–68% higher at site 15-QU than at site 16-QU. Higher tillage frequency and use of silage corn were the suggested reasons for the higher soil erosion rates at site 15-QU compared with site 16-QU, which had been used for hay and small grains. Key words: 137Cs, erosion, deposition, soil conservation

A thousand-year erosional and sedimentation history in karst watersheds based on OSL dating and palynological techniques

2021 ◽  
Author(s):  
Zihao Cao ◽  
Qihua Ke ◽  
Keli Zhang ◽  
Zhuodong Zhang
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Loss Rate ◽  
Local Economic Development ◽  
Osl Dating ◽  
Dominant Factor ◽  
Rocky Desertification ◽  
Peak Cluster ◽  
The Past ◽  
Soil Loss Rate

<p>Rocky desertification is a serious environmental issue in karst regions that restricts food production and hinders local economic development. Generally, soil loss is known as a dominant factor driving rocky desertification. However, it is difficult to couple rocky desertification with the soil loss rate based on a database from short-term field plot observations. Hence, it is imperative to reconstruct the history of soil loss over long-term periods and to correlate the rocky desertification process with the soil loss rate. In karst regions, the most common geomorphic landforms are closed peak-cluster depressions. Researchers have shown that estimating soil loss from hillslopes based on a sediment deposition rate in a peak-cluster depression is possible. In this study, two typical peak-cluster depressions with different degrees of rocky desertification were selected, and sediment cores with lengths of 2 m were sampled from the depressions to determine pollen taxa, soil properties and sediments dating at different depths.The results showed that the burial ages of the sediments in the depressions were different in the time series. During the past millennium, soil loss in the LJWD watershed showed an overall decreasing and then increasing trend. While the change in soil erosion was more complex in the DJT watershed, high and low rates appeared alternately in the 748±100 – 2018 period. The alluvial pollen analysis demonstrated that the soil erosion changes in both watersheds were closely related to human farming activities and vegetation landscape changes. The soil loss history over the past 1000 years was insufficient to reveal the evolution of rocky deserts in karst areas, indicating that the formation of rocky deserts should have occurred over a longer historical period. Overall, the optically stimulated luminescence (OSL) dating and palynological techniques were reliable in the investigation of local erosional history in karst regions.</p>

Evaluation of CCHE2D hydrodynamic and sediment transport model to simulate erosional sources in row crop agriculture in Midwest US

2020 ◽  
Author(s):  
Robert Wells ◽  
Yafei Jia ◽  
Henrique Momm ◽  
Carlos Castillo ◽  
Dalmo Vieira ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Soil Loss ◽  
Transport Model ◽  
Landscape Evolution ◽  
Small Scale ◽  
Agricultural Fields ◽  
Data Set ◽  
Sediment Transport Model ◽  
Total Soil ◽  
Physically Based

<p>Soil erosion due to rainfall and overland flow can be detrimental to agricultural management and long-term agricultural sustainability. Although numerous conservation measures and planning strategies have greatly reduced the amount of sediment moving within the landscape, there are still unresolved questions concerning initiation of particle motion, susceptibility to erosion, total soil loss, sediment transport and general measurement theory. Within agricultural fields, ephemeral erosion is particularly harmful because these sources can accelerate sediment transport, often yield more sediment than interrill sources and are more challenging to mitigate. In this study, terrain data were collected by aerial photogrammetry using an unmanned aerial system (UAS) following planting and approximately one month later, while climate variables during the period were collected using NexRad radar. Imagery was captured within seven agricultural fields (six in Iowa and one in Minnesota), ranging in size from 0.6 to 3.6 hectare (1.6 to 8.8 acre). Considering the small scale in topographic variation between two surveys, extreme efforts were applied to image processing and geospatial registration. Advanced models for camera calibration utilizing Micmac open-source photogrammetry software package were used to account for complex distortion patterns in the raw image data set. The undistorted images were then processed using Agisoft Photoscan for camera alignment, model georeferencing and dense point cloud generation (millions to billions of points per survey), from which digital elevation models (DEMs; 10 to 57 million cells) were produced. A physically-based finite element hydrodynamic and sediment transport model (CCHE2D, developed at the National Center for Computational Hydroscience and Engineering) was applied to simulate hydrological (runoff), sediment detachment (raindrop splash, sheet flow, and concentrated flow erosion) and sediment transport/deposition landscape evolution processes. Simulated geomorphological and sediment budget results over time were compared to field observations for model input parameter adjustment and consequently quantification of estimates. Integration of high-resolution spatial and temporal topographic measurements with physically-based numerical models support the development and validation of dynamic landscape evolution models needed for accurate prediction and quantification of gully initiation, evolution and impact on total soil loss and effective conservation management planning.</p>

scholarly journals Representativeness of airborne brake wear emission for the automotive industry: A review

2021 ◽  
pp. 095440702199301
Author(s):  
Florian Philippe ◽  
Martin Morgeneyer ◽  
Maiqi Xiang ◽  
Maheandar Manokaran ◽  
Brice Berthelot ◽  
...  
Keyword(s):  
Automotive Industry ◽  
Particle System ◽  
Experimental Methods ◽  
Urban Environments ◽  
Exhaust Emission ◽  
Research Groups ◽  
The Past ◽  
System Characterization ◽  
Brake Wear ◽  
Pm10 Emissions

Brake wear gives 16%–55% by mass to total non-exhaust traffic related PM10 emissions in urban environments. While engines have become cleaner in the past decades, few improvements were made to lower non-exhaust emission until recently. Researchers have developed several experimental methods over the past years to assess brake emissions. However, observations tend to differ from a method to another with respect to many disciplines, ranging from particle system characterization to brake cycles, and it remains difficult to compare results of different research groups. It is so crucial to get a consensus on the standard experimental method. The following article lists limits which influence measurements and has to be taken into account when comparing works from different laboratories. This article also discusses how to design tests to get a relevant braking particle system characterization.

scholarly journals Modelling Hydrological Processes in Agricultural Areas with Complex Topography

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 750
Author(s):  
Luciano Massetti ◽  
Chiara Grassi ◽  
Simone Orlandini ◽  
Marco Napoli
Keyword(s):  
Soil Loss ◽  
Agricultural Fields ◽  
Field Crops ◽  
Conservation Measures ◽  
Broad Leaved Forest ◽  
Olive Groves ◽  
Good For ◽  
Agricultural Areas ◽  
Post Hoc ◽  
Soil Conservation Measures

Agricultural intensification and soil mismanagement have been recognized among the main causes of soil erosion in Mediterranean climate areas such as the Arbia stream basin (Tuscany, Italy). This study aims at predicting soil loss from agricultural fields as it is essential for providing reliable information for prioritizing soil conservation measures. Thus, measured soil loss from 243 agricultural fields within the Arbia stream basin during the period 2007–2010 were used to calibrate and validate the ArcSWAT 2012 model at hydrological response units (HRU) scale. Analysis of variance with post-hoc Tukey honest significant test was used to assess significant measured soil loss differences between slope steepness classes and land covers. Soil loss estimation was always “very good” for irrigated field crops, olive groves, and vineyards, “good” for unirrigated field crops, and “unsatisfactory” for broad-leaved forest. The model succeeded in the quantitative assessment of erosive processes at HRU scales. Its application to the whole Arbia stream basin estimated that 31% of the total surface is subjected to higher erosion levels. This approach might help facilitate the identification of priority areas that need the implementation of conservation measures.

Croton lindquistii (Euphorbiaceae): a new arborescent species from western Mexico

Phytotaxa ◽  
2014 ◽  
Vol 166 (3) ◽  
pp. 235 ◽  
Author(s):  
VICTOR W. STEINMANN
Keyword(s):  
New Species ◽  
Deciduous Forests ◽  
Agricultural Fields ◽  
Western Mexico ◽  
The Past ◽  
Tropical Deciduous Forests ◽  
A New Species

Croton lindquistii, a new species in Croton subg. Geiseleria sect. Eluteria subsect. Eluteria, is described and illustrated. It occurs in the tropical deciduous forests of western Mexico from Sonora to Oaxaca. The species is economically important, and during the past four decades, plants have been extensively harvested for their straight, hard, and durable trunks that are used as fence posts and stakes in agricultural fields. Although the exact affinities of C. lindquistii are unknown, it is similar to both C. niveus and C. pseudoniveus. It differs from the former by having ovate to cordiform leaves, fruiting pedicels less than 3 mm long, and spiciform thyrses that are very compact with the axis obscured by the buds. It differs from the latter by having 15–16 stamens per flower and stellate-pubescent ovaries and fruits. The name Croton fantzianus has been misapplied to Croton lindquistii. A key is provided that distinguishes the new species from the five other members of Croton sect. Eluteria subsect. Eluteria that have ovaries and fruits with stellate pubescence.

scholarly journals ESTIMATION OF SOIL LOSSES BY THE IMPROVED TILLAGE HOMOGENIZATION MODEL AND RUSLE MODEL

2020 ◽  
Vol XLIII-B3-2020 ◽  
pp. 961-967
Author(s):  
S. Bouhlassa ◽  
N. Bouhsane
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Environmental Problem ◽  
Scientific Methods ◽  
Rusle Model ◽  
The Past ◽  
Homogenization Model ◽  
Soil Erosion By Water ◽  
Soil Losses ◽  
Sheet Erosion

Abstract. Soil erosion by water is a major environmental problem in the Mediterranean areas. It results in land degradation and soil losses, decreases soil structural stability, and increases soil erodibility. Hence, the need for reliable scientific methods for obtaining soil erosion data becomes crucial. The study aims to estimate soil loss in the Moroccan watershed using two soil erosion estimation models and to discuss the differences between those models. The first model used in this study is the improved tillage homogenization model (T-H) which permits to predict the magnetic susceptibility values after erosion, the second one is the empirical model based on the Revised Universal Soil Loss Equation RUSLE. The results showed that: i) higher soil losses using tillage homogenization (T-H) model have occurred in the upper and lower slopes in the cultivated transect, and in the middleslopes and lower slopes in the forested transect; ii) the average of annual soil loss obtained by RUSLE model is about 20.21 t/ha/yr; iii) T-H model allows us to estimate the total cumulative soil erosion during the past and, while RUSLE model is designed for predicting annual soil loss resulting from sheet erosion under given conditions.

Evidence of prehistoric wind erosion of the Mackenzie Basin, South Island, New Zealand: an assessment based on 137Cs and Kawakawa-Oruanui tephra

Soil Research ◽  
2015 ◽  
Vol 53 (1) ◽  
pp. 56 ◽  
Author(s):  
H. D. Leckie ◽  
P. C. Almond
Keyword(s):  
New Zealand ◽  
Soil Erosion ◽  
Soil Loss ◽  
Peak Concentration ◽  
Volcanic Glass ◽  
Bare Ground ◽  
Vegetation Degradation ◽  
The Past ◽  
Mackenzie Basin ◽  
Reference Plot

Many authors have reported significant soil erosion resulting from the grazing of sheep, rabbit plagues and invasion of the exotic Hawkweed (Hieracium sp.) in the sub humid alpine region of Mackenzie Basin, South Island, New Zealand. In the present study, we investigated the soil redistribution of four study plots with varying vegetation depletion over historic (54 years) and long (25 ka) time scales. Historic soil loss, quantified by bomb fallout 137Cs, under plots of depleted short tussock and herbfield vegetation was no more than the adjacent undisturbed reference plot of red tussock (Chionochloa rubra). This indicates the present landscape characterised by soil and vegetation degradation is not due to erosion since 1953. There is no evidence from the present study to suggest that establishment and rapid invasion of Hieracium sp. and major periodic rabbit plagues have accelerated soil erosion over the past 54 years. By contrast, low topsoil thickness under Hieracium sp. indicates that Hieracium sp. is colonising bare ground and may have, at least in the short-term, a stabilising effect. Long-term soil loss was quantified by the profile distribution of volcanic glass originating from Kawakawa-Oruanui tephra (KOT). The peak concentration, and hence the tephra’s 25.4 ka isochron, occurred at a depth of 70–85 cm at the reference plot. The degraded plots showed significant decreases in glass concentration and depth to peak concentration with progressively shallower soils and vegetation depletion. This equated to a minimum erosion rate averaged over the past ~25.4 k years of 0.020 mm year–1 in the most eroded plot. The extent of bare ground and topsoil thickness were poor indicators of soil erosion status. The tephra results show a potentially long history of soil erosion that has predisposed soil and vegetation degradation within the European era.

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