Potential Loss of Toxic Elements from Slope Arable Soil Erosion Into Watershed in Southwest China: Effect of Spatial Distribution and Land-Uses

The watershed-scale distribution and loss of potentially toxic elements (PTEs) through soil erosion from slope lands to a watershed has not yet been systematically studied, especially in small mountain watersheds with high geological background PTEs in Southwest China. In this study, the spatial distribution, loss intensities and ecological risks of 12 PTEs were investigated in 101 soil samples from four types of land use in a typical watershed, Guizhou Province. Moreover, in order to avoid over- or underestimation of the contamination level in such specific geologies with significant variability in natural PTE distribution, the local background values (local BVs) were calculated by statistical methods. The dry arable land had the highest loss intensity of PTEs and was the largest contributor of PTEs (more than 80%) in the watershed, even though it covers a much smaller area compared to the forest land. The loss of Cd, As, Sb, and Hg from slope arable lands into the watershed leads to a relatively high potential ecological risk. The study suggested that both PTEs content with different types of land-uses and intensities of soil loss are of great importance for PTEs’ risk assessment in the small watershed within a high geological background region. Furthermore, in order to reduce the loss of PTEs in soil, the management of agricultural activities in arable land, especially the slope arable land, is necessary.

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Spatial Variabilities of Runoff Erosion and Different Underlying Surfaces in the Xihe River Basin

Water ◽

10.3390/w11020352 ◽

2019 ◽

Vol 11 (2) ◽

pp. 352 ◽

Cited By ~ 1

Author(s):

Ning Wang ◽

Zhihong Yao ◽

Wanqing Liu ◽

Xizhi Lv ◽

Mengdie Ma

Keyword(s):

Spatial Distribution ◽

Soil Erosion ◽

River Basin ◽

Loess Plateau ◽

Arable Land ◽

Alluvial Soil ◽

Underlying Surface ◽

Spatial Gradient ◽

Hydrological Process ◽

The Loess Plateau

Runoff erosion capacity has significant effects on the spatial distribution of soil erosion and soil losses. But few studies have been conducted to evaluate these effects in the Loess Plateau. In this study, an adjusted SWAT model was used to simulate the hydrological process of the Xihe River basin from 1993 to 2012. The spatial variabilities between runoff erosion capacity and underlying surface factors were analyzed by combining spatial gradient analysis and GWR (Geographically Weighted Regression) analysis. The results show that the spatial distribution of runoff erosion capacity in the studying area has the following characteristics: strong in the north, weak in the south, strong in the west, and weak in the east. Topographic factors are the dominant factors of runoff erosion in the upper reaches of the basin. Runoff erosion capacity becomes stronger with the increase of altitude and gradient. In the middle reaches area, the land with low vegetation coverage, as well as arable land, show strong runoff erosion ability. In the downstream areas, the runoff erosion capacity is weak because of better underlying surface conditions. Compared with topographic and vegetation factors, soil factors have less impact on runoff erosion. The red clay and mountain soil in this region have stronger runoff erosion capacities compared with other types of soils, with average runoff modulus of 1.79 × 10−3 m3/s·km2 and 1.68 × 10−3 m3/s·km2, respectively, and runoff erosion power of 0.48 × 10−4 m4/s·km2 and 0.34 × 10−4 m4/s·km2, respectively. The runoff erosion capacity of the alluvial soil is weak, with an average runoff modulus of 0.96 × 10−3 m3/s·km2 and average erosion power of 0.198 × 10−4 m4/s·km2. This study illustrates the spatial distribution characteristics and influencing factors of hydraulic erosion in the Xihe River Basin from the perspective of energy. It contributes to the purposeful utilization of water and soil resources in the Xihe River Basin and provides a theoretical support for controlling the soil erosion in the Hilly-gully region of the Loess Plateau.

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Discrepancies in Karst Soil Organic Carbon in Southwest China for Different Land Use Patterns: A Case Study of Guizhou Province

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16214199 ◽

2019 ◽

Vol 16 (21) ◽

pp. 4199

Author(s):

Zhenming Zhang ◽

Xianfei Huang ◽

Yunchao Zhou ◽

Jiachun Zhang ◽

Xubo Zhang

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Type ◽

Southwest China ◽

Potassium Dichromate ◽

Soil Samples ◽

Guizhou Province ◽

Land Uses ◽

Karst Areas

The assessment of soil organic carbon (SOC) in mountainous karst areas is very challenging, due to the high spatial heterogeneity in SOC content and soil type. To study and assess the SOC storage in mountainous karst areas, a total of 22,786 soil samples were collected from 2,854 soil profiles in Guizhou Province in Southwest China. The SOC content in the soil samples was determined by the oxidation of potassium dichromate (K2Cr2O7), followed by titration with iron (II) sulfate (FeSO4). The SOC storage was assessed based on different land uses. The results suggested that the average SOC density in the top 1.00 m of soil associated with different land uses decreased in the following order: Croplands (9.58 kg m−2) > garden lands (9.07 kg m−2) > grasslands (8.07 kg m−2) > forestlands (7.35 kg m−2) > uncultivated lands (6.94 kg m−2). The SOC storage values in the 0.00–0.10 m, 0.00–0.20 m, 0.00–0.30 m and 0.00–1.00 m soil layers of Guizhou Province were 0.50, 0.87, 1.11 and 1.58 Pg, respectively. The SOC in the top 0.30 m of soil accounted for 70.25% of the total within the 0.00–1.00 m layer in Guizhou Province. It was concluded that assessing SOC storage in mountainous karst areas was more accurate when using land use rather than soil type. This result can supply a scientific reference for the accurate assessment of the SOC storage in the karst areas of southwestern China, the islands of Java, northern and central Vietnam, Indonesia, Kampot Province in Cambodia and in the general area of what used to be Yugoslavia, along with other karst areas with similar ecological backgrounds.

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Geochemistry of rare earth elements in soils under different land uses in a typical karst area, Guizhou Province, Southwest China

Canadian Journal of Soil Science ◽

10.1139/cjss-2017-0043 ◽

2017 ◽

Cited By ~ 5

Author(s):

Guilin Han ◽

Zhaoliang Song ◽

Yang Tang

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Southwest China ◽

Guizhou Province ◽

Karst Area ◽

Land Uses

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Geochemical variation and contamination level of potentially toxic elements in land-uses urban soils

International Journal of Environmental & Analytical Chemistry ◽

10.1080/03067319.2021.1977286 ◽

2021 ◽

pp. 1-18

Author(s):

Md Saiful Islamd ◽

Abubakr M. Idris ◽

Abu Reza Md Towfiqul Islam ◽

Khamphe Phoungthong ◽

Mir Mohammad Ali ◽

...

Keyword(s):

Urban Soils ◽

Toxic Elements ◽

Potentially Toxic Elements ◽

Contamination Level ◽

Land Uses ◽

Geochemical Variation

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Assessment of Anthropogenic Sources of Potentially Toxic Elements in Soil from Arable Land Using Multivariate Statistical Analysis and Random Forest Analysis

Sustainability ◽

10.3390/su12208538 ◽

2020 ◽

Vol 12 (20) ◽

pp. 8538 ◽

Cited By ~ 1

Author(s):

He Huang ◽

Yong Zhou ◽

Yujie Liu ◽

Ke Li ◽

Liang Xiao ◽

...

Keyword(s):

Spatial Distribution ◽

Random Forest ◽

Toxic Elements ◽

Arable Land ◽

Principal Component ◽

Potentially Toxic Elements ◽

Anthropogenic Sources ◽

Random Forest Analysis ◽

Background Values ◽

Mining Areas

In order to study the spatial distribution and anthropogenic sources of potentially toxic elements in Xiangzhou, soil samples were collected from arable land and were analyzed for five different potentially toxic elements: Cd, Hg, As, Pb, and Cr. Inverse distance weighting (IDW) was used to study the spatial distribution of potentially toxic elements in the soil, while principal component analysis (PCA) and random forest analysis (RFA) were applied to examine the anthropogenic sources. It was shown that the combination of multiple analysis tools provides an effective way of delineating multiple potentially toxic elements from anthropogenic sources. The results showed that the average contents of Cd, Hg, and Cr in soils were lower than the background values of Hubei, whereas the average concentrations of As and Pb in soils were higher than the background values of Hubei. Through PCA, it was concluded that human activities contributed more than 60% of the As, Pb, and Cr concentrations in Xiangzhou soils, which was verified by a random forest simulation methodology. Through random forest analysis, Pb, As, and Cr in the soil were found to originate from factories and enterprises, livestock farms, mining areas, and traffic; Cd in the soil was found to originate from mining and the processing of minerals, human production and construction activities, and agricultural irrigation; and Hg in the soil was found to originate from livestock manure, mining and processing of minerals, and human industrial production. The results of this study could provide support for better management of soil pollution through prevention practices such as specific industrial governance and layout optimization.

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Effects of Different Land Uses and Cultivation Periods on Spatial Distribution of Soil Nutrients in Karst Mountainous Region*

Chinese Journal of Appplied Environmental Biology ◽

10.3724/sp.j.1145.2011.00063 ◽

2011 ◽

Vol 17 (1) ◽

pp. 63-68 ◽

Cited By ~ 1

Author(s):

Chuanyan ZHOU ◽

Xun CHEN ◽

Guoyi ZHOU ◽

Junhua YAN

Keyword(s):

Spatial Distribution ◽

Soil Nutrients ◽

Mountainous Region ◽

Land Uses

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Modelling Agricultural Controls for Flooding and Soil Erosion

The Oxford Handbook of Food, Water and Society ◽

10.1093/oxfordhb/9780190669799.013.56 ◽

2018 ◽

pp. 776-796

Author(s):

Roger Moussa ◽

Bruno Cheviron

Keyword(s):

Spatial Distribution ◽

Model Structure ◽

Land Uses ◽

Research Challenges ◽

Water And Sediment ◽

Flow Processes ◽

Cultivation Practices ◽

Modelling Strategies ◽

The Impact ◽

Significant Factors

Floods are the highest-impact natural disasters. In agricultural basins, anthropogenic features are significant factors in controlling flood and erosion. A hydrological-hydraulic-erosion diagnosis is necessary in order to choose the most relevant action zones and to make recommendations for alternative land uses and cultivation practices in order to control and reduce floods and erosion. This chapter first aims to provide an overview of the flow processes represented in the various possible choices of model structure and refinement. It then focuses on the impact of the spatial distribution and temporal variation of hydrological soil properties in farmed basins, representing their effects on the modelled water and sediment flows. Research challenges and leads are then tackled, trying to identify the conditions in which sufficient adequacy exists between site data and modelling strategies.

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Topographic Position, Land Use and Soil Management Effects on Soil Organic Carbon (Vineyard Region of Niš, Serbia)

Agronomy ◽

10.3390/agronomy11071438 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1438

Author(s):

Snežana Jakšić ◽

Jordana Ninkov ◽

Stanko Milić ◽

Jovica Vasin ◽

Milorad Živanov ◽

...

Keyword(s):

Land Use ◽

Surface Layer ◽

Spatial Distribution ◽

Soil Erosion ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Compaction ◽

Soil Management ◽

Forest Land ◽

Topographic Position

Spatial distribution of soil organic carbon (SOC) is the result of a combination of various factors related to both the natural environment and anthropogenic activities. The aim of this study was to examine (i) the state of SOC in topsoil and subsoil of vineyards compared to the nearest forest, (ii) the influence of soil management on SOC, (iii) the variation in SOC content with topographic position, (iv) the intensity of soil erosion in order to estimate the leaching of SOC from upper to lower topographic positions, and (v) the significance of SOC for the reduction of soil’s susceptibility to compaction. The study area was the vineyard region of Niš, which represents a medium-sized vineyard region in Serbia. About 32% of the total land area is affected, to some degree, by soil erosion. However, according to the mean annual soil loss rate, the total area is classified as having tolerable erosion risk. Land use was shown to be an important factor that controls SOC content. The vineyards contained less SOC than forest land. The SOC content was affected by topographic position. The interactive effect of topographic position and land use on SOC was significant. The SOC of forest land was significantly higher at the upper position than at the middle and lower positions. Spatial distribution of organic carbon in vineyards was not influenced by altitude, but occurred as a consequence of different soil management practices. The deep tillage at 60–80 cm, along with application of organic amendments, showed the potential to preserve SOC in the subsoil and prevent carbon loss from the surface layer. Penetrometric resistance values indicated optimum soil compaction in the surface layer of the soil, while low permeability was observed in deeper layers. Increases in SOC content reduce soil compaction and thus the risk of erosion and landslides. Knowledge of soil carbon distribution as a function of topographic position, land use and soil management is important for sustainable production and climate change mitigation.

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