Spatial and temporal dynamics of rainfall erosivity in the karst region of southwest China: Interannual and seasonal changes

Xu, Xiaojin; Yan, Youjin; Dai, Quanhou; Yi, Xingsong; Hu, Zhang; Cen, Longpei

doi:10.1016/j.catena.2022.106763

Cited by 22 publications

(12 citation statements)

References 62 publications

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“…In nonkarst forests, Hg efflux via soil erosion and runoff accounts for less than 5% of total Hg inputs, ,, except during the deforestation that causes a pulse of soil Hg erosion. ,, In this study, the high soil erosion resulting in the unusually high Hg accumulation in the low-lying land of the karst forest watershed is highlighted. The surface soil Hg concentration in the low-lying land is 4–10 times higher than the values observed in most remote/rural forest soil. , Hg transported through soil erosion increases the Hg burden to the downstream aquatic ecosystems where inorganic Hg can be transformed into highly toxic methylated Hg and then bioaccumulated and biomagnified via food chains. − In addition, the high connectivity of ground and underground water flow in the karst forest − also promotes soil Hg leaching into the groundwater and increases the risk of groundwater Hg pollution. Using the Hg isotopic tracing techniques, an earlier study has shown that Hg in groundwater was derived from the surface soil Hg leaching .…”

Section: Discussionmentioning

confidence: 99%

“…The karst region of southwest China is one of the three primary karst areas in the world . The relatively shallow and discontinuous soil layers, extensive rock exposure, and water leakage of karst ecosystems lead to extremely sensitive and fragile ecology. − Therefore, karst forests may exhibit a unique Hg biogeochemical cycling in contrast to other forest ecosystems. − This hypothesis is based upon the heterogeneity of the rocky landscape, discontinuous vegetation covers, and soil layers − that alter the soil chemistry and atmospheric deposition spatially. In addition, the highly fragmented carbonate rock landscape is prone to erosion , and therefore accelerates soil Hg migration with runoff and leaching …”

Section: Introductionmentioning

confidence: 99%

“…The complexity of the karst landscape and hydrological processes − present challenges in tracing the sources, accumulation, and migration of Hg. To adequately capture the signal and variability of Hg cycling in this ecosystem, we increased the spatial and temporal resolution of the sampling regimes to measure process heterogeneity and identify areas of Hg hotspots (i.e., areas with elevated Hg concentrations) caused by soil Hg migration.…”

Section: Introductionmentioning

confidence: 99%

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Elevated Mercury Deposition, Accumulation, and Migration in a Karst Forest

Du,

Wang,

Yuan

et al. 2023

Environ. Sci. Technol.

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The karst forest is one of the extremely sensitive and fragile ecosystems in southwest China, where the biogeochemical cycling of mercury (Hg) is largely unknown. In this study, we investigated the litterfall deposition, accumulation, and soil migration of Hg in an evergreen-deciduous broadleaf karst forest using high-resolution sampling and stable isotope techniques. Results show that elevated litterfall Hg concentrations and fluxes in spring are due to the longer lifespan of evergreen tree foliage exposed to atmospheric Hg 0 . The hillslope has 1−2 times higher litterfall Hg concentration compared to the low-lying land due to the elevated atmospheric Hg levels induced by topographical and physiological factors. The Hg isotopic model suggests that litterfall Hg depositions account for ∼80% of the Hg source contribution in surface soil. The spatial trend of litterfall Hg deposition cannot solely explain the trend of Hg accumulation in the surface soil. Indeed, soil erosion enhances Hg accumulation in soil of low-lying land, with soil Hg concentration up to 5-times greater than the concentration on the hillslope. The high level of soil Hg migration in the karst forest poses significant ecological risks to groundwater and downstream aquatic ecosystems.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Elevated Mercury Deposition, Accumulation, and Migration in a Karst Forest

Du,

Wang,

Yuan

et al. 2023

Environ. Sci. Technol.

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“…Due to the combined impact of climate, topography, vegetation, soil, and human interventions, the Loess Plateau has a wide area of soil erosion and has become one of the most severe regions of soil erosion in China [12,13]. Rainfall erosivity indicates the potential capacity of rainfall to cause soil erosion [14]. It constitutes the primary driving force behind soil water erosion and stands as one of the key factors of modeling soil erosion and water environment dynamics.…”

Section: Introductionmentioning

confidence: 99%

Rainfall Erosivity Characteristics during 1961–2100 in the Loess Plateau, China

Li,

Xiao,

Hao

et al. 2024

Remote Sensing

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Rainfall erosivity, which signifies the inherent susceptibility of soil erosion induced by precipitation, plays a fundamental role in formulating a comprehensive soil loss equation (RUSLE). It stands as a crucial determinant among the foundational factors considered in a comprehensive soil loss equation’s establishment. Nonetheless, the prediction and quantification of future alterations in rainfall erosivity under the influence of global warming have been relatively limited. In this study, climate change was widely evaluated and 10 preferred global climate models in the Loess Plateau were selected by using the data sets of 27 models simulating climate change and the CN05.1 data set provided by the latest CMIP6. The monthly precipitation forecast data were obtained by using the delta downscaling method. Combined with trend analysis, significance test, and coefficient of variation, the annual rainfall erosivity during 1961–2100 under four SSP scenarios was analyzed and predicted. Among the 27 GCM models used in this paper, the most suitable climate models for simulating monthly precipitation in the Loess Plateau were CMCC-CM2-SR5, CMCC-ESM2, TaiESM1, EC-Earth3, EC-Earth-Veg-LR, INM-CM4-8, CAS-ESM2-0, EC-Earth-Veg, ACCESS-ESM1-5, and IPSL-CM6A-LR. In comparison to the base period (1961–1990), during the historical period (1961–2014), the average annual rainfall erosivity on the Loess Plateau amounted to 1259.64 MJ·mm·hm−2·h−1·a−1, showing an insignificant downward trend. In the northwest of Ningxia, Yulin City and Yanan City showed a significant upward trend. In the future period (2015–2100), the annual rainfall erosivity continues to constantly change and increase. The potential average increase in rainfall erosivity is about 13.48–25.86%. In terms of spatial distribution, most areas showed an increasing trend. Among these regions, the majority of encompassed areas within Shanxi Province, central Shaanxi, and Inner Mongolia increased greatly, which was not conducive to soil and water conservation and ecological environment construction. This study offers a scientific reference for the projected future erosivity characteristics of the Loess Plateau.

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“…Research on rainfall erosivity in soil erosion mainly focuses on two aspects. Firstly, by measuring and analyzing rainfall erosivity, we can quantitatively assess the impact of rainfall events on regional soil erosion in terms of time and space, providing a scientific basis for soil conservation and land management [5,6]. Secondly, analyzing and studying rainfall erosivity enable us to predict future trends in soil erosion.…”

Section: Introductionmentioning

confidence: 99%

Characteristics and Projection of Rainfall Erosivity Distribution in the Hengduan Mountains

Liang

Zhang

et al. 2023

Land

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This study examines the spatiotemporal variations of rainfall erosivity in the Hengduan Mountains, known for their rugged terrain and high potential for soil erosion risks, over the past 30 years. Additionally, it investigates the changing trends of rainfall erosivity between 2025 and 2040 under the Sustainable Development Pathway 2–4.5 (SSP2–4.5), using four Global Climate Models (GCMs) based on the Coupled Model Intercomparison Project phase 6 (CMIP6). The results indicate: (1) The annual distribution of rainfall erosivity in the Hengduan Mountains exhibited significant seasonal variations, ranking in the order of summer > autumn > spring > winter on a seasonal scale. (2) Over the past 30 years, there has been a slight decrease in annual precipitation and a corresponding slight increase in rainfall erosivity. Periodic extreme values occur every 6–8 years. (3) Spatially, rainfall erosivity demonstrates a decreasing gradient from southeast to northwest. There is a significant positive correlation between rainfall erosivity and precipitation, while a significant negative correlation exists with elevation in the vertical direction. Furthermore, the northeastern part of the Hengduan Mountains exhibits an increasing trend of rainfall erosivity, while the southern region experiences a decreasing trend. (4) Considering the joint driving forces of increased precipitation and erosive rainfall events, rainfall erosivity is expected to significantly increase in the future, posing a more severe risk of soil erosion in this region.

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Spatial and temporal dynamics of rainfall erosivity in the karst region of southwest China: Interannual and seasonal changes

Cited by 22 publications

References 62 publications

Elevated Mercury Deposition, Accumulation, and Migration in a Karst Forest

Elevated Mercury Deposition, Accumulation, and Migration in a Karst Forest

Rainfall Erosivity Characteristics during 1961–2100 in the Loess Plateau, China

Characteristics and Projection of Rainfall Erosivity Distribution in the Hengduan Mountains

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