Effects of topographic factors on runoff and soil loss in Southwest China

Zhang, Xingqi; Hu, Maochuan; Xinya, Guo; Yang, Hong; Zhang, Zhenke; Zhang, Keli

doi:10.1016/j.catena.2017.10.013

Cited by 110 publications

(65 citation statements)

References 44 publications

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“…Field experiments were conducted in forest soil from July 2018 to August of 2018 in Yangjie Catchment (102 • 55 E, 23 • 37 -23 • 44 N) in the southwestern karst area of Jianshui Town in Yunnan Province, China. The karst regions in Southwest China are the largest continuous karst regions in the world [35]. We selected three typical forest lands (e.g., Pinus Yunnanensis plantation, secondary forestland, and natural grassland) at the foot of the slope.…”

Section: Site Descriptionmentioning

confidence: 99%

Section: Spatial Variation Of Dyeing Distributionmentioning

confidence: 99%

“…This phenomenon is important in soil hydrological processes (e.g., the soil water cycle and water infiltration rate). The preferential flow pathway of secondary forestland is extremely developed because of the following: (1) the special morphology and high heterogeneity of the soil structure in karst regions [35], (2) the fact that the fracture between rock and soil has become a preferential pathway for transporting surface water to deep soil layers [51], and (3) the non-uniform distribution of fissures in surface soil, which is caused by the lack of uniform vegetation cover. The characteristic parameters of the preferential flow (e.g., ID (infiltration depth), UF, DC, PF, and L i ) can be calculated using the image data of stained vertical profiles, which can quantitatively evaluate the characteristics of dyeing morphology and the differences under various infiltration conditions and reveal the non-uniform characteristics of preferential flow under different infiltration conditions in karst regions ( Table 3).…”

Section: Spatial Variation Of Dyeing Distributionmentioning

confidence: 99%

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Effects of Grass and Forests and the Infiltration Amount on Preferential Flow in Karst Regions of China

Kan

Cheng

et al. 2019

Water

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Preferential flow is an important water infiltration phenomenon in karst regions. The response of preferential flow to vegetation restoration requires urgent investigation due to the special soil structure of karst regions. In order to study the effect of vegetation restoration on water movement in karst regions, four kinds of ponded water infiltration experiments were carried out in Pinus Yunnanensis plantation forestland, secondary forestland, and natural grassland. A brilliant blue dyeing experiment was conducted to visualize the distribution of water infiltration in soil (a total of 150 stained images from vertical soil slices). Results showed that the average depth of matrix flow in natural grassland was approximately six times those in plantation and secondary forestlands. An increase in matrix flow will have a negative effect on the development of preferential flow. Water transported in preferential flow paths affects the distribution of nutrients and organic matter in the soil. However, preferential flow in grassland can promote the accumulation of available nutrients, and preferential flow in plantations can inhibit the loss of organic matter. Preferential flow in grasslands and forest plantations is less than that in native forests soils. Preferential flow increases the percolation of water in soils. The effect is that preferential flow can obstructs water uptake by the roots under low rainfall conditions, and decreases surface runoff before soil saturation under high rainfall conditions. In the process of nutrient element migration, preferential flow has a good contribution, which is conducive to the migration and accumulation of elements required for surface vegetation growth. The contribution of preferential flow needs to be considered in studies on vegetation restoration planning and land degradation.

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Section: Site Descriptionmentioning

confidence: 99%

Section: Spatial Variation Of Dyeing Distributionmentioning

confidence: 99%

Section: Spatial Variation Of Dyeing Distributionmentioning

confidence: 99%

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Effects of Grass and Forests and the Infiltration Amount on Preferential Flow in Karst Regions of China

Kan

Cheng

et al. 2019

Water

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“…Previous studies found that topography had a considerable impact on runoff generation, soil erosion and subsequent nutrient loss [24,53]. The differences in correlation between ELEV and total runoff depth, TN and TP can be mainly attributed to land use and soil vertical zone differentiation in the TGRA.…”

Section: Discussionmentioning

confidence: 93%

“…However, factors in different studies showed different correlations with runoff and nutrient loss processes. For instance, the impact of slope gradient on the runoff generation and soil erosion is not always linearly positive [24]. Therefore, in regions with a large spatial heterogeneity, the correlation between runoff and nutrients and environmental factors cannot be generalized, and thus needs to be studied in detail.…”

Section: Introductionmentioning

confidence: 99%

Spatial Variation Pattern Analysis of Hydrologic Processes and Water Quality in Three Gorges Reservoir Area

Chen

Zhang

et al. 2019

Water

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The Three Gorges Project (TGP) has greatly enhanced the heterogeneity of the underlying surface in the Three Gorges Reservoir Area (TGRA), thereby affecting the hydrologic processes and water quality. However, the influence of the differences of underlying surfaces on the hydrologic processes and water quality in the TGRA has not been studied thoroughly. In this research, the influence of the heterogeneity of landscape pattern and geographical characteristics on the spatial distribution difference of hydrologic processes and water quality in the different tributary basins of the TGRA was identified. The TGRA was divided into 23 tributary basins with 1840 sub-basins. The spatial differentiation of the hydrologic processes and water quality of the 23 tributary basins was examined by the Soil and Water Assessment Tool (SWAT). The observed data between 1 January 2010 and 31 December 2013 were used to calibrate and validate the model, after which the SWAT model was applied to further predict the runoff and water quality in the TGRA. There are 25 main model parameters, including CN2, CH_K2 and SOL_AWC, which were calibrated and validated with SWAT-Calibration and Uncertainty Procedures (SWAT-CUP). The landscape patterns and geomorphologic characteristics in 23 tributary basins were investigated and spatially visualized to correlate with surface runoff and nutrient losses. Due to geographical difference, the average total runoff depth (2010-2013) in the left bank area (538.6 mm) was 1.4 times higher than that in the right bank area (384.5 mm), total nitrogen (TN) loads in the left bank area (6.23 kg/ha) were 1.9 times higher than in the right bank area (3.27 kg/ha), and total phosphorus (TP) loads in the left bank area (1.27 kg/ha) were 2.2 times higher than in the right bank area (0.58 kg/ha). The total runoff depth decreased from the head region (553.3 mm) to the tail region (383.2 mm), while the loads of TN and TP were the highest in the middle region (5.51 kg/ha for TN, 1.15 kg/ha for TP), followed by the tail region (5.15 kg/ha for TN, 1.12 kg/ha for TP) and head region (3.92 kg/ha for TN, 0.56 kg/ha for TP). Owing to the different spatial distributions of land use, soil and geographical features in the TGRA, correlations between elevation, slope gradient, slope length and total runoff depth, TN and TP, were not clear and no consistency was observed in each tributary basin. Therefore, the management and control schemes of the water security of the TGRA should be adapted to local conditions.

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Hedgerows enhance the size selectivity of eroded sediment from sloping farmland under simulated rainfall experiment

Xiao,

Guo,

Xia

et al. 2024

Earth Surf Processes Landf

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The particle size distribution (PSD) of eroded sediment can effectively reflect changes in erosion processes. Hedgerows provide significant soil and water conservation benefits and influence erosion processes. However, the impact of hedgerows on the PSD of eroded sediment remains unclear. Therefore, three slope conditions (control check, CK; only hedgerow root, R; and whole hedgerow, P) involving the configuration of two slope gradients (15 and 25°) were established, and simulated rainfall experiments were conducted under three rainfall intensities (60, 90, and 120 mm/h). The PSD, sediment sorting process, and sediment particle agglomeration degree under the different slope conditions were compared to evaluate the influence of hedgerows on the size selectivity of eroded sediment during water erosion. Moreover, the direct and indirect effects of hedgerows on the sorting process and sediment particle agglomeration degree were revealed via correlation analysis and partial least squares path modelling (PLS–PM). Compared with those under CK slope conditions, the average clay, fine silt, and coarse silt contents under R slope conditions decreased by 1.37%, 0.06%, and 1.71%, respectively, whereas the sand content increased by 0.46%. Under P slope conditions, the average clay, fine silt, and coarse silt contents increased by 32.61%, 38.71%, and 36.14%, respectively, whereas the average sand content decreased by 47.30%. Under CK slope conditions, sediment sorting occurred primarily during the early stages of rainfall. R slope conditions caused an increase in the duration of early‐stage sediment sorting but caused a reduction in the degree of sorting, whereas P slope conditions exhibited interceptive sorting of sand throughout the rainfall event. Under R slope conditions, more aggregates were dispersed into individual particles due to raindrop impact, whereas under P slope conditions, more fine particles aggregated initially, but loose aggregates were dispersed into individual particles during the later rainfall stages. The enrichment rates of fine silt and coarse silt were positively correlated with slope conditions, whereas they were negatively correlated with the enrichment rate of sand. However, there was no significant relationship between the slope conditions and the aggregation rates of particles of various sizes. PLS–PM indicated that hedgerows directly and indirectly affect sorting processes and sediment particle agglomeration degree by regulating runoff and sediment erosion, and the direct effects exceed the indirect effects. These findings provide a comprehensive understanding of the influential mechanisms of hedgerows on controlling soil erosion.

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Effects of topographic factors on runoff and soil loss in Southwest China

Cited by 110 publications

References 44 publications

Effects of Grass and Forests and the Infiltration Amount on Preferential Flow in Karst Regions of China

Effects of Grass and Forests and the Infiltration Amount on Preferential Flow in Karst Regions of China

Spatial Variation Pattern Analysis of Hydrologic Processes and Water Quality in Three Gorges Reservoir Area

Hedgerows enhance the size selectivity of eroded sediment from sloping farmland under simulated rainfall experiment

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