Effects of land disturbance on runoff and sediment yield after natural rainfall events in southwestern China

2017 ◽  
Vol 24 (10) ◽  
pp. 9259-9268 ◽  
Author(s):  
Xiaomeng Guo ◽  
Tianyang Li ◽  
Binghui He ◽  
Xiaorong He ◽  
Yun Yao
1998 ◽  
Vol 78 (4) ◽  
pp. 699-706 ◽  
Author(s):  
S. I. Gill ◽  
M. A. Naeth ◽  
D. S. Chanasyk ◽  
V. S. Baron

Currently, there is interest in Western Canada in extending the grazing season using perennial and annual forages. Of greatest concern is the environmental sustainability of these grazing systems, with emphasis on their ability to withstand erosion. A study to examine the runoff and sediment yields of annual and perennial forages in central Alberta was initiated in 1994. Runoff and sediment yield were quantified under snowmelt and rainfall events for two seasons. Rainfall simulation was used to further examine runoff under growing season conditions. Four forage treatments (two annuals: triticale and a barley/triticale mixture and two perennials: smooth bromegrass and meadow bromegrass) and three grazing intensities (light, medium and heavy) were studied, each replicated four times. Total annual runoff was dominated by snowmelt. Generally runoff volumes, sediment yields, sediment ratios and runoff coefficients were all low. Bare ground increased with increasing grazing intensity and was significantly greater in annuals than perennials for all grazing intensities. Litter biomass decreased with increasing grazing intensity and was generally similar in all species for both years at heavy and medium grazing intensities. Results from the rainfall simulation corroborated those under natural rainfall conditions and generally indicated the sustainability of these grazing systems at this site. Key words: Forages, soil erosion, sustainability, rainfall simulation


Author(s):  
Ke Liang ◽  
Xiaorong He ◽  
Binghui He ◽  
Xiaomeng Guo ◽  
Tianyang Li

Abstract Land disturbance and slope length play key roles in affecting runoff-associated nitrogen (N) and phosphorus (P) losses in different forms under natural rainfall. Field monitoring was conducted in nine plots located parallel on a 15° purple slope in southwest China. Three slope lengths (20-, 40-, 60-m) combined with measures of artificial disturbance and natural restoration were implemented. The highest N concentration was observed in soft rainfall events across all plots. The highest P concentration was recorded in heavy rainfall events for the artificially disturbed plots and in soft rainfall events for the naturally restored plots. Land disturbance differed orthophosphate concentration in 20-m plot, and affected N and P loss amounts in different forms. Slope length differed total dissolved phosphorus concentration in naturally restored plots, and also differed the loss amounts of total dissolved nitrogen and orthophosphate in artificially disturbed plots. Naturally restoration reduced loss amounts of total nitrogen and total phosphorus by 62.14–79.05% and 79.28–83.43% relative to artificial disturbance, respectively. Concentrations of nitrate-nitrogen, total phosphorus and dissolved phosphorus were closely correlated with rainfall and runoff variables, respectively, in artificially disturbed plots. Our results highlight the dominant role of natural restoration in reducing erosion and nutrient loss in sloping land.


2021 ◽  
Vol 10 (4) ◽  
pp. 209
Author(s):  
Chih-Ming Tseng ◽  
Yie-Ruey Chen ◽  
Chwen-Ming Chang ◽  
Yung-Sheng Chue ◽  
Shun-Chieh Hsieh

This study explores the impact of rainfall on the followed-up landslides after a severe typhoon and the relationship between various rainfall events and the occurrence, scale, and regional characteristics of the landslides, including second landslides. Moreover, the influence of land disturbance was evaluated. The genetic adaptive neural network was used in combination with the texture analysis of the geographic information system for satellite image classification and interpretation to analyze land-use change and retrieve disaster records and surface information after five rainfall events from Typhoon Morakot (2009) to Typhoon Nanmadol (2011). The results revealed that except for extreme Morakot rains, the greater the degree of slope disturbance after rain, the larger the exposed slope. Extreme rainfall similar to Morakot strikes may have a greater impact on the bare land area than on slope disturbance. Moreover, the relationship between the bare land area and the index of land disturbance condition (ILDC) is positive, and the ratio of the bare land area to the quantity of bare land after each rainfall increases with the ILDC. With higher effective accumulative rainfall on the slope in the study area or greater slope disturbance, the landslide area at the second landslide point tended to increase.


1997 ◽  
Vol 77 (4) ◽  
pp. 669-676 ◽  
Author(s):  
S. C. Nolan ◽  
L. J. P. van Vliet ◽  
T. W. Goddard ◽  
T. K. Flesch

Interpreting soil loss from rainfall simulators is complicated by the uncertain relationship between simulated and natural rainstorms. Our objective was to develop and test a method for estimating soil loss from natural rainfall using a portable rainfall simulator (1 m2 plot size). Soil loss from 12 rainstorms was measured on 144-m2 plots with barley residue in conventional tillage (CT), reduced tillage (RT) and zero tillage (ZT) conditions. A corresponding "simulated" soil loss was calculated by matching the simulator erosivity to each storm's erosivity. High (140 mm h−1) and low (60 mm h−1) simulation intensities were examined. The best agreement between simulated and natural soil loss occurred using the low intensity, after making three adjustments. The first was to compensate for the 38% lower kinetic energy of the simulator compared with natural rain. The second was for the smaller slope length of the simulator plot. The third was to begin calculating simulator erosivity only after runoff began. After these adjustments, the simulated soil loss over all storms was 99% of the natural soil loss for CT, 112% for RT and 95% for ZT. Our results show that rainfall simulators can successfully estimate soil loss from natural rainfall events. Key words: Natural rainfall events, simulated rainfall, erosivity, tillage


2012 ◽  
Vol 57 (8) ◽  
pp. 1610-1625 ◽  
Author(s):  
Víctor Hugo Durán Zuazo ◽  
José Ramón Francia Martínez ◽  
Iván García Tejero ◽  
Carmen Rocío Rodríguez Pleguezuelo ◽  
Armando Martínez Raya ◽  
...  

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