scholarly journals Coupling the modified SCS-CN and RUSLE models to simulate hydrological effects of restoring vegetation in the Loess Plateau of China

2012 ◽  
Vol 9 (3) ◽  
pp. 4193-4233 ◽  
Author(s):  
G. Y. Gao ◽  
B. J. Fu ◽  
Y. H. Lü ◽  
Y. Liu ◽  
S. Wang ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Soil Loss ◽  
Curve Number ◽  
Rainfall Runoff ◽  
The Loess Plateau ◽  
Rusle Model ◽  
Initial Abstraction ◽  
Runoff And Soil Loss ◽  
Scs Cn ◽  
Runoff Production

Abstract. Predicting event runoff and soil loss under different land covers is essential to quantitatively evaluate the hydrological responses of vegetation restoration in the Loess Plateau of China. The Soil Conservation Service Curve Number (SCS-CN) and Revised Universal Soil Loss Equation (RUSLE) models are widely used in this region to this end. This study incorporated antecedent moisture condition (AMC) in runoff production and initial abstraction of the SCS-CN model, and considered the direct effect of runoff on event soil loss by adopting a rainfall-runoff erosivity factor in the RUSLE model. The modified SCS-CN and RUSLE models were coupled to link rainfall-runoff-erosion modeling. The effects of AMC, slope gradient and initial abstraction ratio on curve number of SCS-CN, as well as those of vegetation cover on cover-management factor of RUSLE were also considered. Three runoff plot groups covered by sparse young trees, native shrubs and dense tussock, respectively, were established in the Yangjuangou catchment of Loess Plateau. Rainfall, runoff and soil loss were monitored during the rainy season in 2008–2011 to test the applicability of the proposed approach. The original SCS-CN model significantly underestimated the event runoff, especially for the rainfall events that have large 5-day antecedent precipitation, whereas the modified SCS-CN model could predict event runoff well with Nash-Sutcliffe model efficiency (EF) over 0.85. The original RUSLE model overestimated low values of measured soil loss and under-predicted the high values with EF only about 0.30. In contrast to it, the prediction accuracy of the modified RUSLE model improved satisfactorily with EF over 0.70. Our results indicated that the AMC should be explicitly incorporated in runoff production, and direct consideration of runoff should be included in predicting event soil loss. Coupling the modified SCS-CN and RUSLE models appeared to be appropriate for runoff and soil loss simulation at plot scale in the Loess Plateau. The limitations and future study scopes of the proposed models were also indicated.

scholarly journals Coupling the modified SCS-CN and RUSLE models to simulate hydrological effects of restoring vegetation in the Loess Plateau of China

2012 ◽  
Vol 16 (7) ◽  
pp. 2347-2364 ◽  
Author(s):  
G. Y. Gao ◽  
B. J. Fu ◽  
Y. H. Lü ◽  
Y. Liu ◽  
S. Wang ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Soil Loss ◽  
Curve Number ◽  
Rainfall Runoff ◽  
The Loess Plateau ◽  
Rusle Model ◽  
Runoff And Soil Loss ◽  
Hydrological Effects ◽  
Scs Cn ◽  
Runoff Production

Abstract. Predicting event runoff and soil loss under different land covers is essential to quantitatively evaluate the hydrological responses of vegetation restoration in the Loess Plateau of China. The Soil Conservation Service curve number (SCS-CN) and Revised Universal Soil Loss Equation (RUSLE) models are widely used in this region to this end. This study incorporated antecedent moisture condition (AMC) in runoff production and initial abstraction of the SCS-CN model, and considered the direct effect of runoff on event soil loss by adopting a rainfall-runoff erosivity factor in the RUSLE model. The modified SCS-CN and RUSLE models were coupled to link rainfall-runoff-erosion modeling. The effects of AMC, slope gradient and initial abstraction ratio on curve number of SCS-CN, as well as those of vegetation cover on cover-management factor of RUSLE, were also considered. Three runoff plot groups covered by sparse young trees, native shrubs and dense tussock, respectively, were established in the Yangjuangou catchment of Loess Plateau. Rainfall, runoff and soil loss were monitored during the rainy season in 2008–2011 to test the applicability of the proposed approach. The original SCS-CN model significantly underestimated the event runoff, especially for the rainfall events that have large 5-day antecedent precipitation, whereas the modified SCS-CN model was accurate in predicting event runoff with Nash-Sutcliffe model efficiency (EF) over 0.85. The original RUSLE model overestimated low values of measured soil loss and underpredicted the high values with EF values only about 0.30. In contrast, the prediction accuracy of the modified RUSLE model improved with EF values being over 0.70. Our results indicated that the AMC should be explicitly incorporated in runoff production, and direct consideration of runoff should be included when predicting event soil loss. Coupling the modified SCS-CN and RUSLE models appeared to be appropriate for evaluating hydrological effects of restoring vegetation in the Loess Plateau. The main advantages, limitations and future study scopes of the proposed models were also discussed.

scholarly journals Improved SMA-based SCS-CN method incorporating storm duration for runoff prediction on the Loess Plateau, China

2020 ◽  
Vol 51 (3) ◽  
pp. 443-455
Author(s):  
Wenhai Shi ◽  
Ni Wang
Keyword(s):  
Loess Plateau ◽  
Curve Number ◽  
The Loess Plateau ◽  
Moisture Condition ◽  
Soil Moisture Accounting ◽  
Antecedent Moisture ◽  
Storm Duration ◽  
Service Curve ◽  
Scs Cn ◽  
Runoff Events

Abstract In the Soil Conservation Service Curve Number (SCS-CN) method for estimating runoff, three antecedent moisture condition (AMC) levels produce a discrete relation between the curve number (CN) and soil water content, which results in corresponding sudden jumps in estimated runoff. An improved soil moisture accounting (SMA)-based SCS-CN method that incorporates a continuous function for the AMC was developed to obviate sudden jumps in estimated runoff. However, this method ignores the effect of storm duration on surface runoff, yet this is an important component of rainfall-runoff processes. In this study, the SMA-based method for runoff estimation was modified by incorporating storm duration and a revised SMA procedure. Then, the performance of the proposed method was compared to both the original SCS-CN and SMA-based methods by applying them in three experimental watersheds located on the Loess Plateau, China. The results indicate that the SCS-CN method underestimates large runoff events and overestimates small runoff events, yielding an efficiency of 0.626 in calibration and 0.051 in validation; the SMA-based method has improved runoff estimation in both calibration (efficiency = 0.702) and validation (efficiency = 0.481). However, the proposed method performed significantly better than both, yielding model efficiencies of 0.810 and 0.779 in calibration and validation, respectively.

scholarly journals Modelling the Event-Based Hydrological Response of Mediterranean Forests to Prescribed Fire and Soil Mulching with Fern Using the Curve Number, Horton and USLE-Family (Universal Soil Loss Equation) Models

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1166
Author(s):  
Bruno Gianmarco Carra ◽  
Giuseppe Bombino ◽  
Manuel Esteban Lucas-Borja ◽  
Pietro Denisi ◽  
Pedro Antonio Plaza-Álvarez ◽  
...  
Keyword(s):  
Prescribed Fire ◽  
Soil Loss ◽  
Overland Flow ◽  
Curve Number ◽  
Soil Conditions ◽  
Mediterranean Forests ◽  
Hydrological Response ◽  
Infiltration Excess ◽  
Runoff And Soil Loss ◽  
Scs Cn

The SCS-CN, Horton, and USLE-family models are widely used to predict and control runoff and erosion in forest ecosystems. However, in the literature there is no evidence of their use in Mediterranean forests subjected to prescribed fire and soil mulching. To fill this gap, this study evaluates the prediction capability for runoff and soil loss of the SCS-CN, Horton, MUSLE, and USLE-M models in three forests (pine, chestnut, and oak) in Southern Italy. The investigation was carried out at plot and event scales throughout one year, after a prescribed fire and post-fire soil mulching with fern. The SCS-CN and USLE-M models were accurate in predicting runoff volume and soil loss, respectively. In contrast, poor predictions of the modelled hydrological variables were provided by the models in unburned plots, and by the Horton and MUSLE models for all soil conditions. This inaccuracy may have been due to the fact that the runoff and erosion generation mechanisms were saturation-excess and rainsplash, while the Horton and MUSLE models better simulate infiltration-excess and overland flow processes, respectively. For the SCS-CN and USLE-M models, calibration was needed to obtain accurate predictions of surface runoff and soil loss; furthermore, different CNs and C factors must be input throughout the year to simulate the variability of the hydrological response of soil after fire. After calibration, two sets of CNs and C-factor values were suggested for applications of the SCS-CN and USLE-M models, after prescribed fire and fern mulching in Mediterranean forests. Once validated in a wider range of environmental contexts, these models may support land managers in controlling the hydrology of Mediterranean forests that are prone to wildfire risks.

Combined effects of rainfall regime and plot length on runoff and soil loss in the Loess Plateau of China

2018 ◽  
Vol 109 (3-4) ◽  
pp. 397-406
Author(s):  
Jianbo LIU ◽  
Guangyao GAO ◽  
Shuai WANG ◽  
Bojie FU
Keyword(s):  
Loess Plateau ◽  
Soil Loss ◽  
Rainfall Regime ◽  
Runoff Coefficient ◽  
Land Uses ◽  
The Loess Plateau ◽  
Slope Length ◽  
Erosive Rainfall ◽  
Runoff And Soil Loss ◽  
Rainfall Regimes

ABSTRACTThe purpose of this paper was to study the interaction effects of rainfall regime and slope length on runoff and soil loss under different land uses. Event runoff and soil loss in forest, shrub and grass were measured in plots with lengths of 5, 9 and 13m in the Loess Plateau from 2008 to 2016. A total of 59 erosive rainfall events were recorded and classified into three rainfall regimes. Firstly, the results showed that the runoff coefficient was grass>shrub>forest, and soil loss was grass>forest>shrub, but the differences between forest and shrub in runoff and between grass and forest in soil loss did not reach significant levels. Secondly, rainfall regimes had an important effect on runoff and soil loss under different land uses. The lowest runoff coefficients and the highest soil loss in regime 2 were found in shrub and forest land, respectively, which differed from that of regime 1. In total, rainfall regime 1 had the highest runoff coefficient of 0.84–2.06%, followed by regime 3 with 0.33–0.88% and regime 2 with 0.04–0.06%. Soil loss in forest and grass land had a different order of regime 3>regime 1>regime 2. Thirdly, both the runoff coefficient and soil loss decreased with increasing plot length, while the effect of slope length on runoff/soil loss were influenced by land use type and rainfall regimes.

Initial Abstraction Ratio in the SCS-CN Method in the Loess Plateau of China

2011 ◽  
Vol 54 (1) ◽  
pp. 163-169 ◽  
Author(s):  
S. Fu ◽  
G. Zhang ◽  
N. Wang ◽  
L. Luo
Keyword(s):  
Loess Plateau ◽  
The Loess Plateau ◽  
Initial Abstraction ◽  
Scs Cn

scholarly journals The Effects of Rainfall Intensities and Duration on SCS-CN Model Parameters under Simulated Rainfall

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1595
Author(s):  
Xiaoxian Wang ◽  
Huaxing Bi
Keyword(s):  
Rainfall Intensity ◽  
Model Fitting ◽  
Curve Number ◽  
Model Parameters ◽  
Event Analysis ◽  
Simulated Rainfall ◽  
Rainfall Runoff ◽  
Analysis Method ◽  
Initial Abstraction ◽  
Scs Cn

The Soil Conservation Service curve number (SCS-CN) method has been widely used in rainfall-runoff modelling; however, the direct effects of rainfall intensities and duration, which are major factors in hydrological engineering design, on its parameters (initial abstraction ratio (λ) and potential maximum storage (S), the latter is transformed into curve number (CN)) have seldom been studied. In this study, we chose simulated rainfall experiments on runoff plots (30 mm/h, 180 min; 60 mm/h, 90 min; 90 mm/h, 60 min) to obtain synchronized rainfall-runoff data and calculated the parameters using general model fitting and event analysis methods every ten minutes throughout the duration. The results indicate that the parameters changed with rainfall intensities and duration. S decreased as the rainfall intensities increased. Under the same rainfall intensity, the S increased with the duration overall. The corresponding λ changed with rainfall intensities and duration, and has no obvious relationship under different rainfall intensities. Initial abstraction in the event analysis method is the same as the actual situation and we chose these parameters obtained with the event analysis method as our selected parameters. These selected parameters and the parameters obtained using Fu et al.’s method which was based on the standardized procedure in NEH-630 were evaluated by the Nash–Sutcliffe efficiency (NSE), the percentage deviation coefficient (PBIAS), and the ratio of the root mean square error to the standard deviation of measured data (RSR). The results show that the statistics for the selected parameters satisfied the evaluating standard, and have a better value, while the statistics for the parameters obtained by Fu et al.’s method declined as the rainfall intensity increased, and PBAIS was out of the standard range under 90 mm/h rainfall intensity condition. This indicates that the rainfall intensities and duration have important effects on the parameters of the model, and the parameters vary dynamically with the rainfall intensity and duration. These results could be useful for hydrological design in which engineers consider the return period (i.e., rainfall intensities and duration).

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