A generalized relation between initial abstraction and potential maximum retention in SCS‐CN‐based model

2006 ◽  
Vol 4 (4) ◽  
pp. 245-253 ◽  
Author(s):  
S.K. Mishra ◽  
R.K. Sahu ◽  
T.I. Eldho ◽  
M.K. Jain
Keyword(s):  
Initial Abstraction ◽  
Potential Maximum ◽  
Scs Cn ◽  
Maximum Retention

scholarly journals A Modified Distributed CN-VSA Method for Mapping of the Seasonally Variable Source Areas

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1270
Author(s):  
Kishore Panjabi ◽  
Ramesh Rudra ◽  
Pradeep Goel ◽  
Syed Ahmed ◽  
Bahram Gharabaghi
Keyword(s):  
Source Area ◽  
Moisture Distribution ◽  
Runoff Generation ◽  
Topographic Wetness Index ◽  
Runoff Simulation ◽  
Variable Source ◽  
Study Results ◽  
Potential Maximum ◽  
Scs Cn ◽  
Maximum Retention

Many watershed models employ the Soil Conservation Service Curve Number (SCS-CN) approach for runoff simulation based on soil and land use information. These models implicitly assume that runoff is generated by the Hortonian process and; therefore, cannot correctly account for the effects of topography, variable source area (VSA) and/or soil moisture distribution in a watershed. This paper presents a new distributed CN-VSA method that is based on the SCS-CN approach to estimate runoff amount and uses the topographic wetness index (TWI) to distribute the runoff-generating areas within the watershed spatially. The size of the saturated-watershed areas and their spatial locations are simulated by assuming an average annual value of potential maximum retention. However, the literature indicates significant seasonal variation in potential maximum retention which can considerably effect water balance and amount of nonpoint source pollution. This paper focuses on developing a modified distributed CN-VSA method that accounts for the seasonal changes in the potential maximum retention. The results indicate that the modified distributed CN-VSA approach is better than distributed CN-VSA to simulate runoff amount and spatial distribution of runoff-generating areas. Overall, the study results are significant for improved understanding of hydrological response of watershed where seasonal factors describe the potential maximum retention, and, thus, saturation excess runoff generation in the watershed.

scholarly journals Application of Risk Analysis in the Screening of Flood Disaster Hot Spots and Adaptation Strategies

Land ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Er-Chiang Huang ◽  
Pei-Wen Li ◽  
Shao-Wei Wu ◽  
Chao-Yuan Lin
Keyword(s):  
Surface Runoff ◽  
Flood Control ◽  
Land Development ◽  
Storage Space ◽  
Human Beings ◽  
Environmental Complexity ◽  
The Difference ◽  
Potential Maximum ◽  
Scs Cn ◽  
Maximum Retention

In recent years, Taiwan has established a sound flood control foundation in terms of river management. Due to climate change and land development, surface runoff has increased. In addition, the functions of flood control engineering facilities have their limits. Surface runoff cannot be fully absorbed by rivers, and frequent floods still occur in some areas. According to the characteristics of water flowing along the terrain to low-lying land, the terrain features can be used to find out the hot areas prone to flooding and the appropriate location of flood storage space for improving flooding. On the basis of the natural terrain environment, the disaster risk framework is used to manage environmental complexity, and to carry out research on flood warning and governance decision-making systems, so that human beings can coexist with the uncertainty of flood risk. In this study, the Zhuoshuixi Basin was used as the sample area, the SCS-CN method was used to analyze the excess runoff, and the risk concept was used to establish a flood evaluation model. In addition, through the changes in land use, the SCS-CN method estimates the difference of potential maximum retention, quantifies the variation of excess rainfall in each watershed division, and uses the digital elevation model to calculate the depression site to analyze the relationship between the difference of potential maximum retention and the depression space of the watershed. The results show that the adaptation strategy for high-risk flooded areas should be strengthened, and areas with large water storage space and a small potential maximum retention difference can be the best location for offsite compensation.

scholarly journals Sensitivity analysis of a simplified precipitation-runoff model to estimate water availability in Southern Portuguese watersheds

2021 ◽  
Vol 10 (2) ◽  
pp. 33-47
Author(s):  
Tiago N. Martins ◽  
Manuel Mendes Oliveira ◽  
Maria M. Portela ◽  
Teresa Eira Leitão
Keyword(s):  
Sensitivity Analysis ◽  
Water Availability ◽  
Surface Flow ◽  
Model Parameters ◽  
Southern Portugal ◽  
Measured Flow ◽  
Management Policies ◽  
Runoff Model ◽  
Potential Maximum ◽  
Maximum Retention

The water availability estimation in large regions is a relevant procedure to define broad water resources management policies but may prove difficult due to the lack of data and uncertainty to related regional hydrological and hydrogeological characterization. BALSEQ, a daily sequential water budget model, was applied in a set of twenty-two watersheds in southern Portugal, aiming to understand the possible relations between the model parameters and watershed characteristics that may allow assembling calibration functions for non-monitored watersheds. A sensitivity analysis was conducted by comparing BALSEQ results with measured surface flow, focusing specifically on the fraction of the potential maximum retention (φ) and the maximum amount of water available in the soil for evapotranspiration (AGUT) parameters and the underlying hydrogeological conceptual model that ultimately controls the surface-groundwater interactions. The overall results did not allow to identify clear relations that permit extrapolation to other regions without data as the sensitivity analysis procedures returned similar results for wide intervals of parameters for the majority of watersheds. The results confirmed that the groundwater discharge is an important component for the total measured surface flow and that the φ parameter should not be overlooked when calculating direct runoff. Poor adjustments between the model results and measured flow were observed in watersheds with a low Surface flow – Rainfall ratio.

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 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 Application of the SCS–CN Method to the Hancheon Basin on the Volcanic Jeju Island, Korea

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3350
Author(s):  
Minseok Kang ◽  
Chulsang Yoo
Keyword(s):  
Negative Correlation ◽  
The Other ◽  
Jeju Island ◽  
Antecedent Soil Moisture ◽  
Moisture Condition ◽  
Soil Moisture Condition ◽  
Rainfall Events ◽  
Initial Abstraction ◽  
Other Hand ◽  
Scs Cn

This study investigates three issues regarding the application of the SCS–CN (Soil Conservation Service–Curve Number) method to a basin on the volcanic Jeju Island, Korea. The first issue is the possible relation between the initial abstraction and the maximum potential retention. The second is the determination of the maximum potential retention, which is also closely related to the estimation of CN. The third issue is the effect of the antecedent soil moisture condition (AMC) on the initial abstraction, maximum potential retention and CN. All of these issues are dealt with based on the analysis of several rainfall events observed in the Hancheon basin, a typical basin on Jeju Island. In summary, the results are that, firstly, estimates of initial abstraction, ratio λ, maximum potential retention, and CN were all found to be consistent with the SCS–CN model structure. That is, CN and the maximum potential retention showed a strong negative correlation, and the ratio λ and the maximum potential retention also showed a rather weak negative correlation. On the other hand, a significant positive correlation was found between CN and the ratio λ. Second, in the case where the accumulated number of days is four or five, the effect of antecedent precipitation amount is clear. The antecedent five-day rainfall amount for the AMC-III condition is higher than 400 mm, compared to the AMC-I condition of less than 100 mm. Third, an inverse proportional relationship is found between the AMC and the maximum potential retention. On the other hand, a clear linear proportional relation is found between the AMC and CN. Finally, the maximum potential retention for the Hancheon basin is around 200 mm, with the corresponding CN being around 65. The ratio between the initial abstraction and the maximum potential retention is around 0.3. Even though these results are derived by analyzing a limited number of rainfall events, they are believed to properly consider the soil characteristics of Jeju Island.

Determination of SCS-CN initial abstraction ratio in a catchment prone to flash floods

2020 ◽  
Vol 15 (1) ◽  
pp. 112-123 ◽  
Author(s):  
Martin Caletka ◽  
Monika Šulc Michalková
Keyword(s):  
Surface Runoff ◽  
Soil Conservation ◽  
Curve Number ◽  
Flash Floods ◽  
Soil Conservation Service ◽  
Initial Abstraction ◽  
Service Curve ◽  
Scs Cn ◽  
Proper Setting

Abstract The soil conservation service - curve number method is a globally used approach to simulations of surface runoff for its simplicity and applicability. Nevertheless, relevant simulations require proper setting of the model's components. This work focuses on optimization of initial abstraction ratio λ in the Husí potok sub-catchments in Czech Republic. Due to favorable morphology, the watershed is prone to flash floods and accurate modeling of surface runoff is of high interest. The analysis was conducted using pairs of discharge and rainfall measurements. The results outline that the traditional value λ= 0.2 is too high in this watershed and should be reduced.

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