On the Ia–S relation of the SCS-CN method

2006 ◽  
Vol 37 (3) ◽  
pp. 261-275 ◽  
Author(s):  
M.K. Jain ◽  
S.K. Mishra ◽  
P. Suresh Babu ◽  
K. Venugopal
Keyword(s):  
Curve Number ◽  
United States Department ◽  
Large Set ◽  
Department Of Agriculture ◽  
Validation Data ◽  
Proposed Model ◽  
Storm Rainfall ◽  
Service Curve ◽  
Scs Cn ◽  
Better Than

The initial abstraction (Ia) versus maximum potential retention (S) relation in the Soil Conservation Service Curve Number (SCS-CN) methodology was revisited, and a new non-linear relation incorporating storm rainfall (P) and S was proposed and tested on a large set of storm rainfall-runoff events derived from the water database of United States Department of Agriculture-Agriculture Research Service (USDA-ARS). Employing root mean square error (RMSE), the performance of both the existing and proposed models was evaluated using the complete database, and for model calibration and validation, data were split into two groups: based on ordered rainfall (P-based) and runoff (Q-based). A specific formulation of the proposed model Ia=λS(P/(P+S))α with λ=0.3 and α=1.5 was found to generally perform better than the existing Ia=0.2S, and therefore was recommended for field applications. When evaluated using the observed Ia data, the proposed version performed significantly better than the existing one.

An updated hydrological review on recent advancements in soil conservation service-curve number technique

2010 ◽  
Vol 1 (2) ◽  
pp. 118-134 ◽  
Author(s):  
P. K. Singh ◽  
M. L. Gaur ◽  
S. K. Mishra ◽  
S. S. Rawat
Keyword(s):  
Soil Conservation ◽  
Curve Number ◽  
Estimation Methods ◽  
Soil Conservation Service ◽  
Hydrologic Models ◽  
Relative Significance ◽  
Storm Rainfall ◽  
Service Curve ◽  
Hydrology And Water Resources ◽  
Scs Cn

Although many hydrologic models are available for the estimation of direct runoff from storm rainfall, most models are limited because of their intensive input data and calibration requirements. The Soil Conservation Service-Curve Number (SCS-CN) technique has been applied successfully throughout the entire spectrum of hydrology and water resources, even though originally it was not intended to deal with and solve certain issues such as erosion and sedimentation and environmental engineering. This manuscript includes an updated review of this popular technique with its critical performance analysis under various hydrological applications. The study highlights its provenance and its conceptual and empirical foundations followed by relative significance of the parameter CN and various estimation methods and issues related to the Ia and S relationship. Finally, notable recent advancements available in the literature are discussed for their structural strengths and applicability in real world problems.

scholarly journals ANALISIS MEKANISME PEMBENTUKKAN LAHAR BERDASARKAN KAJIAN RETENSI AIR DI SUB DAS OPAK, DAERAH ISTIMEWA YOGYAKARTA

2017 ◽  
Author(s):  
Ahmad Cahyadi ◽  
Henky Nugraha ◽  
Anggit Priadmodjo
Keyword(s):  
Soil Conservation ◽  
Curve Number ◽  
Soil Conservation Service ◽  
Storm Rainfall ◽  
Service Curve ◽  
Scs Cn

Erupsi Gunungapi Merapi tahun 2010 menyebabkan banyak kerusakan infrastruktur. Kerusakan ditimbulkan oleh bencana primer gunungapi seperti awan panas dan hujan abu gunungapi, serta bencana sekunder yang berupa banjir lahar. Penelitian ini bertujuan menganalisis proses/mekanisme pembentukkan lahar berdasarkan pada kajian retensi air permukaan oleh material permukaan pada kejadian hujan sesaat (storm rainfall). Metode yang digunakan adalah perhitungan retensi air dengan metode SCS-CN (Soil Conservation Service-Curve Number). Perhitungan nilai CN (Curve Number) didasarkan pada data citra multitemporal yang dikombinasikan dengan survei lapangan dan wawancara mendalam dengan penduduk di sekitar wilayah terdampak yang kemudian dianalisis dengan menggunakan sistem informasi geografis (SIG). Hasil analisis menunjukkan bahwa nilai retensi justru meningkat setelah terjadi erupsi, namun demikian berdasarkan hasil wawancara debit di Sungai Opak setelah terjadi hujan menjadi semakin besar karena adanya banjir lahar. Banjir lahar ini merupakan kejadian yang pertama kali terjadi sejak sekitar 80 tahun terakhir. Berdasarkan analisis yang dilakukan, diketahui bahwa kemampuan material hasil erupsi (baru) untuk meresapakan air cukup tinggi, namun pada bagian bawahnya terdapat lapisan lama dengan porositas yang lebih rendah. Hal ini menyebabkan lapisan atas permukaan tanah di lokasi kajian mengalami kejenuhan dan memicu gerakan akibat gravitasi yang kemudian membentuk aliran banjir lahar.

scholarly journals Variability of the Initial Abstraction Ratio in an Urban and an Agroforested Catchment

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 415 ◽  
Author(s):  
Adam Krajewski ◽  
Anna E. Sikorska-Senoner ◽  
Agnieszka Hejduk ◽  
Leszek Hejduk
Keyword(s):  
Land Use ◽  
Curve Number ◽  
Threshold Value ◽  
Storm Events ◽  
Direct Runoff ◽  
Initial Abstraction ◽  
Land Use Types ◽  
Rainfall Depth ◽  
Storm Rainfall ◽  
Service Curve

The Curve Number method is one of the most commonly applied methods to describe the relationship between the direct runoff and storm rainfall depth. Due to its popularity and simplicity, it has been studied extensively. Less attention has been given to the dimensionless initial abstraction ratio, which is crucial for an accurate direct runoff estimation with the Curve Number. This ratio is most often assumed to be equal to 0.20, which was originally proposed by the method’s developers. In this work, storm events recorded in the years 2009–2017 in two small Polish catchments of different land use types (urban and agroforested) were analyzed for variability in the initial abstraction ratio across events, seasons, and land use type. Our results showed that: (i) estimated initial abstraction ratios varied between storm events and seasons, and were most often lower than the original value of 0.20; (ii) for large events, the initial abstraction ratio in the catchment approaches a constant value after the rainfall depth exceeds a certain threshold value. Thus, when using the Soil Conservation Service-Curve Number (SCS-CN) method, the initial abstraction ratio should be locally verified, and the conditions for the application of the suggested value of 0.20 should be established.

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 Pemodelan Tutupan Lahan Untuk Menjamin Keberlanjutan Debit Sungai (Suatu Studi Di Sub DAS Cikapundung-Maribaya)

2021 ◽  
Vol 6 (2) ◽  
pp. 121-139
Author(s):  
Aditya Dwifebri Christian Wibowo ◽  
Mahawan Karuniasa ◽  
Dwita Sutjiningsih
Keyword(s):  
Land Use ◽  
River Water ◽  
Water Scarcity ◽  
Soil Conservation ◽  
Curve Number ◽  
Soil Conservation Service ◽  
Land Conversion ◽  
Forest Land ◽  
Service Curve ◽  
Scs Cn

Changes in land use in the Cikapundung watershed, ie changes in forest land to built-up land, have an impact on the quantity of river water. Changes in land use in the Cikapundung River catchment are not ideal conditions for absorbing water. If land conversion is not controlled, it can have a large impact on reducing the availability of water resources for subordinate areas or what is called water scarcity. Analysis that takes into account land use and discharge can be done with several hydrological analysis methods, one of them is the Soil Conservation Service Curve Number (SCS-CN) method. Based on the calculation, the CN value was changed in 2014 from 57.275 to 62.591 where land cover changes began to occur.   Keywords: land use, river water, water scarcity, hydrology, CN value

scholarly journals CN Modeling for Predicting Discharge in Lesti Sub-watershed

2019 ◽  
Vol 8 (12) ◽  
pp. 4890-4896
Keyword(s):  
United States ◽  
Land Use ◽  
Curve Number ◽  
The United States ◽  
United States Department ◽  
Department Of Agriculture ◽  
Mathematical Formula ◽  
States Department ◽  
Soil Group ◽  
Rainfall Depth

This research intends to accurately mapping the Curve Number (CN) that is as the function of cover type, land use treatment, hydrology condition, and hydrologic soil group in the Lesti sub-watershed,. The methodology consists of to build the suitable CN modeling for predicting discharge in the Lesti sub-watershed and then to evaluate the result accurately. The value of CN is obtained from the mathematical formula with the input is rainfall depth and discharge. The result of CN modeling for the Lesti sub-watershed is accurate enough as is made by the United States Department of Agriculture (USDA) in USA. In addition, the CN mapping can be directly used by the engineers of the manager and designer on the water resources structures in Lesti sub-watershed

scholarly journals ASSESSING THE IMPACT OF URBANIZATION ON DIRECT RUNOFF IN DISTRICT 8, HO CHI MINH CITY

2021 ◽  
Vol 11 (3) ◽  
pp. 145-156
Author(s):  
Van Minh NGUYEN ◽  
Elena Yurievna ZAYKOVA
Keyword(s):  
Remote Sensing ◽  
Surface Runoff ◽  
Soil Conservation ◽  
Curve Number ◽  
Ho Chi Minh City ◽  
Soil Conservation Service ◽  
Impact Of Urbanization ◽  
Service Curve ◽  
The Impact ◽  
Scs Cn

Ho Chi Minh City (HCMC) is among the cities that are most at risk of fl ooding worldwide. Urbanization processes have led to a change in land use, which in turn has resulted in an increase in impervious surfaces and runoff , thus again leading to the risk of fl ooding in the city. The aim of the article is to study the impact of urban development (on the example of District 8 of HCMC) on surface runoff using a combination of the interpretation of remote sensing images of the earth (ERS) Google Earth and the SCS-CN model (the Soil Conservation Service curve number). Theoretical models are used to analyze the relationship between the typology of buildings and areas of open and impervious surfaces. The interpretation of remote sensing images was carried out in the ArcGIS program. The method used to calculate surface runoff is the Soil Conservation Service Curve Number (SCS-CN) method developed by the US Soil Conservation Service and is suitable for assessing the eff ects of land-use/land cover change due to urbanization. The results of the study show the volume of surface runoff in areas with diff erent levels of urbanization in district 8 of HCMC, assessing the impact of urbanization processes on surface runoff and revealing new opportunities for managing this process. The combination of remote sensing interpretation and SCS-CN model makes it possible to assess the impact of urban development on surface runoff . Urbanization and an increase in built-up area strongly aff ect fl ooding, reducing the soil retention.

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