scholarly journals SCS-CN parameter determination using rainfall-runoff data in heterogeneous watersheds – the two-CN system approach

2012 ◽  
Vol 16 (3) ◽  
pp. 1001-1015 ◽  
Author(s):  
K. X. Soulis ◽  
J. D. Valiantzas
Keyword(s):  
Land Cover ◽  
Spatial Variability ◽  
System Approach ◽  
Parameter Determination ◽  
Rainfall Runoff ◽  
Simple Method ◽  
Rainfall Depth ◽  
Natural Watersheds ◽  
Scs Cn

Abstract. The Soil Conservation Service Curve Number (SCS-CN) approach is widely used as a simple method for predicting direct runoff volume for a given rainfall event. The CN parameter values corresponding to various soil, land cover, and land management conditions can be selected from tables, but it is preferable to estimate the CN value from measured rainfall-runoff data if available. However, previous researchers indicated that the CN values calculated from measured rainfall-runoff data vary systematically with the rainfall depth. Hence, they suggested the determination of a single asymptotic CN value observed for very high rainfall depths to characterize the watersheds' runoff response. In this paper, the hypothesis that the observed correlation between the calculated CN value and the rainfall depth in a watershed reflects the effect of soils and land cover spatial variability on its hydrologic response is being tested. Based on this hypothesis, the simplified concept of a two-CN heterogeneous system is introduced to model the observed CN-rainfall variation by reducing the CN spatial variability into two classes. The behaviour of the CN-rainfall function produced by the simplified two-CN system is approached theoretically, it is analysed systematically, and it is found to be similar to the variation observed in natural watersheds. Synthetic data tests, natural watersheds examples, and detailed study of two natural experimental watersheds with known spatial heterogeneity characteristics were used to evaluate the method. The results indicate that the determination of CN values from rainfall runoff data using the proposed two-CN system approach provides reasonable accuracy and it over performs the previous methods based on the determination of a single asymptotic CN value. Although the suggested method increases the number of unknown parameters to three (instead of one), a clear physical reasoning for them is presented.

scholarly journals SCS-CN parameter determination using rainfall-runoff data in heterogeneous watersheds. The two-CN system approach

2011 ◽  
Vol 8 (5) ◽  
pp. 8963-9004 ◽  
Author(s):  
K. X. Soulis ◽  
J. D. Valiantzas
Keyword(s):  
Spatial Variability ◽  
System Approach ◽  
Parameter Determination ◽  
Rainfall Runoff ◽  
Unknown Parameters ◽  
Simple Method ◽  
Rainfall Depth ◽  
Natural Watersheds ◽  
Scs Cn

Abstract. The Soil Conservation Service Curve Number (SCS-CN) approach is widely used as a simple method for predicting direct runoff volume for a given rainfall event. The CN values can be estimated by being selected from tables. However, it is more accurate to estimate the CN value from measured rainfall-runoff data (assumed available) in a watershed. Previous researchers indicated that the CN values calculated from measured rainfall-runoff data vary systematically with the rainfall depth. They suggested the determination of a single asymptotic CN value observed for very high rainfall depths to characterize the watersheds' runoff response. In this paper, the novel hypothesis that the observed correlation between the calculated CN value and the rainfall depth in a watershed reflects the effect of the inevitable presence of soil-cover complex spatial variability along watersheds is being tested. Based on this hypothesis, the simplified concept of a two-CN heterogeneous system is introduced to model the observed CN-rainfall variation by reducing the CN spatial variability into two classes. The behavior of the CN-rainfall function produced by the proposed two-CN system concept is approached theoretically, it is analyzed systematically, and it is found to be similar to the variation observed in natural watersheds. Synthetic data tests, natural watersheds examples, and detailed study of two natural experimental watersheds with known spatial heterogeneity characteristics were used to evaluate the method. The results indicate that the determination of CN values from rainfall runoff data using the proposed two-CN system approach provides reasonable accuracy and it over performs the previous original method based on the determination of a single asymptotic CN value. Although the suggested method increases the number of unknown parameters to three (instead of one), a clear physical reasoning for them is presented.

scholarly journals Determination of Curve Number for snowmelt-runoff floods in a small catchment

2015 ◽  
Vol 370 ◽  
pp. 167-170 ◽  
Author(s):  
L. Hejduk ◽  
A. Hejduk ◽  
K. Banasik
Keyword(s):  
Soil Conservation ◽  
Curve Number ◽  
Rainfall Runoff ◽  
Snowmelt Runoff ◽  
Ungauged Catchments ◽  
Department Of Agriculture ◽  
Small Catchment ◽  
Rainfall Depth ◽  
Runoff Events

Abstract. One of the widely used methods for predicting flood runoff depth from ungauged catchments is the curve number (CN) method, developed by Soil Conservation Service (SCS) of US Department of Agriculture. The CN parameter can be computed directly from recorded rainfall depths and direct runoff volumes in case of existing data. In presented investigations, the CN parameter has been computed for snowmelt-runoff events based on snowmelt and rainfall measurements. All required data has been gathered for a small agricultural catchment (A = 23.4 km2) of Zagożdżonka river, located in Central Poland. The CN number received from 28 snowmelt-runoff events has been compared with CN computed from rainfall-runoff events for the same catchment. The CN parameter, estimated empirically varies from 64.0 to 94.8. The relation between CN and snowmelt depth was investigated in a similar procedure to relation between CN and rainfall depth.

scholarly journals Technical Note: Determination of the SCS initial abstraction ratio in an experimental watershed in Greece

2007 ◽  
Vol 11 (6) ◽  
pp. 1825-1829 ◽  
Author(s):  
E. A. Baltas ◽  
N. A. Dervos ◽  
M. A. Mimikou
Keyword(s):  
Spatial Distribution ◽  
Technical Note ◽  
Rainfall Runoff ◽  
Average Ratio ◽  
Initial Abstraction ◽  
The Difference ◽  
Geological Formations ◽  
Scs Cn ◽  
Runoff Events

Abstract. The present study was conducted in an experimental watershed in Attica, Greece, using observed rainfall/runoff events. The objective of the study was the determination of the initial abstraction ratio of the watershed. The average ratio (Ia/S) of the entire watershed was equal to 0.014. The corresponding ratio at a subwatershed was 0.037. The difference was attributed to the different spatial distribution of landuses and geological formations at the extent of the watershed. Both of the determined ratios are close to the ratio value of 0.05 that has been suggested from many studies for the improvement of the SCS-CN method.

Simple method for optical parameter determination of inhomogeneous thin films

1993 ◽  
Vol 232 (1) ◽  
pp. 18-20 ◽  
Author(s):  
K. Bah ◽  
A. Czapla ◽  
T. Pisarkiewicz
Keyword(s):  
Thin Films ◽  
Optical Parameter ◽  
Parameter Determination ◽  
Simple Method

Development of a simple method for the determination of single nucleotide polymorphisms

2010 ◽  
Vol 34 (8) ◽  
pp. S75-S75
Author(s):  
Weifeng Zhu ◽  
Zhuoqi Liu ◽  
Daya Luo ◽  
Xinyao Wu ◽  
Fusheng Wan
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Simple Method ◽  
Single Nucleotide

Determination of the Prospective Processed Cacao Product and Calculation of the Added Value in Agro-Tourism Based on Cacao Agroindustry in Pidie Jaya Regency

2018 ◽  
Vol 22 (1) ◽  
pp. 33-42
Author(s):  
◽  
Tajuddin Bantacut ◽  
Sapta Raharja
Keyword(s):  
System Approach ◽  
Added Value ◽  
Assessment Criteria ◽  
Cocoa Bean ◽  
Cocoa Beans ◽  
Bayes Method ◽  
Cocoa Products ◽  
Processed Products ◽  
Derivative Products

Abstract Utilization of cocoa bean to be a derivative products in industrial is wide enough, that it is necessary to determine the priority of the processed products development. This study aimed to determine the prospective processed cocoa products with a system approach using Bayes method and assessed the potential of added value by using Hayami method. Based on several assessment criteria indicated that chocolate bar is the priority product that needs to be developed and followed by several other processed products. This development was able to produce the added value of Rp 135.000 per kg of cocoa beans. Result indicated that by processing the cocoa beans into chocolate bar could provide a considerable income for the businessman.

A Standard Primary Toxicity Bioassay Using Daphnia Magna as a Test Species

1977 ◽  
Vol 12 (1) ◽  
pp. 27-50 ◽  
Author(s):  
L.A. Behie ◽  
J.E. Zajic ◽  
D. Berk ◽  
R.J.P. Brouzes ◽  
V.A. Naish
Keyword(s):  
Statistical Analysis ◽  
Daphnia Magna ◽  
Biological Indicator ◽  
Pulp And Paper ◽  
Toxicity Bioassay ◽  
Simple Method ◽  
Test Species ◽  
Test Organisms ◽  
Dilution Water

Abstract Although Daphnia magna have been widely used in the determination of the toxicity of various substances, there are no reports in the literature that describe a rigorous bioassay method using this organism as a test species. The test described herein involves the standariza-tion of various important aspects of the method such as the age of the test organisms, and the dilution water used for the preparation of the various toxicant concentrations. Also described is a simple method for the statistical analysis of the results. The sensitivity of the proposed bioassay is demonstrated by determining the toxicity of various pulp and paper effluents. Finally, extensive bioassays were carried out simultaneously with rainbow trout and Daphnia magna indicating that Daphnia are as good a biological indicator of acute toxicity as fish.

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