The runoff simulation by SCS-CN model in a catchment area (original) (raw)
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Proceedings 2021, 2021
The NRCS-CN method for calculating the maximum runoff is widely used in hydrological practice due to its easy adaptation and application. The method is based on the perception that catchment conditions (soil cover, land use and climatic conditions) can be expressed by the number of a territorial unit called the CN curve. The main factors that determine the numbers of the CN curves are the hydrological soil group, land use, the method of soil cultivation, the hydrological conditions and the previous soil conditions. In connection with this the purpose of this publication is: to calculate the maximum runoff during the flood occurred in the period 31.07.-02.08.2014 on the Scut River near the town of Mizia by the NRCS-CN method. For this purpose, a Geographic Information System (GIS) has been created, which includes the following layers: soil types and subtypes (soil map in M: 1: 200000), land use (map of restored property, 2013), average rainfall for the period 31.07.2014-2.08.2014 (information from NIMH and EA "Fight against hail"), slopes (digital terrain model, 2011). The main results of the conducted research are the calculated volume and maximum runoff of the formed high wave, which flooded the town of Mizia.
Application of SCS-CN Model in Runoff Estimation
Proceedings of the 2015 International Symposium on Material, Energy and Environment Engineering, 2015
Runoff calculation is an important part of regional runoff forecast and water resources evaluation model. The Soil Conservation Service (SCS) curve number (CN) model developed by the U.S. Department of Agriculture National Resources Conversion Service (NRCS) is the most popular and widely applied model for direct runoff estimation. This article will introduce the basic principles of SCS model, review and summary the application, development and improvement of the model, points out the shortcomings of the existing model. Finally, prospects for the future development of this model are conducted.
Estimation of Runoff by using SCS Curve Number Method Integrated with GIS
IARJSET, 2017
Rainfall, runoffs are the most important hydrological variables used in the most of the water resources applications. The information pertaining to occurrence of runoff further helps in water management practices. Runoff is normally generated on limited areas i.e. impervious or less impervious areas, saturated areas etc. Whereas neighboring vegetated areas do not generate any direct runoff. This needs to be taken into account of rainfall-runoff modeling and thus in the delineation of the areas. The input parameters which influence runoff component vary spatially at micro levels. A runoff model has been developed on the basis of SCS-CN method in the present study for predicting runoff.
Soil Conservation Service (SCS) model has been applied in the present study for the estimation of runoff from an agricultural watershed. The Karso watershed is about 2793 ha, is a part of Damodar Barakar catchment, which is situated in Hazaribagh district of Jharkhand State. This method involves various types of information related to Hydrologic soil Group, vegetation and antecedent moisture condition of the watershed. The soil map, land use map have been prepared by the information available at Soil Conservation Department, Damaodar Valley Corporation, Hazaribagh and topographical maps were collected from Survey of India, Calcutta. ERDAS IMAGINE-8.4 software was used for the rectification of reference map, soil map and land use map of the watershed. The vector layers were generated in ARC/INFO and used as input to derive modified Soil Conservation Service (SCS) Curve Number for study area. The SCS model was then applied to estimate the runoff for daily storm and was validated comparing it with the measured runoff of few selected events of monsoon period for the year 1993.
AQUA — Water Infrastructure, Ecosystems and Society
This present study investigates different techniques for estimating the surface runoff using the Soil Conservation Service Curve Number (SCS-CN) method for the Aghanashini River in Karnataka, India. The SCS-CN method is a simplified approach for runoff estimation, but it does not take into account the actual moisture content in the soil. Consequently, insignificant moisture level changes could induce significant variations in the runoff. The study analyzes six different models based on the SCS-CN method, including the original SCS-CN model and several variations with added features (SCS-CN with slope correction, SCS-CN with λ-optimization, Mishra and Singh, Michel-Vazken -Perrin (MVP), Activation Soil Moisture Accounting SCS-CN). The accuracy of each model was compared using several goodness-of-fit statistics. Furthermore, based on the flood frequency analysis, three large flood events were reported in 2005, 2013, and 2014. The results showed that the MVP model was the best-performi...
Rainfall-Runoff Modeling Using NRCS-CN method and GIS approach
Rainfall-Runoff modeling is a hydrological modeling which is extremely important for water resources planning, development, and management. In this paper, Natural Resource Conservation Service-Curve Number (NRCS-CN) method along with Geographical Information System (GIS) approach was used to evaluate the runoff resulting from the rainfall of four stations, namely, Bilodra, Kathlal, Navavas and Rellawada of Sabarmati River basin. The rainfall data were taken for 10 years (2005-2014). The curve number which is the function of land use, soil and antecedent moisture condition (AMC) was generated in GIS platform. The CN value generated for AMC- I, II and III were 57.29, 75.39 and 87.77 respectively. Using NRCS-CN method, runoff depth was calculated for all the four stations. The runoff depth calculated with respect to the rainfall for Bilodra, Kathlal, Navavas and Rellawada shows a good correlation of 0.96. The computed runoff was compared with the observed runoff which depicted a good c...
A MODIFIED SCS-CN BASED MODEL FOR LONG TERM HYDROLOGIC SIMULATION
TJPRC, 2014
Long term management of water resources in a catchment requires input from hydrological studies in the form of estimation or forecasting of the magnitude of hydrological variables. Such forecasts are useful in many ways, like warning of extreme floods or droughts, and help optimize the operation of systems, like reservoirs and power plants. This paper attempts to improve the original Soil Service Conservation Service Curve Number (SCS-CN) concept to perform long-term hydrologic analysis for a humid watershed, namely Hemavati, a tributary of River Cauvery in Karnataka State. Besides, the SCS-CN approach widely used as a simple method for predicting direct runoff volume for a given rainfall eventhas been evaluated for its applicability to humid catchment. The model inputs include daily rainfall, evaporation, and the model describes antecedent moisture (AM) by incorporating effect of antecedent rainfall without considering different antecedent moisture conditions (AMC). The model performs satisfactorily with efficiency of 87.51% and 88.71% in calibration and validation, respectively. The average relative error is of the order of 10%, which is tolerable
ESTIMATION OF RUNOFF FOR THE WATERSHED USING SCS-CURVE NUMBER METHOD AND GIS
Runoff is the most important factor considered in watershed management, which depends mainly on the physiographic characteristics of the watershed. In this paper, Estimation of runoff Potential is carried out for Gadela watershed located in Udaipur district, Rajasthan by the most popularly used SCS-Curve number approach, along with GIS. The watershed is delineated and divided into 10 sub basins, using Arc GIS to find the runoff from each sub basin. To calculate the runoff depth, the rainfall of the area from 1994-2014 for 20 years is considered. The thematic maps such as Land use/ Land cover and soil map, were prepared in the Arc GIS environment and overlaid to find the Curve number values. The yearly and basin wise runoff was calculated and presented in the graph. The results found that, runoff depth was more during 2006, which is about 62% of the total average rainfall of 650mm and less runoff in 1998, which is 22%. The average runoff in the watershed basin wise was 115.96mm, of the average rainfall 535.65mm. The sub basin 10 was having the highest runoff, followed by basin 6 and basin 9 and the lowest runoff observed in Sub basin 1 and the Sub basin2. The reason for the runoff from a watershed is, due to the presence of cultivated area about 54.2% of the total area, Scrub land of 44% and forest area only 0.6%.
The runoff coefficient (C) represents the relationship between the surface runoff volume and the precipitated volume. It is used in engineering projects for flood estimation methods. Although C values are tabulated and consecrated in hydrological engineering, as if they were constant, they may not correspond to the reality, because in the same catchment, they can vary according to the intensity, temporal and spatial distribution of precipitation events, humidity conditions, and ground cover. This study had the objective of analyzing extreme events of precipitation and the corresponding flows to obtain experimental runoff coefficients (C) and compare them with the tabulated values. The study was conducted in four experimental catchments in the State of São Paulo, Brazil, with different land uses and soils. The runoff coefficients (C) were obtained from the analysis of hydrograms and using a digital filter, which allowed the separation of the direct runoff, of the total flow. When ana...