Applying the stocking index to the determination of the curve number parameter in the forest catchment area

In SCS-CN method, curve number is significant parameter in estimating runoff from the catchment of the reservoir or inflow to the reservoir. As this curve number is function of several parameters like hydrological soil group, LULC, land treatment, hydrologic conditions and AMC, the selection of CN for prediction of inflow to the lake or reservoir is considered as a crucial in the hydrological studies. LULC, micro-watershed, drainage density, and catchment slope are obtained using spatial analysis and also SCS Curve Number value for Ponnaniyaru dam catchment area is derived from the LULC data. Further, CN value is evaluated from actual rainfall data and runoff volume collected at the reservoir. The study reveals the significant variation of CN value among each event. The present case study highlights the sensitiveness of CN value in the computation of runoff from the watershed. Keywords: Curve number, LULC, AMC, drainage density.

Download Full-text

Exponent determination in a poorly gauged basin system in Nigeria based on flow characteristics investigation and regionalization method

SN Applied Sciences ◽

10.1007/s42452-021-04302-3 ◽

2021 ◽

Vol 3 (3) ◽

Author(s):

O. A. Fasipe ◽

O. C. Izinyon

Keyword(s):

Catchment Area ◽

Flow Characteristics ◽

Curve Number ◽

Homogeneity Test ◽

Small Hydropower ◽

Ungauged Sites ◽

River Basin Development ◽

Research Findings ◽

Resources Conservation

AbstractIn this study, a method for estimating the exponent “n” values of the catchment-area equations of four sub-basins within the poorly gauged Benin-Owena River Basin Development Authority (BORBDA) in Nigeria is presented to enable the estimation of flows at ungauged sites within the basin and the determination of small hydropower (SHP) potential at different locations in each sub-basin and the entire basin. Optimal prediction of streamflow characteristics in poorly gauged basin requires developing a methodology for extrapolation of data from gauged to ungauged sites within the basin. Four sub-catchments of BORBDA, a poorly gauged basin in Nigeria, were investigated using Remote Sensing (RS), Geographic Information System (GIS), statistical techniques, and Natural Resources Conservation Service-Curve Number (NRCS-CN) hydrological model. Discharge values at gauged sites (Qg) were obtained from recorded discharge values collected for 12 months at an established gauging station in each sub-basin. RS and GIS techniques were used to develop classification maps and obtain crucial data like curve number (CN), elevation, Hydrologic Soil Group (HSG), rainfall intensity, slope, area of gauged and ungauged required for evaluating spatial discharge (ungauged) utilizing NRCS-CN model. From the established model for each sub-basin, exponent “n” in the relationship between discharge and catchment area was obtained to be 0.23, 0.41, 0.71, and 0.74. Using the lumped modeling approach, which considers a watershed as a single unit for computation, where watershed parameters and variables were to be averaged produced “n” = 0.52 for BORBDA area, which is within the range of 0.5–0.85 suggested by previous researchers. Obtained BORBDA exponent “n” was validated for use in the entire basin through soil homogeneity test by generating BORBDA soil map which confirms the four sub-basins investigated share similar HSG A, B, and D with BORBDA. The exponent “n” value is useful for predicting flows in ungauged parts of the basin. The exponent “n” value obtained for the basin is helpful in the assessment of discharge and determination of SHP potential at different locations within the poorly gauged BORBDA basin, and the dissemination of the research findings will find practical use and guide to practicing hydrologists in Nigeria and locations around the world with similar challenges of poorly gauged basins particularly Africa and other developing countries.

Download Full-text

Determination of water erosion in Kowsar catchment area and evaluation of Gabion structures in its control

Environmental Earth Sciences ◽

10.1007/s12665-020-09248-0 ◽

2020 ◽

Vol 79 (22) ◽

Author(s):

Mohammad Albaji ◽

Behnaz Ershadian ◽

Abdolhossein Noori Nejad ◽

Ebrahim Mohammadi ◽

Shoja Ghorban Dashtaki

Keyword(s):

Catchment Area ◽

Water Erosion

Download Full-text

A New Empirical Approach to Calculating Flood Frequency in Ungauged Catchments: A Case Study of the Upper Vistula Basin, Poland

Water ◽

10.3390/w11030601 ◽

2019 ◽

Vol 11 (3) ◽

pp. 601 ◽

Cited By ~ 7

Author(s):

Dariusz Młyński ◽

Andrzej Wałęga ◽

Tomasz Stachura ◽

Grzegorz Kaczor

Keyword(s):

Empirical Model ◽

Catchment Area ◽

Flood Frequency ◽

Ungauged Catchments ◽

Volume Determination ◽

Statistical Verification ◽

Observation Series ◽

Data Estimation

The aim of the work was to develop a new empirical model for calculating the peak annual flows of a given frequency of occurrence (QT) in the ungauged catchments of the upper Vistula basin in Poland. The approach to the regionalization of the catchment and the selection of the optimal form of the empirical model are indicated as a novelty of the proposed research. The research was carried out on the basis of observation series of peak annual flows (Qmax) for 41 catchments. The analysis was performed in the following steps: statistical verification of data; estimation of Qmax flows using kernel density estimation; determination of physiographic and meteorological characteristics affecting the Qmax flow volume; determination of the value of dimensionless quantiles for QT flow calculation in the upper Vistula basin; verification of the determined correlation for the calculation of QT flows in the upper Vistula basin. Based on the research we conducted, we found that the following factors have the greatest impact on the formation of flood flows in the upper Vistula basin: the size of catchment area; the height difference in the catchment area; the density of the river network; the soil imperviousness index; and the volume of normal annual precipitation. The verification procedure that we performed made it possible to conclude that the developed empirical model functions correctly.

Download Full-text

Possibility of Using Selected Rainfall-Runoff Models for Determining the Design Hydrograph in Mountainous Catchments: A Case Study in Poland

Water ◽

10.3390/w12051450 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1450 ◽

Cited By ~ 3

Author(s):

Dariusz Młyński ◽

Andrzej Wałęga ◽

Leszek Książek ◽

Jacek Florek ◽

Andrea Petroselli

Keyword(s):

Catchment Area ◽

Peak Flow ◽

Rainfall Runoff ◽

Peak Flows ◽

Mountainous Catchment ◽

Mountainous Catchments ◽

Relative Errors ◽

Runoff Hydrographs

The aim of the study was to analyze the possibility of using selected rainfall-runoff models to determine the design hydrograph and the related peak flow in a mountainous catchment. The basis for the study was the observed series of hydrometeorological data for the Grajcarek catchment area (Poland) for the years 1981–2014. The analysis was carried out in the following stages: verification of hydrometeorological data; determination of the design rainfall; and determination of runoff hydrographs with the following rainfall-runoff models: Snyder, NRCS-UH, and EBA4SUB. The conducted research allowed the conclusion that the EBA4SUB model may be an alternative to other models in determining the design hydrograph in ungauged mountainous catchments. This is evidenced by the lower values of relative errors in the estimation of peak flows with an assumed frequency for the EBA4SUB model, as compared to Snyder and NRCS-UH.

Download Full-text

A critical evaluation of the methods for the determination of required volumes for detention tank

E3S Web of Conferences ◽

10.1051/e3sconf/20184500088 ◽

2018 ◽

Vol 45 ◽

pp. 00088 ◽

Cited By ~ 6

Author(s):

Mariusz Starzec

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Catchment Area ◽

Critical Evaluation ◽

Design Parameters ◽

Method Of Calculation ◽

Rainfall Duration ◽

Detention Tank ◽

Artificial Neural

Simplified methods allow a straightforward and quick determination of parameters of interest. A simplified method of calculation to be used must provide sufficiently accurate simulation results. This paper presents the results of tests completed to evaluate the effects of the parameters which describe a sewer catchment area and network on the value of Tp, a parameter applied in the Dziopak method [18]. The results of 2997 hydrodynamic simulations allowed to formulate an artificial neural network the application of which enabled the determination of the value of Tp dependent on the design parameters of a sewer catchment area and network. The artificial neural network had a very low error R2 = 0.9972 between the expected and determined values of Tp. The completed tests indicated a relationship by which an increase of the rainfall duration, a parameter used in the dimensioning of detention tank, is concomitant to an increase in the value of Tp. The calculations made so far included an assumption that the Tp value is constant irrespective of the design rainfall duration for the dimensioning of detention tank; this assumption has led to gross calculation errors. The paper also provides proof that the inclusion of these relationships allows a more precise determination of the service volume required for a multi-chamber detention tank.

Download Full-text

Identification of the Relationship between Rainfall and the CN Parameter in Western Carpathian Mountain Catchments in Poland

Sustainability ◽

10.3390/su12229317 ◽

2020 ◽

Vol 12 (22) ◽

pp. 9317

Author(s):

Dariusz Młyński ◽

Andrzej Wałęga

Keyword(s):

Error Function ◽

Strong Relationship ◽

Curve Number ◽

Western Carpathians ◽

Asymptotic Model ◽

Efficiency Coefficient ◽

Direct Runoff ◽

Slope Correction ◽

The Relationship

The aim of this study was to identify the form of the dependence describing the relationship between rainfall (P) and the curve number (CN) parameter using the Natural Resources Conservation Service (NRCS-CN) method in the mountain catchments of the Western Carpathians. The study was carried out in 28 catchments areas in the Western Carpathians in the Upper Vistula Basin, Poland. The study was conducted in the following stages: determination of the volume of the direct runoff using the NRCS-CN method, determination of the P–CN relationship using asymptotic functions, kinetic equation and complementary error function; determination of the volume of the direct runoff from the catchment area, accounting for the correction of the decline; determination of the value of the efficiency coefficient of the analysed models. On the basis of the conducted study, a strong relationship was found between the direct runoff and the rainfall that caused it. The study showed that the empirical values of the CN parameter differed from the values determined on the basis of the volume of rainfall and runoff. The vast majority of study catchments were characterised by a standard P–CN relationship. The kinetic model was found to be the best model to describe the P–CN relationship. The asymptotic model showed the greatest stability for high rainfall episodes. It was shown that the application of the catchment slope correction improved the quality of the NRCS-CN model.

Download Full-text

Determination of number of check dams by artificial neural networks in arid regions of Iran

Water Science & Technology ◽

10.2166/wst.2015.268 ◽

2015 ◽

Vol 72 (6) ◽

pp. 952-959 ◽

Cited By ~ 1

Author(s):

Seyed Ali Asghar Hashemi ◽

Hamed Kashi

Keyword(s):

Curve Number ◽

Absolute Error ◽

Coefficient Of Determination ◽

Ann Model ◽

Effective Parameters ◽

Check Dams ◽

Artificial Neural ◽

Artificial Neural Network Ann ◽

Mlp Model

An artificial neural network (ANN) model with six hydrological factors including time of concentration (TC), curve number, slope, imperviousness, area and input discharge as input parameters and number of check dams (NCD) as output parameters was developed and created using GIS and field surveys. The performance of this model was assessed by the coefficient of determination R2, root mean square error (RMSE), values account and mean absolute error (MAE). The results showed that the computed values of NCD using ANN with a multi-layer perceptron (MLP) model regarding RMSE, MAE, values adjustment factor (VAF), and R2 (1.75, 1.25, 90.74, and 0.97) for training, (1.34, 0.89, 97.52, and 0.99) for validation and (0.53, 0.8, 98.32, and 0.99) for test stage, respectively, were in close agreement with their respective values in the watershed. Finally, the sensitivity analysis showed that the area, TC and curve number were the most effective parameters in estimating the number of check dams.

Download Full-text

Determination of potential retention of the Fryšávka River basin

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis ◽

10.11118/actaun201058050263 ◽

2010 ◽

Vol 58 (5) ◽

pp. 263-270 ◽

Cited By ~ 1

Author(s):

Tomáš Mašíček ◽

František Toman

Keyword(s):

River Basin ◽

Flood Control ◽

Water Retention ◽

Curve Number ◽

Control Measures ◽

Design Parameters ◽

Software Products ◽

Software Applications ◽

Integrated Software

Hydrological models provide design parameters for the design of flood control measures. Runoff from the river basin is primarily determined by the amount of rainfall and water retention of the river basin. The Fryšávka River basin was chosen to determine the potential water retention of the river basin. Before the determination of potential retention preparatory work was carried out: description of the current state of land cover based on a detailed field survey, the representation of hydrological soil groups in the basin found in BPEJ (Bonitované půdně ekologické jednotky – Valuated land–ecological units) maps, delimitation of basin parts by the digital vector layer ZABAGED altimetry (Základní báze geografických dat – Fundamental base of geographic data) – 3D contour and evaluation of basin parts by the runoff curve numbers (CN). The processing of background data was performed by the program ArcGIS 9.2 of ArcView software products using a set of integrated software applications ArcMap, ArcCatalog and ArcToolbox. To assess the potential retention, as part of the hydrologic characteristics of the Fryšávka River basin, the curve number method, a modification of the deterministic episode model DesQ–MAXQ, was used. The average numbers of runoff curves and the data about potential retention of river basin parts are presented in the form of map outputs.

Download Full-text

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

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-370-167-2015 ◽

2015 ◽

Vol 370 ◽

pp. 167-170 ◽

Cited By ~ 2

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.

Download Full-text