scholarly journals Taieri river data to test channel network and river basin heterogeneity concepts

1998 ◽  
Vol 34 (8) ◽  
pp. 2085-2088 ◽  
Author(s):  
R. P. Ibbitt ◽  
A. I. McKerchar ◽  
M. J. Duncan
Keyword(s):  
River Basin ◽  
Channel Network ◽  
Test Channel

scholarly journals Data for Ashley River to test channel network and river basin heterogeneity concepts

1998 ◽  
Vol 34 (1) ◽  
pp. 139-142 ◽  
Author(s):  
A. I. McKerchar ◽  
R. P. Ibbitt ◽  
S. L. R. Brown ◽  
M. J. Duncan
Keyword(s):  
River Basin ◽  
Channel Network ◽  
Test Channel ◽  
Ashley River

scholarly journals Morphometry and geomorphic development of the Bagmati River Basin, Nepal Himalaya

2013 ◽  
Vol 46 ◽  
Author(s):  
Pramila Shrestha ◽  
Naresh Kazi Tamrakar
Keyword(s):  
River Basin ◽  
Quantitative Description ◽  
Drainage System ◽  
Higher Order ◽  
Tectonic Activity ◽  
Mature Stage ◽  
Channel Network ◽  
Order Stream ◽  
Tectonic Zone ◽  
Bagmati River

Morphometric analysis of a watershed provides a quantitative description of the drainage system which is an important aspect of characterization of watershed. The analysis requires measurement of linear features, aerial aspects, gradient of channel network and contributing ground slopes of the drainage basin. The morphometric characteristics at the watershed-scale may contain important information regarding its formation and development because all hydrologic and geomorphic processes occur within the watershed. In this study morphometric property of the Bagmati River Basin (BRB) was investigated using different morphometric attributes and hypsometric analysis in order to investigate geomorphic development of the river basin, in an active tectonic zone. DEM has been prepared from the contour and spot height data using digital topographic maps of 1:25000-scale acquired from the Department of Survey, Nepal. The main stem Bagmati River is the eighth order perennial river that stretches for 206 km with an elongated catchment of area 3761 sq. km. It consists of 39 sub-basins of fourth order and higher. The study shows that the drainage system of the BRB is attaining a mature stage from a youth stage from lower order streams to the higher order streams in geomorphic development process. Some exceptions occurred at higher order stream segments, where drainage development seems to control by structure and lithology. According to the analytical results, erosional stage and level of tectonic activity of sub-basins differ from each other. Generally, the lithology and geological structure seems to control the drainage texture and relief of the BRB. The river system within the Kathmandu Valley is attaining maturity having meandering channels with wide flood plains, whereas rivers of the Lesser Himalaya and the Siwaliks are at youth stage with erosional potential. The downstream part of higher order stream segments are in mature stage having potential for lateral erosion and meander migration. Therefore, the Bagmati River stretch, especially the eight order one poses vulnerability to bank erosion.

scholarly journals The Hydrologic Response of The Eaton River Basin, Quebec

1971 ◽  
Vol 8 (1) ◽  
pp. 102-115 ◽  
Author(s):  
M. A. Carson ◽  
E. A. Sutton
Keyword(s):  
Surface Water ◽  
River Basin ◽  
Parametric Study ◽  
Source Area ◽  
Water Systems ◽  
Hydrologic Response ◽  
Rainfall Runoff ◽  
Channel Network ◽  
Storm Rainfall ◽  
Runoff Production

This paper reports a parametric study of rainfall–runoff relations for 38 storms in the Eaton basin, southeastern Quebec, between 1950 and 1966. In addition to storm rainfall amounts, water table levels in the vicinity of the channel network, as indicated by baseflow prior to storms, appear to be very important in controlling the amount of response of the basin in different storms. Storm runoff is viewed as the product of direct interception by, and subsurface seepage into, expanded surface water systems in the valley floor areas of the basin. This is in agreement with the variable (partial) source area model developed over the last ten years by a number of hydrologists as an alternative to the Horton theory of runoff production.

scholarly journals Effectof Unit Hydrographs and Rainfall Hyetographs on Critical Rainfall Estimates of Flash Flood

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Fanzhe Kong ◽  
Wei Huang ◽  
Zhilin Wang ◽  
Xiaomeng Song
Keyword(s):  
River Basin ◽  
Flash Flood ◽  
Channel Network ◽  
Moisture Condition ◽  
Soil Moisture Condition ◽  
Antecedent Precipitation ◽  
Huai River ◽  
Critical Rainfall ◽  
Xin’Anjiang Model ◽  
Unit Hydrographs

To obtain critical rainfall (CR) estimates similar to the rainfall value that causes minor basin outlet flooding, and to reduce the flash flood warning missed/false alarm rate, the effect of unit hydrographs (UHs) and rainfall hyetographs on computed threshold rainfall (TR) values was investigated. The Tanjia River basin which is a headwater subbasin of the Greater Huai River basin in China was selected as study basin. Xin’anjiang Model, with subbasins as computation units, was constructed, and time-variant distributed unit hydrographs (TVUHs) were used to route the channel network concentration. Calibrated Xin’anjiang Model was employed to derive the TVUHs and to obtain the maximum critical rainfall duration (Dmax) of the study basin. Initial soil moisture condition was represented by the antecedent precipitation index (Pa). Rainfall hyetographs characterized by linearly increasing, linearly decreasing, and uniform hyetographs were used. Different combinations of the three hyetographs and UHs including TVUHs and time-invariant unit hydrographs (TIVUHs) were utilized as input to the calibrated Xin’anjiang Model to compute the relationships between TR and Pa (TR-Pa curves) by using trial and error methodology. The computed TR-Pa curves reveal that, for given Pa and UH, the TR corresponding to linearly increasing hyetograph is the minimum one. So, the linearly increasing hyetograph is the optimum hyetograph type for estimating CR. In the linearly increasing hyetograph context, a comparison was performed between TR-Pa curves computed from different UHs. The results show that TR values for different TIVUHs are significantly different and the TR-Pa curve gradient of TVUHs is lower than that of TIVUHs. It is observed that CR corresponds to the combination of linearly increasing hyetograph and TVUHs. The relationship between CR and Pa (CR-Pa curves) and that between CR and duration (D) (CR-D curves) were computed. Warnings for 12 historical flood events were performed. Warning results show that the success rate was 91.67% and that the critical success index (CSI) was 0.91. It is concluded that the combination of linearly increasing hyetograph and TVUHs can provide the CR estimate similar to the minimum rainfall value necessary to cause flash flooding.

scholarly journals Horton laws for hydraulic–geometric variables and their scaling exponents in self-similar Tokunaga river networks

2014 ◽  
Vol 21 (5) ◽  
pp. 1007-1025 ◽  
Author(s):  
V. K. Gupta ◽  
O. J. Mesa
Keyword(s):  
River Basin ◽  
Data Sets ◽  
Large Network ◽  
Anomalous Scaling ◽  
Self Similarity ◽  
Channel Network ◽  
Scaling Exponents ◽  
Stream Discharge ◽  
Theoretical Predictions ◽  
Self Similar

Abstract. An analytical theory is developed that obtains Horton laws for six hydraulic–geometric (H–G) variables (stream discharge Q, width W, depth D, velocity U, slope S, and friction n') in self-similar Tokunaga networks in the limit of a large network order. The theory uses several disjoint theoretical concepts like Horton laws of stream numbers and areas as asymptotic relations in Tokunaga networks, dimensional analysis, the Buckingham Pi theorem, asymptotic self-similarity of the first kind, or SS-1, and asymptotic self-similarity of the second kind, or SS-2. A self-contained review of these concepts, with examples, is given as "methods". The H–G data sets in channel networks from three published studies and one unpublished study are summarized to test theoretical predictions. The theory builds on six independent dimensionless river-basin numbers. A mass conservation equation in terms of Horton bifurcation and discharge ratios in Tokunaga networks is derived. Assuming that the H–G variables are homogeneous and self-similar functions of stream discharge, it is shown that the functions are of a power law form. SS-1 is applied to predict the Horton laws for width, depth and velocity as asymptotic relationships. Exponents of width and the Reynolds number are predicted and tested against three field data sets. One basin shows deviations from theoretical predictions. Tentatively assuming that SS-1 is valid for slope, depth and velocity, corresponding Horton laws and the H–G exponents are derived. Our predictions of the exponents are the same as those previously predicted for the optimal channel network (OCN) model. In direct contrast to our work, the OCN model does not consider Horton laws for the H–G variables, and uses optimality assumptions. The predicted exponents deviate substantially from the values obtained from three field studies, which suggests that H–G in networks does not obey SS-1. It fails because slope, a dimensionless river-basin number, goes to 0 as network order increases, but, it cannot be eliminated from the asymptotic limit. Therefore, a generalization of SS-1, based on SS-2, is considered. It introduces two anomalous scaling exponents as free parameters, which enables us to show the existence of Horton laws for channel depth, velocity, slope and Manning friction. These two exponents are not predicted here. Instead, we used the observed exponents of depth and slope to predict the Manning friction exponent and to test it against field exponents from three studies. The same basin mentioned above shows some deviation from the theoretical prediction. A physical reason for this deviation is given, which identifies an important topic for research. Finally, we briefly sketch how the two anomalous scaling exponents could be estimated from the transport of suspended sediment load and the bed load. Statistical variability in the Horton laws for the H–G variables is also discussed. Both are important open problems for future research.

scholarly journals Geomorphologic Analysis of Small River Basin within the Framework of Fractal Tree

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2480
Author(s):  
Meiyan Feng ◽  
Kwansue Jung ◽  
Joo-Cheol Kim
Keyword(s):  
River Basin ◽  
Growth Process ◽  
River Basins ◽  
Small River ◽  
Channel Network ◽  
Limited Region ◽  
Anisotropic Property ◽  
Small River Basin ◽  
Bifurcation Process ◽  
Geomorphologic Analysis

This paper presents the modified framework of geomorphologic analysis based on the concept of fractal tree. Especially, it is intended to provide hydrologic practitioners with the information on the fractal property of small river basins. To this end, the complete drainage path network is applied to a growth process of a fractal tree for the basin of interest by connecting a channel network to overland drainage pathways. The growth process of a fractal tree would occur only within the limited region possessing channel flow properties in a natural river basin. The exponent of the intra basin type of Hack’s law could show a variable trend in small river basins mainly due to anisotropic property of the catchment planform. The bifurcation process of a drainage path network might be more sensitive to the growth step of the fractal tree than the meandering process of drainage path segment. The fractal dimension from the sinuosity of a channel segment is relatively stable compared to the one from the bifurcation process of the network, so that the geomorphologic features of a small river basin can be characterized by the anisotropic property of catchment planform as well as the bifurcation property of drainage path network with the growth of the fractal tree.

scholarly journals Horton laws for Hydraulic-Geometric variables and their scaling exponents in self-similar river networks

2014 ◽  
Vol 1 (1) ◽  
pp. 705-753
Author(s):  
V. K. Gupta ◽  
O. J. Mesa
Keyword(s):  
River Basin ◽  
Field Experiments ◽  
Future Research ◽  
Large Network ◽  
Anomalous Scaling ◽  
Channel Network ◽  
Scaling Exponents ◽  
Open Problems ◽  
Self Similar ◽  
Similar Solutions

Abstract. An analytical theory is presented to predict Horton laws for five Hydraulic-Geometric (H-G) variables (stream discharge Q, width W, depth D, velocity U, slope S, and friction n'). The theory builds on the concept of dimensional analysis, and identifies six independent dimensionless River-Basin numbers. We consider self-similar Tokunaga networks and derive a mass conservation equation in the limit of large network order in terms of Horton bifurcation and discharge ratios. It is applied to obtain self-similar solutions of type-1 (SS-1), and predict Horton laws for width, depth and velocity as asymptotic relationships. Exponents of width and the Reynold's number are predicted. Assuming that SS-1 is valid for slope, depth and velocity, corresponding Horton laws and the H-G exponents are derived. The exponent values agree with that for the Optimal Channel Network (OCN) model, but do not agree with values from three field experiments. The deviations are substantial, suggesting that H-G in network does not obey optimality or SS-1. It fails because slope, a dimensionless River-Basin number, goes to 0 as network order increases, but, it cannot be eliminated from the asymptotic limit. Therefore, a generalization of SS-1, based in self-similar solutions of Type-2 (SS-2) is considered. It introduces two anomalous scaling exponents as free parameters, which enables us to show the existence of Horton laws for channel depth, velocity, slope and Manning's friction. The Manning's friction exponent, y, is predicted and tested against observed exponents from three field studies. We briefly sketch how the two anomalous scaling exponents could be estimated from the transport of suspended sediment load and the bed load. Statistical variability in the Horton laws for the H-G variables is also discussed. Both are important open problems for future research.

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