Overland-flow travel time versus Reynolds number a comment

1977 ◽  
Vol 35 (1-2) ◽  
pp. 203-204
Author(s):  
Mohammad Akram Gill
Keyword(s):  
Reynolds Number ◽  
Travel Time ◽  
Overland Flow

Overland-flow travel time versus Reynolds number

1977 ◽  
Vol 32 (1-2) ◽  
pp. 175-182 ◽  
Author(s):  
Stanley S. Butler
Keyword(s):  
Reynolds Number ◽  
Travel Time ◽  
Overland Flow

scholarly journals Climate, landscape and vegetation controls of behavioral catchments on dominant runoff response and catchment travel time distribution

2021 ◽  
Author(s):  
Chatchai Jothityangkoon ◽  
Haruetai Maskong
Keyword(s):  
Travel Time ◽  
Overland Flow ◽  
Theoretical Perspective ◽  
Hydrologic Model ◽  
Runoff Generation ◽  
Catchment Scale ◽  
Physical Relationship ◽  
Relative Contribution ◽  
Hillslope Scale ◽  
The Impact

The three dominant processes contributing to runoff as proposed by the Dunne diagram are Hortonian overland flow (HOF), Dunne overland flow (DOF) and subsurface storm flow (SSF). Using a theoretical perspective, we investigate the impact of climate, soil, topography and vegetation on catchment water balance and the probability distribution of the travel times of each runoff generation component in respect of the connected instantaneous response function (CIRF) including the interaction of a partial contributing area connecting to the outlet. A simple distributed hydrologic model is used to capture the effect of the catchment response and to estimate the CIRFs under different possible integration of combined effect of climate, soil, topography and vegetation. A set of dimensionless similarity parameters represent catchment functions and provide a quantitative explanation of the conceptual Dunne diagram. Behavioral catchments are defined from the empirical range of the Budyko curve and mainly compatible to the physical relationship as illustrated in the Dunne diagram. The results consistent with the Dunne diagram are: (1) DOF and SSF dominates in humid for behavioral sand and silt catchments, (2) HOF dominates in arid for behavioral silt and clay catchments. Inconsistent results are: (1) SSF dominates in arid for behavioral sand, silt and clay catchments, (2) HOF dominates in humid for behavioral clay catchment and (3) no dominant HOF for behavioral sand catchment. For HOF and DOF dominates, the distribution of CIRFs can be grouped into similar shapes, which depend on the relative contribution of hillslope scale and catchment scale. For SSF behavioral catchments, the shape of the CIRFs depends on the dryness index. The combined catchment CIRFs of mean travel time for runoff responses consists with the higher first peak from the HOF and/or DOF and the second peak from the SSF.

scholarly journals A Comprehensive Planning Framework for Urban Inland Oil Spill Management

2021 ◽  
Author(s):  
Marija Eric
Keyword(s):  
Monte Carlo ◽  
Travel Time ◽  
Oil Spill ◽  
Overland Flow ◽  
Hot Spot ◽  
Series Data ◽  
Comprehensive Planning ◽  
Planning Framework ◽  
Simulation Results ◽  
Storm Sewer

Oil spills occurring on land have accounted for at least one third or over 24,000 of all land spills (approximately 76,000) of various substances reported in Ontario from 1988 to 2013. The objective of this research was to develop a comprehensive planning framework for urban inland oil spill management encompassing all three stages of spill management: (1) prevention, (2) control and (3) response. An inland oil spill database was developed and the source of each spill was analyzed. Preliminary analyses determined that approximately 46 % of spills occur at fixed locations (stationary spills), 21 % of spills involve moving vehicles (transportation-related), 13 % involve moving vehicle accidents (transportation-related accidents) and 20 % were categorized as other kinds of spills. Sub-databases were developed for both stationary and transportation-related spills which include numeric and non-numeric data variables. Hot spot analyses (optimized version) were performed on a subset of transportation-related spills to develop a highway spill model. The highway spill model illustrates that the majority of highway spills (75 %) occur at interchanges and the remaining spills occur either on the highway (8 %) or at unknown locations (17%). A macro program was developed to simulate future spill events based on historical spill events of gasoline spills within the case study area. The variables under study were fitted with distributions and Monte Carlo or Iman Conover methods were used to generate simulation results spreadsheets of spill series data based on the fitted distributions. The final macro program generated 30,000 simulation results spreadsheets and compiled the results in an aggregate spreadsheet. Descriptive statistics of the numeric variables were calculated and used to recommend spill management strategies. A simulation results spreadsheet with predicted spill records was used to develop a Geographic Information Systems (GIS) model to delineate spill pathways and calculate travel-time for overland flow and channel flow within the storm sewer system (geometric network). The model delineates the overland spill path and traces the spill path through the storm sewer network. The travel-time for each type of path is calculated and can be summed to determine the total travel-time for each predicted spill. Keywords: inland oil spill, comprehensive planning framework, spill management, prevention, control, response, stationary, transportation-related, hot spot analysis, macro program, Monte Carlo, Iman Conover, simulation, GIS, travel-time, spill path, geometric network

scholarly journals Kinematics motion of paddy in hot air pulse flow

2020 ◽  
Vol 187 ◽  
pp. 04011
Author(s):  
Nuttapong Wongbubpa ◽  
Krawee Treeamnuk ◽  
Tawarat Treeamnuk
Keyword(s):  
Reynolds Number ◽  
Travel Time ◽  
Motion Analysis ◽  
Tube Length ◽  
Pulse Flow ◽  
Total Distance ◽  
Hot Air ◽  
Actual Movement

This research aims to study the characteristic of paddy motion under the hot air pulse flow in the drying tube length 2 m by using the kinematics motion analysis. The equations of paddy motion are analyzed to evaluate the pattern of paddy motion, total distance that the paddy can travel through the drying tube and Reynolds number of paddy. Results found that Model I, II and III consume the paddy travel time of approximately 1.3, 5.0 and 2.2 s and give a total distance of 2.6, 2.7 and 2.5 m and they have maximum travel velocity of 4.12, 1.37 and 1.85 m/s respectively. When considering the Reynolds number, the models I, II and III give the most values from similar calculations with 1,837, 1,816 and 1,821 respectively. Based on various parameters from all of models, Model III was the closest characteristic of paddy motion to the actual movement in the system.

scholarly journals Influence of Vegetation Coverage on Hydraulic Characteristics of Overland Flow

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1055
Author(s):  
Zekang Cai ◽  
Jian Wang ◽  
Yushuo Yang ◽  
Ran Zhang
Keyword(s):  
Reynolds Number ◽  
Soil Erosion ◽  
Vegetation Cover ◽  
Overland Flow ◽  
Resistance Coefficient ◽  
Vegetation Coverage ◽  
Hydraulic Characteristics ◽  
The Loess Plateau ◽  
Artificial Grass ◽  
The Relationship

Soil erosion is a major problem in the Loess Plateau (China); however, it can be alleviated through vegetation restoration. In this study, the overland flow on a slope during soil erosion was experimentally simulated using artificial grass as vegetation cover. Nine degrees of vegetation coverage and seven flow rates were tested in combinations along a 12° slope gradient. As the coverage degree increased, the water depth of the overland flow increased, but the flow velocity decreased. The resistance coefficient increased with increasing degree of coverage, especially after a certain point. The resistance coefficient and the Reynolds number had an inverse relationship. When the Reynolds number was relatively small, the resistance coefficient decreased faster; however, when it exceeded 600, the resistance coefficient decreased at a slower rate. A critical degree of vegetation cover was observed in the relationship between the resistance coefficient and submergence degree. When the degree of coverage was greater than 66.42%, the resistance coefficient first decreased and then increased with a higher submergence degree. Finally, the formula for the resistance coefficient under vegetation coverage was derived. This formula has a relatively high accuracy and can serve as a reference for predicting soil erosion.

scholarly journals A Comprehensive Planning Framework for Urban Inland Oil Spill Management

2021 ◽  
Author(s):  
Marija Eric
Keyword(s):  
Monte Carlo ◽  
Travel Time ◽  
Oil Spill ◽  
Overland Flow ◽  
Hot Spot ◽  
Series Data ◽  
Comprehensive Planning ◽  
Planning Framework ◽  
Simulation Results ◽  
Storm Sewer

Oil spills occurring on land have accounted for at least one third or over 24,000 of all land spills (approximately 76,000) of various substances reported in Ontario from 1988 to 2013. The objective of this research was to develop a comprehensive planning framework for urban inland oil spill management encompassing all three stages of spill management: (1) prevention, (2) control and (3) response. An inland oil spill database was developed and the source of each spill was analyzed. Preliminary analyses determined that approximately 46 % of spills occur at fixed locations (stationary spills), 21 % of spills involve moving vehicles (transportation-related), 13 % involve moving vehicle accidents (transportation-related accidents) and 20 % were categorized as other kinds of spills. Sub-databases were developed for both stationary and transportation-related spills which include numeric and non-numeric data variables. Hot spot analyses (optimized version) were performed on a subset of transportation-related spills to develop a highway spill model. The highway spill model illustrates that the majority of highway spills (75 %) occur at interchanges and the remaining spills occur either on the highway (8 %) or at unknown locations (17%). A macro program was developed to simulate future spill events based on historical spill events of gasoline spills within the case study area. The variables under study were fitted with distributions and Monte Carlo or Iman Conover methods were used to generate simulation results spreadsheets of spill series data based on the fitted distributions. The final macro program generated 30,000 simulation results spreadsheets and compiled the results in an aggregate spreadsheet. Descriptive statistics of the numeric variables were calculated and used to recommend spill management strategies. A simulation results spreadsheet with predicted spill records was used to develop a Geographic Information Systems (GIS) model to delineate spill pathways and calculate travel-time for overland flow and channel flow within the storm sewer system (geometric network). The model delineates the overland spill path and traces the spill path through the storm sewer network. The travel-time for each type of path is calculated and can be summed to determine the total travel-time for each predicted spill. Keywords: inland oil spill, comprehensive planning framework, spill management, prevention, control, response, stationary, transportation-related, hot spot analysis, macro program, Monte Carlo, Iman Conover, simulation, GIS, travel-time, spill path, geometric network

scholarly journals How catchment characteristics influence hydrological pathways and travel times in a boreal landscape

2021 ◽  
Vol 25 (4) ◽  
pp. 2133-2158
Author(s):  
Elin Jutebring Sterte ◽  
Fredrik Lidman ◽  
Emma Lindborg ◽  
Ylva Sjöberg ◽  
Hjalmar Laudon
Keyword(s):  
Groundwater Recharge ◽  
Travel Time ◽  
Overland Flow ◽  
Geometric Mean ◽  
Base Cation ◽  
Travel Times ◽  
Soil Frost ◽  
Landscape Type ◽  
Hydrological Responses ◽  
Tracking Model

Abstract. Understanding travel times and hydrological pathways of rain and snowmelt water transported through the landscape to recipient surface waters is critical in many hydrological and biogeochemical investigations. In this study, a particle-tracking model approach in Mike SHE was used to investigate the pathway and its associated travel time of water in 14 partly nested, long-term monitored boreal sub-catchments of the Krycklan catchment (0.12–68 km2). This region is characterized by long and snow-rich winters with little groundwater recharge and highly dynamic runoff during spring snowmelt. The geometric mean of the annual travel time distribution (MTTgeo) for the studied sub-catchments varied from 0.8 to 2.7 years. The variations were related to the different landscape types and their varying hydrological responses during different seasons. Winter MTTgeo ranged from 1.2 to 7.7 years, while spring MTTgeo varied from 0.5 to 1.9 years. The modelled variation in annual and seasonal MTTgeo and the fraction of young water (<3 months) was supported by extensive observations of both δ18O and base cation concentrations in the different streams. The travel time of water to streams was positively correlated with the area coverage of low-conductive silty sediments (r=0.90, P<0.0001). Catchments with mixed soil–landscape settings typically displayed larger variability in seasonal MTTgeo, as contrasting hydrological responses between different soil types (e.g. peat in mires, till and silty sediments) are integrated. The areal coverage of mires was especially important for the young water contribution in spring (r=0.96, P<0.0001). The main factor for this was attributed to extensive soil frost in mires, causing considerable overland flow during the snowmelt period. However, this lower groundwater recharge during snowmelt caused mire-dominated catchments to have longer stream runoff MTTgeo than comparable forest catchments in winter. Boreal landscapes are sensitive to climate change, and our results suggest that changes in seasonality are likely to cause contrasting responses in different catchments depending on the dominating landscape type.

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