Overland flow under rainfall

some aspects related to modelling and conditioning factors
  • 160 Pages
  • 0.62 MB
  • English
Landbouwuniversiteit te Wageningen? , [Wageningen, The Netherlands?
Runoff -- Simulation methods., Rain and rainfall -- Simulation met
StatementJ.L.M.P. de Lima.
The Physical Object
PaginationXII, 160 p. :
ID Numbers
Open LibraryOL19304511M

Then, simulated rainfall experiments were performed on five slope gradients (5°, 10°, 15°, 20°, and 25°) with an extreme rainfall intensity of 80 mm h −1. The results showed that Froude number and flow velocity of the overland flow decreased, whereas flow resistance increased exponentially with litter incorporation :// Overland flow was simulated using kinematic wave theory.

Mixing zone depths ranged from to cm and were a linear function of rainfall intensity.

Description Overland flow under rainfall FB2

Also, the fraction of solute present in the mixing zone at the time of ponding which was extracted into overland flow was a An overland flow system Overland flow under rainfall book of three slopes (each 25 m long by 3 m wide and gradient of 4%) and receiving UASB effluent, demonstrated complete removal of parasite eggs when receiving a constant flow of influent containing 14 eggs/l (Chernicharo et al., ).

In another trial, slope removal efficiency was 99% under intermittent influent Overland flow under rainfall book Effects of patternedArtemisia capillarison overland flow velocity under simulated rainfall Article in Hydrological Processes 26(24) November with 22 Reads How we measure 'reads' In book: Encyclopedia of Hydrological Sciences.

to predict both the onset of ponding under rainfall, and. RAINFALL EXCESS OVERLAND FLOW This study concerns the theory and some practical aspects of overland flow under rainfall. Of the conditioning factors and processes which govern the generation of overland flow, the following were studied: depression storage, infiltration, morphology and :// Under intermittent rainfall, apparent infiltration rates are reduced by 30%–45% in comparison with those from experiments under constant rainfall intensity ( mm/h versus a mean of mm/h under constant intensity rain), and runoff ratios are reduced (an average of % runoff versus a mean of % under constant intensity rain).

Abstract. Forest cover and its management and perturbations could significantly affect the surface runoff (part of the precipitation that does not penetrate into the soil and not accumulate on its surface), overland flow (surface runoff and streams), soil erosion, and runoff water :// OVERLAND FLOW UNDER RAINFALL: SOME ASPECTS RELATED TO MODELLING AND CONDITIONING FACTORS Proefschrift ter verkrijging van de graad van doctor in de landbouwwetenschappen, op gezag van de rector magnificus, dr.

H.C. van der Plas, in het openbaar te verdedigen op vrijdag 8 december des namiddags te vier uur in de aula   Overland flow is a very important aspect of the water cycle and can be generated under two different physical mechanisms.

The infiltration excess overland flow is formed (named also Hortonian overland flow after Horton E. R.), when the rainfall intensity exceeds the soil infiltration capacity in an area (Liu et al., ). This study concerns the theory and some practical aspects of overland flow under rainfall.

Of the conditioning factors and processes which govern the generation of overland flow, the following were studied: depression storage, infiltration, morphology and wind. Special attention was paid to wind-driven rain and its effect on raindrops   incidence of rainfall in the overland flow process.

A method, based on the kinematic wave theory, is presented in which overland flow, under rainfall from any dominant direction, is simplified by taking a one-dimensional flow process by means of spatial rotation of the surface (assumed to be a plane).

Details Overland flow under rainfall PDF

Further the acceleration of Yang Pingping,Wang Yunqi,Zhang Huilan,Wang teristics of overland flow resistance under interaction of rainfall intensity and unit discharge and surface roughness[J]?file.

Mechanics of Sheet Flow under Simulated Rainfall. Friction factors are presented for spatially varied sheet flow with rainfall on a hydraulically smooth surface as obtained from both surface profile and hot film surface probe measurements. The results are presented in the form f = C/R, in which C increases with rainfall intensity and surface ?dockey= Overland flow generation in drylands.

Bare soils in drylands are directly exposed to rain impact and sunlight, leading to the formation of structural and sedimental soil seals [], and biological soil crusts [].Together, seals and crusts form a compacted, disturbed layer at the soil surface, characterized by low saturated hydraulic conductivity [33, 34].

2. Define the flow path from the upper-most portion of the catchment to the design point. Divide the flow path into reaches of similar flow type (e.g., overland flow, shallow swale flow, gutter flow, etc.).

Determine t he length and slope of each reach. Determine the time of concentration, criteria manual/   from Storm Rainfall Chapter 10 10–2 (VI-NEH, July ) Baseflow occurs when there is a fairly steady flow from natural storage.

The flow comes from an aqui-fer that is replenished by infiltrated rainfall or sur-face runoff. Changes in this type of runoff seldom appear soon enough after a storm to have an influ-&H/NEHhydrology/chpdf. The removal of nutrients by overland flow remains a major source of non-point pollution in agricultural land.

In this study, a mathematical model of ammonium nitrogen transport from soil solution to overland flow was established. The model treated the mass transfer coefficient (km) as a time-dependent parameter, which was not a constant value as in previous studies, and it was evaluated with a   Australian Rainfall and Runoff (ARR) Book 3 Peak Flow Estimation.

Fitting to Gauged Data to obtain: • Flood Frequency if you have gauged data, • Regional Flood Models (rural catchments) - (Regional overland flow paths or watercourses etc. Simple flow in channels; Flow   tested using data collected for overland flow under simulated rainfall carried out in plots with vegetation.

The available data were obtained exploring a wide range of rainfall intensities (from 60 to mm h−1) and slopes (from to %), and with four   Overland flow is surface runoff that occurs in the form of sheet flow on the land surface without concentrating in clearly defined channels.

This type of flow is the first manifestation of surface runoff, since the latter occurs first as overland flow before it has a chance to flow into channels and become The FullSWOF-ZD program simulates the complete overland flow processes and then quantify the curb inlet efficiency under the constant rainfall and constant upstream inflow conditions.

One thousand road modeling cases with different longitudinal slopes, cross slopes, and   overland flow) and saturation excess runoff (Dune and Black overland flow) (Freeze ).

Infiltration excess runoff often occurs from patches where soils become saturated at the surface.

Download Overland flow under rainfall PDF

This happens when rainfall intensity exceeds the infiltration capacity of the soils. Hortonian overland flow is   HUANG Manxiang, ZHANG Shen, ZHANG Guoliang, ZHANG iumei. Losses of Nitrogen Nutrient in Overland Flow from Farmland in Beijing under Simulated Rainfall Conditions[J].Acta Geographica Sinica,58(1):   Overland flow resistances on varying slope gradients and partitioning on grassed slopes under simulated rainfall Chengzhong Pan1, Lan Ma2, John Wainwright3, and Zhouping Shangguan4 1Key Laboratory of Water Sediment Sciences, College of Water ?sequence.

Characteristics of overland flow resistance under interaction of rainfall intensity and unit discharge and surface roughness by Yang, Pingping and Wang, Yunqi and Zhang, Huilan and Wang, Yujie Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering, ISSN03/, Vol Issue 6, pp.

- ?kw=SubjectTerms:OVERLAND-FLOW. Vegetation plays an important role in reducing soil erosion. By exploring the allocation and coverage of different types of vegetation, we can improve management practices that can significantly reduce soil erosion. In this experiment, we study runoff and sediment losses on a shrub-grass planted, grass planted, and bare slope under different rainfall ://   He has directly conducted and also managed several major flood studies and overland flow mapping projects for urban catchments.

Steve is a contributing author and co-editor of Australian Rainfall and Runoff Book 9 ‘Runoff in Urban Areas’. An analytical solution for the time of concentration for overland flow on a rectangular plane surface is derived using the kinematic wave equation under the Green-Ampt ://(ASCE)HE The distributions indicate how the overland sheet flow, under the influence of dikes and topography, concentrates into channels and flows out of the watershed.

The flows over the slopes are sheet runoff, but complex recirculations are developed in the main channel. The. Overland flow never exceeded the laminar and subcritical regime; the Reynolds number reacted differently with AI and rainfall intensity, whereas the Froude number has similar reaction with both parameters.

Re, Fr and n follow with AI logarithmic, linear and power functions respectively. Finally, AI is a good predictor of soil ://  Effects of patterned Artemisia capillaris on overland flow resistance under varied rainfall intensities in the Loess Plateau of China Guanhua Zhang 1, 2, Guobin Liu [email protected] 2, Liang Yi 3 and Pingcang Zhang 1  transport due to overland flow with rainfall.

However, future research and data on the saltation length of grains under very shallow flow and with or without rainfall are needed in order to fully account for all of the saltation processes which occur in overland flow with rainfall.

In a recent study, Julien and Simons () presented