Paper should be a substantial original Article that involves several techniques or approaches, provides an outlook for Luo, J., Zheng, Z., Li, T. & He, S. Spatial heterogeneity of microtopography and its influence on the flow convergence of slopes under different rainfall patterns. Note, in Figure 7, that infiltration capacity declines during the storm, due to the pores being filled with Bracken, L. J. Each of these factors can weaken the effect of depressions to some extent, and the combination of all three factors determined the original shape of the RDOC. Schematic of the stage division in RDOF construction. 5.2.1.3 Large Watersheds: These watersheds are less sensitive to high-intensity-rainfalls of short duration. They have rich wildlife and plenty of vegetation. On the land surface, it is a geographical unit in which the hydrological cycle and its components can be analyzed. Role of snow in runoff processes in a subalpine hillslope: Field study in the Ward Creek Watershed, Lake Tahoe, California, during 2000 and 2001 water years. hydrosphere: Groundwaters and river runoff. If material is not included in the articles Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To explore the influence of single hydrological factors on the OT, we continued to adopt the idea of homogenization. From an overall perspective, the results of the curve-fitting are reliable (i.e., R>0.9). 2: 18. Before filling, a 5-cm layer of soil was placed in each tank, and a layered filling was used. Therefore, our primary goal was to construct a convenient function to express the outflow process. The rainfall intensity at 2-year, 5-year, and 10-year return periods in Nanjing was 0.824mm/min, 1.044mm/min, and 1.209mm/min, respectively. Usually a watershed is defined as the area that appears, on the basis of topography, to contribute all the water that passes through a given point of a stream. Rather than size, shape of the watershed plays a dominant role. Horton, R.E. Overland flow is one of the causes of soil erosion and water loss. It is easily determined by contour map and drainage map of the basin. During a rainfall event, the overland flow (Fig. Chu, X., Yang, J., Chi, Y. Ebel, B.A. The only exception to this pattern was the RDOC with a return period of 2 years and a slope of 2.5, whose surface outflow rate did not markedly increase until the relative depression storage reached ~0.1. The DR is calculated as follows: where Ssurface is the surface area of the entire slope, including the depressions, and Sprojection is the projection area perpendicular to the direction of the slope. Hydrology. With the application of every hydrological factor, the LevenbergMarquardt method was used to optimize the values of B and D. The optimization results are summarized in Table5. The reason for this error is mainly due to the surface outflow exhibiting a certain degree of volatility. ; Hogan, M.P. The authors declare no competing interests. Werner, M., Reggiani, P., Roo, A. D., Bates, P. & Sprokkereef, E. Flood forecasting and warning at the river basin and at the European scale. Water flux in soil and subsoil on a steep forested slope. ; McGlynn, B.L. A Watershed Illustration. Although the OTs of varying rainfall intensities and slopes exhibit little regularity, certain overall tendencies can be seen. A homogenized RDOC was achieved based on shape analysis; it was parameterized by the outflow threshold and the reciprocal of the curve index of two outflow stages (B and D). Ultimately, this leads to a slightly earlier spillover time in local areas compared to the spillover time of the total areas and causes RDST to decrease. Theoretically, all depressions should reach the spillover point simultaneously. (PDF) Overland flow on rangeland watersheds - ResearchGate In the gentle rising stage, the relative depression storage increased significantly more than the surface outflow rate. ; Seibert, J. ; Ebel, B.A. Groundwater phosphate dynamics in a river riparian zone: Effects of hydrologic flowpaths, lithology, and redox chemistry. (1932). The RDOCs constructed under different hydrological factors are summarized according to their different depression rates in Fig. The RDOCs have a second flat stage in their curves (Fig. Flume experiments were conducted to investigate the hydrodynamics of flow through rigid emergent vegetation arranged in combinations with three densities (Dense, Middle, and Sparse) and three . This may be due to the soil crust caused by water scouring, which led to a decrease in the infiltration rate and an increase in the surface outflow. Determination of overland sheet flow depths, velocities and celerities across the hillslope in watershed modeling is important towards estimation of surface storage, travel times to streams and soil detachment rates. The dimensions of the soil tank were 1.5m 0.5m 0.65m. For simulating outflow, standardized depressions were constructed on the soil trough. J. The reason for the decrease in the relative depression storage corresponding to the OT is likely due to the faster outflow rate and reduced infiltration rate resulting from the greater rainfall intensity. Get the most important science stories of the day, free in your inbox. ; Ebel, B.A. By excluding the influence of time, we simultaneously combined the surface outflow with the depression storage. The confining influence of the rough surface gradually decreases with the increasing formation of overland flow, which greatly facilitates the process of runoff confluence. Using the predicted flow depths, the apparent Mannings. Rossi, M. J. 5.2) -, The greatest straight-line distance between any two points on the perimeter, The greatest distance between the outlet and any point on the perimeter, The length of the main stream from its source (projected to the perimeter) to the outlet, Fig. where Q sw represents the instantaneous stream water discharge at the catchment outlet, Q of, the instantaneous discharge of overland flow and Q gw, the instantaneous discharge of groundwater (expressed in L s 1).EC SW is the instantaneous EC measured in the stream. These findings demonstrate the nonlinear influence of each hydrological factor on the OT. ; Bencala, K.E. To fully explore the hydrological response of RDOCs under different hydrological factors, we conducted this study with three return periods, four slopes, and four depression depths (Table1). Changes in the outflow threshold point under the influence of different slopes and rainfall return periods: (a) SORT and (b) RDST. Physics-based hydrologic response simulation: Foundation for hydroecology and hydrogeomorphology. Thus, an urban watershed is more vulnerable to flooding if the drainage system is inadequate. The actual surface outflow under the influence of depressions at a given moment may then be calculated. Furthermore, it accelerated the speed of the surface outflow, as surface roughness was reduced. The soil is mostly sandy and little annual rainfall occurs. Knights Press. A watershed is a basic unit of hydrological behavior. In recent years, studies on depressions have focused on the functional and structural features18 related to the appearance of overland flow. In overland flow, wastewater is sprayed onto an inclined vegetated terrace and slowly flows to a collection ditch. most exciting work published in the various research areas of the journal. Partial area contributions to storm runoff in a small New England watershed. The Horton-Strahler ordering scheme. Grismer, M.E. Simulation of overland flow considering the influence of topographic depressions, $${\rm{DR}}=({{\rm{S}}}_{{\rm{surface}}}/{{\rm{S}}}_{{\rm{projection}}}-1)\times 100 \% $$, $${\rm{SOR}}=\frac{{{\rm{R}}}_{{\rm{out}}}}{{{\rm{R}}}_{yield}};$$, $${\rm{RDS}}=\frac{{\rm{DS}}}{{\rm{DSM}}},$$, $$\frac{{\rm{SOR}}}{{{\rm{SOR}}}_{{\rm{T}}}}=1-{\left(1-\frac{{\rm{RDS}}}{{{\rm{RDS}}}_{{\rm{T}}}}\right)}^{\frac{1}{{\rm{B}}}}\,{,{\rm{RDS}} < {\rm{RDS}}}_{{\rm{T}}},$$, $$\frac{{{\rm{SOR}}-{\rm{SOR}}}_{{\rm{T}}}}{1{-{\rm{SOR}}}_{{\rm{T}}}}=1\,-\,{\left(1-\frac{{{\rm{RDS}}-{\rm{RDS}}}_{{\rm{T}}}}{1{-{\rm{RDS}}}_{{\rm{T}}}}\right)}^{\frac{1}{{\rm{D}}}},RDS\ge {{\rm{RDS}}}_{{\rm{T}}},$$, $${\rm{SOR}}=\{\begin{array}{l}{{\rm{SOR}}}_{{\rm{T}}}\times \left(1\,-\,{\left(1-\frac{{\rm{RDS}}}{{{\rm{RDS}}}_{{\rm{T}}}}\right)}^{\frac{1}{{\rm{B}}}}\right),\,{{\rm{RDS}} < {\rm{RDS}}}_{{\rm{T}}}\\ (1{-{\rm{SOR}}}_{{\rm{T}}})\times \left(1\,-\,{\left(1-\frac{{{\rm{RDS}}-{\rm{RDS}}}_{{\rm{T}}}}{1{-{\rm{RDS}}}_{{\rm{T}}}}\right)}^{\frac{1}{{\rm{D}}}}\right){+{\rm{SOR}}}_{{\rm{T}}},\,{\rm{RDS}}\ge {{\rm{RDS}}}_{{\rm{T}}}\end{array}.$$, $${{\rm{RDS}}}_{0}=\frac{{{\rm{DS}}}_{0}}{{\rm{DSM}}}.$$, $${{\rm{SOR}}}_{0}=\{\begin{array}{l}{{\rm{SOR}}}_{{\rm{T}}}\times \left(1\,-\,{\left(1-\frac{{{\rm{RDS}}}_{0}}{{{\rm{RDS}}}_{{\rm{T}}}}\right)}^{\frac{1}{{\rm{B}}}}\right),\,{{\rm{RDS}}}_{0}{ < {\rm{RDS}}}_{{\rm{T}}}\\ (1{-{\rm{SOR}}}_{{\rm{T}}})\times \left(1\,-\,{\left(1-\frac{{{\rm{RDS}}}_{0}{-{\rm{RDS}}}_{{\rm{T}}}}{1{-{\rm{RDS}}}_{{\rm{T}}}}\right)}^{\frac{1}{{\rm{D}}}}\right){+{\rm{SOR}}}_{{\rm{T}}},\,{{\rm{RDS}}}_{0}\ge {{\rm{RDS}}}_{{\rm{T}}}\end{array}.$$, $${{\rm{R}}}_{{\rm{out}}}{={\rm{R}}}_{{\rm{yield}}}\times {{\rm{SOR}}}_{0}.$$, $${\rm{D}}{\rm{S}}{\prime} =\frac{{{\rm{DS}}}_{0}{+{\rm{R}}}_{{\rm{yield}}}{-{\rm{R}}}_{{\rm{out}}}}{{\rm{DSM}}}.$$, $${\rm{RD}}{\rm{S}}{\prime} =\frac{{\rm{D}}{\rm{S}}{\prime} }{{\rm{DSM}}};$$, $${\rm{SO}}{\rm{R}}{\prime} =\{\begin{array}{l}{{\rm{SOR}}}_{{\rm{T}}}\times \left(1\,-\,{\left(1-\frac{{\rm{RD}}{\rm{S}}{\prime} }{{{\rm{RDS}}}_{{\rm{T}}}}\right)}^{\frac{1}{{\rm{B}}}}\right),\,{{\rm{RD}}{\rm{S}}{\prime} < {\rm{RDS}}}_{{\rm{T}}}\\ (1{-{\rm{SOR}}}_{{\rm{T}}})\times \left(1\,-\,{\left(1-\frac{{{\rm{RD}}{\rm{S}}{\prime} -{\rm{RDS}}}_{{\rm{T}}}}{1{-{\rm{RDS}}}_{{\rm{T}}}}\right)}^{\frac{1}{{\rm{D}}}}\right){+{\rm{SOR}}}_{{\rm{T}}},{\rm{RD}}{\rm{S}}{\prime} \ge {{\rm{RDS}}}_{{\rm{T}}}\end{array}.$$, https://doi.org/10.1038/s41598-020-63001-y. Differences in overland flow, hydrophobicity and soil - ScienceDirect Journal of Hydrology 505(21), 6577 (2013). However, changes in the depression rate have a greater impact on B than those of rainfall intensity. Where Dd basically describes the average distance between streams and L0 approximates the average length of overland flow from the divides of the stream channels. ; Soulsby, C. How does landscape structure influence catchment transit times across different geomorphic provinces? However, the main classification of watershed is discussed broadly on the basis of size and land use. Drainable porosities from the sandbox experiment reflect both the saturation thickness of the sand and its water retention characteristics that both depend on the bedslope of the sandbox. Woolhiser et al. Topography driven conceptual modeling, FLEX-Topo. When water enters the watershed too quickly for the land to absorb it, flooding can occur. Because forests resist flow of overland water, the peak discharge is reduced. Physical watershed modeling based on continuity and kinematic wave equations for surface and subsurface runoff that include parameterization for the subsurface soil properties, surface topography and roughness and surface-subsurface exchange through a thin surface boundary layer have progressed considerably in the past two decades. It requires careful characterization of the flow processes. These properties of watersheds significantly affect the characteristics of runoff and other hydrological processes. Changes in SORT and RDST under the influence of different hydrological factors: (a) depression rate; (b) rainfall return period; (c) slope. The small channels formed by erosion and runoff in the area are obliterated by tillage operations. The derivation of a catchment unit hydrograph caused by a storm rainfall is often related to two flow components, i.e., surface (overland flow) and subsurface (saturated subsurface stormwater flow).Saturated flow in hillslope soil is considered to be initiated when the wetting front from infiltration of rainwater arrives at the lower boundary of a permeable soil layer or shallow water table. This repeated observation of much larger effective hydraulic conductivities within the sandbox was somewhat inconsistent with the column-measured fine-sand hydraulic properties described above and listed in, Despite the use of large onflow rates and steep slopes in an effort to develop sheet flow across the fine sand, in nearly all of the sandbox experiments with 143 mm deep sand and onflow rates greater than ~2 Lpm (~33 mm, While several sandbox runoff experiments were conducted at the three fine-sand depths of 71, 143 and 215 mm, and a variety of slopes, onflow rates and initial soil moisture conditions from dry to uniformly wetted, we chose to focus on the soil moisture conditions more likely to develop in a hillslope between storms; referred to here as the state of natural drainage. Hansen, B. Estimation of surface runoff and water-covered area during filling of surface microrelief depressions. ; Mirus, B.B. This law is an expression of topological phenomenon, and is a measure of drainage efficiency. The difference between the RSCF and RDOC is their ordinates. These are dominated by buildings, roads, streets, pavements, and parking lots. 5.4.2.1 Channel Order: The first-order streams are defined as those channels that have no tributaries. Land-use changes such as urbanization that alter rates of erosion, infiltration, overland flow, or evapotranspiration. In these watersheds, interception is significant, and evapotranspiration is a dominant component of the hydrologic cycle. Differences in overland flow, hydrophobicity and soil - ScienceDirect Why does the amount of overland flow varies in a drainage basin from season to season? 12. Local schematic map of standardized depressions. To facilitate the application of the function to actual hydrological simulations, the establishment of function parameter values and the hydrological responses of different factors were further studied. This was possibly the result of the convergence of accumulated water on the surface resulting in a rapid flow moving toward the boundary of the soil trough. Construction, removal, and sedimentation of reservoirs and stormwater detention ponds. In contrast to previous studies, this work was conducted to develop a solution for the application of overland simulations under the influence of topographic depressions in hydrological models. There is lesser development of streams in agricultural watersheds. Berger, C.; Schulze, M.; Rieke-Zapp, D.; Schlunegger, F. Rill development and soil erosion: A laboratory study of slope and rainfall intensity. Soil Science Society of America Journal 64(5), 17491758 (2000). Hillslope hydrologic connectivity controls riparian groundwater turnover: Implications of catchment structure for riparian buffering and stream water sources. It is also the main driving factor for the migration of pollutants, sediment production, and topographic evolution [1,2,3,4].Overland flow characteristics are mainly affected by surface coverage, slope, and flow discharge [5,6].Vegetation plays an important role in the benign cycle of the ecological environment and has become . In terms of depression rate and rainfall return period, the values of B both show a decreasing tendency with the increase in the depression rate or rainfall intensity. To prevent soil stratification, the soil was gently shaved with a shovel, and the soil layer was tightly combined. ; Loague, K. How runoff begins (and ends): Characterizing hydrologic response at the catchment scale. The surface outflow was determined from the discharge collected every 30s, and the depression storage was calculated from the difference between the surface outflow curves under the depression and without depressions. Flood disasters are among the most destructive natural disasters faced by humans. The infiltration amount is subtracted from the outflow result of the non-depression experiment to obtain Ryield. Overland Flow - an overview | ScienceDirect Topics Shi, P. et al. The basin geomorphology plays an important role in the transition of water from the overland region to channels (streams) and also from the channel of one order to the other. The most common and important channel characteristics of the watersheds are: The quantification of these physical and geomorphologic properties of watershed/basin are important for estimating the watershed hydrologic processes. Engineering hydrology. However, although we are confident with our results, a limited number of experiments were performed, and therefore more studies are required to confirm our findings. https://doi.org/10.1038/s41598-020-63001-y, DOI: https://doi.org/10.1038/s41598-020-63001-y. Transactions, American geophysical union, 13, 350-361. Overland flow is generated at a point on a hillslope only after surface ponding takes place. At least perhaps we should note that (a) laminar overland-interflow dominates in less disturbed grassland/forest areas where infiltration rates are high whether or not slopes are steep, and (b) separate overland-interflow zones that are modeled as laminar processes from concentrated flow lines (e.g., determined from GIS based flow paths) modeled as turbulent flows. Soil monitoring instruments were used to ensure that the soil had been saturated, artificial rainfall was stopped, and the surface water of the soil was cleared. Ponding cannot occur until the surface soil layers become saturated. The experimental instruments, including an artificial rainfall generator and slope-changeable soil tank, are shown in Fig. ; McKenzie, N.J.; Glover, M.R. ; Dunn, S.M. Anderson, M.G. ; VanderKwaak, J.E. 5.2.2.6 Coastal Watershed: The watersheds in coastal areas may partly be urban and are in dynamic contact with the sea. & Chapman, T. G. Measurement and analysis of depression storage on a hillslope. of basin of different order. The complete calculation procedure of the RDOF applied in a hydrological model is provided as part of this work, and the hydrological responses to the function parameters of different hydrological factors and parameter estimation were also performed. (2009) conducted numerical experiments and proposed the relative surface connection function (RSCF) as a functional connectivity indicator22. Watershed area is comprised of two sub-components; Stream areas and Inter-basin areas. Ridges and hills that separate two watersheds are called the drainage divide.