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Simulation of Runoff Hydrograph on Soil Surfaces with Different Microtopography Using a Travel Time Method at the Plot Scale.

Zhao L, Wu F - PLoS ONE (2015)

Bottom Line: The flow velocity in each grid cell (vi) was derived from the upstream flow accumulation area using vm.The runoff rate at the slope outlet for each respective travel time was estimated by finding the sum of the rain rate from all contributing cells for all time intervals.The results show positive agreement between the measured and predicted runoff hydrographs.

View Article: PubMed Central - PubMed

Affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, China; College of Forestry, Guizhou University, Guiyang, Guizhou, China; USDA-ARS National Soil Erosion Research Laboratory, 275 South Russell Street, West Lafayette, Indiana, United States of America.

ABSTRACT
In this study, a simple travel time-based runoff model was proposed to simulate a runoff hydrograph on soil surfaces with different microtopographies. Three main parameters, i.e., rainfall intensity (I), mean flow velocity (vm) and ponding time of depression (tp), were inputted into this model. The soil surface was divided into numerous grid cells, and the flow length of each grid cell (li) was then calculated from a digital elevation model (DEM). The flow velocity in each grid cell (vi) was derived from the upstream flow accumulation area using vm. The total flow travel time through each grid cell to the surface outlet was the sum of the sum of flow travel times along the flow path (i.e., the sum of li/vi) and tp. The runoff rate at the slope outlet for each respective travel time was estimated by finding the sum of the rain rate from all contributing cells for all time intervals. The results show positive agreement between the measured and predicted runoff hydrographs.

No MeSH data available.


Related in: MedlinePlus

Photograph of surface microtopography with a smooth surface (a), mounds (b) and depressions (c).
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pone.0130794.g004: Photograph of surface microtopography with a smooth surface (a), mounds (b) and depressions (c).

Mentions: The laboratory experiments contained three types of surface microtopographies, i.e., mound, depression and smooth surface (Fig 4). The soil box is 1.2 m long and 1.2 m wide, divided midway into two 0.6 m wide study areas. The soil box has drainage holes at the bottom and the study was conducted under free-drainage conditions. The rainfall intensity applied was 50 mm/h. Runoff samples were collected at five-minutes intervals to develop a runoff hydrograph. Before the rain was applied, the surface microtopography was measured using an instantaneous profile laser scanner with a horizontal resolution of 1.5 mm and a vertical resolution of 0.5 mm [20]. These measured relative elevations were used to create DEMs, which were used to run the runoff model proposed in this study. The size of each grid cell for each DEM was 2 mm.


Simulation of Runoff Hydrograph on Soil Surfaces with Different Microtopography Using a Travel Time Method at the Plot Scale.

Zhao L, Wu F - PLoS ONE (2015)

Photograph of surface microtopography with a smooth surface (a), mounds (b) and depressions (c).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4477983&req=5

pone.0130794.g004: Photograph of surface microtopography with a smooth surface (a), mounds (b) and depressions (c).
Mentions: The laboratory experiments contained three types of surface microtopographies, i.e., mound, depression and smooth surface (Fig 4). The soil box is 1.2 m long and 1.2 m wide, divided midway into two 0.6 m wide study areas. The soil box has drainage holes at the bottom and the study was conducted under free-drainage conditions. The rainfall intensity applied was 50 mm/h. Runoff samples were collected at five-minutes intervals to develop a runoff hydrograph. Before the rain was applied, the surface microtopography was measured using an instantaneous profile laser scanner with a horizontal resolution of 1.5 mm and a vertical resolution of 0.5 mm [20]. These measured relative elevations were used to create DEMs, which were used to run the runoff model proposed in this study. The size of each grid cell for each DEM was 2 mm.

Bottom Line: The flow velocity in each grid cell (vi) was derived from the upstream flow accumulation area using vm.The runoff rate at the slope outlet for each respective travel time was estimated by finding the sum of the rain rate from all contributing cells for all time intervals.The results show positive agreement between the measured and predicted runoff hydrographs.

View Article: PubMed Central - PubMed

Affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, China; College of Forestry, Guizhou University, Guiyang, Guizhou, China; USDA-ARS National Soil Erosion Research Laboratory, 275 South Russell Street, West Lafayette, Indiana, United States of America.

ABSTRACT
In this study, a simple travel time-based runoff model was proposed to simulate a runoff hydrograph on soil surfaces with different microtopographies. Three main parameters, i.e., rainfall intensity (I), mean flow velocity (vm) and ponding time of depression (tp), were inputted into this model. The soil surface was divided into numerous grid cells, and the flow length of each grid cell (li) was then calculated from a digital elevation model (DEM). The flow velocity in each grid cell (vi) was derived from the upstream flow accumulation area using vm. The total flow travel time through each grid cell to the surface outlet was the sum of the sum of flow travel times along the flow path (i.e., the sum of li/vi) and tp. The runoff rate at the slope outlet for each respective travel time was estimated by finding the sum of the rain rate from all contributing cells for all time intervals. The results show positive agreement between the measured and predicted runoff hydrographs.

No MeSH data available.


Related in: MedlinePlus