|
Information and Service
|
|
| This Article | |
 |
Supporting info |
|
PDF(287KB) |
|
Reference |
| Service and feedback | |
|
Add to Citation Manager |
|
Cite This Article |
|
Email Alert |
| Keywords | |
|
micromechanisms of watershed flow concentration |
|
grid drop |
|
overland flow velocity formula |
|
spatial velocity field |
|
watershed runoff concentration time |
|
digital elevation model |
| Authors | |
|
Rui Xiaofang |
|
Yu Mei |
|
Liu Fanggui |
|
Gong Xinglong |
| PubMed | |
|
Article by |
|
Article by |
|
Article by |
|
Article by |
Calculation of watershed flow concentration based on the grid drop concept
Rui Xiaofang1,2; Yu Mei1,2; Liu Fanggui1,2; Gong Xinglong1,2
1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, P. R. China
2. College of Hydrology and Water Resources, Hohai University, Nanjing 210098, P. R. China
The grid drop concept is introduced and used to develop a micromechanism-based methodology for calculating watershed flow concentration. The flow path and distance traveled by a grid drop to the outlet of the watershed are obtained using a digital elevation model (DEM). Regarding the slope as an uneven carpet through which the grid drop passes, a formula for overland flow velocity differing from Manning’s formula for stream flow as well as Darcy's formula for pore flow is proposed. Compared with the commonly used unit hydrograph and isochronal methods, this new methodology has outstanding advantages in that it considers the influences of the slope velocity field and the heterogeneity of spatial distribution of rainfall on the flow concentration process, and includes only one parameter that needs to be calibrated. This method can also be effectively applied to the prediction of hydrologic processes in un-gauged basins.