One- and two-dimensional modelling of overland flow in semiarid shrubland, Jornada basin, New Mexico

Abstract

Abstract:Two distributed parameter models, a one-dimensional (1D) model and a two-dimensional (2D) model, are developed to simulate overland flow in two small semiarid shrubland watersheds in the Jornada basin, southern New Mexico. The models are event-based and represent each watershed by an array of 1-m 2 cells, in which the cell size is approximately equal to the average area of the shrubs.Each model uses only six parameters, for which values are obtained from field surveys and rainfall simulation experiments. In the 1D model, flow volumes through a fixed network are computed by a simple finite-difference solution to the 1D kinematic wave equation. In the 2D model, flow directions and volumes are computed by a second-order predictor-corrector finite-difference solution to the 2D kinematic wave equation, in which flow routing is implicit and may vary in response to flow conditions.The models are compared in terms of the runoff hydrograph and the spatial distribution of runoff. The simulation results suggest that both the 1D and the 2D models have much to offer as tools for the large-scale study of overland flow. Because it is based on a fixed flow network, the 1D model is better suited to the study of runoff due to individual rainfall events, whereas the 2D model may, with further development, be used to study both runoff and erosion during multiple rainfall events in which the dynamic nature of the terrain becomes an important consideration.

Infrastructure effects on floods in the Mekong River Delta in Vietnam

“…Development and application of numerical models based on the Saint Venant equations for rivers and floodplains to simulate inundation extent for different purposes are common worldwide (Cunge, 1975;Daluz Vieira, 1983;Abbott et al, 1986;Chow et al, 1988;Bates et al, 1996;Harvouet and Van Haren, 1996;Moussa and Bocquillon, 1996;Romanowicz et al, 1996;Keskin and Agiralioglu, 1997;Dutta et al, 2000Dutta et al, , 2003Horritt and Bates, 2001;Werner et al, 2005;Howes et al, 2006). In the MRD, the flood propagation in rivers and floodplains with models solving the equations of Saint Venant were developed.…”

Overland flow computations in urban and industrial catchments from direct precipitation data using a two-dimensional shallow water model

“…A similar approach has been used in small rural catchments by Howes et al (2006) and by Kiwa & Zheleznyak (2005). In none of these cases urban fioods were considered.…”

Two-dimensional numerical models for overland flow simulations

“…with: (7,8,9,10) and ignoring also the depth gradient terms one may obtain the following kinematic model:…”

“…In this context, the 2D fully dynamic shallow water equations seem to be the required approach to deal with that situation because it allows one to analyse in depth the flow behaviour in locally complex topography. On the other hand, the use of different approximations of the unsteady flow equations is very common in order to simulate the overland flow processes leading to the kinematic and diffusive wave models [1,3,7,9,12]. Several authors have studied the conditions in which those approximations are completely justified [14][15][16]21].…”