The FLO Diffusive 1D-2D Model for Simulation of River Flooding

Abstract

An integrated 1D-2D model for the solution of the diffusive approximation of the shallow water equations, named FLO, is proposed in the present paper. Governing equations are solved using the MArching in Space and Time (MAST) approach. The 2D floodplain domain is discretized using a triangular mesh, and standard river sections are used for modeling 1D flow inside the section width occurring with low or standard discharges. 1D elements, inside the 1D domain, are quadrilaterals bounded by the trace of two consecutive sections and by the sides connecting their extreme points. The water level is assumed to vary linearly inside each quadrilateral along the flow direction, but to remain constant along the direction normal to the flow. The computational cell can share zero, one or two nodes with triangles of the 2D domain when lateral coupling occurs and more than two nodes in the case of frontal coupling, if the corresponding section is at one end of the 1D channel. No boundary condition at the transition between the 1D-2D domain has to be solved, and no additional variable has to be introduced. Discontinuities arising between 1D and 2D domains at 1D sections with a top width smaller than the trace of the section are properly solved without any special restriction on the time step.

Analyzing the Performances of Water User Associations to Increase the Irrigation Sustainability: An Application of Multivariate Statistics to a Case Study in Italy

“…The irrigation at the farm level is mainly based on surface and sprinkler irrigation systems, only a few farmers use micro-irrigation. Water fees are charged from the Many of these WUAs are paid by local administrations for the ordinary maintenance of land reclamation works, purposed to soil conservation and watershed management; several works managed by the WUAs are important to avoid the flooding risk in valley areas, often highly urbanized [36][37][38]. Each WUA takes care of a portion of the Calabrian territory, where it manages most irrigation systems covering the command area.…”

A Method to Improve the Flood Maps Forecasted by On-Line Use of 1D Model

“…Therefore, the models used for urban flood simulations need to account for the specific processes of the urban environment, where the stormwater follows multiple flow paths such as crossroads, sewers and buildings [6,[18][19][20]. Prediction of flooding effects can be carried out using several numerical models, which can be categorized into (a) one-dimensional (1D) models, (b) two-dimensional (2D) models, and (c) one-dimensional river flow models coupled with two-dimensional floodplain flow (1D-2D) models [21,22]. The 1D hydrodynamic models are computationally efficient, but they are not able to simulate flow diffusion on a continuous surface; on the contrary, the 2D models offer a high level of accuracy, but are computationally intensive [13].…”

A Two-Dimensional Finite Element Channel/Lake Flood Model; Case Study of Edko Drain/Lake, Egypt

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“…Arico et al 5 used novel coupling 1D-2D strategy which has been proposed in the shallow water models' framework. Governing equations are written in diffusive form and solved in the water level unknown.…”