River network solution for a distributed hydrological model and applications

Abstract

Abstract:A simultaneous solution for one-dimensional unsteady¯ow routing for a network of rivers has been developed, which can be used either with a complete distributed hydrological model, a simple rainfall-runo model or as a stand alone river routing model. Either dynamic or kinematic solution schemes can be selected to simulate the river¯ows. The river network is either generated from the Digital Elevation Model (DEM) or directly input to the model. The model can handle any number of upstream channels and computational points. A sparse matrix solution algorithm is used to solve the 2N Â 2N matrix resulting from N nodes in the network. A submodule generates the initial water depth and discharge at each computational point from equilibrium discharge in the absence of observed initial conditions. The model is applied in three sub-catchments of the Chao Phraya river basin, Thailand, considering three dierent conditions. The simulated results show good agreement with observed discharges and provide insight to water level¯uctuations, especially where tributaries join the main channel.

A discontinuous Galerkin method for modeling flow in networks of channels

“…Each channel segment is treated as an individual channel and the channels are coupled with one another through the prescription of interior boundary conditions at the junction [4,5,6,7]. One such junction is represented in Figure 1 by the circle.…”

“…In other flow regimes, not only the junction equations, but the number of junction equations and the number of characteristic equations needed are also different from that in a subcritical flow regime [8,12,7]. For example, if subcritical flow conditions exist in all three channels that form the junction in Figure 1, then the forward characteristic equation will be applicable to Channels 1 and 2 and the backward characteristic equation will be applicable to Channel 3.…”

Flood inundation mapping for the Gwadar city

“…A schematic demonstrating of all of the components of IISDHM model is shown in Figure 2. IISDHM is capable of modeling both the overland and sub-surface flow ( [8], [9], [10], [11], [12] & [13]). For the subsurface flow, it makes use of 3D Richards Equations.…”

A Sub-Catchment Based Approach for Modelling Nutrient Dynamics and Transport at a River Basin Scale

“…The nutrient model was built within an existing process-based and distributed hydrological model called IISDHM, (Jha et al 2000;Dutta et al 2000Dutta et al , 2006Asokan and Dutta 2008;Dutta and Nakayama 2009;Kabir et al 2011). There are advancements made in alternative hydrological modelling approach using artificial neural network and optimizing techniques such as genetic algorithm (Taormina and Chau 2015;Saeidifarzad 2014;Wu et al 2009;Chen et al 2015;Chau and Wu 2010).…”