CGRG Bibliography of Canadian Geomorphology
Search Results
Author : Hamdi, Y.; St-Hilaire, A.; and Bobée, B.
Date : 2002.
Title : Spatial integration of inputs to a conceptual hydrological model : Comparison of two algoritms.
Publication : Annual Meeting of the Canadian Geophysical Union. May 18-21, 2002, Banff, Alberta.
Issue :
Page(s) :
Abstract
The quality of hydrological model simulations and/or predictions is affected by a number of factors, which include the model’s inherent mathematical representation of hydrological dynamics, model calibration and the sensitivity of the model to each of its parameters, and the quality of meteorological and physiographic inputs in the model. Meteorological inputs will be computed from a network of stations in or near the drainage basin. This network is often subjected to temporal variations in its spatial density. Stations are closed or opened, in accordance with changes in administrative regulations, cost-effectiveness, etc. Precipitation is the most important input to hydrological models. A number of simple conceptual models only allow for one daily precipitation input, which implies that data from all stations on or neighbouring the drainage basin must be spatially integrated. In many instances, weighted averages are calculated, and the development of methods to assign weights to each stations is left to the user. To alleviate this problem, two algorithms were developed to calculate spatial averages of precipitation. The first algorithm uses the geostatistical method known as kriging for spatial interpolation of precipitation. Weights were assign to existing stations using a theoretical semi-variogram model, fitted to the calculated semi-variograms. A evenly spaced grid of interpolated precipitation is produced using the krigged data for each time step, which is then averaged for the entire drainage basin. The second proposed algorithm assigns weights to each station using Thiessen polygons. The polygons are automatically drawn, using as input the station location, and a schematized drainage basin boundary. The weight associated to each station is calculated from the ratio of Thiessen polygon area enclosed in the basin, to that of the entire drainage area. Both methods can be used to simulate real or hypothesized changes in meteorological network density, thereby allowing for the quantification of its impact on flow simulations and/or prediction.
Bibliography of Canadian Geomorphology