Identification of homogeneous regions for flood frequency analysis

Regional flood frequency analysis I: Homogeneity statistics

“…Whilst it would be possible to produce significance levels for this test from extensive simulations, it is clear that the CV test in its present form is unsuitable for use in assessing region homogeneity. The writer has, however, used this test in an earlier study (Wiltshire, 1986a), the results of which are not greatly diminished by the findings of the simulation experiments reported here.…”

“…For example, in New Zealand, Mosley (1981) used cluster analysis to form groups of basins characterized by specific mean annual flood and coefficient of variation, Waylen & Woo (1984) have formed groups of basins in British Columbia on the basis of five different parameters of the peak-over-threshold flood series, and differentiated between them using discriminant analysis. The present writer has experimented with iterative search techniques which locate optimum divisions of the basin characteristic dataspace based on analysis of variance of flood statistics (Wiltshire, 1985(Wiltshire, , 1986a. Examples of the second approach to basin classification include the work of White (1975) who used a factor analysis of basin characteristic data to identify collections of physically similar basins in Pennsylvania.…”

Flow regimes of Himalayan rivers of Nepal: nature and spatial patterns

“…Geographical regions have been identified based upon political, administrative, river basin and climatic boundaries (Arnell et al, 1990). This approach yields regions connected by location but frequently internally heterogeneous in terms of hydrological and physical characteristics (Wiltshire, 1986). Regionalisation based upon basin characteristics (Acreman and Sinclair, 1986) assumes catchments with similar physical properties produce similar hydrological responses; but climate is typically the first order control upon runoff (Krasovskaia, 1997).…”

Hydrologic similarity among catchments under variable flow conditions

“…Acreman and Sinclair (1986) grouped 186 catchments in Scotland into five homogeneity regions based on six basin characteristics, viz., drainage area, stream frequency, channel slope, mean annual rainfall, fraction of basin covered by lakes and soil type index. Wiltshire (1986) grouped 376 British catchments into five homogeneous regions based on catchment attributes such as basin area, average annual rainfall and urban fraction. Burn and Goel (2000) grouped catchments in central India for flood frequency estimation using attributes such as catchment area, stream length and main channel slope.…”