|
|
 |
Search published articles |
 |
|
Showing 1 results for Physiographical Space
Zahra Sheikh, Abdol_hamid Dehvari, Farhad Farsadnia, Volume 8, Issue 25 (9-2014)
Abstract
The physiographical and climatological
attributes of basins and maximum annual flood statistics were obtained from 38
hydrometric stations of Mazandaran province with minimum and maximum
statistical periods of 13 and 56 years. The first, homogenous regions based on
neighborhood approach were determined using canonical kriging method. The Canonical
Correlation Analysis was used to design physiographic space using the six
physiographic variables affecting the flood and two hydrological variables. The
Gaussian model had the best fit to semi-variogram model in 10, 20, 50 and 100
year return periods, and regional estimates obtained using ordinary Kriging
technique based on physiography space. The accuracy of results was evaluated
using L-moments method for regional flood frequency analysis. In this method,
Ward hierarchical clustering has been used to the determination of homogeneous
regions. Homogeneity areas were adjusted by using homogenous and discordancy
tests. Using goodness-of-fit Z DIST the Generalized Logistic
distribution was selected for all clusters as the best regional distribution
and regional estimates obtained by parameters selected distribution. Finally,
performance methods evaluated using Jack Knife procedure and the five
statistical indexes BIAS, BIASr, RMSE, RMSEr and NASH. Both methods give the
same and desirable performance based on NASH, however results of other indexes
showed that canonical kriging method provide better performance than linear
moments. Increasing the return periods
will improve the estimation, but the L-moments offers better performance for
short return periods.
|
|