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A STOCHASTIC INDEX METHOD FOR CALCULATING ANNUAL FLOW DURATION CURVES IN INTERMITTENT RIVERS
Author(s) -
Rianna Maura,
Efstratiadis Andreas,
Russo Fabio,
Napolitano Francesco,
Koutsoyiannis Demetris
Publication year - 2013
Publication title -
irrigation and drainage
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.421
H-Index - 38
eISSN - 1531-0361
pISSN - 1531-0353
DOI - 10.1002/ird.1803
Subject(s) - quantile , statistics , duration (music) , flow (mathematics) , index (typography) , standard deviation , hydrology (agriculture) , generalization , scale (ratio) , mathematics , streamflow , probability distribution , environmental science , drainage basin , geography , computer science , geology , cartography , mathematical analysis , geotechnical engineering , art , geometry , literature , world wide web
Flow duration curves are useful tools to estimate available surface water resources, at the basin scale. These represent the percentage of time during which discharge values are exceeded, irrespective of their temporal sequence. Annual flow duration curves are useful tools for evaluating all flow quantiles of a river and their confidence intervals, by removing the effects of variability from year to year. However, these tools fail to represent the hydrological regime of ephemeral rivers, since they cannot account for zero flows. In this work we propose a technique for calculating annual flow duration curves and their standard deviation in the case of intermittent rivers. In particular, we propose a generalization of the stochastic index method, in which we use the concept of total probability and order statistics. The method is proposed to determine the conditional distribution of positive flows, for given probability of dryness, and is implemented on three catchments in Italy and Greece, with low (<5%) and high (>40%) frequency of zero flows, respectively. Copyright © 2013 John Wiley & Sons, Ltd.