Is It Realistic To Define A 100-Year Drought For Water Management?⁽¹⁾

By Tiao J. Chang and Jennifer R. Stenson⁽²⁾

Abstract:

The concept of recurrence interval has been used for years in engineering designs. Can the same concept be applied to the drought analysis? This paper uses the plotting position method to define drought of various recurrence intervals based on streamflow data. The method of truncation level was applied to the same data to examine the defined drought. Based on the method of truncation level, drought duration and its corresponding flow deficit were investigated. Eighteen flow gage stations from the Scioto River Basin in Ohio were selected for the study. The results show that flows of 100-year droughts using the plotting position method are practically nil. On the other hand, flows of droughts using the truncation method are gradually decreasing with an increase in truncation level, where flows of 95 percent are approximately equal to those of two-year droughts defined by the plotting position. It is also shown that there is a strong correlation between drought duration and deficit.

(KEY TERMS: drought; recurrence interval; truncation level; streamflow; precipitation; correlation coefficient.)

1. Paper No. 90035 of the Water Resources Bulletin.

2. Respectively, Professor, Department of Civil Engineering, Ohio University, Athens, Ohio 45701-2979; and Engineer, Burgess & Niple, Ltd., Columbus, Ohio (former Graduate Student at Ohio University).





For more information on this or any other paper contact Terry Chang by email at tjchang@bobcat.ent.ohiou.edu

Copyright © 1997