**4.3 Deficit and dry duration observational data**

The deficit is the difference between the volume of water shortage and the threshold, while duration is defined as the total time the deficit occurred. The results of the analysis showed that the duration and deficit do not have the same visual pattern and this means the deficit value does not describe the duration value and vice versa.

The debit deficit on the Very Dry criteria (based on Qaw80), consecutive (run-length) (d), and the total deficit (run-sum) was recorded from January 3 to October 3, 1991, with a total deficit of 142,928 (m3 /sec. Ten daily) and 27 ten daily followed by May 1 to Dec 1, 1997 with 15.88 (m3 /sec. Ten daily) and 22 ten daily, and Jan 1 to Aug 2, 2003 with 46,725 (m3 /sec. Ten daily) and 25 ten daily, respectively, as indicated in **Figures 5** and **6**.
