HYDROLOGIC DROUGHT ASSESSMENT FOR TOPLICA RIVER BASIN IN THE CENTRAL SOUTH OF SERBIA

10th International Multidisciplinary Scientific GeoConference - SGEM2010, www.sgem.org, SGEM2010 Conference Proceedings/ ISBN 10: 954-91818-1-2, June 20-26, 2010, Vol. 2, 23-30 pp

ABSTRACT

The paper presents study of hydrologic drought in the period of low flows for the region
of Toplica river in the central South of Serbia. Seven gauge stations from the Republic
of Serbia Hydro-Meteorological Service (RHMZS) Surface Water Observation Network
serve the studied region. These gauge stations represent river basins with the area range
180-2083 km2. Gauge stations are functional for 47 to 56 years.
A review of available drought analysis is given, with focus on the studied region.
Temporal and spatial variation analysis of low flows is performed for the series of 1, 10,
20 and 30 days of low flow duration. Low flow frequency analysis includes outlier
detection by Pilot-Harvey test, which is generally used to obtain an objective detection
of historic events under extreme hydrologic conditions. In order to estimate return
period of detected outliers by Pilot and Harvey test, statistical parameters of the studied
series are adjusted. Calculation of low flow probability for each of the duration of
interest is performed based on adjusted series’ statistics.
Daily flow duration curves for gauge stations are calculated. Maintenance flow is
estimated for each gauge station according to National legal regulation.
An assessment of water deficiency duration in extreme low flow periods, taking
maintenance flow as a threshold is performed and scarce areas pointed out.

Keywords: Toplica river basin, Meteorological drought, Hydrologic drought, Water deficiency