TY - JOUR
T1 - Frequency Analysis of Low and High Flows in Trend
AU - Güçlü, Yavuz Selim
N1 - Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/5
Y1 - 2018/5
N2 - Hydrological variables are under the effect of the climate change impacts, and therefore, this study concentrates on the frequency analyses of low and high flows depending on the duration, leading to a new approach. The durations are selected as month, season, 6-month, and year coupled with the return periods 2-, 5-, 10-, 20-, 50-, 100-, 200-, and 500-years. The frequencies are equivalent to the reverse of these return periods. Increasing and decreasing trends are identified within the low and high flows, and the necessary graphs are presented. Similar to intensity-duration-frequency (IDF) curves, the proposed frequency-flow-duration curves are obtained instead of flow-duration-frequency (QDF) curves. The curves present important inputs for many hydrological events including flood forecasting, dam reservoir calculations, urban drainage design evaluations, transportation network planning, availability of agricultural land, groundwater recharge, etc. Furthermore, the flow values that may appear over n-year frequency on the curves are calculated by taking into consideration the Gamma cumulative probability distribution function. For the study area with applications Görele River, Turkey, flow measurements are used and the necessary conclusions are derived. As a result, the comparison for high and low values separately present significant information so that monotonically decreasing trend are generally observed for high values (wet periods) and non-monotonically increasing trend for low values (drought periods).
AB - Hydrological variables are under the effect of the climate change impacts, and therefore, this study concentrates on the frequency analyses of low and high flows depending on the duration, leading to a new approach. The durations are selected as month, season, 6-month, and year coupled with the return periods 2-, 5-, 10-, 20-, 50-, 100-, 200-, and 500-years. The frequencies are equivalent to the reverse of these return periods. Increasing and decreasing trends are identified within the low and high flows, and the necessary graphs are presented. Similar to intensity-duration-frequency (IDF) curves, the proposed frequency-flow-duration curves are obtained instead of flow-duration-frequency (QDF) curves. The curves present important inputs for many hydrological events including flood forecasting, dam reservoir calculations, urban drainage design evaluations, transportation network planning, availability of agricultural land, groundwater recharge, etc. Furthermore, the flow values that may appear over n-year frequency on the curves are calculated by taking into consideration the Gamma cumulative probability distribution function. For the study area with applications Görele River, Turkey, flow measurements are used and the necessary conclusions are derived. As a result, the comparison for high and low values separately present significant information so that monotonically decreasing trend are generally observed for high values (wet periods) and non-monotonically increasing trend for low values (drought periods).
KW - frequency analysis
KW - high flows
KW - IDF curves
KW - low flows
KW - QDF curves
UR - http://www.scopus.com/inward/record.url?scp=85044850955&partnerID=8YFLogxK
U2 - 10.1002/clen.201800113
DO - 10.1002/clen.201800113
M3 - Article
AN - SCOPUS:85044850955
SN - 1863-0650
VL - 46
JO - Clean - Soil, Air, Water
JF - Clean - Soil, Air, Water
IS - 5
M1 - 1800113
ER -