TY - JOUR
T1 - Nonstationarity-based evaluation of flood frequency and flood risk in the Huai River basin, China
AU - Sun, Peng
AU - Wen, Qingzhi
AU - Zhang, Qiang
AU - Singh, Vijay P.
AU - Sun, Yuyan
AU - Li, Jianfeng
N1 - Funding Information:
This work is financially supported by the Fund for Creative Research Groups of National Natural Science Foundation of China (Grant No.: 41621061 ), the National Science Foundation for Distinguished Young Scholars of China (Grant No.: 51425903 ), the National Natural Science Foundation of China (No. 41601023 , No. 41771536 ), the State Key Laboratory of Earth Surface Processes and Resource Ecology (Grant No.: 2017-KF-04 ), Open Research Fund of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin (China Institute of Water Resources and Hydropower Research) (Grant No. IWHR-SKL-201720 ) and by the Research Grants Council of the Hong Kong Special Administrative Region, China ( HKBU 22301916 ). Our cordial gratitude should be extended to the editor, Prof. Dr. Geoff Syme, and anonymous reviewers for their professional and pertinent comments and revision suggestions which are greatly helpful for further quality improvement of our manuscript.
PY - 2018/12
Y1 - 2018/12
N2 - Using monthly streamflow data from 9 gauging stations covering a period of 1960–2014 across the Huai River basin, China, the Pettitt method and GAMLSS model were used to quantify flood frequency and related implications for flood hazards. Results indicated that: (1) no significant change points were observed in flood flows at the Huangchuan, Hengpaitou and Bengbu stations. However, significant hydrological alterations were detected for flood flows at other 6 stations with change points during ∼2000; (2) flood flows at the Bantai, Jiangjiaji and Hengpaitou stations were nonstationary but stationary flood flows were detected at other 6 stations. The Weibull distribution was the appropriate probability distribution describing flood flows across the Huai River basin and the lognormal distribution is the second best distribution; (3) no significant difference was detected for 10- and 20-year flood frequencies using the Pearson III type distribution function under the stationarity assumption. However, significant and increasing differences were expected for 30-, 50- and 100-year floods. It can be concluded that the assumption of stationarity, if the flood flows are actually nonstationary, can produce biased flood frequencies using Pearson III type distribution, and this result provides a critical reference for flood frequency analysis under the nonstationarity and/or stationarity assumption; (4) after 30 years, the flood magnification factor at Hengpaitou and Bengbu stations increased from 1 to 1.12 and from 1 to 1.06, respectively, implying higher flood risks at the Hengpaitou station. In addition, after 30 years, the return period of 100 year flood decreased from 100 years to less 70 years at the Hengpaitou station and from 100 years to nearly 78 years, implying higher frequency of floods with return periods of 100 years. Moreover, significant relations were detected between annual peak flood flow and flood-affected crop areas, implying that annual peak flood flow can be taken as an indicator of flood disasters across the Huai River basin and even in the Anhui province.
AB - Using monthly streamflow data from 9 gauging stations covering a period of 1960–2014 across the Huai River basin, China, the Pettitt method and GAMLSS model were used to quantify flood frequency and related implications for flood hazards. Results indicated that: (1) no significant change points were observed in flood flows at the Huangchuan, Hengpaitou and Bengbu stations. However, significant hydrological alterations were detected for flood flows at other 6 stations with change points during ∼2000; (2) flood flows at the Bantai, Jiangjiaji and Hengpaitou stations were nonstationary but stationary flood flows were detected at other 6 stations. The Weibull distribution was the appropriate probability distribution describing flood flows across the Huai River basin and the lognormal distribution is the second best distribution; (3) no significant difference was detected for 10- and 20-year flood frequencies using the Pearson III type distribution function under the stationarity assumption. However, significant and increasing differences were expected for 30-, 50- and 100-year floods. It can be concluded that the assumption of stationarity, if the flood flows are actually nonstationary, can produce biased flood frequencies using Pearson III type distribution, and this result provides a critical reference for flood frequency analysis under the nonstationarity and/or stationarity assumption; (4) after 30 years, the flood magnification factor at Hengpaitou and Bengbu stations increased from 1 to 1.12 and from 1 to 1.06, respectively, implying higher flood risks at the Hengpaitou station. In addition, after 30 years, the return period of 100 year flood decreased from 100 years to less 70 years at the Hengpaitou station and from 100 years to nearly 78 years, implying higher frequency of floods with return periods of 100 years. Moreover, significant relations were detected between annual peak flood flow and flood-affected crop areas, implying that annual peak flood flow can be taken as an indicator of flood disasters across the Huai River basin and even in the Anhui province.
KW - Annual peak flood flow
KW - Flood magnification factor
KW - GAMLSS
KW - Nonstationarity
KW - Return period
UR - http://www.scopus.com/inward/record.url?scp=85055163846&partnerID=8YFLogxK
U2 - 10.1016/j.jhydrol.2018.10.031
DO - 10.1016/j.jhydrol.2018.10.031
M3 - Journal article
AN - SCOPUS:85055163846
SN - 0022-1694
VL - 567
SP - 393
EP - 404
JO - Journal of Hydrology
JF - Journal of Hydrology
ER -
