Impact of large-scale reservoir operation on flow regime
in the Chao Phraya River basin, Thailand
Taichi Tebakari1, Junichi Yoshitani2 and Pongthakorn Suvanpimol3
1 Department of Environmental Engineering, Toyama Prefectural University, 5180 Kurokawa,Imizu-shi, Toyama, 939-0398, Japan
2 National Institute for Land and Infrastructure Management, 1 Asahi, Tsukuba City, Ibaraki Prefecture,305-0804, Japan
3 Office of Hydrology and Water Management, Royal Irrigation Department of Thailand, 811 Samsen Road,Dusit, Bangkok, 10300, Thailand
Abstract:
The Chao Phraya River basin, the largest basin in Thailand, is located in the centre of the northern part of the country. This basin has two large-scale reservoirs: the Bhumibol Reservoir on the Ping River and the Sirikit Reservoir on the Nan River. A comparison of the annual and monthly flow regimes downstream from the reservoirs before and after reservoir development showed a constant increase in low flow and a drastic decrease in high flow. The spectrum of the daily discharge was analysed using the fast Fourier transform on data collected in the area of Nakhon Sawan and immediately downstream from the Bhumibol Reservoir after the reservoir was constructed. The flow at Nakhon Sawan had a periodic characteristic of 7 days. The water released from the Bhumibol Reservoir at hydrological station P.12 also had a periodic characteristic of 7 days. Reservoir operations have a significant impact on the hydrological cycles. The effect of human activities is evident in the spectrum analysis of recorded historical discharge data.
Copyright © 2012 John Wiley & Sons, Ltd.
KEY WORDS flow regime; FFT; reservoir operation; chao Phraya River
Received 31 January 2009; Accepted 13 March 2012
HYDROLOGICAL PROCESSES
Hydrol. Process. 26, 2411–2420 (2012)
Published online 12 May 2012 in Wiley Online Library
(wileyonlinelibrary.com) DOI: 10.1002/hyp.9345
