Daily flow simulation in Thailand Part II: Unraveling effects of reservoir operation

• We quantify reservoir effects on water balance, daily flow regime and extreme flows. model flows in naturalized baseline operation scenarios with wflow_sbm. Sirikit Bhumibol reservoirs increase low reduce high flow. baseflow contribution flashiness. mitigated many historical incidents. Upper region of the Greater Chao Phraya River (GCPR) basin Thailand. The upper GCPR is highly regulated by multipurpose reservoirs, which obviously have altered natural streamflow. Understanding quantitative such alteration crucial for effective resource management. Therefore, this study aims to assess how affects basin. For purpose, we reconstructed streamflow (no reservoir) using (?1 km resolution) distributed model. To overcome data scarcity, ran global parameterization. A target storage-and-release-based module was applied scenario. results were analyzed comparison observations a wet year, dry period 1989–2014. resulted more evaporation. It inverted seasonality smoothed decreasing flows, increasing mean greater contribution, lower prevented or annual flood peaks minimum markedly terms both magnitudes frequencies, but their timing became variable difficult predict. Altogether, highlighted importance decision making real-time operation, remain challenging practice.