Multi-model Climate Change Projections for Belu River Basin, Myanmar under Representative Concentration Pathways

Abstract

Climate change impacts and adaptation related studies in Myanmar are scanty. Therefore this study aims to project future climate scenarios considering two key meteorological parameters-temperature and precipitation -in Belu River Basin in Myanmar. Multi-GCMs approach with ten different GCMs on 10 th to 90 th percentile uncertainty range is studied using time series data of nine meteorological stations. Quantile mapping technique is used to correct the bias in raw GCM data. Bias corrected GCM ensembles are analysed for a wide range of climate scenarios to get the complete picture of climate change pattern for 21 st century. All ten GCM ensembles (four RCP scenarios) indicate that the monsoon to get wetter as well as delayed. August will witness highest amount of rainfall. More rain concentrating over shorter time span suggests likely increase in extreme precipitation events. Only a slight increase is expected on the overall annual precipitation (-1.78~+ 9.14%, range of values from four scenarios). Minimum temperature is found to increase almost twice (+0.64~+5.27C) as compared to maximum temperature (+0.56~+2.82°C) under different scenarios. Summer is the hardest hit season with May and April the most affected months for maximum and minimum temperatures respectively. These results are very useful for further research on assessment of vulnerability and adaptation on water resources and water use sectors in Belu River Basin in Myanmar.

Bias correction of climate models for hydrological modelling – are simple methods still useful?

“…The impact that climate change poses on a low-latitude mountainous cryosphere like the Himalayas and its resulting climate-driven response on mountainous river hydrology have been well covered by existing literature (Barnett et al, 2005;Adam et al, 2009;Khadka et al, 2014;Panday et al, 2014). In an effort to understand the impact of climate change in the future, climate research bodies around the world have been modelling Earth's climate with global climate models (GCMs) which generate meteorological variables by solving the equations of thermodynamics, mass and momentum (Aung et al, 2016).…”

“…Regional climate models (RCMs) may then be used to refine the output spatial resolution which is forced using GCM output as lateral boundary conditions. However, due to systematic and random model errors, GCM simulations often show considerable deviation from observation (Aung et al, 2016). By the nature of their dependence on the parent GCM, RCMs inherit a part, if not all, of the bias.…”

Climate Change and Reservoir Impacts on 21st-Century Streamflow and Fluvial Sediment Loads in the Irrawaddy River, Myanmar

“…Similar to these findings, a recent study by Ghimire et al (2019) also shows that north and north-eastern parts of the Irrawaddy Basin may experience 16-20% and 21-28% increments in precipitation during the 2040s and 2080s, respectively, under RCP 4.5 and RCP 8.5 (compared to their baseline period of . Over the Belu River Basin (a small basin adjacent to the eastern part of IRB), Myanmar, the average precipitation is projected to vary with no clear trends (−1.8-9.1%, range of values from four RCPs: RCP 2.6, 4.5, 6.0, and 8.5) (Aung et al, 2016). Considering the entirety of Myanmar, under RCP 4.5 and RCP 8.5, precipitation is projected to increase by 6-23% during the 2041-2070 period compared to a baseline period of 1980-2006(Horton et al, 2017.…”

“…In Belu River Basin, Myanmar (an adjacent basin to the IRB from East), the minimum temperature changes are almost double compared to changes in maximum temperature (Aung et al, 2016). For example, in the 2080s, minimum (maximum) temperature increases by 5.3°C (2.82°C) for RCP 8.5 (compared to the baseline period .…”

“…In terms of extreme weather events occurring between 1995 and 2014, Myanmar is identified as the world's second most affected country as per the Global Climate Risk Index (CRI) (Kreft et al, 2015). However, there is only a handful of climate change and human impact assessments focusing on Myanmar to date (Aung et al, 2016;Taft and Evers, 2016). Of particular relevance to the focus of this study, Myanmar has attracted numerous foreign hydropower investors, due to its undeveloped potential for largescale hydropower generation, resulting in accelerated socioeconomic growth over the last few decades (Kattelus et al, 2015).…”