PRELIMINARY RESULTS OF ENSEMBLE RIVER

0 downloads 0 Views 2MB Size Report
Projection of river discharge in. Indochina Peninsula under climate change using flow routing model 1K-FRM with 5- minute spatial resolution and the.
PRELIMINARY RESULTS OF ENSEMBLE RIVER DISCHARGE PROJECTION Using the SOUSEI and KAKUSHIN MRI-AGCM 3.2H Dataset In the Indochina Peninsula Region Patinya HANITTINAN, Yasuto TACHIKAWA, Yutaka ICHIKAWA, Kazuaki YOROZU Dept. of Civil and Earth Resources Eng., Kyoto University, Kyoto, Japan 1. STUDY AREA

2. OBJECTIVE AND RESEARCH METHODOOGY 



Projection of river discharge in Indochina Peninsula under climate change using flow routing model 1K-FRM with 5minute spatial resolution and the 60km spatial resolution GCM dataset (MRI-AGCM3.2H) from SOUSEI and KAKUSHIN experiments. To investigate the changes in river discharge of major river basin in the Indochina peninsula under the latest CMIP5 high concentration climate change scenarios (RCP8.5)

3. DATASETS

Data collection

Research Framework

MRI-AGCM 3.2H Datasets (Present: 1979-2009) MRI-AGCM 3.2H ( 2075-2099) Total Runoff Generation (ROF)

Topographic data (DEMs)

Extraction of MRI-AGCM 3.2H datasets

Hydrologic simulation: 1K-FRM Present (1979-2009)

river discharge simulation in the Indochina Peninsula

Future (2075-2099)

Ensemble River Discharge Projection

Annual max discharge

Annual min Annual mean discharge discharge

Evaluate the changes ratio of present and future, 60-km, river discharges projections

4. FLOW ROUTING MODEL

GCMs datasets (MRI-AGCM 3.2H 60-km resolution)



Watershed model: The topography of the catchment is modelled using the 8-direction method which assumes the flow direction onedimensionally to the steepest gradient direction. Each slope element determined by the flow direction is represented by a rectangle formed by the two adjacent nodes of grid cells.



Flow model: A kinematic wave model is applied to all slope units and runoff is routed according to the flow direction information. The basic form of the kinematic wave flow equation is: m 1 m A Q 5 i0  1  Q   A   q L ( x, t ) m    n B t x 3 where, A(x, t) is the flow cross-sectional area, Q(x, t) is the flow discharge, qL(x, t) is the lateral inflow per unit length, i0 is the slope, n is the Manning roughness coefficient, and B is the width of the flow.

5. PRELIMINARY RESULTS OF ENSEMBLE RIVER DISCHARGE PROJECTION MRI-AGCM 3.2H (SOUSEI) 





Fig. 1a) Ratio of Annual Maximum discharge (SOUSEI)

Fig. 2a) Ratio of Annual Minimum discharge (SOUSEI)

Fig. 3a) Ratio of Annual Mean discharge (SOUSEI)

There was a slightly increasing of the mean of annual maximum discharge in some locations with the ratio smaller than 1.3. The lower Mekong and Red River Basin are expected to change significantly with flow ratio between 2.29-3.02. A trend of decreasing in maximum flow can be found in the portion of Chao Phraya River and west side of Irrawaddy basin with the ratio between 0.29 and 0.60. The mean of annual minimum discharge is expected to increase in most of the Indochina peninsula region. The smallest increasing rate with the flow ratio up to 1.59 can be found in the central Irrawaddy, the lower part of Chao Phraya, The northernmost Mekong, and Mekong Delta. The more moderate rate of flow increase can be found at the west and northern Chao Phraya Basin, and the Central Mekong basin. The Red River basin is expected to saw discharge increase the most with flow ratio between 2.59-3.30. The increasing trend of the mean of annual mean discharge is detected at the Mekong, Chao Phraya, and Mekong Delta, with flow ratio up to 1.69.The mean discharge at the central Irrawaddy and Red River Basin signals are both indicate significant increase trend with flow ratio between 1.69 – 4.00

MRI-AGCM 3.2H (KAKUSHIN)  



The mean of annual maximum discharge is expected to increase at the central Irrawaddy, Mekong Delta, and most significantly at the Red River Basin with flow ratio between 2.61-3.16. The mean of annual minimum discharge is expected to increase slightly at the northern region of Mekong and central Irrawaddy River Basin with flow ratio up to 1.29. On the contrary, The central Mekong region and Red River Basin discharge may fell slightly compared to the present period. The mean of annual minimum discharge is expected to increase broadly, with flow ratio between 1.61-2.60 in the Irrawaddy, Salween, and Red River Basin. The flow ratio less than 1.60, but the clearest increasing trend can be found at the East of Mekong Delta.

6. REFERENCES

Fig. 1b) Ratio of Annual Maximum discharge (KAKUSHIN)

Fig. 2b) Ratio of Annual Minimum discharge (KAKUSHIN)

Fig. 3b) Ratio of Annual Mean discharge (KAKUSHIN)

Hartmann, D.L., A.M.G. Klein Tank, M. Rusticucci, L.V. Alexander, S. Brönnimann, Y. Charabi, F.J. Dentener, E.J. Dlugokencky, D.R. Easterling, A. Kaplan, B.J. Soden, P.W. Thorne, M. Wild and P.M. Zhai (2013) Observations: Atmosphere and Surface. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Tachikawa, Y., Hunnukumbura, P. B., Yorozu, K., and Apipattanavus, S. (2010) Projection of River Discharge in Thailand under Climate Change and its Impact on Water Resources, Proc. of 2010 AIT-KU Joint Symposium on Human Security Engineering, Bangkok, Thailand, November 25-26, pp. 102-108