Assessing Long-Term Climate Trends of Bharathapuzha Basin, Kerala, India

Anu Varughese, M. S. Hajilal


Hydrologic models are widely used as important tools in climate change impact studies. For operationalising the hydrologic models need proper bias correction in the climate data. This study aims at finding out the best suitable climate model by comparing downscaled re-analysis data on precipitation and temperature from five regional climate models (RCM’s) derived from different Global Climate Models (GCM’s) with observed data of Bharathapuzha river basin, Kerala, on the basis of the four statistical parameters (standard deviation, correlation coefficient, coefficient of variation and centered root mean square difference). The GFDL-CM3 RCM compared better with the observed data and hence, was used for further data analysis. Bias in precipitation was corrected using power transformation which corrects the mean and coefficient of variation (CV) of the observations. Since temperature is approximately normally distributed, it was corrected by fitting it to the mean and standard deviation of the observations. Comparison of the post-processed climate data to observed climate data was carried out. It is predicted that there may be a decrease of 4% to 7% in average annual rainfall during 2041-70 compared to the present day average values, whereas the decrease may be up to 10% to 15% during 2071-99. Based on the results obtained, the annual maximum and minimum temperatures are expected to increase in the future. The results obtained can be utilised in formulating future water resources management plans and for assessing the impact of climate change in the area using hydrologic models.


CORDEX; Bias Correction; Regional Climate Model; RCP’


Bijukumar, A.S.; Philip, A.; Ali, S.; Sushama, and Raghavan, R. 2013. Fishes of River Bharathapuzha, Kerala, India: diversity, distribution, threats and conservation. Journal of Threatened Taxa 5(15): 4979–4993.

Bocchiola, D.; Diolaiuti, G.; Soncini A.; Mihalcea, C.; Mosconi, B.; Agata, C.D.; Mayer C.; Lambrecht, A.; Rosso, R. and Smiraglia, C. 2011. Prediction of future hydrological regimes in poorly gauged high altitude basins: the case study of the upper Indus, Pakistan. Hydrology and Earth System Sciences 15: 2059–2075. doi:10.5194/hess-15-2059-2011.

Christensen, J. H.; Boberg, F.; Christensen, O. B.; and LucasPicher, P. 2008. On the need for bias correction of regional climate change projections of temperature and precipitation. Geophysical Research Letters 35: L20709. doi:10.1029/2008gl035694.

CWRDM. 2004. Master Plan for Drought Mitigation in Palakkad District. CWRDM/WMD/04/2. CWRDM, Kozhokode. 123 pages.

Deque, M.; Rowell, D.P.; Lüthi, D.; Giorgi, F.; Christensen, J.H.; Rockel, B.; Jacob, D.; Kjellström, E.; De Castro, M. and Hurk, V. B. 2007. An inter comparison of regional climate simulations for Europe: assessing uncertainties in model projections. Climate Change 81: 53–70.

Dobor, Z.; Barcza, T. H. A.; Havasi, F.; Horv, P.; Ittz and Bartholy, J. 2015. Bridging the gap between climate models and impact studies: the FORESEE Database. Geoscience data journal 2:1–11. doi: 10.1002/gdj3.22

Frei, C.; Christensen, J.H.; Deque, M.; Jacob, D.; Jones, R.G. 2003. Daily precipitation statistics in regional climate models: Evaluation and intercomparison for the European Alps. Journal of Geophysical Research 108 (D3), 4124. doi:10.1029/2002JD002287.

Giorgi, F. 2006. Regional climate modeling: status and perspectives. Journal de Physique IV 139:101–118.

Giorgi, F.; Jones, C. and Asrar, G.R. 2009. Addressing climate information needs at the regional level: the CORDEX framework. WMO Bulletin 58(3):175-182

Guhathakurta, P. and Rajeevan, M. 2007. Variabilities in the rainfall pattern over India. International Journal of Climatology 28: 1453-1469. 17.

Hurkmans, R.; Terink W, Uijlenhoet R, Torfs P, Jacob D. 2010. Changes in streamflow dynamics in the Rhine Basin under three high-resolution regional climate scenarios. Journal of Climate 23: 679-699.

IPCC (Intergovernmental Panel on Climate Change). 2014. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Geneva, Switzerland, 151 pages.

Jha, M.; Z. Pan, E.S. Takle, and Gu, R. 2004. Impacts of climate change on stream flow in the Upper Mississippi River Basin: A regional climate model perspective, Journal of Geophysical Research 109, D09105, doi:10.1029/2003JD003686.

Leander, R. and Buishand, T. 2007. Resampling of regional climate model output for the simulation of extreme river flows. Journal of Hydrology 332: 487-496.

Niemann, J.D. and Eltahir, E.A.B. 2005. Sensitivity of regional hydrology to climate changes, with application to the Illinois River basin. Water Resources Research vol. 41, W07014, doi: 10.1029/2004WR003893

Patwardhan, S.; Kulkarni, A. and Kumar, K.K. 2014. Impact of Climate Change on the Characteristics of Indian Summer Monsoon Onset. International Journal of Atmospheric Sciences Vol. 201695,

Raneesh, K.Y. and Thampi, S.G. 2011. A study on the impact of climate change on stream flow at the watershed scale in the humid tropics. Hydrological Sciences Journal 56: 946-965.

Raneesh, K.Y. and Thampi, S.G. 2013. Bias correction for RCM predictions of precipitation and temperature in the Chaliyar River Basin. Journal of Climatology and Weather Forecast 1(1):1-6.

Teng, J. N. J.; Potter, F. H. S.; Chiew, L.; Zhang, B.; Wang, J.; Vaze and Evans, J. P. 2015. How does bias correction of regional climate model precipitation affect modelled runoff? Hydrology and Earth System Sciences 19, 711–728. doi:10.5194/hess-19-711-2015.

Terink, W.; Hurkmans, R.T.W.L.; Torfs, P.J.J.F. and Uijlenhoet, R. 2010. Evaluation of a bias correction method applied to downscaled precipitation and temperature reanalysis data for the Rhine basin. Hydrology and Earth System Sciences 14: 687–703.

Teutschbein, C. and Seibert, J. 2010. Regional climate models for hydrological impact studies at the catchment scale: a review of recent modeling strategies. Geography Compass 4(7): 834–860.

Teutschbein, C.; Wetterhall, F. and Seibert, J. 2011. Evaluation of Different Downscaling Techniques for Hydrological Climate-Change Impact Studies at the Catchment Scale. Climate Dynamics 37(9-10): 2087-2105. doi:10.1007/s00382-010-0979-8.

Full Text: PDF


  • There are currently no refbacks.

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.

COPYRIGHT of this Journal vests fully with the National Instional Institute of Ecology. Any commercial use of the content on this site in any form is legally prohibited.