Multiscale Statistical Downscaling

This a sponsored project of Dr. Maheswaran funded by Department of Science and Technology(DST), India. The project is a part of the Inspire Faculty Award received by the Dr. Maheswaran. 

This project proposes a multi-resolution climatic downscaling approach using discrete wavelet transform. The MATLAB source codes are provided through this website for applications to other case studies and to receive feedback from a wider audience.

What is Wavelet based Multi-resolution Climatic Downscaling tool? 

A two- fold application of wavelet analysis is demonstrated in the proposed approach. Firstly, Multi- scale Wavelet Entropy i.e. MWE in conjunction with K- means and Principal Component Analysis (PCA) is used for selecting the suitable input variables. Secondly, Discrete Wavelet Transform (DWT) is employed to obtain the wavelet sub-time series for the selected input variables. The decomposed sub time series of different climate variables are then combined using the MLR or SoV model at each decomposition level and final outcome is added to obtain the simulated time series. 

References: 

Sehgal, V., Lakhanpal, A. , Maheswaran, R., Khosa, R., Sridhar, V. (2016). Application of multi-scale wavelet entropy and multi- resolution Volterra models for climatic downscaling. Journal of  ydrology. http://dx.doi.org/10.1016/j.jhydrol.2016.10.048

Lakhanpal, A, Sehgal, V., Maheswaran, R., Khosa, R., Sridhar, V. (2017). A non-linear and non-stationary perspective for downscaling mean monthly temperature: a wavelet coupled second order Volterra model. Stochastic Environmental Research and Risk Assessment 31, no. 9 (2017): 2159-2181. https://link.springer.com/article/10.1007/s00477-017-1444-6

Agarwal, A., Maheswaran, R., Sehgal, V., Khosa, R., Sivakumar, B., & Bernhofer, C. (2016). Hydrologic regionalization using wavelet-based multiscale entropy method. Journal of Hydrology, 538, 22-32. http://dx.doi.org/10.1016/j.jhydrol.2016.03.023

Yeditha, P.K., Rathinasamy, M., Agarwal, A.,SIvakumar B, (2021), Intercomparison of downscaling models with a special emphasis on wavelet based hybrid models. Journal of Hydrology.