Skip to main content
Log in

Impact of Urbanization on Heavy Rainfall Events: A Case Study over the Megacity of Bengaluru, India

  • Published:
Pure and Applied Geophysics Aims and scope Submit manuscript

Abstract

This study is about the simulation and observational analysis of a heavy rainfall event (HRE) and its sensitivity to land-use changes. The impact of urbanization on processes and mechanisms of rainfall including cloud processes is discussed. This study is based on high-resolution (2 km), time-ensemble simulation of one of the HREs that occurred on 27 May 2017 over the city of Bengaluru in the southern part of India. The simulations are carried out using the Weather Research and Forecasting (WRF) model, which is coupled with a single-layer urban canopy model (UCM). The high-resolution (30 s) land-use data derived from the Indian Space Research Organization (ISRO) for the year 2016–2017 is shown to be realistic in representing the current land-use scenario with a threefold increase in urbanization when compared to USGS land-use data of 1991–1992. Simulation and analysis of large-scale circulation patterns revealed that the event was triggered and sustained by the low-pressure system and cyclonic circulation over the Bay of Bengal. Simulated rainfall was found to be remarkably sensitive to land-use changes as shown by control (USGS) and test (ISRO) simulations. The rainfall intensity and spatial distribution are close to observation in test simulations with relatively less error at station scale with a correlation of 0.49 (95% significance) when compared to control simulations, indicating the importance of realistic representation of land use in the model and its impact on heavy rainfall processes. The test simulation which represents the current urbanization scenario has shown a significant increase in rainfall by over 100–200%. The surface energy fluxes and thermodynamic indices as shown by test simulations are favorable to HREs, and also consistent with the current land-use scenario with increased urbanization. This study demonstrated how a realistic representation of land-use data in the model can help to improve model skill. The main limitation of this research work is that it is based on the generic parameterization of urbanization using single-layer UCM. An in-depth study based on multi-layer UCM and city-specific parameterization of urbanization using sub-kilometer-scale land-use data including buildings would further enhance our understanding on this subject.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Adopted from USGS (1992; left panel) and ISRO (2017; right) used in the WRF-UCM simulation study

Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13

Similar content being viewed by others

References

Download references

Acknowledgements

The authors gratefully acknowledge the Department of Science and Technology, Govt. of India, for sponsoring projects under grant-in-aid projects (SB/S4/AS-113/2013, SB/S4/AS-120/2014, and INT/RUS/RFBR/P-336). We acknowledge the project funded by the National Mission on Himalayan Studies (NMHS) of the Ministry of Environment, Forest and Climate Change, Govt. of India (grant no: GBPNI/ NMHS-2019-20/MG/315). The authors also acknowledge the Head, CSIR 4PI, for support and encouragement. The CSIR 4PI high-performance computing (HPC) facility used for computing is gratefully acknowledged.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to S. Himesh.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Sahoo, S.K., Himesh, S. & Gouda, K.C. Impact of Urbanization on Heavy Rainfall Events: A Case Study over the Megacity of Bengaluru, India. Pure Appl. Geophys. 177, 6029–6049 (2020). https://doi.org/10.1007/s00024-020-02624-8

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00024-020-02624-8

Keywords

Navigation