[A-AS15] Progress in dense observation and numerical modeling of micro-scale meteorology

[AAS15-P06] Quantifying the Impact of Future Urbanization on Urban Microclimate Over Mumbai Metropolitan Region, India.

*Vinayak Nitin Bhanage¹, Han Soo Lee¹, Shirishkumar Gedam² (1.CSRE,Indian Institute of Technology,Bombay,India. and Graduate School for International Development and cooperation,Hiroshima University,Japan, 2.CSRE,Indian Institute of Technology,Bombay,India)

Keywords:WRF-UCM, LULC, Urban Microclimate, Mumbai

Mumbai Metropolitan Region(MMR) is one of the fastest-growing metropolitan regions in India and experiencing rapid Urban Expansion. According to the 2011 census report, the population of MMR is more than 23.15 million, while this number is expected to increase by up to 30 million by the year 2031. This increment in population and the process of urban expansion will induce the significant alterations in the Land Use Land Cover (LULC) distribution of the MMR further; it will adversely influence the Urban Microclimate of the region. To address this issue, the current study has been carried out to enumerate the effect of the future LULC on urban climate over the MMR. In the first part of the study, we have derived the distribution of current (2018) LULC by processing the latest satellite images obtained from the Landsat, while the future (2050) LULC was simulated using an ANN-based CA-Markov algorithm. In the later part of the study, the estimated LULC dataset was ingested into the WRF-UCM model, and two separate simulations were performed for current and future LULC scenarios under the same exceedingly hot conditions of May 2018. During these simulations, we assigned the fixed initial and lateral boundary conditions, which were acquired from the NCEP FNL dataset. The output from a WRF-UCM model for the current scenario was validated with the in-situ observations. The validation results for near-surface air temperature, relative humidity, and wind speed showed a more significant correlation (r>0.70) with observed in situ datasets. Comparative analysis of these simulations conducted for the current and future scenarios shows that by 2050 due to the expansion of urban areas, the mean surface air temperature over the urban areas of MMR will increase by 2.39°c the mean surface air temperature of the rapidly growing urban centers like Kalyan, Ambarnath, Ulhas Nagar will increase by 4-5°c.