Signature of LULC induced Regional Climate Change over Eastern India: A Modeling and Observational Approach

The impact of local climate change induced by urbanization or changes in the Land Use and Land Cover (LULC) has been contributing as much as ~50% of the total rise in surface air temperature over the Eastern Indian state of Odisha. While analysing the physical mechanism of such rise, it is found that the changes in the specific heat capacity of the surface regulates the changes in the surface energy budget of the region. A slight change in the energy budget may significantly disturb the regional/local climate balance thereby simulating the primary meteorological parameters such as the temperature and surface heat fluxes. LULC which characterises the surface properties can contribute immensely to the energy budget cycle through biophysical and biochemical processes like evaporation, evapotranspiration, shortwave and long wave radiation, absorption and reflection. In this study, we used observational and modeling techniques to quantify the ramifications of LULC changes on the climate of Odisha during the period 2004-2015. A significant change in the spatial pattern of temperature has been observed towards the eastern part of the region.  We try to find out whether this shift in temperature pattern is because of LULC or global climate forcing. Significant diversification in the agricultural practices have also been noticed in the region in the recent times.  To evaluate such effects, Weather Research and Forecasting (WRF) mesoscale modeling system has been enforced to visualize how significantly changes in LULC have impacted parameters like surface temperature, heat fluxes, humidity etc. However, the modeling results also follow consistency with that of the observational signatures and a rise of ~0.5-1.0 ^oC has been observed. Along with the spatial analysis, vertical profiles are also studied where we found significant impact of changed LULC on specific humidity and temperature. This study discusses the dynamics of land-atmosphere interactions instigated by local LULC effects.

Keywords: LULC, urbanization, remote sensing, numerical modeling, climate change