NUMERICAL SIMULATION ON URBAN HEAT ISLAND AND ITS IMPACT ON LOCAL CIRCULATIONS IN INDONESIAS FUTURE CAPITAL OF NUSANTARA Rahastuti Tiara Adysti (a), Muhammad Rais Abdillah (b), Nurjanna Joko Trilaksono (b)
(a) Meteorology Study Program, Faculty of Earth Science and Technology, Institut Teknologi Bandung
(b) Atmospheric Science Research Group, Faculty of Earth Science and Technology, Institut Teknologi Bandung
Abstract
The development of the Nusantara Capital City (IKN) will inevitably transform the land cover of this area due to city construction. Potentially, the built-up or urban cover area will increase attributed to urbanization that will occur in this future capital city. A previous study has shown that the projected increase in urban areas in the IKN is expected to contribute to temperature rise in the region. However, the impact of urban expansion goes beyond temperature changes, it also affects wind patterns and circulations. Therefore, simulating the impact of land cover changes on wind patterns and circulations in the IKN is crucial for a comprehensive understanding of its effects on the local weather.
This study conducted weather simulations using the mesoscale numerical weather prediction model, Weather Research and Forecasting (WRF), coupled with the Urban Canopy Model (UCM), on modified land cover based on the plans for the development of the IKN. The simulation results were compared with weather simulations on the land cover prior to the development of the IKN. According to the simulation results, under strong upwind and no rainfall conditions, the presence of urban areas in the IKN region led to an increase in temperature, a decrease in wind speed, and an increase in convergence in the area. However, during nighttime simulations (6 p.m. to 12 a.m. local time), the increasing temperature tends to occur mainly in the Core Government Center (KIPP) area. Additionally, wind speed tends to increase around the KIPP area. Land cover changes not only affected the IKN region but also had an impact on the downwind area, resulting a significant decrease in wind speed (reaching greater than 2 m/s) in that area at night. This reduction in wind speed decreased turbulence during the night, which consequently led to a significant temperature decrease (reaching greater than 0.75 degree Celsius) in that area.
Keywords: Nusantara Capital City (IKN), Land cover, Wind patterns and circulations, Weather Research and Forecasting (WRF), Urban Canopy Model (UCM)
Topic: Interdisciplinary Earth Science and Technology
