资源环境科技发展态势分析平台

Despite a globally growing proportion of cities located in regions of complex terrain, interactions between urbanization and complex terrain and their meteorological impacts are not well understood. We utilize numerical model simulations and satellite data products to investigate such impacts over San Miguel de Tucuman, Argentina. Numerical modeling experiments show urbanization results in 20-30% less precipitation downwind of the city and an eastward shift in precipitation upwind. Our experiments show that changes in surface energy, boundary layer dynamics, and thermodynamics induced by urbanization interact synergistically with the persistent forcing of atmospheric flow by complex terrain. With urbanization increasing in mountainous regions, land-atmosphere feedbacks can exaggerate meteorological forcings leading to weather impacts that require important considerations for sustainable development of urban regions within complex terrain.

Plain Language Summary Rapid urbanization produces a variety of challenges including management of food and water security, pollution, and vector borne diseases. Several cities around the globe within regions of complex terrain face additional challenges. Urbanization impacts from land cover change and human activity in cities could potentially be amplified through persistent forcing of clouds and precipitation from flow interactions with complex terrain. This important feedback is not yet understood. This study examines the impact of the city of San Miguel de Tucuman in northwestern Argentina, located in the vicinity of Andes, on regional weather. Our analysis finds that urbanization leads to changes in cloud and rain formation around the city and over the mountains further downwind. Changes in clouds and rainfall caused by urbanization have the potential to reduce stream flow from higher elevations and adversely impact available water resources. While this study focuses on a single city, broader implications of this work suggest that urbanization in regions of complex terrain has significant impacts on regional precipitation that could affect food and water availability. By addressing the unknown meteorological feedbacks of urbanization within complex terrain, urban planning can be more strategic toward the end goal of future urban sustainability, particularly in developing countries.