从“热岛”到“雨岛” 专家解读“晚高峰”为何频遇阵雨

Core Viewpoint - The increase in urban rainfall during peak hours is attributed to the "rain island effect," which is a consequence of the "heat island effect" in cities [2][3]. Group 1: Urban Climate Effects - The "heat island effect" refers to urban centers being significantly warmer than surrounding rural areas, with temperature differences of 2°C-3°C due to artificial structures and reduced green spaces [2]. - The "rain island effect" is formed as urban pollutants create condensation nuclei that lead to cloud formation, resulting in increased rainfall in urban areas [2][3]. Group 2: Urbanization and Flooding - Rapid urbanization has transformed agricultural land into urban areas, increasing impervious surfaces and reducing water absorption, which exacerbates flooding during heavy rainfall [3]. - Climate change is also a significant factor contributing to extreme weather events, including urban flooding [3]. Group 3: Urban Flood Management Strategies - The concept of "sponge cities" aims to enhance urban resilience to environmental changes and natural disasters by improving rainwater absorption and management [3][4]. - The "big sponge" approach emphasizes integrated flood management at the watershed level, considering urban areas alongside surrounding natural ecosystems [4]. - The Chinese government has initiated policies to strengthen urban flood management, focusing on source reduction, drainage systems, and emergency responses [4].