Spatio-Temporal Effects of Extreme Weather on Sustainable Land Use in Chongqing: A Mountainous Chinese Metropolis

Global climate change has amplified extreme weather events, threatening ecological security and sustainable development. The impact of extreme weather events on sustainable land use (SLU) has attracted increasing attention. While previous studies have focused on the average effect, the question of whether its impacts vary across SLU levels remains unexplored. This knowledge gap is particularly pronounced in mountainous Chongqing, where complex terrain and urban heat islands interact to compound heterogeneous climate risks. To bridge this gap, we construct an indicator system based on the United Nations Sustainable Development Goals (SDGs) with which to assess the spatio-temporal evolution of SLU across all 38 districts of Chongqing from 2013 to 2023. The results show that Chongqing’s SLU level fluctuated upwards between 2013 and 2023, with high-value areas concentrated in the central urban core areas and regional gaps narrowing. Extreme climate indices exhibited significant spatial heterogeneity, with heat islands in urban areas, cold events in mountainous regions, floods in the southeast and droughts in the central western area. By overcoming average-effect limitations through quantile regression, this study further examines the heterogeneous effects of extreme weather on SLU across different development levels. It finds that simple daily intensity index (SDII) exerted stable negative effects—and the number of heavy precipitation days (R10), very wet days (R95p), monthly maximum value of daily maximum temperature (TXx) and diurnal temperature range (DTR) showed positive effects. While most climate variables exhibited stable effects, a critical finding was the divergent effect of variables such as tropical nights (TR20), which negatively impacted low SLU areas but positively influenced high SLU areas. This mechanistically confirms that regions at different levels of development experience fundamentally distinct impacts from the same climatic stressors. By focusing on uneven regional impacts and identifying region-specific extreme weather types, this study provides empirical support for targeted climate adaptation and balanced land management in mountainous cities.