Lei Zhang

In the evolving backdrop of anthropogenic climate change, forest wildfires have increasingly raised concerns due to their pronounced adverse impacts on regional water quality. These events could emerge as pivotal determinants in future water quality degradation trajectories. Building upon the outlined concerns regarding forest wildfires and their subsequent impact on water quality, this study embarks on a comprehensive exploration of such intricate relationships, using the Chongqing "8·19" forest fire as a representative case. Through leveraging regional water quality monitoring data, real-time meteorological surveillance data, and atmospheric pollutant concentration data (black carbon and organic matter), an integrative methodological approach is employed. This approach synergistically combines spatial statistics, buffer zone analysis, airflow trajectory analysis, and potential source apportionment models to holistically scrutinize this multifaceted relationship. Navigating through the ramifications of wildfires, notably exemplified by the Chongqing "8·19" forest fire, this study meticulously outlines the conspicuous impacts on regional water quality, unraveling pathways not solely confined to direct ash deposition but also intertwined with indirect interactions of atmospheric pollutants. Post-wildfire, an explicit diminution was documented in stations classified as Class III and above on the Water Quality Index (WQI), concurrently witnessing a sharp incline in Total Nitrogen and turbidity levels during August and September, reaching peaks at 3.33 mg/L and 111.7 NTU, respectively. Moreover, an alignment was discerned between the northern and northwestern particulate pollutant migration—subsequent to the fire—and areas recording elevated atmospheric Black Carbon and Organic Matter concentrations, concomitant with the principal zones of water quality impairment. This research unveils a complex, multifaceted conduit of wildfire repercussions on water quality, spotlighting an imperative for integrative future inquiries that encapsulate both the direct and indirect consequences of biomass burning. Such investigations propel us toward formulating comprehensive, actionable watershed management strategies, particularly crucial amidst escalating anthropogenic climate alterations.

Farmland protection is important for ensuring national food security and promoting sustainable socioeconomic development. China has a far lower amount of farmland area per capita than the global average. To improve farmland productivity, the Chinese government has implemented a basic farmland protection system (BFPS). A comprehensive and systematic analysis of the evolution mechanism of the BFPS, the failures of the BFPS and the key measures of the modern BFPS reform is lacking in the current literature. Based on a systematic review of the history of China’s BFPS, this study first summarizes the evolutionary mechanism of the BFPS, then analyzes the current conflicts faced by the BFPS on this basis, proposes several main breakthrough strategies for improving the BFPS and finally provides key ideas for further strengthening the development of the BFPS in the future. The results of this study show that China’s BFPS has gone through three development stages since 1963 and that there are differences in the main factors hindering the improvement in basic farmland productivity in the different stages. Correspondingly, the systems adopted to meet the demands for basic farmland protection are also different. The evolution of the BFPS is similar to a “scale” that constantly seeks balance between “system demand” and “system supply”. In the present stage, the main conflicts faced by China’s BFPS are between basic farmland quality and requirements for supplementary delimitation and production patterns; between basic farmland quantity, urban development and food security; and between basic farmland-use regulation and modern agriculture and the market economy. The Chinese government should further optimize the BFPS through improving the delimitation system, establishing a classified protection system and strengthening the basic farmland protection compensation system. To accelerate the establishment of a territorial spatial planning system in the future, the BFPS should also be fully integrated with the concept of an ecological civilization, be applied to resolve the contradiction between development and protection and be used to help improve the land-space-utilization control system, thus creating a unified development guide for national land.