野外-城市界域森林火险时空演变趋势及火险等级划分

野外-城市界域(WUI)人类活动密集,火灾风险极大,在该区域进行森林火险的合理性评价和时空演变趋势分析,对保护区域生态环境和社会经济可持续发展具有重要意义。以北京近郊九龙山林场为研究对象,基于相关火险驱动因子指标数据,运用层次分析法评估研究区2004、2009、2014、2019年森林火险指数,通过Theil-Sen Median趋势分析、全局莫兰指数和局部莫兰指数分析探究森林火险指数的变化趋势及空间聚集性,并基于历史火情数据和地理探测器模型验证火险区划的合理性和准确性。结果表明:(1) 九龙山林场内火险指数整体的集聚特征变化较大,61.58%的区域火险指数不显著增加,5.62%的区域微显著增加,32.80%区域为不显著减少和微显著减少。(2) 森林火险指数空间上呈正相关,森林火险高值聚集区域分布于东部低海拔地区,在研究时间段内面积减少4.89%,低值聚集区域分布于西部高海拔地区,面积减少2.19%。(3) 森林火险区划结果显示,九龙山林场森林高火险区域面积占比最小,主要分布于研究区中部,由于人类活动的影响,高火险区覆盖范围扩大。(4) 区划合理性验证结果显示,研究区森林火险等级空间分异性较好,与实际火点分布具有高度一致性。研究结果较好的反应了研究区森林火险时空格局变化,为九龙山林场进一步合理规划防火设施布局,加强火险管控力度,完善防火应急能力奠定数据基础,提示管理部门应加强防火宣传,以最大限度发挥九龙山的生态环境效益,保障林区周边人民生命财产安全。

Temporal and spatial evolution of forest fire risk and classification of fire risk levels in wildland-urban interface areas

The wildland-urban interface (WUI) is characterized by dense human activities and high fire risk. It is crucial to assess forest fire risk systematically, analyzing its temporal and spatial changes for the protection of the ecological environment and the promotion of sustainable social and economic development in this area. We conducted an evaluation of the forest fire risk index in 2004, 2009, 2014, and 2019 using the analytic hierarchy process. The evaluation utilized data on relevant factors influencing forest fire risk in Jiulong Mountains Forest Farm, situated in the suburbs of Beijing. The changing trends and spatial clustering of the forest fire risk index were explored through Theil-Sen Median trend analysis, global Moran''s I index, and local Moran''s I index analysis methods. To validate the categorization of forest fire levels, we conducted an analysis using historical fire incidents and the Geodetector model. The results showed that: (1) The overall aggregation characteristics of the fire risk index within Jiulong Mountains Forest Farm exhibit significant variability. Specifically, 61.58% of the area did not show a significant increase, 5.62% of the area experienced a slight increase, and 32.80% of the area did not exhibit a significant reduction or slightly decreased. (2) The forest fire risk index demonstrated positively spatial correlation, with high-value aggregation area distributed in the low-altitude eastern regions, where the forest fire risk is high. During the study period, the area of high-value aggregation decreased by 4.89%. In contrast, low-value aggregation area are distributed in the high-altitude western regions, where the forest fire risk is low, and the area decreased by 2.19%. (3) Forest fire risk zoning results indicated that the high-risk area in Jiulong Mountains Forest Farm had the smallest proportion, primarily located in the central region. However, due to human activities, the coverage of high-risk areas has expanded. (4) The validation results of zoning rationality indicate that the spatial differentiation of forest fire risk levels in the study area was good, displaying a high level of consistency with the actual distribution of fire points. This study effectively captures the temporal and spatial changes in forest fire risk in the study area, laying a data foundation for fire prevention facility layout planning, increasing intensity of fire risk management, and the enhancement of emergency response capabilities. It is advisable for management authorities to boost fire prevention awareness, thereby maximizing the ecological benefits of Jiulong Mountains and ensuring the safety of life and property for the people in the surrounding regions.