Spatiotemporal distribution characteristics of forest fires in Hunan based on point pattern methods

Forests are the most widely distributed, complex, and resources- abundant ecosystems on dry land. Wildfire is a special and important factor affecting forest ecosystem. Discovering the dynamics and trends of forest fires in time and space helps to grasp the rules of forest fire occurrence, which is a fundamental work for deploying fire prevention priorities.

Using forest fire archive data from Hunan province over the past 24 years (1999-2022) as the data source, spatial statistical methods such as Ripley K function, center point and standard deviation ellipse method, and kernel density analysis were used to analyze the spatial clustering, forest fire density changes, and expansion trends of forest fires in Hunan province.

The total density of forest fires in Hunan province from 1999 to 2022 was 0.008 7 times /(km²·a), and there were three forest fire aggregation points in space. The annual forest fire density of unit area from 1999 to 2003 was 0.016 7 times, from 2004 to 2008 it was 0.034 8 times, from 2009 to 2013 it was 0.021 times, from 2014 to 2018 it was 0.005 times, and from 2019 to 2022 it was 0.006 times. The forest fire distribution in Hunan province during the 3 periods from 1999 to 2013 had multiple aggregation areas, and since 2014, the forest fire aggregation areas have not been obvious.

There is a significant spatial clustering and geographical correlation in the spatial and temporal distribution of forest fires in Hunan province from 1999 to 2022 and the overall forest fire density shows a fluctuating downward trend. There are obvious high-density areas of forest fires, including Loudi city, Zhuzhou city, Chenzhou city, and the eastern part of Shaoyang city, the overall average center of forest fires from 1999 to 2022 is located in Shaoyang city, the spread trend of forest fires in Hunan province is to expand towards Yongzhou and Chenzhou cities in the southeast; And the forest fire density significantly decreased between 2013 to 2018, as well as 2019 to 2022. The GDP development distribution of various districts in Hunan province from 1999 to 2022 shows a high degree of aggregation, mainly in the Changsha-Zhuzhou-Xiangtan region, as well as Hengyang and Yiyang cities. There is a tiny spatial variation of GDP distribution, and the overlapping area of GDP distribution and the spatial distribution of forest fires accounts for 71.29%, which is relatively high.