基于侵蚀循环理论的河南省降雨型地质灾害易发性分区

The Susceptibility Zoning of Rainfall Type Geological Hazards in Henan Province Based on Erosion Cycle Theory

三面环山、西高东低的地貌格局以及较为集中的降雨期,使得河南省由降雨侵蚀引发的地质灾害具有明显的时空分布特征。为有效地做好区域降雨型地质灾害的防灾减灾工作,基于侵蚀循环理论及流域系统稳定性判断的超熵模型,利用地理信息处理技术,对河南省降雨型地质灾害易发性进行分区。结果表明:降雨型地质灾害易发区主要分布在河南省山地丘陵地区;其中极高易发区和高易发区都主要分布在豫北太行山山地丘陵区,豫西崤山、熊耳山、伏牛山、嵩山、外方山山地丘陵区以及豫南桐柏山、大别山山地丘陵区;中易发区在崤山和大别山地区分布较少,在其他山地地区分布零散,在南阳盆地周围分布相对集中;低易发区在伊河、洛河、北汝河流域分布稍多,在其他山地地区分布数量极少。2019年以前,河南省已发生的4899处地质灾害中,共有4575处灾害点分布在文中划分的不同地质灾害易发性分区内。其中,极高易发区范围内的灾害点占总数的63.23%,高易发区和中易发区范围内的灾害点共占总数的34.29%,低易发区范围内灾害点占总数的2.48%。易发性分区结果与地质灾害空间分布具有很高的吻合度,说明利用超熵值对降雨型地质灾害的评价分区结果与实际情况相符合,可以用来指导区域防灾减灾工作。

The topographical pattern of Henan Province,which is surrounded by mountains on three sides,higher elevations in the west and lower elevations in the east,as well as the relatively concentrated rainfall period,make the geological hazards triggered by rainfall erosion in the province have obvious spatial and temporal distribution characteristics.In order to effectively prevent and reduce regional rainfall-type geological disasters, based on the theory of erosion cycle and the su-perentropy model of watershed system stability judgment, the susceptibility of rainfall-type geological disasters in Henan Province were divided by geographic information processing technology. The results are as follows. The areas prone to rain-fall geological disasters are mainly distributed in mountainous and hilly areas of Henan Province. The extremely high and highly prone areas are mainly distributed in the mountainous and hilly areas of the Taihang Mountains in northern Henan, as well as the mountainous and hilly areas of Xiao Mountains, Xiong′er Mountains, Funiu Mountains, Song Mountains, and Waifang Mountains in western Henan, as well as the mountainous and hilly areas of Tongbai Mountains and Dabie Mountains in southern Henan. The intermediate-prone areas are not as widely distributed in the Xiao Mountains and Dabie Mountains, but scattered in other mountain regions, and are relatively concentrated around the Nanyang Basin. The low-prone areas are more distributed in the Yi River, Luo River and Beiru River basin, but few in other mountainous areas. Be-fore 2019, among the 4 899 geological disasters that had occurred in Henan Province, a total of 4 575 disaster sites were distributed in the different geological disaster-prone zones classified in the paper. Among them, 63. 23% of the total disas-ter sites were in the areas of extremely high risk, 34. 29% were in the areas of high risk and medium risk, and 2. 48% were in the areas of low risk. The results of susceptibility zoning are highly consistent with the spatial distribution of geological hazards, indicating that the evaluation zoning results of rainfall type geological hazards using super entropy values are con-sistent with the actual situation and can be applied to guide regional disaster prevention and reduction.