2010~2025年环县暴雨时空演变特征分析

Analysis of the Spatio-Temporal Evolution Characteristics of Heavy Rainstorms in Huan County from 2010 to 2025

摘要: 利用甘肃省庆阳市环县20个乡镇2010~2025年汛期日降水量数据，以及对应年份的灾情资料，采用线性趋势分析、空间插值等方法，分析了环县16年间暴雨的时空分布与变化规律。结果表明：(1) 近16年来环县暴雨整体呈现西少东多、北少南多的分布特征，暴雨发生次数由西北向东南逐渐递增：其中八珠、木钵、曲子一带暴雨发生次数最多，甜水、南湫、罗山、毛井一带暴雨发生次数最少。(2) 暴雨发生次数是影响当地受灾频次的最主要因素，洪涝灾害主要由暴雨事件驱动；特殊案例表明，暴雨强度、持续时间、空间分布，以及与人类活动的叠加效应等因素，都会对受灾情况产生影响。(3) 环县暴雨主要集中在7~8月，5~6月、9~10月暴雨频次依次递减，这一特征与我国东部季风区的暴雨分布规律高度吻合。(4) 个例分析发现，2013年环县暴雨空间差异显著，暴雨次数高度集中，曲子镇、洪德镇暴雨次数明显高于其他乡镇，呈现“两点突出、多点普遍”的分布格局，这两个区域是当年暴雨致灾风险最高的区域。2018年环县暴雨呈现东多西少、东南部集中的特征，暴雨次数自西北向东南递增，木钵镇暴雨次数为全县最高，整体分布呈现连续渐变特征，为以东南部为核心的单峰分布格局。

Abstract: Utilizing daily precipitation data from the flood season (2010~2025) across 20 townships in Huan County Qingyang City, Gansu Province, alongside corresponding disaster records, this study employs linear trend analysis and spatial interpolation to examine the spatiotemporal distribution and evolutionary patterns of heavy rainfall a 16-year period. The results indicate the following: (1) Over the past 16 years, heavy rainfall in Huan County has exhibited a spatial distribution by a “west-to-east” and “north-to-south” gradient, with the frequency of events gradually increasing from the northwest to the southeast. Specifically, the frequencies were recorded in the Bazhu, Mubo, and Quzi areas, while the lowest frequencies occurred in the Tianshui, Nanchiu, Luoshan, andjing areas. (2) The frequency of heavy rainfall is the primary driver of local disaster occurrence, with flood disasters being predominantly triggered by these events. Case studies further demonstrate that such as rainfall intensity, duration, spatial distribution, and the synergistic effects of human activities also significantly influence the severity of disaster impacts. (3) Heavy rainfall in Huan County is concentrated in July and August, with frequencies decreasing sequentially in the May-June and September-October periods. This temporal pattern is highly consistent with the heavy rainfall distribution characteristics of the East Monsoon region. (4) Individual case analyses reveal distinct spatial variations. In 2013, heavy rainfall was highly concentrated, with Quzi and Hongde townships recording higher frequencies than other areas, forming a “two-point prominence, multi-point prevalence” pattern; these two regions represented the highest disaster risk zones that year. In 2018, the distribution shifted toward the east and southeast, with frequencies increasing from northwest to southeast. Mubo Township recorded the highest frequency in the county, exhibiting a continuous gradient a unimodal distribution pattern centered in the southeast.