基于蒸发胁迫和土壤湿度的长江流域骤旱时空演变特征OA
Spatiotemporal evolution characteristics of flash droughts in the Yangtze River Basin based on evaporative stress and soil moisture
骤发干旱突发性强、可预见性差、破坏力大,往往对自然生态和社会经济活动产生较大影响.深入探究长江流域骤旱事件的时空演变规律,可为区域灾害风险防范提供参考.以长江流域为研究对象,基于 1980-2023 年GLEAM v4.1 数据集的蒸散发与土壤湿度数据,分别采用标准化蒸发胁迫比和土壤湿度百分位数方法识别骤旱事件,分析两类骤旱事件的时空演变规律.结果表明:两类骤旱在频次、历时和强度方面均呈现较大差异.基于标准化蒸发胁迫比识别的骤旱高频区主要位于长江流域上游西北部,且频次呈显著上升趋势,平均历时为6～7 候(5 d为1 候),强度等级主要为轻度和中度;而基于土壤湿度百分位数识别的骤旱高频区则集中于长江流域中下游,平均历时为8～11 候,强度等级以极度为主,且呈显著增强趋势.基于蒸发胁迫的骤旱频次、历时及强度在空间分布上高度一致,而基于土壤湿度的相关骤旱特征则无明显的空间一致性.不同要素对骤旱过程的响应存在显著差异,可针对不同类型骤旱特征建立分区监测预警体系,从而提升长江流域骤旱防御能力.
Flash droughts,characterized by sudden onset,poor predictability,and great damage,sub-stantially impact both natural ecosystems and socio-economic activities.Understanding the spatiotemporal evolution of such events in the Yangtze River Basin is crucial for informing regional disaster management.Focusing on the Yangtze River Basin,we used GLEAM v4.1 evapotranspiration and soil moisture data during 1980-2023 to identify flash droughts and analyze their spatiotemporal evolution based on stand-ardized evaporative stress ratio and soil moisture percentiles methods.The flash droughts identified by these two methods differ considerably in frequency,duration,and intensity.Evaporative stress-based flash droughts occur most frequently in the northwestern upper reaches with a significant rising trend.Their average duration is 6-7 pentads with primarily mild and moderate intensity.In contrast,soil mois-ture-based flash droughts are concentrated in the middle and lower reaches with a significant increasing trend.Their average duration is 8-11 pentads with predominantly extreme intensity,which continues to increase significantly.Evaporative stress-based drought characteristics exhibit strong spatial consistency,whereas soil moisture-based droughts show inevident spatial consistency.These findings highlight the dif-ferent response features of atmospheric and soil moisture components during flash drought events,thus providing references for establishing a regional monitoring and early warning system to enhance drought resilience in the Yangtze River Basin.
刘梦飞;江善虎;王孟浩;曾莉萍
河海大学 水文水资源学院,江苏 南京 210098河海大学 水文水资源学院,江苏 南京 210098||河海大学 水灾害防御全国重点实验室,江苏 南京 210098河海大学 水灾害防御全国重点实验室,江苏 南京 210098||河海大学 农业科学与工程学院,江苏 南京 210098贵州新气象科技有限责任公司,贵州 贵阳 550002
天文与地球科学
骤旱蒸发胁迫土壤湿度时空演变特征长江流域
flash droughtevaporative stresssoil moisturespatiotemporal evolution characteristicsthe Yangtze River Basin
《水资源与水工程学报》 2026 (3)
1-10,10
国家自然科学基金项目(52479009、52409019)江苏省自然科学基金项目(BK20241515)
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