[目的]揭示黄土高原典型区域百年尺度干旱演化特征,与地貌类型耦合阐明气象干旱的时空变化规律,进而为北洛河流域综合治理提供科技支撑。[方法]基于1915—2020年北洛河流域1 km分辨率的平均气温及降水数据,计算了年际标准化降水蒸散指数(SPEI),并结合Theil-Sen Median趋势分析、Mann-Kendall检验、小波分析、反距离权重插值(IDW)等方法,分析了流域内100余年不同地貌类型区的气象干旱时空演变特征。[结果](1)北洛河流域降水量及平均气温的空间分布差异较大,总体呈现东南向西北递减的特点;降水量多呈条带状分布,平均气温沿河道自上而下梯度增加,上游区(丘陵沟壑区)降水量相对较少,下游区(阶地平原区)平均气温相对偏高;(2) 1915—2020年北洛河流域SPEI-12震荡明显,干旱事件交替出现且弱减,下降速率为-0.04/10 a, 1942年,1990年和2010年为旱势转折年,并以1990年最为明显;周期变化大致可从1960年分为两个时期,之前以10 a, 17 a为主,其后为3 a, 7 a, 30 a左右,10 a和30 a周期在不同时期干旱变化中起主导作用;(3) SPEI-12的不显著下降趋势具有全域性且由东北向西南有增大趋势,表明北洛河流域总体呈弱旱化发展;(4)不同年代干旱事件发生频率差异较大,1990s重旱和特旱发生频率最高;2000s不同类型干旱事件发生的总频率最大,其中上游区(丘陵沟壑区)和下游区(阶地平原区)可达70%,而中游区(土石山林区和高原沟壑区)约为60%;(5)不同类型干旱空间分布存在异质性,轻旱发生频率有自南向北逐渐降低的趋势,中旱发生频率与之相反。总体来看,北洛河流域上游区(丘陵沟壑区)易发生中旱,下游区(阶地平原区)更易发生轻旱,重旱高发区在流域内零散分布,特旱的发生概率仅为1.69%~2.10%。[结论]全球变暖引发的旱化趋势在黄土高原地区的影响客观存在,北洛河流域不同地貌类型区气象干旱发生的高频类型略有差别,未来应提升中下游地区的抗旱减灾能力。
在新工科背景下,“双线”混融教学模式逐渐成为各高校更佳的教学模式,然而高校地质类专业的“双线”混融教学模式整体尚处于探索、实践阶段。《水文地质学基础》作为专业核心课程,承担着专业知识和专业情感“双领航”的重要任务,系统化、多层次、全过程地探索该课程“双线”混融教学模式,具有典型性、代表性、迫切性。本文以《水文地质学基础》课程为例,通过内容重构,模式革新,助力综合型人才培养、精准施教,教学相长,助力知识与情感双领航、思政元素如盐化汤,情怀育人,助力知识–素养–情感三培育,设计和构建体现地质类学科需求的“双线”混融教学模式,具有较高的理论价值、实践价值和思政价值,助力于提升地质类专业课程教学模式的多元性、创新性、前瞻性。In the context of the new engineering, the “dual line” blended teaching model has gradually become a better teaching mode for various universities. However, the “dual line” blended teaching mode for geological majors in universities is still in the exploratory and practical stage as a whole. As a core course of the major, “Fundamentals of Hydrogeology” undertakes the important task of “dual guidance” of studying professional knowledge and developing professional emotions, thus systematically, multi-level, and fully exploring the “dual line” blended teaching mode of this course is typical, representative, and urgent. This paper takes the course “Fundamentals of Hydrogeology” as an example and designs and constructs a “dual line” blended teaching model that reflects the needs of geological disciplines through three major approaches: firstly, content reconstruction and mode innovation are carried out to assist in the cultivation of comprehensive talents;additionally, precise teaching and learning complement each other are hoped to help to guide both knowledge and emotions;furthermore, similar to the melting of salt in soup, courses with ideological-political elements and cultivating emotions can help students cultivate their knowledge, literacy, and emotions. This model has high theoretical value, practical value, and ideological and political value, which is helpful for enhancing the diversity, innovation, and foresight of the teaching mode of geological courses.
暂无评论