青藏高原隆升的气候环境效应与黄土高原构造侵蚀

青藏高原的隆升使亚洲地区乃至全球范围的气候特征发生了巨大变化。其中,22 Ma B.P.改变了东亚地面行星风系并出现季风效应;8.5 Ma B.P.东亚季风效应增强,干旱化程度的加剧,黄土高原风尘堆积开始;3.6 Ma B.P.起,青藏高原隆升对全球气候变化的驱动与放大作用增强;1.2 Ma B.P.以来,青藏高原隆升对亚洲现代冬夏季风气候效应逐级增强。第四纪以来青藏高原的隆升,使黄土高原发生了阶段性抬升与构造变形,并引起多种黄土地质灾害与水土侵蚀,其中,黄土高原的抬升,导致侵蚀基准面下降,为重力侵蚀、沟谷溯源侵蚀和流水侵蚀提供了有利条件;构造变形会造成黄土产生构造裂隙、节理,增大黄土的侵蚀速率,促进黄土的坍塌和滑坡等侵蚀灾害的发生;地形突变带、活动断裂带、地震活动带等稳定性条件差的黄土分布区,是黄土侵蚀最剧烈的地区。

Climatic and Environmental Effect of Qinghai-Tibet Platean Uplift on Tectonic Erosion of Loess Plateau

Qinghai-Tibet Plateau uplift has caused great changes in Asian and global climate.Planetary wind system was changed and monsoon effect appeared around 22 Ma B.P.in East Asia;The monsoon effect of East Asia became stronger,aridity and desertification was intensified,widely spreading Aeolian dust began to accumulate in the Chinese Loess Plateau;The global climate change was droved and intensified by the plateau uplift since 3.6 Ma B P;The monsoon effect of Asian present-day climate was increasingly intensified since 1.2 Ma B P.Since Quaternary,the uplift and structure deformation taken place in the Chinese Loess Plateau and caused geological hazard and soil erosion due to the Qinghai-Tibet Plateau uplift.And the uplift of Loess Plateau induced gravitational erosion,backing up erosion and water erosion;The structure deformation resulted in loess collapse and landslide;The soil erosion is most intense in great tectonic deformation zones,active fault zones and seismic zones.