西安全新世环境变化及对人类活动的影响  

Holocene environmental change and its impact on human activities in Xi’an

作　　者：赵艳 岳大鹏 赵景波 刘乐[1] 刘怡婷 杨宇哲 ZHAO Yan;YUE Dapeng;ZHAO Jingbo;LIU Le;LIU Yiting;YANG Yuzhe(School of Geography and Tourism,Shaanxi Normal University,Xi'an 710119,China;State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,CAS,Xi'an 710061,China)

机构地区：[1]陕西师范大学地理科学与旅游学院,西安710119 [2]中国科学院地球环境研究所,中国科学院黄土与第四纪地质国家重点实验室,西安710061

出　　处：《地理科学进展》2022年第7期1274-1287,共14页Progress in Geography

基　　金：国家自然科学基金重点项目(42130507);黄土与第四纪地质国家重点实验室项目(SKLLQG2013,SKLLQG2106)。

摘　　要：为揭示西安地区全新世环境变化及其对人类活动的影响,论文运用土层元素含量、CaCO含量和磁化率等指标研究了白鹿塬全新世各土层发育时的环境变化。结果表明:该区的中全新世古土壤受到中等程度的化学风化,尚未达到脱钾阶段,土壤类型为亚热带黄棕壤。该层古土壤发育时的年均温度约为16℃,年均降水量约为920 mm。中全新世夏季风活动占主导地位,夏季风带来的降水量约为570 mm。晚全新世黄土受到低等程度的化学风化,具有碱性褐色土的特点,发育时的年均温度为11~13℃,年均降水量为600~700 mm。晚全新世夏季风活动与冬季风相近,夏季风带来的降水量在350 mm左右。在中全新世晚期的6000~5000 a BP之间,发生了气候变冷干的事件,在冷干事件期间土壤侵蚀强烈,当时堆积的黄土在广大地区受到侵蚀消失,仅在少数剖面存留。晚全新世黄土发育时的沙尘暴堆积率至少是中全新世古土壤发育时的2.3倍。中全新世气候温暖湿润,导致古土壤粘化强、持水性较好、含水量充足,非常利于当时温带作物和部分亚热带作物发展与农业生产,这是当时人类活动较强和村落分布较广的主要原因。晚全新世黄土也具有优良土壤的特性,当时降水量和土壤水分含量基本能够满足温带旱地农业生产的需要,这是晚全新世关中平原人类活动逐渐增强的重要原因之一。In order to reveal the Holocene environmental change and its impact on human activities in Xi’an, the environmental conditions of Holocene soil layer formation in Bailuyuan were examined by using the indicators of soil element content, CaCO3content, and magnetic susceptibility. The results show that the middle Holocene paleosol in this area has been subjected to moderate chemical weathering and has not yet reached the potassium removal stage. The soil type is subtropical yellow brown soil. The average annual temperature during the development of this layer of paleosol was about 16 ℃ and the average annual precipitation was about 920 mm.The middle Holocene summer monsoon was dominant, and the precipitation brought by the summer monsoon was about 570 mm. The late Holocene loess was chemically weathered to a low degree and was characterized by alkaline brown soil. The average annual temperature during its development was 11-13 ℃ and the average annual precipitation was 600-700 mm. The activity of the late Holocene summer monsoon was similar to that of the winter monsoon, and the precipitation brought by the summer monsoon was about 350 mm. During 6000-5000 a BP in the late middle Holocene, the climate became cold and dry. During the cold and dry period, soil erosion was strong. The accumulated loess was eroded and disappeared in a large area and remained only in a few sections. The accumulation rate of sandstorm deposits in the late Holocene loess was at least 2.3 times that in the middle Holocene paleosol. The warm and humid climate in the middle Holocene led to strong soil viscosity, good water holding capacity, and sufficient soil water content, which was very conducive to the development of temperate crops and some subtropical crops and agricultural production at that time, and was the main reason for strong human activities and wide distribution of human settlements at that time. The late Holocene loess also has excellent soil property. During its formation, the precipitation and soil water content can ba

关 键 词：全新世环境变化 夏季风降水 地球化学元素 人类活动 西安白鹿塬 

分 类 号：P534.632[天文地球—第四纪地质学]