The Disaster Event Response To Environmental Changes Recorded By Phytolith In Chaohu Area

The growing recognition that global change and sustainable development has brought into focus some fundamental questions, in which the disaster led to huge human damage is one of the main questions of them. The research methods contrast among environment changes recorded by phytolith and sediment grain size and pollen and environmental magnetism, and human activities during the disaster period obtained by the historical literature and archaeological data and instrumental record lead to analyzing historical environmental changes and disaster which brought to human impacts on environment changes and human adaptation, which can be gotten comprehensive conclusion about historical human-natural relationship in Chaohu area.Located in the transition zone of subtropical and warm temperature, Chaohu lake area has frequently dominated by the east low-cyclone and anticyclone leading high frequency natural disasters. Through these analyzing of the phytolith and sediment grain size and pollen and environmental magnetism and research on the historical literature and archaeological data and instrument record, some conclusions about research on human impact on environmental disasters and human adaptation are as follow:(1) According to systematic research on the phytolith fossils of core Nanlin in the Caohu Lake, the phytoliths in the area can be divided into six zones. Based on changes in the main components in the phytolith zones and principal components analysis, the evolution of paleoenvironment and paleoclimate since the middle Holocene is reconstructed. There are three cold periods (5600-5200aB.P, 4600-3600 aB.P,2500-2100aB.P.)and three warmth periods (5200-4600aB.P,,3600-2500aB.P, 2100-1800aB.P.) since 5600aB.P . The main types of phytolith indicated warm climate are fan type and square-rectangle type. The main types of phytolith indicated cold climate are sinuate/smooth bar type and short/long point types. The disaster event year recorded by the phytolith are 5500aB.P.,4500 aB.P,2500 aB.P,2100 aB.P.(2)The phytolith fossils of core AC2 from the Caohu Lake can be divided into three zones. Based on changes in the main components in the phytolith zones and...