A Study On The Historical Environment Of The SuoYangcheng Area During Ming And Qing Dynasty

This research takes the two cultural relics the Yulin Caves and the Suoyangcheng as main objects to explore the environmental change of this area during Ming and Qing dynasty.The research draws four conclusions behind:1.The wind velocity in Guazhou is quite high,while the annual average wind velocity is 3.14m/s.The wind velocity is relatively high during spring and summer,while the annual wind velocity in summer is 4.28m/s,which is the highest among the four seasons.The sanddriving wind also occurs mainly in spring and summer,while the frequency of sand-driving wind is 20.5% and the highest frequency occurs in August among the 12 months,which is 44.8%.So the wind condition in Guazhou is sufficient to form the Yardang landform.2.The direction of the yardang landform in Suoyangcheng is almost coincident with the prevailing wind direction while it is inconsistent with the flood direction.Therefore,wind erosion is the main force to form the yardang landform.Suoyangcheng is the cultural relics from Tang dynasty to Ming dynasty.In the background of Little Ice Age during the Ming dynasty,the wind velocity is quite high and the human activities all makes it a environmental fragile area.The strong wind erosion makes the the yardang landform.3.The 14 C dating result and the cultural relics on the ground of the Suoyangcheng all indicate that the yardang landform formed in the Ming Dynasty.4.The research results of the historical flood in 1911 indicate that the peak discharge is 809m3/s,and its recurrence interval is 105 yr.During the year of 1911,the climate changes from cold to warm,the unstable climate change caused unstable precipitation,and there were quite few plant on the land to retain the precipitation,which might be the reasons of the historical flood in 1911.