Qinghai Ming Great Wall Clinlate And Disease Characteristics Of Development

Northwest of China is in the characterization of complicated and various climate with high temperature, low but centralized precipitation less than evaporation and strong wind frequently. Under this climate environment, Ming Great Wall distributed in Qinghai Province is of diverse characterization of disease development for variability in construction technology and preserving environment. Consequently, it is significant to make and implement reasonable conservation countermeasures based on correct recognition of preserving environment and rational analysis of disease of Ming Great Wall.Based on theory of meteorology, field investigation, monitoring, labarotary tests and numerical modeling were used in this paper to study characteristics of climate environment and diseases development of the Great Wall in Ming Dynasty in Datong, Huangzhong, Huzhu and Menyuan, which were selected from 11 Countries in Qinghai Province for their numerous distribution of Great Wall and various climate.Conclusions of this paper were summarized as fllows:(1) Generally, one or several factors would be dominating in the formation and development of any typical disease of Great Wall among various factors that might existed. For instance, precipitation is the key factor of gully and so are precipitation, evaporation and air temperature of scaling stripping and velocity and direction of wind of sapping. Hazards of these diseases might be limited or even precluded if key factor(s) could be distinguished and corresponding measures could be made reasonably.(2) Results of wind erosion test indicate that main surface diseases of soil specimens are scaling stripping and sapping with a low erosion quantity if wind velocity is less than 22 m/s. The erosion quantity increases sharply and main surface disease turns to sapping with a wind velocity of 28 m/s. In comparison with low wind velocity, erosion time has a more obvious effect on sapping quantity of soil specimen for high wind velocity.(3) Wind field simulated by Fluent Software shows that distinct might velocity would exist at different height of wall under a same wind field applied outside. Wind velocity might increase obviously at both end and top of windward side of wall. The variation erosion quantity 1 might be attributed to the diffenent direction of wall. Wind velocity increases most obviously when the wall with an angle between prevailing wind direction is about 30°, leading to the highest sapping quantity in accordance with results of field investigation.