Research On Microclimate Improvement Mechanism Of Greening Landscape In Mogao Grottoes

Mogao Grottoes expanded the scale of greening in 1960s-1980 s,which formed the oasis climate environment.This kind of environment is conductive to the protection of cultural relics,but also takes new problems.In order to facilitate the physical environment of cave murals and statues,this paper researched the micro climate environment of the whole area of Mogao Grottoes,especially for the square in front of caves.This paper takes some research and the results are as follows.(1)Taking the software of GIS as information management platform,this paper established Landscape Information Model(LIM)of Mogao Grottoes for greenings,accurately obtained the spatial data information of greening and relative attribute information,and analyzed greening information with native modules.Practice has proved that GIS can integrate the survey and mapping information,which can provide the necessary spatial data for simulation.We can finish the landscape analysis of LIM with native modules.It has high feasibility as the the information management platform of heritage-input.(2)This paper,for the first time,tried to quantify the Mogao grottoes outside the mechanism of the physical environment through field tests and numerical simulation method.According to the statistical analysis for quantitative data,time specific gravity which can meet with the condition of natural ventilation inside the cave can be analyzed out.The results show that the interaction of thermal pressure ventilation and wind pressure ventilation affects the unilateral opening of natural ventilation for Mogao grottoes.If(35)T(29)2,the grottoes satisfy the conditions of thermal pressure ventilation.When the average wind speed outside in East wind is larger than 0.12m/s,the grottoes can meet with the conditions of wind pressure ventilation.While the average wind speed outside in West wind is about 0.25m/s,the grottoes can meet with the conditions of wind pressure ventilation.Except for Grotto 148,other grottoes which can satisfy the condition of natural ventilation is more than 50%.This means the intensive oasis landscape can still meet with the requirements of anatural ventilation.(3)In view of the problems existing in the greening landscape renovation from the functional perspective of the protection of cultural relics,suggestions are given for the grottoes.The results show that the distance between cliff face and forest belt too small and greening planting density too concentrated to Grotto 148 are important reasons for why does the square before micro climate condition cannot meet the caves in a certain degree through the numerical simulation.And accordingly this paper gives greening landscape renovation plan for Grotto 148 surroundings.With specific climatic conditions of the Mogao Grottoes in Dunhuang oasis landscape as the research object,this paper focuses on the linkage among the climatic environmental landscape,the micro climate environment above the square in front of caves and micro flow in the cave,reveals the protection effect of cultural relics for the oasis landscape Mogao Grottoes,exploratory simulates greening landscape renovation suggestions for the micro climate environment of square in front of grottoes.This paper lays the foundation for the outdoor thermal environment and wind environment,which makes possibility to the simulation of guidance and accurate prediction of heritage environment of site landscape design to improve the existing environment protection of cultural relics.The above research not only provides guidance for the green transformation of Mogao Grottoes,but also provides technical reference for the study of the outdoor physical environment of moderate or large scale,which has special research value.