Environmental Quality Evaluation And 3D Reconstruction Of Cultural Heritage In Typical Areas Of Xinjiang Silk Road

The Silk Road in Xinjiang,as the most distinctive cultural tourism resource,has attracted the attention of the world for its rich historical and cultural heritages.However,most of the heritages along the route are mainly rammed earth construction.Most of it is placed outdoors and directly connected to the earth.They are susceptible to nature and human intervention.The problem of the existence of cultural heritage is becoming more and more obvious.Remote sensing technology can not only enable rapid and efficient monitoring of cultural heritages,but also provide digital data for the visual preservation of cultural sites.This study discusses the typical cultural heritage of the Xinjiang Silk Road.And using long-term series of Landsat remote sensing data,analyze the changes in the environment and landscape in the region over the past 30 years.And show the possible effects of the environment on the cultural heritage.Secondly,with the help of the Remote Sensing Ecological Index and the Analytical Hierarchical Process,a rating system for the quality of the ecological environment and the sensitivity of the location landscape in the region was set up.And clarify the trend of change in environmental quality around cultural sites.That are easily disturbed by the environment through the environmental impact assessment.We use of remote sensing data from Landsat,Sentinel-2A,GF-2 and LiDAR to analyze and visualize the characteristics of cultural sites.It draw the following conclusions:(1)From the results of NDVI,LST and TVDI indicators in the region.NDVI has shown a growing trend in the past 30 years.It can suppresses the phenomenon of desertification and has a positive meaning for the protection of cultural sites.LST showed a volatile upward trend.And it presents the effects of "desert heat island" and "oasis cold island".The TVDI is high overall and the mean change is not obvious.The mean of TVDI change is not obvious,the regional drought is more uniform.The types of land use in the concentrated area of cultural heritage are mainly unused land,arable land and grassland with a smaller distribution of building land and water.Among them,the arable land increase from year to year.Grassland changes fluctuate significantly,but the general trend is increasing.The water and the unused land showed an overall downward trend.From the perspective of land use transfer.Frequent transfers between different types of land use.Cultivated and construction land are expanded to unused land on the basis of the original.This phenomenon has put great pressure on the protection of the surrounding cultural heritages.The increase of grassland mainly comes from cultivated land and unused land.And mainly distributed in staggered zone.The distribution of the grassland contributes to the survival of the cultural heritage in the oasis.The decrease in water mainly resulted in unused land and grassland.The water is far from the cultural heritages and has little influence.(2)The results of the evaluation of the ecological quality based on the Remote Sensing Ecological Index are as follows.The area where the quality of the ecological environment has deteriorated the most and reached 74.28 % in the past 30 years.The proportion of the area in which the ecological environmental quality has improved is only 0.80 %.The quality of the ecological environment shows a trend of overall decline and local improvement.And the process is relatively slow.The results of the assessment of landscape sensitivity using Analytical Hierarchical Process are as follows.The landscape sensitivity of most sites in the region remains unchanged,with an area ratio of approximately 83.73 %.The second is the area with increased sensitivity,which is about 11.69 %.The overall sensitivity of the site landscape shows the property of a gradual shift from extremely sensitive areas and insensitive areas to medium and highly sensitive areas.And the sensitivity of the sites landscape change more drastically.According to the comprehensive results of the environmental assessment,the proportion of deterioration in ecological quality around the location and the proportion of increased sensitivity to the landscape show an increasing trend.The severity of the environment has affected the long-term survival of cultural sites.(3)Compare the properties of ruins under medium and high resolution remote sensing data.We found that based on two-dimensional remote sensing data,only the degree of Cultural heritages change can be observed at the macro level.However,there is a lack for accurate and comprehensive remote sensing surveillance of heritages.And the 3D remote sensing data can implement the real 3D model of the sites through fast and efficient point cloud data.And it can provide digital material to protect and restore cultural heritage.