Based on the GWR (geographically weighted regression) model supported by ArcGIS, the research explores the multi-scale relationship between vegetation change, climatic factors, and the sensitivity of vegetation to climate factors using AVHRR vegetation cover data combined with temperature and precipitation data in China from 1982–2010. Compared with the general linear regression (Ordinary Least Square, OLS) model, GWR gives a much better fitting result, with the goodness of fit increased from 0.3 to 0.6. The relationship between NDVI, annual rainfall, and average annual temperature has a significant spatial heterogeneity. Regression coefficients of climatic factors decrease from north to south and are higher in the northwest dry region of China. Temperature is more influential than rainfall on NDVI in most areas of China. Each ecological zone has different spatial scales when NDVI and the climatic factors maintain a stable relationship.
In order to study the distribution of fracture controlled by layer thickness and lithology, clastic rock of 6-7th Member, Yanchang Formation in Longdong area is selected as investigated subject, and the areal density of their structural fractures is meassured. Measured fracture densities show that the layer thickness of clastic sequence has an effect on fracture density. Compared with thicker layer, it is easier for thinner layer to develop structural fracture, which is related to the different stress concentration near fracture tip in different layer thickness. Within a certain thickness range, fracture density has an exponential relationship with layer thickness, while the fracture density remains mostly unchanged when thickness exceeds 250 cm. Under the condition of same layer thickness and different lithology, the value of fracture densities from small to large follow the order of medium sandstone, fine sandstone, siltstone and mudstone, which means that in the same tectonic setting and layer thickness, the smaller the size range is, the larger the fracture density will be. Besides, there is an exponential relationship between fracture density and grain size, which may be caused by the different stress between grains of different size. By multivariate statistics and mechanism analysis, layer thickness is the key factor in controlling fractures’ development compared with lithology.