NDVI characteristics and precipitation sensitivity of urban agglomeration in Central Shanxi Basin

The overall NDVI characteristics and precipitation sensitivity in the study area from 2000 to 2018 were investigated using NDVI images of urban agglomeration in central Shanxi basin in 2000,2005,2010,and 2018 as well as the climate data of China’s surface cumulative annual value data set(1981-2010)in accordance with the method such as the geographically weighted regression model.As can be seen from the results,first,the overall NDVI pattern of urban agglomeration in central Shanxi basin,China has been changed and distributed along the topography in the shape of strip.Second,the spatial evolution of NDVI in the study area is varied significantly with the trend of expansion as a whole and a shrinking trend in some areas.Third,the overall precipitation in the study area presents a declining trend from the west to the east,while the NDVI precipitation sensitivity shows a decreasing trend from west to east.To be specific,the west and the east have a positive value of 1.3129 with strong sensitivity and a negative value of-1.0908 with weak sensitivity,respectively.The study results are expected to provide a scientific basis for restoring vegetation and formulating disaster prevention policies for urban agglomeration in Central Shanxi Basin.

省际边界区县域产业结构时空演变及影响因素——以晋陕豫黄河金三角地区为例

选取2005,2010和2016年晋陕豫黄河金三角地区各县域统计数据,计算产业结构提升系数,揭示县域产业结构时空演变的基本特征,并利用地理探测器分析产业结构演变的影响因素。结果表明:2005—2016年,研究区产业结构水平整体处于提升状态,且阶段性特征显著;产业结构水平有明显的空间集聚特征,且产业结构高水平的县域呈“C型”包围低水平县域的态势,被包围地区基本处于紧邻省界线的县域和中心地带,深刻反映出省际边界地区的“切变”效应对产业调整的影响;产业结构演变是人口、市场和技术等因素的综合表现,整体而言,人口和市场要素对研究区产业结构演变的影响力较高,不同自然单元分区的主导因素存在差异,在区域合作的背景下,初步呈现出区域内在动力向外部要素转变的特征。

青藏高原腹地湖泊沉积粒度特征及其古环境意义

选择青藏高原腹地可可西里为研究区,通过对该区湖泊沉积物粒度参数的分析,并且与其他环境代用指标进行比较,探讨了中更新世以来可可西里地区的环境演变。结果表明:粒度参数的变化特征可以很好地指示湖泊水位的变化,能反映湖区气候的变化情况,粒度参数所指示的湖泊水位波动及环境变化得到了其他环境代用指标很好的支持,说明对沉积物粒度研究是恢复区域气候环境变化的一种有效途径。同时该区湖泊沉积物粒度参数的变化规律和深海氧同位素曲线在冰期—间冰期旋回尺度上有较好的一致性,但也出现不同的变化特征,表明这一区域既有与全球一致的气候特征,也受区域气候变化影响,其原因可能与青藏高原的抬升有一定关系。