基于SPEI的内蒙古地区近55年干旱时空变化趋势分析

研究干旱变化的特征,有利于预防干旱发生.利用1961～2016年内蒙古境内的气温、降水数据计算得到不同时间尺度的标准化降水蒸散指数,结合趋势分析法、Mann-Kendall突变检验法和消除趋势波动(DFA)分析法,分析不同时间尺度干旱演变趋势及未来干旱预测.结果表明:①内蒙古年际干旱呈现增加趋势,1995年发生突变,由湿润转变为干旱.总体上,内蒙古地区呈现东部干旱程度加重,而西部减缓的趋势.轻旱发生频率较高,且东南部干旱的发生较多.②春、夏和秋季存在明显变干及突变趋势,且突变年份不一致,而冬季有不太明显的变湿趋势.春、夏和秋季干旱发生较为严重且范围较广.③在未来,内蒙古地区干旱将保持现有趋势,干旱仍持续一段时间.     

蒙古国夜间灯光数据的适用性分析

夜间灯光数据为城镇化和区域发展监测提供了强有力的数据和技术支撑,但其具体适用性还有待进一步探讨。基于GIS及遥感技术,通过对DMSP/OLS和NPP/VIIRS数据进行校正获取1992―2018年蒙古国夜间灯光数据,分析了夜间灯光数据对欠发达国家研究的适用性。研究结果表明：(1)蒙古国夜间灯光在首都城市群集聚效应明显,呈现“中北部集中,铁路沿线增长较快”的空间格局;灯光总值在2010年之后呈现明显增长的趋势,表明电力供应实现快速、稳定增长。(2)空间尺度越大,夜间灯光数据适用性越强、对社会经济活动的估算精度越高;在同一省级尺度上,只有当城镇化率大于30%并且人口未大量流失时夜间灯光数据才与人口数量有正相关性,否则呈负相关或不相关。(3) NPP/VIIRS监测到的定居点数量多于DMSP/OLS,稳定的电力供应是定居点是否被监测到的关键。     

基于Hurst指数的1982–2013年蒙古高原植被动态变化趋势及其影响因素分析（英文）

This study analyzed the spatial and temporal variations in the Normalized Difference Vegetation Index(NDVI) on the Mongolian Plateau from 1982–2013 using Global Inventory Modeling and Mapping Studies(GIMMS) NDVI3 g data and explored the effects of climate factors and human activities on vegetation. The results indicate that NDVI has slight upward trend in the Mongolian Plateau over the last 32 years. The area in which NDVI increased was much larger than that in which it decreased. Increased NDVI was primarily distributed in the southern part of the plateau, especially in the agro-pastoral ecotone of Inner Mongolia. Improvement in the vegetative cover is predicted for a larger area compared to that in which degradation is predicted based on Hurst exponent analysis. The NDVI-indicated vegetation growth in the Mongolian Plateau is a combined result of climate variations and human activities. Specifically, the precipitation has been the dominant factor and the recent human effort in protecting the ecological environments has left readily detectable imprints in the NDVI data series.