近30年天山北坡改进型遥感生态指数时空变化及其驱动因素

天山北坡是西北地区重要的生态功能区和重要经济带,受气候变化和人类活动的影响,脆弱的生态环境面临着巨大挑战,但目前对该地区生态环境质量时空变化、特征及驱动力的认识较少。为此,本文利用改进型遥感生态指数(ERSEI)、空间自相关分析、多元线性回归分析和地理加权分析方法揭示天山北坡1990、2000、2010和2020年4个时期生态环境质量时空变化、特征及其驱动因素。结果表明:(1)1990-2020年天山北坡ERSEI先大幅下降后逐渐恢复并持续上升,生态环境质量逐渐改善并趋于稳定,总体呈“东优西劣”的空间格局;(2)天山北坡生态环境对气候变化较为敏感,温度是ERSEI变化的最重要驱动因子;(3)不同驱动因素对ERSEI的影响存在显著的空间异质性,自然因素对局部ERSEI空间分异起主导作用,人为因素则对年际ERSEI变化产生重要影响。这表明气候变化和人类活动显著影响ERSEI变化,未来应科学规划各类经济活动,减缓气候变化效应,提升天山北坡生态安全和环境可持续性。

Effect of Topography and Accessibility on Vegetation Dynamic Pattern in Mountain-hill Region

Knowledge of both vegetation distribution pattern and phenology changes is very important.Their complicated relationship with elevation and accessibility were explored through a geographically weighted regression(GWR) framework in Fujian province,China.The 16-day time series of 250 m Moderate Resolution Imaging Spectroradiometer(MODIS) Enhanced Vegetation Index(EVI) dataset from 2000 to 2010 was applied.Wavelet transform method was adopted to decompose the original time series and construct the annual maximum EVI and amplitude of the annual phenological cycle(EVI).Candidate explaining factors included topographic conditions,accessibility variables and proportions of primary vegetation types.Results revealed very strong positive influence from parameters of elevation and accessibility to big rivers and negative effect from accessibility to resident on both maximum EVI and phenological magnitude through ordinary linear least square(OLS) regression analysis.GWR analysis revealed that spatially,the parameters of topography and accessibility had a very complex relationship with both maximum EVI and phenology magnitude,as a result of the various combinations of environmental factors,vegetation composition and also intensive anthropogenic impact.Apart from the continuously increasing trend of phenology magnitude with increasing altitude,the influence of topography and accessibility on maximum EVI and phenological magnitude generally decreased,even from strongly positive to negative,with increasing altitude or distance.Specially,the most rapid change of correlation coefficient between them was observed within a low elevation or close distance;less variation was discovered within a certain range of medium altitude or distance and their relationship might change above this range.Non-stationary approaches are needed to better characterize the complex vegetation dynamic pattern in Mountain-hill Region.

2000—2020年广西植被覆盖时空变化及其影响因素研究

基于2000—2020年MODIS增强型植被指数数据,采用趋势分析、变异系数等方法分析广西21年EVI值时空变化趋势,并利用地理探测器模型对广西植被覆盖的驱动机制进行了研究。结果表明,2000—2020年广西植被覆盖整体呈现稳中有升的趋势,多年平均EVI值为0.399 3。广西植被改善区域面积为55.92%,主要分布于研究区中部和南部;区域空间上,EVI值主要表示为低波动变化,低波动区域面积占比为84.16%。9个环境因子对EVI值的解释力从大到小依次是植被类型>地貌类型>GDP>人口>坡度>高程>土壤类型>气温>降水量,环境因子两两相互作用,均为非线性增强交互关系。

推动构建区域命运共同体重要实践:中国与东盟交通基础设施合作分析

中国正在依托“一带一路”国际合作倡议同周边国家共建基础设施空间实体互联互通网络,与东南亚国家合作建设的交通运输项目尤能体现以连通破解对抗的理念。这种中国式地缘空间改良路径明显区别于西方地缘政治学的固有逻辑,是推动构建区域命运共同体的重要实践。具体而言,中国通过硬件物理媒介与周边地理空间建立深度连接,连通性的增强有利于改良中国与邻国的自然地理结构,优化周边陆海地缘空间的相对关系,提升区域整体的协同程度,孕育互利共赢、命运与共的价值理念。在“一带一路”建设的东南亚案例中,中老铁路有助于提升交通网络的连通密度,雅万高铁有利于增强运载效率,国际陆海贸易新通道有益于拓宽辐射范围,从而推动中国与共建国家协同联动,促进命运共同体的空间地理目标,体现中国式地缘空间意涵。