基于光谱数据的祁连山不同生态区植被覆盖时空变化特征被引量：4

Spatiotemporal Dynamics of Vegetation Coverage in Different Ecological Areas of the Qilian Mountains Based on Spectral Data

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摘要时序光谱遥感植被指数是公认的监测植被覆盖变化的有效指标,在大范围植被覆盖动态变化监测中发挥着重要作用。祁连山地处中国西部甘肃和青海两省交界处,地理位置特殊,对维持中国西部生态安全具有重要作用。随着全球气候变化,祁连山区的气候也出现了不同程度的变化,并且近些年来国家在祁连山实施了多项生态环境保护工程措施。针对祁连山不同生态区植被覆盖变化现状及未来趋势研究的不足,基于1 km分辨率的SPOT-VGT-NDVI光谱数据,运用数理统计法、空间叠置法分析了祁连山不同生态区植被覆盖时空格局、植被稳定性和未来演化趋势,探寻出敏感区域,为区域生态安全、生态工程建设提供理论基础,进而为林草部门制定祁连山保护规划和植被恢复措施提供科学依据。研究结果表明:1998年—2018年间祁连山植被NDVI呈波动上升趋势,增速为0.32%·a^(-1);柴达木盆地荒漠生态区和帕米尔—昆仑山—阿尔金山高寒荒漠草原生态区NDVI变化率较小,仅为0.14%·a^(-1)和0.27%·a^(-1),而内蒙古高原中部草原化荒漠生态区和江河源区-甘南高寒草甸草原生态区的变化率较大,分别为0.54%·a^(-1)和0.57%·a^(-1)。空间上,祁连山植被NDVI呈现东南区域高,西北区域低,整体改善,局部恶化的趋势,恶化区域和改善区域面积分别占祁连山总面积的28.37%和40.76%;分析发现祁连山植被较为稳定,较高波动和高波动变化区域面积合计为0.22×10^(4) km^(2),占1.20%;未来呈良性发展趋势和恶性发展趋势的面积分别占祁连山总面积的42.82%和26.40%,其中持续性恶化的面积占25.56%。祁连山-植被恶化区域主要为高海拔雪线附近的高寒草原和高寒荒漠、中东部城镇周围地区和河湖周围的植被脆弱区域,国家应将此区域作为以后治理的重点区。 Time series spectral remote sensing vegetation index is considered an effective index for monitoring vegetation coverage change and plays an important role in monitoring the dynamic change of vegetation coverage in a large area.Qilian Mountains,located at the junction of Gansu and Qinghai provinces,play an important role in maintaining ecological security in western China.In recent years,affected by global climate change,the climate in Qilian Mountains has changed to different degrees,and the state has implemented a series of environmental protection projects in the Qilian Mountains.Given the lack of research on the status and future trends of vegetation coverage in different ecological regions of Qilian Mountains,this research based on SPOT-VGT-NDVI spectral data with a resolution of 1 km,used mathematical statistics and spatial superposition method to analyze the spatial and temporal patterns,vegetation stability and future evolution trend of vegetation coverage in different ecological regions of Qilian Mountains,and explored sensitive areas.It provides a theoretical basis for regional ecological security and ecological engineering construction,and further provides a scientific basis for forest and grassland departments to formulate Qilian Mountain protection planning and vegetation restoration measures.The results show that:From 1998 to 2018,vegetation NDVI in Qilian Mountains showed a fluctuating upward trend,with an increased rate of 0.32%·a^(-1).The NDVI variation rates in the desert ecological area of Qaidam Basin and the Alpine desert steppe ecological area of the Palmier-Kunlun Mountain and the Altun Mountains were relatively low,only 0.14%·a^(-1) and 0.27%·a^(-1),while the variation rates in the steppe desert ecological area of the central Inner Mongolia Plateau and the river source area of the Gannan alpine meadow steppe were relatively large,respectively 0.54%·a^(-1) and 0.57%·a^(-1).Spatially,the vegetation NDVI of the Qilian Mountains is high in the southeast and low in the northwest,with overa

作者潘冬荣韩天虎闫浩文 PAN Dong-rong;HAN Tian-hu;YAN Hao-wen(Faculty of Geomatics,Lanzhou Jiaotong University,Lanzhou 730070,China;Gansu Grassland Technical Extension Station,Lanzhou 730010,China)

机构地区兰州交通大学测绘与地理信息学院甘肃省草原技术推广总站