基于遥感的石河子绿洲冷岛效应时空变化特征及其影响因子分析

论文基于1989、2000和2013年Landsat TM/ETM+和Land 8 TIRS 遥感数据、植被指数（NDVI）、土地利用/土地覆被变化（LUCC）及年均气温等资料分析了石河子绿洲冷岛效应时空变化特征及其影响因子。结果表明：近25 a来,石河子绿洲冷岛效应总体呈先增强后减弱趋势,且市区南部和中东部存在两个高温中心,城市南北向扩展快于东西向。NDVI和地表温度（T_S）负相关性显著（R=-0.912）,且极高温区和高温区植被指数低,反之亦然。1989—2000年极低温区和低温区所占范围扩大,增幅为1.1倍,主要是水域面积增加显著,并由林地、草地、耕地转入,绿洲冷岛效应增强;2000—2013年耕地与草地面积均减小,而极高温区和高温区面积比例从19.64%增加到26.75%,增幅达36.20%,主要是建设用地扩大,致使绿洲冷岛效应减弱,表明T_S与NDVI和LUCC关系密切。此外,城市化指数和气温也是影响绿洲冷岛效应的因子。石河子绿洲气温上升与全球变暖相一致,在未来城市发展中,充分发挥绿洲冷岛效应就显得尤为重要。

Spatial-temporal Characteristics and Factor Analysis of the Cold Island Effect in the Shihezi Oasis Based on Remote Sensing Images

The paper analyzes the characteristics of spatial-temporal change and factors of the cold island effect in the Shihezi Oasis based on the remote sensed Landsat TM/ETM+ and Landsat 8 TIRS data in 1989, 2000 and 2013 as well as NDVI, LUCC and annual average rainfall data. The results showed that the cold island effect of Shihezi Oasis firstly went weakened and then became strengthened in recent 25 years. There were two heat center, which located in the southern and eastern of the study area. NDVI and LST have a significant negative correlation (R= -0.912). The vegetation index in extreme-high temperature and high temperature area is low. In 1989-2000, the proportion of extreme-low temperature and low temperature area increased 1.1 times. The reason is that some grassland, woodland and farmland turned into water which led to the cold island effect of oasis increased. During 2000-2013, the area of farmland and grassland reduced, while the proportion of extreme-high temperature and high temperature area increased from 19.64% to 26.75%, since the expansion of construction land resulted in the weakening of the oasis cold island effect. It disclosed that LST is closely related with NDVI and LUCC. In addition, urbanization index and temperature are also influence factors of the cold island effect. The temperature risen in the Shihezi Oasis is consistent with global warming. It is important that we should make use of the cold island effect of the oasis in the future urban development.