滨海半城市化地区植被覆盖度的时空变化——以青岛市崂山区为例

基于青岛市崂山区1990、1997、2002、2008年四期TM遥感影像数据,利用遥感二分像元估算模型和归一化植被指数,定量研究了半城市化地区的植被覆盖度演化过程及其时空动态变化特征,结果表明:研究区植被覆盖度演变具有快速性、差异性和不稳定性特征;1990-1997年,植被平均覆盖度由48.71%下降到24.74%,是植被覆盖度下降最快时期;2002-2008年间,植被平均覆盖度由23.58%增加到44.49%,属于植被覆盖恢复时期。整体空间变化呈现分散和无序特征,地形因子显著影响植被覆盖度的分布及变化。从气候因素和人为活动影响两个方面分析了造成崂山地区植被覆盖度下降的原因,对降雨量与各地区植被覆盖度进行了相关性分析,划分出气候影响显著区域。最后通过主成份分析定量研究气候、人为因素对当地植被覆盖度的影响程度,结果发现城市化作用是造成植被覆盖度变化的主要因素。

Spatial and Temporal Variations of Vegetation Coverage in Coastal Peri-urban Area:A Case Study of Laoshan District,Qingdao

Based on 1990,1997,2002 and 2008 Landsat TM images of Laoshan District in Qingdao City,and through the second sub-pixels of remote sensing and normalized difference vegetation index(NDVI),evolvement and spatiotemporal characteristics of vegetation coverage in the coastal peri-urban area was quantitatively studied.Results indicated that the evolvement of vegetation coverage in the area had the characteristics of rapid,variant and instable.From 1990 to 1997 is the period which vegetation coverage decreased the most sharply from 48.71% to 24.74%.In 2002~2008,vegetation coverage was recovered,with average coverage vegetation increasing from 23.58% to 44.49%.Analyzing spatial changing characteristics in the whole area,vegetation coverage was appeared dispersive and out-of-order,topographic conditions were of great importance to the distribution of the vegetation and the process of vegetation coverage changes.Analyzing the reasons for the degeneration of vegetation coverage from climatic factors to human activities,based on correlation analysis between precipitation and vegetation coverage,the areas with significant correlations was divided.Principle component analysis method was performed on the influence factors,and results indicated that urbanization is a principle reason leading to the degeneration of vegetation coverage made off in Laoshan District.