陕北黄土高原景观破碎化的时空动态研究

景观破碎化受到自然环境背景及社会经济活动的影响,并限制区域发展.为揭示景观破碎化的时空变化特征,整合了MODIS(中分辨率成像光谱仪)影像逐旬数据与多时段景观类型数据,并对其进行了分析.比较1987～2002年景观破碎化的年际差异表明,陕北黄土高原的景观破碎化过程较缓慢,但具有区域差异,且与景观类型组成息息相关.结果表明,林地的破碎化水平变化显著,而农、草地的破碎化水平变化相对缓慢.年际变化分析有助于说明区域景观破碎化的趋势,而年内季节变化则能帮助认识景观破碎化过程的周期规律.

Spatial-temporal dynamics of landscape fragmentation in North Shannxi Loess Plateau

The study of landscape fragmentation is an important means to reveal regional ecological processes.By using the remote sensing data of 1987,1997 and 2002,and the GIS tools,some representative quantitative indices of the landscape spatial structure and landscape fragmentation in North Shannxi Loess Plateau were calculated,aimed to investigate the relationships between landscape ecological structure and landscape pattern in this area.The results showed that cropland contributed most to the extent of landscape fragmentation,but unused land lacked obvious relationship with it.To get large-area images accurately and promptly is very important for monitoring ecological process in regional scale.Moderate-Resolution Imaging Spectroradiometer(MODIS) images in 2003 were used to derive monthly landscape fragmentation information calculated with Local Index of Spatial Associations(LISA) based on Spatial Statistical Analysis(SSA).The analysis of the fragmented landscape types showed that human disturbance had a main contribution to the seasonal landscape fragmentation.Furthermore,with the increasing percentages of cropland and unused land,landscape became more fragmented,while forestland coverage had inverse effects on the fragmentation.