气候变化对元上都遗址区景观格局的影响

Climate changes affecting regional landscape patterns at Xanadu

为了研究气候变化对内蒙古元上都遗址区景观格局的影响,运用小波分析、遥感技术等方法,分析了1981-2010年元上都遗址区气候变化规律和1990年、2000年、2010年3个不同时期的景观格局动态。结果表明:元上都遗址区近30 a年均气温呈上升趋势,年际变率为0.065℃·a-1,在30 a低频区和10 a中频区呈明显冷暖交替期。年降水量呈下降趋势,但变化趋势不显著,在25 a的低频区呈明显干旱期,而10 a的中频区呈干湿交替,受气候暖干化的影响仍将持续;元上都遗址区草地景观优势度在降低,景观结构变化较大。其中草地、水域、湿地与沼泽面积在减小,而耕地、林地、居民点和沙地面积在增加,沙地面积增幅显著,20 a间年均增加9.55 km2;近30 a来,气候变化不是主导元上都遗址区景观格局变化的主要因素,气候变化与沙地、草地面积相关性最大。而2000年后的区域开发和相关生态工程是导致遗址区景观稳定性降低的主要因素。

To study the effects of climate change on landscape patterns at sites in Xanadu, wavelet transformation and remote sensing were used to analyze the climate change rules from 1981-2010 for landscape pattern dynamics in three different periods: 1990, 2000, and 2010. Results showed that the annual temperature had a rising tendency over the nearly 30 years with an interannual variation of 0.065·a-1years. Zone temperature changes alternated between a low frequency of 30 years and high frequency of 10 years. Annual precipitation declined slightly with interannual variation of 0.07mm·a-1. The low frequency of 25 years experienced drought;whereas, the low frequency of 10 years alternated between wet and dry. Dominance of the grass landscape declined on this site. Structural landscape changes included a decrease in grasslands, water areas, wetlands, and swamps; while farmland, woodland, residential places, and sandy areas increased. For instance, sandy areas increased 9.55 km2 in nearly 20 years. Over this 30 year period, climate change was not the dominant factor that changed the landscape pattern; climate change associated with sandy and grassland areas were greatest. As regional development and relevant eco-engineering being the main factors contributing to reduce stability of these landscape sites.