可可西里1970-2013年气候变化特征及其对景观格局的影响

气候变化对青藏高原景观产生的影响越来越强烈,本文使用1990、2000和2013年3期遥感影像资料,选取具有代表性的6个景观类型,通过ArcGIS 10.0和ERDAS 9.2软件进行数据处理,研究了可可西里国家级自然保护区景观格局变化特征;结合当地1970—2013年气象数据,分析该区气候变化特征及其对景观格局的影响。结果表明:44年间可可西里保护区的降水量以20.3 mm/10年的速率显著上升,年平均温度以0.38 ℃/10年的速率上升,从2000年开始,该区降水量和年平均温度均出现较大幅度增长;但44年间的潜在蒸散量和相对湿度没有明显的趋势性变化。该区冰川和永久积雪、水域、高寒草甸和高寒草原景观格局变化的主要驱动因子分别为年平均温度、降水量、潜在蒸散量和相对湿度。冰川和永久积雪、水域、沼泽湿地景观的变化体现在连续11年间的气候累积效应与该区域气候的波动周期一致;而高寒草甸和高寒草原则受到短时间(2~5年)气候变化的影响,说明可可西里植被的脆弱性。气候变化对可可西里的景观分布具有重要影响。 

Characteristics of climate change in Hoh Xil and its impact on landscape pattern during 1970-2013

Climate change has strongly affected landscape pattern of Qinghai-Tibet Plateau. Remote sensing data of 1990, 2000 and 2013 that contain six typical landscape types were chosen and analyzed by applying ArcGIS(10.0) and ERDAS(9.2) to illustrate the changes of landscape pattern in Hoh Xil National Nature Reserve. Climate data from 1970 to 2013 and its contribution to the landscape pattern change have been analyzed. The results showed that precipitation increased significantly at a rate of 20.3 mm/10 years, and annual average temperature increased at a rate of 0.38 ℃/10 years in Hoh Xil. Annual average temperature, precipitation, potential evapotranspiration and relative humidity were the key driving factors of glaciers and permanent snow, water body, alpine meadow and grassland area expansion, respectively. Glaciers and permanent snow, water body, and marsh wetland responded to 11-year cumulative climate effects, which is coincident with the weather cycle of the region; whereas alpine meadow and grassland were affected by 2-5 years short climate change, which indicated the fragility of the Hoh Xil region. In a word, climate change has an important influence in landscape change of Hoh Xil National Nature Reserve.