新疆干旱区湿地景观格局遥感动态监测与时空变异

为了解和掌握全球变化环境下中国干旱区湿地的分布现状、变化过程和时空格局特征,该文通过多源遥感技术手段,采用面向对象分类方法和目视解译相结合,完成了干旱区湿地信息的多期监测,实现了新疆地区2000、2005和2010年的湿地分布制图,并利用动态度模型和地统计方法计算了近10 a时空变化情况,分析了湿地变化的时空特征。研究结果表明:1)近10 a来全疆干旱区湿地约增加了10.1%,2010年新疆湿地总面积达到22 438 km2,较2000年约增加了2 065 km2;2)在类型构成上,2010年河流湿地、湖泊湿地、沼泽湿地和人工湿地所占比例分别为42.73%、29.43%、17.98%、8.92%和0.94%;3)在空间分布上,南北疆呈现不均衡,南疆湿地约占总体的76%,北疆湿地仅占24%;主要分布在塔里木流域,以河流湿地为主,空间分布差异显著;4)新疆湿地面积总体上呈增多的趋势,不同类型的湿地面积变化幅度差异较大。沼泽湿地和人工湿地的动态度分别为:2.58%、2.43%,河流湿地与湖泊湿地的动态度为:0.59%、0.43%;净增量最大的是沼泽湿地和河流湿地,分别增加了827.92和531.86 km2,占湿地净增量的65.85%。在变化原因上,全球变暖、新疆区域气温升高和降水增多是湿地近年来增加的主要原因;人类活动的干扰,加剧了湿地变化的复杂性和空间差异性。研究结果可为区域生态环境变化研究以及湿地资源的保护规划提供数据支持和结论参考。

Remote sensing detection and spatio-temporal change analysis of wetlands in Xinjiang arid region

Abstract: As a part of globle ecosystem, the wetland plays an important role in arid region eco_environment system. The area change of wetland will greatly influence the regional environment. In order to understand the wetlands distribution status, change processes and temporal pattern characteristics in China arid zones under the environment of global change, this paper used multi-source remote sensing data (TM, ETM+ and CBERS_02) to achieve the arid zone wetlands multi-stage monitoring through object-oriented classification technology and semiautomatic method. Firstly, we used object-oriented technology and hieriarchical classification algorithm, achieved preliminary wetlands infomaiton extraction, and checking the classification accuracy of the primary result by manual visual interpretation. Then, we completed 3 times wetlands distribution mapping on year 2000, 2005 and 2010. On that basis, we analyzed the characteristics of wetland spatial distribution and temporal variation in the past 10 years via land use dynamic change model and the geo-statistical method. The research results show that, 1) Wetlands in Xinjiang arid area has increased by about 10% in the last 10 years on the whole. The total area of wetlands reached to 22 438 km2 in 2010 in Xinjiang arid region of China, which increased approximately 2 065 km2 compared with the area in 2000. 2) In the spatial distribution, wetlands in the southern and northern Xinjiang are uneven. Wetlands in the southern Xinjiang accounted for about 76% in total wetlands area, and wetlands in the northern Xiangjiang only accounted for 24%. Wetlands Xinjiang arid area mainly distributed in the south of Xinjiang Tarim river basin. And in different basins, wetlands spatial distribution have different characteristics. 3) On wetland types composition, in year 2010, the ratio of river wetland, lake wetland, marsh wetland and artificial wetland are 42.73%, 29.43%, 17.98%, 8.92% and 0.94% respectively. 4) In change process, all type wetlands showed a growing trend in the past 10 years, but the increasing amount and magnitude are different. The variation on different type wetland presents different characteristics and inter-class differences are large. Among them, the dynamic change of marsh wetland and constructed wetland are 2.58 % and 2.43%; The dynamic change of rivers wetlands and lake wetlands are 0.59% and 0.43%. The largest net increased values are marsh wetland and river wetland, which increased by 827.92 km2 and 531.86 km2 respectively, account for 65.85% of the total increase amount. With the Global warming, rising temperature and increasing precipetation in resent years in Xinjiang district is the main driving force of wetlands increase. And, the human activity intensified the complexity of wetland spatio-temporal change process.