River islands' change and impacting factors in the lower reaches of the Yangtze River based on remote sensing

摘要: Abstract There are many developing river islands in the Mawutong section of Yangtze River, and their sizes change rapidly. Changes eight were studied using Multi-Spectral Scanner (MSS 1979) Thematic Maps (TM 1990, 2001, 2006 2009). The spectrum typical objects was analyzed by ISI921VF-256T Field Spectroradiometer, bands combined, images interpreted geometric correction, subset images, binarization processing, convolution, clump procedures, visual image interpretation. A number factors that considered to influence evolution analyzed. They include annual runoff, sediment, soil particle composition islands. results show that: 1) Spectroradiometer can help identify correct islands, hence selected (three visible one near infrared) be used extract variation islands' area based on digital processing interpretation; 2) general, lengthened 1979–2006 at various rates, with highest rate during 2001–2006. Their decreased rapidly 2006–2009 except for two islands; 3) erosion sediment deposition major physical processes As no significant trend total runoff 1953–2010 detected, it is likely construction large reservoirs upstream dynamics loads this region have more impact changes than do climate changes.