LIANGLIANG JIA1, ANDREAS BUERKERT2, FUSUO ZHANG1, CHANGYAN TIAN3
1China Agricultural University, College of Resources and Environment, China
2University of Kassel, Organic Crop Production and Agroecosystems Research in the Tropics and Subtropics, Germany
3Chinese Academy of Science, Institute of Ecology and Geography, China
Little is known about time-related changes in the agricultural structure of ancient melt-water oases along the silk road in the hyper-arid Taklamakan desert of Northwest China. Recently released, high-resolution b/w aerial photographs taken in 1956 and an ETM+ satellite image taken in 2002 were used to compare such changes in Yutian oasis at the northern fringe of the Kunlun mountains, where melt-water is used to produce crops on irrigated farmland. Image analysis showed a complete transformation of the oasis' agricultural setting over the time period studied from an extensive agriculture system with a total cultivated surface of 17,970ha, a canal length of 3,133 km and a higher landscape diversity compared to today's 21,300ha oasis surface and a canal length of 4,068 km in 2002. Whereas the modern-day agriculture structure with its chest"=board type system of cement"=lined irrigation canals may fit the need of intensive agriculture based on commodity crops such as maize (Zea mays L.), cotton (Gossypium hirsutum L.) or melon (Cucumis melo L.), it likely consumes much more water than the traditional system. This may lead to the reduction of melt"=water available for the foreland vegetation protecting the oasis from encroaching sand dunes of the surrounding desert.
Keywords: GIS, image analysis, oasis transformation, Taklamakan