干旱区生态环境知识资源中心

Expansion of farmland is recognized as one of the most important human alterations to the environment around the globe. Using field investigations and socioeconomic data in combination with thematic mapper images taken in 1986 and 2000, we analyze farmland area changes and factors correlated with those changes in Liangzhou and Minqin oases, located near the middle and lower reaches of the Shiyang River basin in Gansu province, northwestern China. Between 1986 and 2000, farmland area increased in both oases, but the increase was greater at Minqin oasis. Population growth was positively correlated with farmland area expansion in both locations, as were improved agricultural techniques and economic development. In Liangzhou oasis, farmland expansion was closely linked to the amount of surface water present, while in Minqin oasis, farmed area growth was affected by environmental and weather conditions. These results suggest that economic development at Liangzhou oasis may be leading to environmental degradation downstream, at Minqin oasis.