Land-water resources development and the Decline of the ancient Oasis-towns

The origin and development of an urban center is a complex and long process. The towns in the Heihe River basin experienced seven major development stages. Many factors affected the rise and decline of the urban system in the region. Given that towns are developed from agglomeration of population settlement instead of nomadic herding, this research reveals that the rise and decline of the historical towns was closely related to the advance and retreat of Han Chinese who were mostly farmers in the region. However, our study also shows that over cultivation and over population caused desertification and abandonment of towns in lower and middle reaches of Heihe River basin.