Study on the stability of oasis at different scales

Oasification and desertification are the most fundamental geographical processes that occur in arid regions, and the main goal of arid region development is to make oasis ecosystems evolve more stably and systematically and thus achieve their sustained development. As a complex system of dissipative structures, oasis systems evolve under forces of self- and other-organizational processes. At different scales, the working mechanisms of oasis stability, control goals, and approaches are different. In this paper, a small-scale oasis is defined on basin scale, with a temporal unit of decade and a spatial unit of oasis patch; a middle-scale is defined according to administrative regions, with a temporal unit of century and a spatial unit of basin; a large-scale is defined as arid areas, with a temporal unit of millennium and a spatial unit of administrative region. At small-scales, the coupling of the two processes embodies the coupling of scientific policies, advanced methods and approaches, and the environment and water resources in oasis patches. At middle-scales, the coupling of the two processes embodies macro management of the oasis in the administrative region with a unit of basin: improvement in the quality of mountain environment, reasonable allocation and utilization of water resources, and guarantee of the occurrence of a certain proportion of natural oasis in the region. At large-scales, self-organizational process is more powerful than other-organizational process. The oasis stability relies on the change of climate and geological conditions.