[Dynamic tendency of arid oasis under the influence of water resources decrease--a case study of Ejina oasis in Heihe River Basin].

The runoff changes of arid inland river seriously influenced on the formations and changes of oasis in the lower reach. By the oasis patches dynamic modeling, the vegetation-water interrelated analysis, and the estimation of water demand by the ecological system, the dynamic tendency of the Ejina oasis in the lower reach of Heihe River Basin under difference water resources allocating were studied. The results showed that the lowest water demanded for preserving the present oasis area was about 5.7 x 10(8) m3 based on rational usage of the water resources. Considering the water demand of people and livestock, and the water lose in the water transport process, the incoming runoff through the Langxinshan section should be about 6.0 x 10(8) m3 to preserve the present oasis area before 2015. To regain the oasis area to the level at the primary of 1980s, the demand incoming runoff should be about 8.9 x 10(8) m3, and the runoff through the Zhengyixia section should be 10.9 x 10(8)-13.1 x 10(8) m3.