Dynamic changes of groundwater level and vegetation in water table fluctuant belt in lower reaches of Heihe River:Coupling simulation;

According to soil PH value,total soluble salt content,main iron types and their percentages,the soil desertification and water condition in the lower reaches of Heihe River can be divided into four types.

The distribution of groundwater level in an uninterrupted space was studied under the support of GIS in the lower reaches of Heihe River.

This paper is aimed at a special region of the lower reaches of Heihe River and the problems with its ecosystem of vegetation, discussing synthetically the vegetation .

The groundwater table is of ecological significance in the lower reaches of Heihe river,a fragile ecosystem area.

The river courses in the lower Heihe River are all natural ones with irregular cross sections and great seepage,belonging to broad-shallow type of sandy riverbed.

Spatial feature of soil salinity in groundwater fluctuant region of the lower reaches of the Heihe River;

Influence of water transport project on groundwater level at lower reaches of the Heihe River;

On the basis of assessing the ecological security for the five oases of the middle and lower Heiher River in the middle 1980s and at the beginning of 2000s, the paper analyzes the ecological security change of these oases.