Study On The Relationship Between Groundwater And Predominant Vegetation (Salix) In The Hailiutu River Watershed, Ordos Basin

The Erdos lake and basin plateau area, with vast territory and abundant mineral resource, lies in the northern of Erdos basin, which is the new energy and chemical industry base in 21st century. Lacking water resource and weak ecological environment is the main question of country's energy development for the basin in Drought-semiarid areas. As the energy and mineral resources developing increasely, the development and utilization of groundwater resources is sharping need, and how to reasonable exploit and utilize of groundwater under the principle of the protection of ecological environment, has become major issues of the social sustainable development.Hailiutu river is in the north of Erdos basin, and the connecting between ecosystem and groundwater. It has strong representative in ordos basin. This article chooses Hailiutu river catchment as the research area, with the project help'Sino-Dutch cooperation relationship of water and ecological system',study the relations of groundwater and vegetation ecosystem, the dependent of advantage vegetation:salix on groundwater, and how to describe this relationship, focusing on the following content:1. The groundwater quantity by salix transpiration;2. Calculate the proportion of salix transpiration consuming water;3. Studying the response of vados zone water content on root water uptake.The research content belongs to ecohydrogeology, and the research achievement are very important theoretical and practical.This article is based on the collection, analysis the existing data, as environmental science ground water science and ecology theory a guide, through in-situ experiments, collecting samples and numerical simulation method to study the relationship between groundwater and salix, obtained the following understanding and conclusions of:1. The result of using the White method to calculate the water quantity by salix transpiration is 8.78mm/d,8.62mm/d,10.04mm/d,8.59mm/d(on 2010 October 4, October 5, October 8, October 9);2. The Sapflow monitor the transpiration of salix is 8.78mm/d,8.62mm/d,10.04mm/d, 8.59mm/d (on 2010 October 4, October 5, October 8, October 9), and the result is low than White method result;3. Using isotopic mixing ratio model to calculate the source of water by salix transpiration for knowing the main water source is soil water firstly(63.85%) and then is groundwater(36.15%)((on 2010 September 5, September 14, October 2); And based on mixture ratio and Sapflow the transpiration of salix (on September 5,2010) is that consuming ground water is 4.38 mm and soil water is 7.73 mm; And the consumption of underground water is 2.03 mm, and soil water is 3.59 mm (on October 2);4. Monitoring the soil water content when the salix is grouth on the soil surface, and the results show that the water content change regularly in 20cm-90cm depth. Using hydrus-ID software to simulate the water reveals root water uptake in the vadose zone, and the result show that this layer of soil is affecked by root water uptake.