Author(s): Hongmei Ye; Yuezhen Shi; Guohua Hu
Linked Author(s):
Keywords: Water resources allocation; Vegetation ecological water demand; 3S; Shule River basin
Abstract: With the development and utilization of soil and water resources in inland arid region, the natural water distribution pattern and the natural water cycle were disturbed. Most of the water was allocated to agricultural irrigation, industries and living, and the serious lack of vegetation ecological water which has resulted in forest retrogresses, desertification and water environment degradation in downstream especially. So how to allocate the water resources based on ecological security was raised urgently. The key to solve this problem is how to estimate the vegetation ecological water demand which must be based on the identification of the interaction mechanism between vegetation and hydrology. Shule River Basin, a typical inland river basin in arid region of northwest China, was selected as the study area in this study. Firstly, time series vegetation database was established based on MOD13Q1 images during 2000 to 2008. The dynamic change of vegetation’s area was evaluated by GIS. Secondly, we established the integrated vegetation-groundwater data model based on the observed groundwater level data and the MOD13Q1 data. The ecological groundwater depths were estimated by SPSS software with the results of 2. 2m in high coverage artificial cultivation region, 2. 5m in medium coverage natural vegetation region and 3. 0m in low coverage natural vegetation region. Thirdly, the vegetation ecological water demands were estimated by Aviriyanover formula and the results showed that the vegetation ecological water demand kept rising in high coverage artificial cultivation region with the average annual increase rate of 17. 35% during 2000 to 2008, while the other two natural vegetation ecological water demands remained stable. Finally, According to the analysis of both observed runoff data and precipitation data, we found that the rapid vegetation ecological water demands’ increase in 2003 and increase 2006 was the contributions of the rapid runoff increase in 2002 and increase in 2005.
Year: 2013