|HAN, MING - Chinese Academy Of Sciences|
|ZHAO, CHENGYI - Chinese Academy Of Sciences|
|DISSE, MARKUS - Technical University Of Munich|
|SHI, FENGZHI - Chinese Academy Of Sciences|
|LI, JUYAN - Chinese Academy Of Sciences|
Submitted to: International Union for Quaternary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2015
Publication Date: 3/13/2015
Citation: Han, M., Zhao, C., Feng, G.G., Disse, M., Shi, F., Li, J. 2015. An eco-hydrological approach to predicting regional vegetation and groundwater response to ecological water convergence in dryland riparian ecosystems. International Union for Quaternary Research. p. 1-13.
Interpretive Summary: The eco-hydrological model has attracted substantial research attention recently. To our knowledge, eco-hydrological models established in previous studies have their limitations as applied to ecological restoration studies. It is the first report regarding development and application of eco-hydrological model at a large river basin scale. The eco-hydrological model coupled with groundwater movement and vegetation dynamic was developed in this study. The evaluation of the model was measured by groundwater table and the observed yearly maximum NDVI from 2000 to 2006 indicated that the model can be used at acceptable accuracy. After 6 years’ water convergence, the total amount of groundwater recharge from river was 1.97×109 m3, taking 87.4% of the total amount of water convergence, the water consumed by evapotranspiration (bare soil evaporation and vegetation transpiration) was 1.04×109 m3, taking 46.1% of the total amount of water convergence. The evapotranspiration and the ratio of groundwater net recharge to amount of water convergence varied significantly from 2000 to 2006. They were influenced by both vegetation recovery process and the rise of the groundwater table. Therefore, the coupling model of the groundwater and ecology process is required for making best management practices and schedule of water convergence. The interaction between the hydrology component and vegetation component has been revealed by analysis of water balance and studies of three scenarios. The vegetation dynamic has significant impact on groundwater evapotranspiration, groundwater storage change and groundwater depth, while groundwater depth is a critical feedback variable that determines the vegetation dynamics. The eco-hydrological model developed in this study can be used to help recover vegetation and protect ecology system.
Technical Abstract: To improve the management strategy of riparian restoration, better understanding of the dynamic of eco-hydrological system and its feedback between hydrological and ecological components are needed. The fully distributed eco-hydrological model coupled with a hydrology component was developed based on the modified MODFLOW for characterizing groundwater flow, along with a vegetation dynamic component using Verhulst logistic equation. The validation of the eco-hydrological model by observed data of groundwater and river head and remote sensing data demonstrated that the model is capable of simulating the dynamic of the eco-hydrological system in lower reach of Tarim River. What’s more, the interaction between the hydrological component and ecological component has been revealed by water balance analysis and scenario studies. The vegetation dynamic had significant impact on groundwater evapotranspiration, groundwater storage change and groundwater depth, while groundwater depth is a critical feedback variable that determines the vegetation dynamics, which was proved by both measured and simulated results. The eco-hydrological model presented in this study, could help to restore and protect groundwater dependent ecosystem, particularly for riparian ecosystem.