Quantitative Assessment of Groundwater and Surface Water Interactions in the Hailiutu River Basin, Erdos Plateau, China

Description

This study presents a multi-disciplinary approach for investigating the interactions between groundwater and surface water in the semi-arid Hailiutu catchment in the Erdos Plateau, Northwest China. The study consists of statistical detection of river flow regime shifts at the basin level; multiple in-situ measurements for quantifying groundwater discharges using hydraulic, hydrochemical and temperature methods at a local scale; analysis and simulation of impacts of different land use scenarios on groundwater and surface water interactions at the sub-catchment scale; and the quantification of temporal and spatial groundwater and surface water interactions with hydrochemical tracers and modelling methods at the basin scale. The study found that the river flow consists of mainly groundwater discharges at all scales. The river flow regime has been intensively altered by human activities, such as the construction of reservoirs, water diversion, groundwater exploitation, and reforestation. Water use by plants and crops consumes majority of the precipitation. Groundwater sustains vegetation growth and feeds river discharges. The water resources and ecosystem management priority should reduce evaporative water uses by promoting dry resistant plant species for vegetating sand dunes and lower irrigation demand crops for socio-economic development. Furthermore, the Hailiutu River catchment must manage the groundwater recharge for water resource conservation and the maintenance of healthy ecosystems. Content: Cover Halftitle Title Copyright Summary Samenvatting Acknowledgements Contents Figures and Tables Chapter 1. INTRODUCTION 1.1 BACKGROUND 1.2 RESEARCH OBJECTIVES AND APPROACH 1.3 INNOVATION AND CHALLENGE 1.4 THESIS OUTLINE Chapter 2. THE FLOW REGIME SHIFT IN HAILIUTU RIVER 2.1 INTRODUCTION 2.2 MATERIAL AND METHODS 2.2.1 Study area 2.2.2 Data 2.2.3 Methods of regime shift detection 2.3 RESULTS AND DISCUSSION 2.3.1 Detection of regime shifts 2.3.2 Analysis of the results 2.4 CONCLUSION Chapter 3. A MULTI-METHOD APPROACH TO QUANTIFY GROUNDWATER/SURFACE WATER INTERACTIONS. 3.1 INTRODUCTION3.2 MATERIAL AND METHODS 3.2.1 Study site 3.2.2 Groundwater and stream stage monitoring 3.2.3 Temperature 3.2.4 Discharge measurements 3.2.5 Event sampling for hydrograph separation 3.2.6 Seepage calculation with electrical conductivity (EC) profile 3.3 RESULTS AND DISCUSSION 3.3.1 Measurement and analysis 3.3.2 Discussion 3.4 CONCLUSION Chapter 4. GROUNDWATER-SURFACE WATER INTERACTIONS UNDER DIFFERENT LAND USE SCENARIOS 4.1 INTRODUCTION 4.2 MATERIALS AND METHODS 4.2.1 Study area 4.2.2 Methods 4.2.3 Field Measurements 4.3 RESULTS 4.3.1 Results. 4.3.1.1 Estimation of Catchment water balance4.3.2 Discussion 4.4 CONCLUSION Chapter 5. GROUNDWATER AND SURFACE WATER INTERACTIONS AND IMPACTS OF HUMAN ACTIVITIES IN THE HAILIUTU CATCHMENT, NORTHWEST CHINA 5.1 INTRODUCTION 5.2 MATERIALS AND METHODS 5.2.1 Study area 5.2.2 Discharge measurements 5.2.3 Chemical and isotopic sampling 5.2.4 Groundwater discharge estimation 5.2.5 Groundwater modeling 5.3RESULTS 5.3.1 Discharge measurements and baseflow separation 5.3.2 Isotopic and chemical analysis 5.3.3 Estimation of groundwater discharge using the Cl- chemical profile. 5.3.4 Groundwater modelling results5.3.5 Comparison of seepage estimation and the simulated groundwater discharge 5.4 DISCUSSION 5.5 CONCLUSION Chapter 6 CONCLUSIONS, OUTLOOK AND FUTURE RESEARCH 6.1 CONCLUSIONS 6.2 OUTLOOK AND FUTURE RESEARCH REFERENCES ABOUT THE AUTHOR.