The potential to investigate the integration of surface water and groundwater in New Zealand using remote sensing technique

Surface water bodies are normally linked to groundwater. Rivers, lakes, wetlands and estuaries may act as recharge sources for an aquifer or vice versa (Braaten and Gates, 2001). Understanding the basic principles of groundwater/surface water (GW–SW) interactions is essential to effectively manage water resources. The necessity for sustainable use of groundwater and surface water in New Zealand will continue to increase in the future due to global warming, contamination of water resources and increasing demand for water. A good understanding of groundwater-surface water interactions is important for decision makers and water resources managers.

Remote sensing is a powerful tool to identify the spatial distribution of groundwater discharge and improve our knowledge of the interactions between groundwater and surface water. Discharged groundwater in the surface water features have some signatures such as thermal or chemical which is different from that of surface water and can be sensed remotely. Assessing the thermal infrared imagery from satellite or airborne is an effective method to quickly assess large areas and obtain information about specific locations of the interactions and regional groundwater flow pattern at larger spatial scales. This technique can help in designing groundwater monitoring networks, sampling sites in groundwater and surface water, establishing a baseline for the future of ground level monitoring systems and also for estimating the environmental effects of contaminant migration. The observations during analysis of the thermal images can be considered as a starting point for more rigorous spatial analysis and fieldwork. The exact locations, boundaries and magnitude of the interaction can be verified using field measurements. Remotely sensed data are most accurate when they are combined with numerical modeling, geographic information systems, and field base information (Becker, 2006). This paper reviews the state of knowledge regarding the remote sensing of groundwater/surface water interactions worldwide and describes the existing potential to apply this technique to New Zealand’s water resources. This method can be applied on springs, rivers, lakes, wetlands and estuaries to define the spatial pattern of groundwater/surface water interactions and establish a base line for more detail investigation. Delineating the area of interaction before conducting the experimental tests can save time and reduce cost during the research.