Comprehending the interaction between surface water and groundwater is a crucial aspect of water management and ecological studies, as it functions as a unified entity. This groundwater and surface water interaction processes and the sustainable management practices of water resources are depends on the nature of landscape which varies from mountains to oceans. The process involves in landscapes such as streams, lake and sea are different due to the changes in topography, sub-surface and surface hydraulic properties, rainfall, climate change, groundwater flow and abstractions etc. Because of these governing factors the methods used for the identification of interaction limited to certain landscapes. The existing techniques that used to evaluate the interaction between surface water and groundwater are classified as Physical methods: heat tracers, surface-subsurface head gradients; The chemical methods: electrical conductivity, chemistry of ions; Modelling techniques: mass balance/solute transport modelling of ionic concentration and numerical groundwater flow models. Although each approach has its own drawbacks and uncertainties, combining various approaches is also considered in order to obtain a suitable degree of understanding regarding the interaction between surface water and groundwater. The merits, demerits, suitability, its applicability on both spatial and temporal scales of various methods used for determining the groundwater and surface water interaction studies in different landscapes are discussed in this chapter.