Introduction
Geophysics of inland waters (rivers, lakes, ponds and streams), or Hydrogeophysics, is a branch of Science that studies lakes, rivers, and wetlands, focusing on groundwater-surface water exchange, sediment mapping, and water quality.
It uses physics-based tools to study water dynamics, subsurface structures, and environmental exchanges. This field is essential for managing water resources, tracking climate impacts, and identifying environmental hazards.
Understanding exchanges of groundwater and surface water is essential to water managers and hydrologists for the development of effective water-resources policy, protection, and management. Surface water (including streams, lakes, wetlands, and estuaries) “gains” groundwater discharge via seeps and springs, while surface water also infiltrates into adjacent groundwater under “losing” hydraulic conditions. Groundwater discharge is the main component of stream baseflow, or the channel water flowing in between storm events and snowmelt. Many streams, lakes, and wetlands are primarily sourced by groundwater discharge during dry conditions, while coastal water quality can be strongly influenced by submarine groundwater discharge.
Geophysics of rivers and streams involves the study of how water flows, energy and sediment transport (by saltation, suspension traction) and shape channel morphology. These systems, driven by gravity, operate via erosion, transportation and deposition, creating features like braids, meandering patterns and oxbow lakes.
The unit is intended to help high school students get a better understanding of the following key concepts related to geophysics of inland waters:
Water Storage and Movement: Understanding how groundwater is stored and how it moves through different types of aquifers, including the water table and recharge zones.
Hydrologic Cycle: Recognizing the role of snowpack in natural water storage and how changes in snow accumulation and melt timing affect streamflow and water availability.
Inland Water Ecosystems: Exploring the biological diversity and complex biogeochemical pathways of inland water ecosystems, including the types of bodies of water and the organisms that inhabit them.
Water Balance: Understanding the balance of water entering and leaving the environment, including evaporation, transpiration, precipitation, and runoff.
The geophysics of rivers and streams also involves applying physics principles to study how water, sediment, and the Earth's subsurface interact. Rather than just looking at the water on top, geophysics uses tools to "see" what is happening beneath the riverbed and how the river's energy reshapes the land over time. Throughout the unit, we will explore the following areas of interest:
