Mapping geomorphology, groundwater bodies and springs in Simadal, Norway.

Abstract:

Simadal in Hardanger (Norway) is a narrow valley, famous for the waterfalls Rembedalsfossen and Skjykjedalsfossen which are regulated by Sima hydropower plant. Since the basin has been regulated between 1973-1979 the catchment area was reduced from 146km² to 35 km². There are currently plans for further expansion by also incorporating Skykjedalsvatnet, the last major remaining lake in the basin of Simaelva. In Simadal there are known to be large amounts of ground water, a greater understanding of how the groundwater interacts the river water is desirable in terms of water flow, residence time and water chemistry.

Throughout the autumn of 2013 and winter of 2014 loggers were placed at various measuring points to log temperature and water levels. This included six loggers that measure temperature and pressure, as well as three loggers that measure only temperature. The goal with these loggers was to locate springs and monitor water level changes over a one-year period. In order to further investigate the water quality of the different measurement points, monthly water samples as well as pH-, and conductivity measurements were conducted. The water samples were analyzed for major ions as well as metal ions. The latter was based on earlier reported high copper levels. Flow measurements have been made in the upper and lower parts of Simadal during dry periods. The work has also included the accomplishment of Quaternary mapping; analysis of aerial photography; and using GPR.

Our main concern has been to map the water resources in Simadal by registering groundwater and springs in sediments and rock faces. Furthermore, it has been desirable to draw lines to a larger regional knowledge based water management. It seems to be important to maintain a certain minimum of water of good quality, both for the ecology of the river in general, but perhaps especially considering the sustainable sea trout populations found in Simaelva today. Previous chemical, hydrogeological and fish biology surveys of Simadal have been conducted which we aim to complement.