Geology 230

Groundwater/ Surface Water Interaction

California State University, Sacramento

Week 4:

Arid hydrology and the hyporheic zone    


Upon completion of this unit students should be able to:

  • Discuss the effect of floods or sudden disturbances on stream ecology and the hyporheic zone.

  • Distinguish between the effects of baseflow and overland flow.

  • Examine nutrient, groundwater and flow patterns on a seasonal time scale.


Reading Assignments:

1) Jones and Mulholland:  pp. 111-133


2) Valett, H. M., Fisher, S. G., Grimm, N. B., and Camill, P., 1994, Vertical hydrologic exchange and ecological stability of a desert stream ecosystem, Ecology, v. 75, pp. 548 - 560.


Valett et al


3) Fisher, S. G., Gray, L. J., Grimm, N. B., and Busch, D. E., 1982, Temporal succession in an desert stream ecosystem following flash flooding, Ecological Monographs, v. 52, p. 93-110.


Fisher et al






Tim's summary of Jones and Mulholland, pp. 111- 133:


Arid hydrology


Discussion question from Katy:


Vertical Hydrologic Exchange and Ecological Stability of a Desert Stream Ecosystem (Valett et al., 1994)

Arid fluvial (or riparian) ecosystems are subject to a pendulum of extreme conditions within a small-scale time and space continuum. How does the hyporheic zone mitigate system stability in regards to resistance and resilience in response to a flash flood disturbance?

Katy's summary of Valett article


Discussion question from Michelle:


Temporal Succession in a Desert Stream Ecosystem Following Flash Flooding (Fisher et. al., 1982)

What factors unique to the arid fluvial/riparian zone have the greatest effect on the ecological succession following a flash flood? How does the hyporpheic zone affect the rebuilding of ecosystems post-flood?

Michelle's summary of Fisher article