Hydrologic Science and Engineering

Research

Hydrologic Model
Rainfall fields generated by a multifractal
model on a small watershed of ARS
experimental site of the Lindstrom farm
near Sterling, CO

The HSE faculty members have broad research interests. These include: stochastic characterization and simulation of hydrologic processes, prediction of extreme events, hydrometeorology, hydroclimatology, scaling analysis, watershed erosion and morphology, river basin modeling, and soil moisture patterns and variability.

Research on stochastic hydrology has been an active area at Colorado State University for several decades. Examples include: the characterization of the temporal and spatial variability of hydrological processes such as precipitation and streamflow, the stochastic modeling of precipitation and streamflow at various time scales (e.g. hourly, daily, monthly, and yearly), the development of stochastic modeling schemes for large-scale complex river systems, the formulation and application of stochastic models capable of representing abrupt changes and non-stationarity, the development of statistical procedures for estimating quantiles of extreme precipitation and extreme floods, the characterization of drought dynamics based on probabilistic methods, and the development of methods for record extension and reconstruction of streamflows based on tree ring indices. In addition, specialized software has been developed such as SAMS that is capable of analyzing, modeling, and simulating streamflow at single and multiple sites including the effects of abrupt climate shifts. Furthermore, many of the models, procedures, and software tools developed in our research program have been applied by Federal and local agencies and consulting firms in the United States and elsewhere to tackle engineering problems.

Research on hydrometeorology focuses on hydrologic processes that occur at the interface of the atmosphere and the land surface such as evapotranspiration and soil moisture dynamics. Ongoing research is considering the complementary relationship between evaporation and potential evaporation.

Hydrologic Model
A so-called "parallel" river network, which
exhibits distinctive fractal characteristics

Another active area of research has been river basin morphology. Research in this area focuses on the interaction between hydrologic processes and the land surface. At short time scales, river basin topography can influence the space-time patterns of soil moisture, runoff production, and evapotranspiration.

Examples of research in this area include: assessments of topographic controls on soil moisture patterns and dynamics, interpolation and downscaling of soil moisture observations using topographic information, and estimation of evapotranspiration rates from sites with varying water table depths using remote sensing. At long time scales, runoff and streamflow shape the basin through erosion and sedimentation processes.

Examples of research topics at this time scale are: assessments of fractal and scaling-invariant properties of river basin topography, improvement of models to simulate long-term erosion and sedimentation in watersheds, analysis of the intrinsic variability of geomorphic processes, characterization of feedbacks between hydrologic and geomorphic processes.

Research on river basin modeling includes the mathematical modeling of the various components of the hydrological cycle of river basins based on physical and conceptual equations and relationships. Examples include water balance models at the climatic, annual, and seasonal time scales such as SEAMOD and more complete models developed for smaller time scales, such as HIRO2.

The HSE program advocates the active participation of graduate students in publishing research results in refereed journals, proceedings, books, and digital media. We also encourage and help students to make presentations at professional conferences, workshops, symposia, etc. Examples of HSE publications can be found at the Hydrology Days Proceedings.