Helen Dahlke

Email:  hed23@cornell.edu
Phone: 607-255-0185
Office: 165 Riley Robb Hall
Advisor: Tammo Steenhuis
Degree Program: Ph.D.

Background

I have studied at the Friedrich-Schiller University in Jena, Germany and graduated with a diploma in Geography and minors in Geology and Ecology. My diploma thesis focused on the terrain-based delineation of wetlands in South Africa using GIS.

Current Research Interests

Hillslope Hydrology, hydrological process research, variable source area (VSA) hydrology, landscape analysis, GIS & Applied Geophysics, vegetation analysis.

Research on VSA Hydrology

In my reasearch I look at hydrological processes of variable source areas (VSA). On two hillslopes I study subsurface flow pathways, groundwater table dynamics and spatio-temporal dynamics of VSAs in relation to soil and landscape characteristics. Main emphasis is especially put on the application of Ground Penetrating Radar (GPR) for the characterisation of soil properties and the localization of fragipans.

Development of an online tool for Phosphorous index calculations

Beside my research I am working on the development of an online-accessible Tool for the calculation of the Phosphorous Index considering the location and hydrological processes of Hydrologically Sensitive Areas (HSAs). Based on calculations of daily temporal and spatial dynamics of HSAs in four test catchments (Salmon Creek, Fall Creek, Sixmile Creek and Townbrook watershed) we set up a simulation of their dynamics using Google Earth and Keyhole Markup Language (KML).

Publications

de Alwis, D.A., Easton, Z. M., Dahlke, H. E., Philpot, W. D. and T. S. Steenhuis. 2007. Unsupervised classification of saturated areas using a time series of remotely sensed images. Hydrol. Earth Syst. Sci., 11, 1609-1620, 2007.full text

Helmschrot, J., Dahlke, H. (2006): Inventory and Monitoring of South African Wetlands Integrating Field Data, Earth Observation Data Analysis, and GIS-based Terrain Analysis. Globwetland Symposium 'Looking at wetlands from space', 19./20. October 2006, Frascati, Italy.