Abstract In the summer of 2015 I and Anna Schwyter were selected to work for Penn State’s Hydropedologist, Dr. Henry Lin, as part of Penn State’s Research Experience for Undergraduates program. During this time, we implemented Infiltrometer and Time Domain Reflectometry (TDR) to better understand the hydropedologic processes occurring in the Shale Hills catchment. My focus was on the TDR data we collected. With this data, and with the help of Doug Baldwin, I wanted to answer the questions: Where is the highest concentration of water in Shale Hills? At what depth? How does this year compare to another year, possibly a drier year?

Introduction Infiltrometer, Electromagnetic Induction (EMI), and Time Domain Reflectometry (TDR) are just few methods that can be used to better understand the hydropedologic processes occurring at Shale Hills. Time Domain Reflectometry (TDR) uses electromagnetic wave frequencies to measure the percentage of soil moisture present in the ground at a given time (Ledieu et al, 1986). After gathering TDR data at different times (after a rain event vs. a dry spell), that data can then be used to create Volumetric Soil Moisture maps; these maps, in turn, allow us to see where water is being held within the catchment and help us to answer those initial burning questions.

METHODS 90% Hard Work and Data Collection Gather equipment and head to the field Hike Shale Hills and go to all TDR sites Clean out pipes Collect 2 sets of data at different depths for all TDR sites 10% Map Making and Interpretation Volumetric Soil Moisture Maps Compare 2015 to another year Try to make sense of data and answer those initial questions

Drought Maps of United States Taken from USDA Drought Monitor Website July, 2007 July,

Results

2015 Volumetric Soil Moisture: 10cm TDR Site ● 6/22/15 7/07/15 7/16/15 * Larger TDR dots indicate more soil moisture recorded.

2015 Volumetric Soil Moisture: 40cm TDR Site ● 6/22/15 7/07/15 7/16/15 * White patches on the map are indicative of missing data.

2015 Volumetric Soil Moisture: 80cm TDR Site ● 6/22/15 7/07/15 7/16/15 * Though there is more missing data, we can clearly see that 80cm is the deepest and wettest depth, and is typically observed in the valley and swales.

Interpretations so far… The stream/valley area is consistently the wettest area in the catchment. Swales are also retaining water. Between the months of June-July, the catchment is becoming wetter rather than drying down. The South face of the catchment appears to be overall wetter than the North Face.

Now let’s compare 2007 & 2015

Volumetric Soil Moisture: 10cm 6/22/156/06/07 7/07/157/03/07 7/20/077/16/15 * 2007: Catchment dries up, swales/valley retain some water. *2015: Catchment continues to get wetter, swales/valley retain most water.

Volumetric Soil Moisture: 40cm 6/22/156/06/07 7/07/15 7/03/07 7/16/15 7/20/07 * 2007: More water in swales and valley at a lower depth. * 2015: Not much noticeable change since 10cm depth.

Volumetric Soil Moisture: 80cm 6/22/156/06/07 7/07/157/03/07 7/16/157/20/07 * 2007: Water well retained at this depth; valley wetter than swales. * 2015: Water well retained at this depth; Swales and valley very wet.

Overall Conclusions/Interpretations South Face of the catchment is overall wetter than the North Face of the catchment. - Likely has to do with the variety of vegetation present there that is different than on the North Face (Naithani et al, 2013) is wetter than the 2007 drought year. There is more soil moisture at deeper depths. Water in the catchment is largely retained in the valley and swales. The 2015 year is an anomaly; typically as the summer months go on, the catchment should become drier. This year, there is still quite a bit of moisture, so much so that there was still flowing water in the stream valley during the month of July. In past years, by July the stream would have been dried up.

Acknowledgements Thank you to the National Science Foundation and Penn State University for allowing me to participate in this wonderful learning experience! Thank you to Dr. Henry Lin and Neil Xu for this opportunity to work and learn from them and get real research experience. Thank to Tim White and Sarah Sharkey for all of your wonderful encouragement and support during this program, and thank you to all of the other wonderful ladies of the REU program. Thank you to Doug Baldwin who, without you, I’d probably be really lost and not have much of a presentation. Thank you for all the time you took just to help me and your help in making all of these wonderful maps, and for all of your wonderful guidance. Thank you to Professor Susanne McDowell of Hanover College for pushing me to go for an REU, and to the other Geology professors who supported me and wrote me letters of recommendation. Last but not least, thank you to the amazing Anna Schwyter, my REU work partner and friend. Anna, thank you for being hard working, determined, and encouraging. You made this whole experience absolutely awesome, and I couldn’t have asked for a better partner. I’m so glad that I got to meet and work with you. Thank you!

Works Cited Naithani KJ, Baldwin DC, Gaines KP, Lin H, Eissenstat DM (2013) Spatial Distribution of Tree Species Governs the Spatio-Temporal Interaction of Leaf Area Index and Soil Moisture across a Forested Landscape. PLoS ONE 8(3): e doi: /journal.pone droughtmonitor.unl.edu/ Ledieu, J., P. De Ridder, P. De Clerck, and S. Dautrebande. "A Method of Measuring Soil Moisture by Time-domain Reflectometry." Journal of Hydrology (1986): Sciencedirect.com. Web..