Christina River Basin Critical Zone Observatory

In 2009, the University of Delaware, in collaboration with Stroud Water Research Center, received a $4.3 million grant from the National Science Foundation to establish the Christina River Basin Critical Zone Observatory (CRB-CZO) for researching questions relating to climate change. The CRB-CZO was active from 2009 to 2013.

The CRB-CZO integrated knowledge of water, mineral, and carbon cycles to quantify human impact on Critical Zone carbon sequestration — from soils to sea. It was located in the Piedmont and Atlantic Coastal Plain which provides drinking water to a million people in Delaware and Pennsylvania. CRB-CZO was one of ten NSF-supported critical zone observatories.


The data archive for CRBCZO can be found on HydroShare. If you have trouble accessing the data, please email

Research Experience for Teachers and Undergraduates

From 2014–2016, the CRB-CZO and the Susquehanna Shale Hills Critical Zone Observatory (The Pennsylvania State University) jointly hosted National Science Foundation-funded Research Experience for Teachers (RET)  and Research Experience for Undergraduates (REU) programs. View the completed research.


More than 20 peer-reviewed scientific publications were produced from CRB-CZO research.

A digital mayfly swarm is emerging

Ensign, S., D. Arscott, S. Hicks, A. Aufdenkampe, T. Muenz, J. Jackson, and D. Bressler. 2019. Eos, 100.

Topographic variation in soil erosion and accumulation determined with meteoric 10Be

Marquard, J., R.E. Aalto, T.T. Barrows, B.A. Fisher, A.A. Aufdenkampe, and J.O. Stone. 2018. Earth Surfaces Processes and Landforms 44(1):98–111.

Direct channel precipitation and storm characteristics influence short‐term fallout radionuclide assessment of sediment source

Karwan, D.L., J.E. Pizzuto, R. Aalto, J. Marquard, A. Harpold, K. Skalak, A. Benthem, D.F. Levia, C.M. Siegert, and A.K. Aufdenkampe. 2018. Water Resources Research, 54. 

Soil carbon redistribution and organo-mineral associations after lateral soil movement and mixing in a first-order forest watershed

Fisher, B.A., A.K. Aufdenkampe, K. Yoo, R. Aalto, and J. Marquard. 2018. Geoderma 319:142–155.

Variation of organic matter quantity and quality in streams at Critical Zone Observatory watersheds

Miller, M.P., E.W. Boyer, D.M. McKnight, M.G. Brown, R.S. Gabor, C.T. Hunsaker, L. Iavorivska, S. Inamdar, D.W. Johnson, L.A. Kaplan, H. Lin, W.H. McDowell, and J.N. Perdrial. 2016. Water Resources Research 52(10):8202–8216.

Beryllium-7 wet deposition variation with storm height, synoptic classification, and tree canopy state in the mid-Atlantic USA

Karwan, D. L., C. M. Siegert, D. F. Levia, J. Pizzuto, J. Marquard, R. Aalto, and A. K. Aufdenkampe. 2016. Hydrological Processes 30(1):75–89.

Seasonal dynamics of the soil microbial community structure within the proximal area of tree boles: possible influence of stemflow

Rosier, C.L., D.F. Levia, J.T. Van Stan, A.K. Aufdenkampe, and J. Kan. 2016. European Journal of Soil Biology 73:108–118.

The Role of Critical Zone Observatories in Critical Zone Science

White, T., S. Brantley, S. Banwart, J. Chorover, W. Dietrich, L. Derry, K. Lohse, S. Anderson, A. Aufdenkampe, R. Bales, P. Kumar, D. Richter, and B. McDowell. 2015. Pages 15–17 in J.R. Giardino and C. Houser (editors). Developments in earth surface processes, volume 19: principles and dynamics of the Critical Zone. Elsevier, Cambridge, Massachusetts.

Forest canopy structural controls over throughfall affect soil microbial community structure in an epiphyte-laden maritime oak stand

Rosier, C., J. van Stan, L. Moore, J. Schrom, T. Wu, J. Reichard, and J. Kan. 2015. Ecohydrology 8:1459–1470.

Coupled geochemical and biogeochemical characterization of dissolved organic matter from a headwater stream

Sleighter, R.L., R.M. Cory, L.A. Kaplan, H.A.N. Abdulla, and P.G. Hatcher. 2014. Journal of Geophysical Research: Biogeochemistry 119(8):1520–1537.

The delivery of dissolved organic carbon from a forested hillslope to a headwater stream in southeastern Pennsylvania, USA

Mei, Y., G.M. Hornberger, L.A. Kaplan, J.D. Newbold, and A.K. Aufdenkampe. 2014. Water Resources Research 50(7):5774–5796.

Hydrologic dynamics and geochemical responses within a floodplain aquifer and hyporheic zone during Hurricane Sandy

Sawyer, A.H., L.A. Kaplan, O. Lazareva, and H.A. Michael. 2014. Water Resources Journal 50(6):4877–4892.

A variable source area for groundwater evapotranspiration: impacts on modeling stream flow

Tsang, Y.P., G. Hornberger, L.A. KaplanJ.D. Newbold, and A.K. Aufdenkampe. 2014. Hydrological Processes 28(4):2439–2450.

Characteristic length scales and time‐averaged transport velocities of suspended sediment in the mid‐Atlantic Region, USA

J. Pizzuto, E.R. Schenk, C.R. Hupp, A. Gellis, G. Noe, E. Williamson, D.L. Karwan, M. O’Neal, J.  Marquard, R. Aalto, and J.D. Newbold. 2014. Water Resources Research 50:790–805.

Biological lability of dissolved organic carbon in stream water and contributing terrestrial sources

McLaughlin, C., and L. A. Kaplan. 2013. Freshwater Science 32(4):1219–1230.

Measuring heterotrophic respiration rates of suspended particulate organic carbon from stream ecosystems

Richardson, D.C., J.D. Newbold, A.K. Aufdenkampe, P.G. Taylor, L.A. Kaplan. 2013. Limnology and Oceanography Methods 11:247–261.

Estimation of dissolved organic carbon contribution from hillslope soils to a headwater stream

Mei, Y., G.M. Hornberger, L.A. Kaplan, J.D. Newbold, and A.K. Aufdenkampe. 2012. Water Resources Research 48(9):W09514.

The initial design of data sharing infrastructure for the Critical Zone Observatory

Zaslavsky, I., T. Whitenack, M. Williams, D. Tarboton, K. Schreuders, and A.K. Aufdenkampe. 2011. Pages 145–150 in M. B. Jones and C. Gries (editors). Proceedings of the Environmental Information Management Conference 2011. University of California, Santa Barbara, California.

Characterization and source determination of stream suspended particulate material in White Clay Creek, USA

D.L. Karwan, R. Aalto, A.K. Aufdenkampe, J.D. Newbold, and J.E. Pizzuto. 2011. Applied Geochemistry 26:S354–S356.

Rates of soil mixing and associated carbon fluxes in a forest vs. tilled agricultural field: implications for modeling the soil carbon cycle

Yoo, K., J. Ji, A. Aufdenkampe, and J. Klaminder. 2011. Journal of Geophysical Research: Biogeosciences 116:2156–2202.

Riverine coupling of biogeochemical cycles between land, oceans, and atmosphere

Aufdenkampe, A.K., E. Mayorga, P.A. Raymond, J.M. Melack, S.C. Doney, and S.R. Alin. 2011. Frontiers in Ecology and the Environment 9(1):53–60.

Other Content

Additional archived content can be found on the archived website for the national CZO program.