Researchers at the Susquehanna Shale Hills CZO have developed and implemented a suite of quantitative and qualitative models of critical zone processes. These models characterize the processes that shape the Earth's surface over various time scales. Improving current models and bridging knowledge gaps between different systems are at the core of critical zone research.


Bedrock and Regolith Weathering
Conceptual models of deep CZ structure and function.


Flux PIHM is a fully-coupled land surface hydrologic model with improved land-atmosphere interactions.


Hydrogeochemical Model
Mass balance model for deposition, weathering and transport at SSHCZO.

Hydropedo Toolbox

Hydropedograph Toolbox
A MATLAB-based toolbox for analysis of time series data for soil moisture profiles

Isotope Weathering

Isotopic Estimates of Weathering
Isotope geochemistry (Uranium, Thorium, Beryllium) offer estimates of weathering rates at Shale Hills.


Penn State Integrated Hydrologic Model
Multiprocess, multi-scale hydrologic model.


GIS interface for Penn State Integrated Hydrologic Model
Tightly coupled GIS interface for the Penn State Integrated Hydrologic Model


PIHM-Sediment Transport
The 3D landscape evolution model (PIHMSed) that couples the processes of bedrock uplift, weathering, and regolith.


Penn State Integrated Hydrological Model for Dissolved Organic Carbon
PIHM is a physically based, fully distributed hydrological model

Preferential Flow

Hydrologic Flowpaths and Hydropedology
Vertical and lateral flowpaths provide a "short-circuit" for water flux in the shallow subsurface.