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.

Jump to Individual Models ▼

Conceptual Model for Susquehanna Shale Hills CZO

Conceptual Model for Susquehanna Shale Hills CZO

Modelling News


Water Resources Research Special Collection: Concentration-discharge relations in the critical zone

30 Oct 2017 - Water Resources Research published a new special collection in September 2017 featuring concentration-discharge research from multiple CZOs.

Dr. Ying Fan Reinfelder visits for the 2018 All-Hands Meeting at Penn State

10 May 2018 - Over the course of two days each May, the SSHCZO comes together for the annual All-Hands science meeting at Penn State.  This year, Dr. Ying...

Delegation from China Geologic Survey visits Shale Hills CZO

03 Nov 2017 - During the week of October 30th, Penn State and SSHCZO hosted 15 scientists from the China Geological Survey, with interests ranging from saltwater...

EOS: Taking the Pulse of the Earth’s Surface Systems

04 Dec 2015 - Taking the Pulse of the Earth's Surface Systems In September of 2014, Laurel Larsen (UC Berkley), Elizabeth Hajek (Penn State), and others...

Using a CZO network to explore the architecture, dynamics and evolution of the Critical Zone

03 Nov 2014 - The US CZO National Office has organized a webinar on December 8, 2014 at 11AM - 12:30 PM ET.

Town Hall Meeting at Goldschmidt 2014 - Reactive Transport Modeling

21 May 2014 - A town hall meeting on reactive transport modeling (RTM)will be held from 12:30 to 2 pm on Tuesday, June 10th, in room 308 in Sacramento Convention...

More News >


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.