Our Modeling Framework

Our Modeling Framework

Our Modeling Framework

Assessing outcomes of sudden and long-term changes

Our state-of-the-art modeling framework combines a set of ecosystem models and a global economic model to assess the influences and impacts of many changes affecting food, energy, water, and ecosystem (FEWE) security.

A novel suite of models

Our models will allow us to generate insights on how global changes, such as trade policies and climate, could interact with localized changes, such as land use and management, to influence FEWE security in the Upper Mississippi River Basin.

Three different biophysical models, which have each been created by members of our research team, will simulate ecosystem processes and outcomes.

AgroIBIS agroecosystem model.

This model simulates ecosystem processes – such as water, energy, and nutrient cycling – within terrestrial and cropping systems (e.g., corn, soy, wheat, bioenergy). For example, it can take data on land use and fertilizer use and calculate resulting crop yields. AgroIBIS can also map sources of agricultural runoff and calculate nutrient loss.

THMB hydraulic transport model.

This model calculates how much water and nutrients flow through stream and river networks, based on nutrient loss estimates from AgroIBIS. Importantly, THMB can estimate nutrient loads from a watershed, which we can then use to compare against monitoring data from the USGS. THMB allows us to relate our model outputs directly to nutrient loading metrics used for reducing the Dead Zone in the Gulf of Mexico.

MODFLOW groundwater model.

This model simulates the groundwater system, generating estimates of groundwater levels based on infiltration, plant use, or pumping. For example, it allows us to assess the impacts of tile drainage on groundwater levels and generate output data that AgroIBIS can then use to estimate subsequent impacts on food production. This ability to calculate groundwater impacts is especially important in the Upper Midwest, a flat and wet region where groundwater is close to the ground’s surface and, thus, highly influential to food production and flood risk.

Our modeling framework also addresses a missing link in modeling approaches used currently to assess FEWE security: global economics and how changes in trade policy and supply and demand could influence outcomes for food, energy, water, and ecosystems.

SIMPLE-G economic model.

This model of global agricultural economics and land use, developed by our collaborators at Purdue University, brings the forces of globalization into the picture. The information it will provide includes the effects of ag-related policy and technological changes (e.g., increased nitrogen use efficiency in crops) on food supply and demand, agricultural trade, and food security. For example, it can estimate the ripple effects of country-level diet changes on food demand, agricultural land and fertilizer use, and crop prices.

SIMPLE-G and AgroIBIS communicate with each other in our framework. For example, AgroIBIS will take the land and fertilizer use data from SIMPLE-G to calculate resulting crop yields and water quality.

Diagram of linkages between future scenarios
Diagram of linkages between future scenarios, biophysical modeling, economic and land use modeling, and governance analysis.

“What ifs” for the future

A big value of our modeling suite is that it enables us to construct and evaluate “what if” scenarios for the future of FEWE security. In collaboration with stakeholders, we will develop global scenarios for the year 2050 based on three influential factors – climate change projections, socioeconomic conditions such as agricultural trade, and climate-related policies – and estimate their impacts on food, bioenergy, water, and ecosystems.

One intent of this exercise is to expand the range of plausibility for the future. Our models are capable of handling transformative changes – for example, what if we convert 25% of the land in the Upper Mississippi River Basin to perennial crops – which could help expand horizons on what is both possible and necessary to achieve collective goals for FEWE security.

Aligning with real-life goals

Assessing FEWE security requires selecting measurable indicators and setting relevant goals. We are using a set of ecological indicators and targets that align with those developed under the United Nation’s Sustainable Development Goal framework and federal agencies, such as the U.S. Environmental Protection Agency’s goals for reducing nutrient loads to the Gulf of Mexico.

A table chart of goals indicators

These indicators will be our model outputs. We will determine their implications for FEWE security in partnership with stakeholders, which will help enhance the usefulness of the model results for decision-making.

Two scales of change

Global and local changes matter, and thus we are examining change at both of these scales to broaden the range of questions we can ask and answer.

The whole Upper Mississippi River Basin.

We will examine how global changes and regional policies could impact FEWE security across the entire Upper Mississippi River Basin. This will not only allow us to explore how transformative scenarios could play out at a large scale, but also create a rich space for multi-state discussion about how to achieve collective goals.

It is at this scale that we will use SIMPLE to explore how global economics could shape the future of FEWE security in the Basin.

Sub-regional watersheds.

We have chosen four sub-regions within the Basin, which are representative of the region’s landscapes and ecosystems, to test the outcomes of localized changes in land use, cover, and management, as well as water management, on the provision of ecosystem services and their implications for local FEWE security and biodiversity.

What is unique about our sub-regional modeling will be its focus on groundwater, which is not commonly included in modeling efforts due to its difficulty to measure. We will use MODFLOW to unpack the effects of groundwater management scenarios – for example, how could tile drainage be managed to increase food production but limit nutrient loss.

We will also use our sub-regional modeling to explore how the placement of natural or semi-natural habitats on the landscape could be used to achieve FEWE goals and sustain biodiversity.

A map showing the different types of areas around the Mississippi river

Questions about our modeling framework?