A Modeling Approach to Determining the Relationship Between Erosion and Soil Productivity

TLDR

The authors developed EPIC, a comprehensive mathematical model, to quantify the relationship between soil erosion and productivity across the United States. EPIC integrates physically based modules for erosion, plant growth, hydrology, weather, and economics, running at a daily time step to simulate hundreds of years of land‑use change efficiently. Test results from 15 of 163 simulations across the continental U.S.

Abstract

ABSTRACT A mathematical model called EPIC (Erosion-Productivity Impact Calculator) was developed to determine the relationship between soil erosion and soil productivity throughout the U.S. EPIC continuously simulates the processes involved simultaneously and realistically, using a daily time step and readily available inputs. Since erosion can be relatively slow process, EPIC is capable of simulating hundreds of years if necessary. EPIC is generally applicable, computationally efficient, and capable of computing the effects of management changes on outputs. The model must be comprehensive to define the erosion-productivity relationship adequately. EPIC is composed of physically-based components for simulating erosion, plant growth, and related processes and economic components for assessing the cost of erosion, determining optimal management strategies, etc. The EPIC components include weather simulation, hydrology, erosion-sedimentation, nutrient cycling, plant growth, tillage, soil temperature, economics, and plant environment control. Typical results are presented for 15 of the 163 tests performed in the continental U.S. and Hawaii. These results generally indicate that EPIC is capable of simulating erosion and crop growth realistically.