Despite the critical role that replication plays in the advancement of science, its presence in modelling literature is rare. To encourage others to conduct replication and report success and challenges that facilitate or hinder replication, we present the replication of an agent-based model (ABM) of residential sprawl using the Replication Standard. Replication results achieved relational equivalence. Through the replication process, issues with the original research were identified and corrected in an Improved model, which qualitatively supported original results. A specific challenge affecting alignment of original and Replicate models included capturing model output variability and publishing all original output data for statistical analysis. Through the replication of agent-based models, additional confidence in model behaviour can be garnered and replicated ABMs can become accredited for reuse by others. Future research in the development and refinement of replication methodology and assessments should be cultivated along with a culture of value for replication efforts.
Soil erosion models, typically applied at basin and watershed scales, are rarely evaluated at agricultural field scales due to the lack of spatially-distributed time series data. A novel unmanned aerial vehicle (UAV) methodology was used to quantify farm-field soil erosion from nine UAV surveys and structure-from-motion (SfM). Using a semi-distributed approach, we evaluated soil erosion estimates from the Universal Soil Loss Equation (USLE) and Water Erosion Prediction Project (WEPP). The annual erosion rate, measured with the UAV methodology, was 18.83 t ha−1 yr−1, with USLE and WEPP predictions of 26.23 t ha−1 yr−1 and 16.41 t ha−1 yr−1, respectively. Modelled annual and sub-annual erosion rates with WEPP were within the upper-limit of predictive accuracy, while the USLE tended to systematically overestimate soil erosion rates. These outcomes have implications on the efficacy of conservation efforts, which is highlighted through a discussion and comparison of different best-management practice applications.