Testing FARMSCOPER and LESA-NP against lake sediment-inferred phosphorus budgets: Crose Mere, Hatch Mere & White Mere.
Abstract
The West Midland meres face a critical ecological challenge due to elevated phosphorus (P) concentrations resulting from diffuse and point nutrient pollution. Natural England has employed LESA-NP and FARMSCOPER models to address this issue, yet their effectiveness at the lake catchment scale remains untested. This study presents a proof-of-concept for a coupled model approach to estimate P budgets, using historical lake sediment records and land use scenarios. Three case study sites (Crose Mere, White Mere, and Hatch Mere) were examined, revealing reasonable estimates of diffuse P loads at Crose and Hatch Mere, while a significant historic P source was identified at White Mere. However, challenges persist, including insufficient data for hydrological catchment boundaries and unreliable estimations in model outputs. Recommendations focus on targeted data gathering, model refinement, and site-specific P reduction strategies. Crucially, current approaches may lead to ineffective management, highlighting the need for improved methodologies to address P pollution in the West Midland meres.