Assessing inundation dynamics of conservation reserve program lands to quantify ecosystem services

The conservation reserve program (CRP) plays a vital role in preserving ecologically sensitive lands across the United States by encouraging the voluntary conservation of marginal farmland. Despite its significance, limited tools exist for nationwide continuous monitoring and assessment of hydrological conditions within CRP lands. This study conceptualizes surface water inundation as an indicator of hydrologic connectivity and ecological function, reflecting how water dynamics influence CRP sites resilience. Our study presents a novel, scalable approach to assess inundation dynamics across 1.3 million CRP sites from 2018 to 2024 using a synergistic framework that integrates Sentinel-2 satellite imagery, Dynamic World land cover data, and machine learning classifiers (Support Vector Machine, Random Forest, CART) within Google Earth Engine. Our framework integrates spectral water indices (NDWI, MNDWI and NDMI) with dynamic world land-cover classifications to generate quarterly inundation maps at 10-m spatial resolution, enabling consistent identification of surface-water extent across time. The SVM model achieved best performance in surface water detection. Our analysis shows that the core areas of wetland-related CRP lands consistently hold water seasonally acting natural sponges for agricultural water quality improvement, groundwater recharging and flood mitigation. While the CRP program effectively maintains the inundation performance of wetland-related lands, it also increases inundated areas on non-wetland-related lands, highlighting the valuable contributions of CRP lands to the agricultural landscape nationwide. CRP sites with longer enrollment periods exhibited higher and more stable inundation, indicating improved wetland functionality. Overlays with the national wetlands inventory (NWI) and hydric soil data confirmed strong links between site characteristics and surface water, particularly in the Midwest and Lower Mississippi River Basin. Spring and summer emerged as key periods of persistent or episodic inundation, providing critical habitats for migratory birds and supporting biodiversity. This research provides a long-term hydrological monitoring approach for CRP lands and supports targeted conservation decision-making to identify and implement best practices. By identifying high-priority CRP sites for restoration and demonstrating the utility of real-time, high-resolution remote sensing data, this study provides a valuable foundation for adaptive management and policy strategies that enhance the resilience and functionality of CRP lands.