Integrated Hydrological Model and GIS-based Model to Map Landslides Risks within the Anacostia Watershed of Maryland

Landslides are significant geological hazards that cause extensive damage to property, infrastructure, and human life. This study investigates the impact of rainfall infiltration on landslide susceptibility within the Anacostia River watershed in Maryland, USA. Utilizing the Soil and Water Assessment Tool (SWAT+), we modeled the entire hydrological cycle to simulate rainfall infiltration and runoff. Subsequently, a GIS-based model was developed to map the minimum amount of infiltrating water (Fmin) that will cause slope failure and assess landslide risk using infiltration data derived from SWAT+. The study area was chosen due to more records of historical landslides, and available detailed climate, soil, and land use data for accurate model calibration. The SWAT+ model demonstrated high accuracy, with NSE and Pbias values indicating good performance. The GIS-based model successfully highlighted areas with varying landslide risks, providing a comprehensive assessment of potential landslide-prone zones. Our findings emphasize the critical role of water infiltration in slope stability and offer a robust framework for landslide risk management in regions susceptible to heavy rainfall.