Susmita Dahal
Susmita Dahal is a Ph.D. student in the Department of Biological Systems Engineering at Washington State University, based at the WSU Puyallup Research and Extension Center. Her research focuses on the strategic placement of Green Stormwater Infrastructure (GSI) across landscapes. She uses dynamic computational models to identify where different types of GSI can be most effective for improving stormwater management and supporting resilient communities.
Before joining WSU, Susmita earned her master’s degree in Water Resources Engineering in Nepal in 2023. She also worked for six years with the Department of Water Resources and Irrigation, Government of Nepal, gaining professional experience in irrigation infrastructure development and water-induced disaster management projects. Her work included project planning, engineering design, construction supervision, monitoring and evaluation, and progress reporting for irrigation and river basin projects. Outside of work, Susmita enjoys traveling, reading, and spending quality time with her daughter.
Susmita’s Current Work
Optimizing GSI Placement to Reduce Urban Runoff and Protect Water Quality
Susmita is working with Dr. Joan Wu to build on previous research and improve the Hydrological Sensitivity Indexing (HSI) approach to optimize GSI placement. The HSI method is based on a well‐developed Variable‐Source‐Area (VSA) hydrologic concept, which identifies areas likely to generate runoff. The HSI method uses publicly accessible geospatial data of topography, soil, and land use and land cover (LULC). It is easy to implement within a Geographic Information System (GIS) for effective, automatic applications. However, the method is static and does not consider the dynamics and heterogeneity of hydrologic processes, such as ET, soil water storage, and changing climate conditions. The method also does not differentiate between built environments with or without stormwater controls, e.g., a shopping center with stormwater infrastructure to drain and pipe away stormwater of, say, 10‐yr, 24‐hr events, may generate little to none on‐site runoff much of the time, whereas a paved parking lot with no GSI installed will turn the rain water during a storm essentially completely to runoff.
We propose to improve the HSI approach by (i) adjusting the runoff contribution from built space based on its stormwater management measures; (ii) characterizing the dynamic ET processes of different plant species with weighing factors; and (iii) assessing the suitability of HSI‐based GSI designs under changing climate conditions. We will focus on two common GSI types: rain gardens and bioretention systems, accomplishing the first two tasks in the first year, and the third task in the second year of the Deep Dive.
