Understand Ephemeral Gully Mechanics and Develop Large Scale Decision Support Systems for Improved Watershed Management

点击翻译按钮获取中文摘要

Non-point source pollution especially sediment and phosphorus runoff from agricultural fields are severely impairing several water bodies across the world. In the recent decade, Lake Erie (one of the Great Lakes) is under serious threat due to increased levels of harmful pollutants especially sediment-bound phosphorus. In 2011, the phosphorus-induced algae blooms in Lake Erie were exceedingly high and the summer of 2015 produced the largest algae bloom in 100 years. This degradation is projected to worsen with continued anthropogenic climate and landuse change. ******The research towards reducing the sediment and phosphorus runoff is focused more towards understanding sheet and rill erosion processes, develop Hydrologic and Water Quality (HWQ) models that simulate these processes and use models to investigate policy relevant issues. Only in the recent decade, Ephemeral Gullies (EGs) are identified as a major source and studies have shown that they contribute more than sheet and rill erosion. EGs are localized areas of soil erosion that act as small channels that transfer fine sediment and phosphorus from upland agricultural fields to stream channels. In the last few years, efforts are being made to study EGs resulting from tillage operations (early summer) and are being included as sub-routines in few HWQ models. These developed sub-routines can only simulate EG erosion but not phosphorus runoff. Furthermore, in northern latitudes (Canada), the EGs form not only during early summer (after tillage) but also during late spring as a result of snowmelt processes.******My research program, in the next five years, will advance the understanding of the science behind EG dynamics (e.g. formation, morphology) and the transport mechanisms (e.g. sediment and phosphorus runoff). Furthermore, a novel model capable of identifying EGs and also estimating sediment and phosphorus runoff in all climatic/seasonal conditions under different spatial and temporal scales will be developed. The developed model will be coupled into widely used Soil and Water Assessment Tool (SWAT) and an integrated web-based decision support system (IWBDSS) will be developed. IWBDSS will be applied in watersheds contributing to Lake Erie to support a wide variety of watershed planning, economic and policy analysis and ultimately help Ontario's government vision to reduce 40% phosphorus entering Lake Erie by 2025. The models and decision support systems developed can also be applied in any watershed across Canada or in the world to make better integrated watershed management decisions. Most importantly, my research program will produce next generation engineers/researchers proficient in both field experimentation and usage/development of HWQ models and capable of providing engineered solutions to emerging and future water quantity and quality issues under changing landuse and climate.