Hydrologic connectivity: a management frontier for water quality conservation
Abstract
Hydrologic landscapes are an interconnected tapestry of geomorphic, environmental, and anthropogenic features that work in tandem to confer ecosystem benefits and provide for societal demands. Increasingly, this delicate balance is at risk under the growing pressures of agricultural expansion, urbanization, and climate change. Understanding the role humans play in modulating the dynamic transfer of water, sediment, and nutrients across landscapes is crucial if we are to sustainably manage our shared water resources. In this study, we provide results from geospatial connectivity and erosion mapping, high-frequency aquatic sensing, radioisotope tracing, and field assessment of disconnectivity with the aim of understanding the flux of water and sediment, from source to sink, in a rapidly urbanizing landscape in Kansas, USA. Connectivity and erosion mapping results indicate that, while only 5% of the region's uplands are both susceptible to erosion and highly connected to downstream pathways, these areas represent 37% of region-scale erosion. High-frequency aquatic sensing of turbidity showed that anthropogenic disturbances, including roadway ditches, tile drainage, and impervious surfaces, increase the connectivity of distally located sediment that would - in undisturbed basins - deposit along the sediment cascade. Sediment tracing using plutonium isotopes showed that urbanization homogenizes the source of suspended sediment to be entirely derived from streambank erosion, largely due to the disconnection of upland sediment by impervious surfaces. Integrating these scientific innovations and leveraging knowledge from conservation literature, we propose potential avenues for improving riverine water quality by managing sediment. Future landscape management will require implementing practices that consider the holistic source-to-sink connectivity of sediment and the role humans play in shaping it.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.H36G..05H