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Accueil du site → Doctorat → États-Unis → 2020 → Managing Connectivity to Mitigate Drought, Flooding, and Sediment Transport Across Dryland Landscapes

New Mexico State University (2020)

Managing Connectivity to Mitigate Drought, Flooding, and Sediment Transport Across Dryland Landscapes

Maxwell, Connie M

Titre : Managing Connectivity to Mitigate Drought, Flooding, and Sediment Transport Across Dryland Landscapes

Auteur : Maxwell, Connie M

Université de soutenance : New Mexico State University

Grade : Doctor of Philosophy (PhD) 2020

Increased flooding, droughts, and sediment transport are watershed-scale problems negatively impacting agriculture and ecosystems in drylands worldwide. Vegetation loss in upland watersheds is leading to scouring floods, which in turn decreases infiltration, soil moisture levels, and downstream groundwater recharge. Management to confront these intractable problems has been hindered by a lack of accessible decision support tools for both land and water managers that synthesize the watershed processes that buffer against dryland disturbances. Flood flow connectivities across the landscape create buffer zones through replenishing soil moisture and reducing flood energy, which in turn support multiple functions. The result of this dissertation effort was the development of a decision support tool to facilitate managing flow, the Flood Flow Connectivity to the Landscape (FlowCon) modeling framework. FlowCon quantifies the most efficient management efforts to increase the key watershed buffering functions of increasing infiltration and reducing flow energy. The chapters included in this dissertation are articles that address three components of the tool. The first article presents a generalizable system dynamics model to estimate the effects of support and resulting benefits across a region over time. The second article presents the core structure of the tool that links three spatially explicit, process-based, and predictive routing models. The third article presents an additional module that utilizes vegetation indicators for further model calibration and management plan development. We calibrated the models with measured runoff and the corresponding rainfall events for a six-year period, which included thirty-six flow events. The additional vegetation module used thirty-five years of remotely sensed vegetation data, and identified key vegetation pattern indicators of density, patch size, and bare ground flowlength. The indicators provided critical calibrations for both the core FlowCon method and the additional vegetation calibrations, improving the relationship between the hydrologic modeling results and observed data by 12% and 36% respectively for the linear regression R2 and 69% and 65% respectively for the root mean square error (RMSE). FlowCon provides an efficient assessment framework that integrates watershed process understanding in an accessible decision support tool to achieve tangible improvements in dryland watershed management.


Aperçu du document (ProQuest)

Page publiée le 3 décembre 2021