Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 6 of 6
Full-Text Articles in Entire DC Network
Development Of A Decision Support System Webtool For Historic And Future Low Flow Estimation In The Northeast United States With Applications Of Machine Learning For Advancing Physical And Statistical Methodologies, Andrew F. Delsanto
Doctoral Dissertations
Droughts are a global challenge and anthropogenic climate change is expected to increase the frequency and severity of extreme low flow events. A major challenge for resource managers is how best to incorporate future climate change projections into low flow event estimations, especially in ungaged basins. Using both physically based hydrology models and statistical models, this dissertation contributes novel methodologies to three key challenges associated with 7-day, 10-year low flow (7Q10) estimation in the northeast United States. Chapter 2 builds upon statistically based 7Q10 estimation in ungaged basins by comparing multiple machine learning algorithms to classical statistical methodologies. This chapter’s …
Testing The Impact Of A Freshwater Wetland Restoration On Water Table Elevation And Soil Moisture Using A Parametric Groundwater Modeling Approach, Erika T. Ito
Masters Theses
Wetlands are now recognized for the many social, environmental, ecological, and economic benefits they provide. They improve water quality, support biodiversity, abate floods and storms, and provide local recreational areas. Historically, many wetlands have been drained or altered for residential, commercial, or agricultural use. Effective wetland restoration projects reestablish ecosystem services and mitigate legacy effects of land use change to create self-sustaining systems. However, a persisting lack of scientifically-vetted methodological and evaluation guidelines in the field of restoration ecology has caused many restoration efforts to fail to restore natural wetland hydrologic conditions. By definition, wetlands must be saturated, permanently or …
Hydrologic Structure And Function Of Vernal Pools In South Deerfield, Massachusetts, Charlotte Axthelm
Hydrologic Structure And Function Of Vernal Pools In South Deerfield, Massachusetts, Charlotte Axthelm
Masters Theses
Vernal pools are small, ephemeral wetlands lacking an inlet or outlet. These wetlands, also known as seasonal pools, are found in a wide range of biomes, and their characteristics vary based on location. While the vegetation of western U.S. pools, and amphibians of eastern U.S. pools have been extensively studied, many aspects of vernal pools have not been fully characterized. In particular, although the general seasonal wetting and drying cycle is understood qualitatively, few studies have attempted to quantify the hydrological regime of vernal pools in New England. As water level variation drives many, if not all, of the characteristics …
Sources Of Water And Solutes To The Salar De Atacama, Chile: A Coupled Hydrologic, Geochemical, And Groundwater Modeling Study, Lilly G. Corenthal
Sources Of Water And Solutes To The Salar De Atacama, Chile: A Coupled Hydrologic, Geochemical, And Groundwater Modeling Study, Lilly G. Corenthal
Masters Theses
Focused groundwater discharge in endorheic basins provides opportunities to investigate mechanisms for closing hydrologic budgets in arid regions. The Salar de Atacama (SdA), a closed basin in northern Chile, has accumulated over 1800 km3 of halite and a lithium-rich brine since the late Miocene primarily through evapotranspiration of groundwater. The hydrologic balance of SdA and sources of water and solutes required to explain this deposit are not well constrained. An adapted chloride mass balance method drawing on a database of over 200 water sample sites is applied to a remotely-sensed precipitation dataset to estimate spatially-distributed modern groundwater recharge. Comparing …
Impacts Of Three-Dimensional Non-Uniform Groundwater Flows For Quantifying Groundwater-Surface Water Interactions Using Heat As A Tracer, Jonathan M. Reeves
Impacts Of Three-Dimensional Non-Uniform Groundwater Flows For Quantifying Groundwater-Surface Water Interactions Using Heat As A Tracer, Jonathan M. Reeves
Masters Theses
Heat-as-a-tracer has become a common method to quantify surface water-groundwater interactions (SW/GW). However, the method relies on a number of assumptions that are likely violated in natural systems. Numerical studies have explored the effects of violating these fundamental assumptions to various degrees, such as heterogeneous streambed properties, two-dimensional groundwater flow fields and uncertainty in thermal parameters for the 1-dimensional heat-as-a-tracer method. No work to date has addressed the impacts of non-uniform, three-dimensional groundwater flows on the use of heat-as-a-tracer to quantify SW/GW interactions. Synthetic temperature time series were generated using COMSOL Multiphysics for a three-dimensional cube designed to represent a …
Uncertainty In Climatic Change Impacts On Multiscale Watershed Systems, Olga V. Tsvetkova
Uncertainty In Climatic Change Impacts On Multiscale Watershed Systems, Olga V. Tsvetkova
Open Access Dissertations
Uncertainty in climate change plays a major role in watershed systems. The increase in variability and intensity in temperature and precipitation affects hydrologic cycle in spatial and temporal dimensions. Predicting uncertainty in climate change impacts on watershed systems can help to understand future climate-induced risk on watershed systems and is essential for designing policies for mitigation and adaptation. Modeling the temporal patterns of uncertainties is assessed in the New England region for temperature and precipitation patterns over a long term. The regional uncertainty is modeled using Python scripting and GIS to analyze spatial patterns of climate change uncertainties over space …