Ecohydrology of Natural and Restored Wetlands in a Glacial Plain

More than half of wetland area in the U.S. have been converted to other land use types for agricultural use and development. Limited understanding of ecological services provided to society by wetlands is another reason for the massive wetland loss in the past. Section 404 of the Clean Water Act and the 1989 federal mandate of “no net wetland loss” supported increased efforts for wetland restoration and creation to compensate for two centuries of ecosystem degradation. Hydrology is a critical driver for wetland formation and sustainability, yet few studies have investigated the ecosystem benefits of restored or constructed wetlands relative to natural wetlands. Considering that unexpected ecohydrologic behaviors such as drought have been reported as a main cause of unsuccessful restoration over the U.S., understanding and quantifying water movement within the local seeing is imperative to future wetland restoration. From an environmental engineering perspective, wetlands are regarded as complex environments controlled by regional geomorphology, atmosphere, geologic setting, and human activity. The U.S. Army Corps of Engineers was tasked with developing a hydrogeomorphic assessment approach for wetlands in the various regions throughout the U.S. to facilitate wetland restoration. This effort was redirected in the aftermath of Hurricane Katrina, but the need for assessment tools persists for several remaining regions including the southern coastlines. The first part of the dissertation reports an investigation of impacts of geomorphic settings on hydrologic functions within the St. Lawrence River plain. Regional geomorphology links wetlands and surrounding areas by multiple pathways of water transfer such as groundwater exchange and surface water connections. However, recent U.S. Supreme Court rulings, including Solid Waste Agency of Northern Cook County versus U.S. Army Corps-SWANCC (2001) and Rapanos versus U.S. (2006) overturned federal protection of wetlands by the Clean Water Act unless the wetlands are shown to be geographically connected with jurisdictional waters. These rulings jeopardize mitigation wetlands without federal protection because typical restoration practices often minimize surface water connection as a result of dredge-and-fill methods. Hydrologic behaviors and services of the geographically isolated wetlands (GIWs) were hypothesized to be identical to those of geographically connected wetlands in this study. Experimental evidence suggest that hydrologic connectivity is maintained between GIWs and downstream waters via subsurface flow exchange. Greater correlations for GIWs than the other connectivity types were found between variables including standard deviation of groundwater, geographic attributes (e.g., site elevation) and hydrologic attributes (e.g., duration of subsurface flow reversal). Mean groundwater table depended most strongly on wetland fraction within a drainage area. Water temperature, particularly in summer, strongly influences the environmental suitability for wetland species such as a Blanding’s turtle (Emydoidea blandingii) for nesting in northern New York. Although temperature dependency of wetland fauna has been investigated to determine the range of suitable environmental conditions, the hydrogeomorphic controls on seasonal thermal regimes of wetlands were not addressed in prior studies. In this study, temperature regimes at multiple sites under uniform climate and geologic settings were investigated to understand the controls on wetland temperature in several of hydrogeomorphic settings. Local geomorphology and alterations by wetland restoration affected wetland thermal regimes via various seasonal subsurface flow exchange patterns. Thermal sensitivity is defined as a response in surface water temperature to change in air temperature. Based on wetland temperature measurements, linear regression was used to estimate thermal sensitivity for each site. Summer temperature values were shown as primary determinants by site comparison. In addition, the thermal sensitivity values were compared to site variables to seek for local controls. Results suggest that geographical and hydrologic variables including site elevation, duration of subsurface flow reversal, and standard deviation of wetland stage and groundwater table are significantly correlated with thermal sensitivity. Geomorphic settings are useful resources to characterize site hydrology and thermal functions of wetlands. Wetland restoration practitioners need to carefully choose class-appropriate hydrogeomorphic settings to promote establishment and conservation of temperature-sensitive species. Finally, the impact of the land surface energy budget was measured to assess the patch level controls on evapotranspiration by various wetland species. Infrared thermometry was used within a standard meteorological measurement system to determine energy partitioning between sensible and latent heat fluxes in wetlands. A portable thermal infrared (TIR) camera was used to capture radiometric surface temperature of leaves, i.e., evapotranspiring surfaces, and then to estimate sensible and thus latent heat flux associated with a portable weather station. Two TIR-based methods including TIR temperature-based surface energy balance (SEB) and Bowen ratio () were compared to the well-known Priestley-Taylor (P-T) method for four species-level patches. For wetland plants including hardstem bulrush (Scirpus Spp.), reed canary grass (Phalaris arundinacea), cattail (Typha Spp.) and meadow willow (Salix petiolaris), results are similar for the TIR-based and P-T methods with mean absolute difference of 17.1-53.0 W m-2 and root mean squared difference of 23.4-62.4 W m-2 across sites. Greater differences were found from parameterization of aerodynamic resistance for flexible and tall vegetation structure and especially for greater wind speed. Finally, estimated crop coefficients will be useful for regional wetland restoration planning by providing major losses in local water budget

Impacts of urban decline on local climatology: A comparison of growing and shrinking cities in the post-industrial Rust Belt

Cities such as Detroit, MI in the post-industrial Rust Belt region of the United States, have been experiencing a decline in both population and economy since the 1970's. These “shrinking cities” are characterized by aging infrastructure and increasing vacant areas, potentially resulting in more green space. While in growing cities research has demonstrated an “urban heat island” effect resulting from increased temperatures with increased urbanization, little is known about how this may be different if a city shrinks due to urban decline. We hypothesize that the changes associated with shrinking cities will have a measurable impact on their local climatology that is different than in areas experiencing increased urbanization. Here we present our analysis of historical temperature and precipitation records (1900–2020) from weather stations positioned in multiple shrinking cities from within the Rust Belt region of the United States and in growing cities within and outside of this region. Our results suggest that while temperatures are increasing overall, these increases are lower in shrinking cities than those cities that are continuing to experience urban growth. Our analysis also suggests there are differences in precipitation trends between shrinking and growing cities. We also highlight recent climate data in Detroit, MI in the context of these longer-term changes in climatology to support urban planning and management decisions that may influence or be influenced by these trends

Inference of Soil Hydrologic Parameters from Electronic Soil Moisture Records

Soil moisture is an important control on hydrologic function, as it governs vertical fluxes from and to the atmosphere, groundwater recharge, and lateral fluxes through the soil. Historically, the traditional model parameters of saturation, field capacity, and permanent wilting point have been determined by laboratory methods. This approach is challenged by issues of scale, boundary conditions, and soil disturbance. We develop and compare four methods to determine values of field saturation, field capacity, plant extraction limit (PEL), and initiation of plant water stress from long term in-situ monitoring records of TDR-measured volumetric water content (Θ). The monitoring sites represent a range of soil textures, soil depths, effective precipitation and plant cover types in a semi-arid climate. The Θ records exhibit attractors (high frequency values) that correspond to field capacity and the PEL at both annual and longer time scales, but the field saturation values vary by year depending on seasonal wetness in the semi-arid setting. The analysis for five sites in two watersheds is supported by comparison to values determined by a common pedotransfer function and measured soil characteristic curves. Frozen soil is identified as a complicating factor for the analysis and users are cautioned to filter data by temperature, especially for near surface soils

Korean Newspaper Coverage of Climate Change or Global Warming, 2000-2023 - October 2023

The Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p

Korean Newspaper Coverage of Climate Change or Global Warming, 2000-2022 - December 2022

The Media and Climate Change Observatory Data monitors 130 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p

Korean Newspaper Coverage of Climate Change or Global Warming, 2000-2023 - February 2023

The Media and Climate Change Observatory Data monitors 130 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p

Korean Newspaper Coverage of Climate Change or Global Warming, 2000-2023 - May 2023

The Media and Climate Change Observatory Data monitors 130 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p

Korean Newspaper Coverage of Climate Change or Global Warming, 2000-2023 - September 2023

The Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p

Korean Newspaper Coverage of Climate Change or Global Warming, 2000-2024 - April 2024

The Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p

Korean Newspaper Coverage of Climate Change or Global Warming, 2000-2023 - June 2023

The Media and Climate Change Observatory Data monitors 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://mecco.colorado.edu.</p