Are Streams Protected? Outcomes of Environmental Regulation (open access)

Are Streams Protected? Outcomes of Environmental Regulation

Urban areas experience the loss of natural stream channels through conversion to artificial conveyances. This process tends to target headwater and other low order streams. The purpose of this study is to determine the patterns of stream loss in Denton, Texas, and explore the regulatory structure that manages these streams. Historic and current maps and stream data are used to map Denton's streams and categorize them according to their vertical connectivity as: 1) "intact", streams that are open to the atmosphere and connect to groundwater; 2) "concrete", channelized streams open to the atmosphere but cut off from groundwater; and 3) "buried", streams disconnected from the atmosphere and groundwater. A review of federal, state, and local regulatory codes and interviews with local government officials and other stakeholders elucidates stream management in Denton. Results from these analyses reveal high rates of stream loss in the urban center with low rates overall. The federal Clean Water Act and the local Environmentally Sensitive Areas code serve as the primary protective measures for natural streams. These regulations discourage stream impacts through expensive and complex permitting requirements. However the policies allow minor impacts which may cause cumulative effects. This study aims to inform future policy-making decisions …
Date: August 2017
Creator: Rowen, Zachary
System: The UNT Digital Library
Urban Hydraulic Rhizome: Water, Space, and the City in 20th Century North Texas (open access)

Urban Hydraulic Rhizome: Water, Space, and the City in 20th Century North Texas

During the modern era, the urbanization of water has been facilitated by various privileged discourses, which valorize major engineering interventions for the sake of continued urban growth. This research examines discourse surrounding the 2-th Century proposal and construction of a reservoir near the then-tiny farming community of Grapevine, Texas, for the benefit of urban interests. I argue that urban interests produced Grapevine space as nothing more than a container for city water, by rendering meaningless any conception of space that was not directly articulated with urban economic networks. Modern discourse collapsed Denton Creek space from a watershed and landscape into a dimensionless node in the urban space of flows. In return, rural inhabitants were encouraged to progress and to modernize their own spaces: to become urban. Whereas urban discourse entails an implicit spatial imaginary of networks, I deploy the conceptual framework of settler colonialism to show that a core-periphery relationship remains relevant, and is not reducible to a network spatial ontology.
Date: May 2017
Creator: Simon, James-Eric H.
System: The UNT Digital Library
Assessing Rainfall Interception by Urban Tree Canopies in Denton, Texas (open access)

Assessing Rainfall Interception by Urban Tree Canopies in Denton, Texas

Rainfall interception is one mechanism by which tree canopies can reduce surface runoff in urban areas. The objectives of this research were to: 1) quantify rainfall interception by urban tree canopies, and 2) determine the influence of vegetation and microenvironmental factors on rainfall interception rates. In the city of Denton, Texas, 30 mature post oak (Quercus stellata) and blackjack oak (Quercus marilandica) trees were selected for study. Trees were assigned to one of three categories: clusters of trees on greenspace (CG), isolated trees on greenspace (IG), and isolated trees surrounded by pavement (IP). Throughfall (the volume of water that travels through the canopy and reaches the soil surface) collectors were placed beneath these trees and rainfall collectors were placed in nearby open areas. Throughfall and rainfall were collected daily from 19 March to 4 July. Interception was calculated as the difference between throughfall and gross rainfall. Over the study period, there were 27 days with measurable rainfall; daily rainfall ranged from 1-51 mm. Over the sampling period, rainfall interception for individual trees ranged from -10% to 49%, indicating high spatial variability in interception. Percent interception was highest for the CG treatment (22.7 ± 3.8 SE), intermediate for IG (27.4 ± …
Date: May 2017
Creator: Edington, Patrick
System: The UNT Digital Library