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Water Quality Aspects of an Intermittent Stream and Backwaters in an Urban North Texas Watershed

Description: Pecan Creek flows southeast through the City of Denton, Texas. Characterized as an urban watershed, the basin covers approximately 63.5 km2. Pecan Creek is an intermittent stream that receives nonpoint runoff from urban landuses, and the City of Denton's wastewater treatment plant, Pecan Creek Water Reclamation Plant, discharges effluent to the stream. Downstream from the City of Denton and the wastewater treatment plant, Pecan Creek flows about 6,000 m through agricultural, pasture, and forested landscapes into Copas Cove of Lake Lewisville, creating backwater conditions. Pecan Creek water quality and chemistry were monitored from August 1997 to October 2001. Water quality was influenced by seasonal, spatial, climatic, and diurnal dynamics. Wastewater effluent discharged from the Pecan Creek Water Reclamation Plant had the greatest influence on water quality of the stream and backwaters. Water quality monitoring of Pecan Creek demonstrated that dissolved oxygen standards for the protection of aquatic life were being achieved. Water quality modeling of Pecan Creek was completed to assess future increases in effluent flow from the Pecan Creek Water Reclamation Plant. Water quality modeling indicated that dissolved oxygen standards would not be achieved at the future effluent flow of 21 MGD and at NPDES permitted loadings. Model results with application of a safety factor indicated that the maximum allowable concentrations for a 21 MGD discharge would be 2.3 mg/L of ammonia and 7.0 mg/L of biochemical oxygen demand at summer conditions. Drought conditions that occurred from 1998 to 2001 reduced water levels in Lake Lewisville and impacted dissolved oxygen water quality in Pecan Creek. Water quality observations made during the period of drought allowed for the development of a model to estimate the zone of the dissolved oxygen sag in Pecan Creek based on reservoir elevation. Finally, monitoring results were analyzed with nonparametric statistical procedures to detect water ...
Date: August 2002
Creator: Taylor, Ritchie Don
Partner: UNT Libraries

The Impacts and Costs of Climate Change

Description: The effects of global climate change from greenhouse gas emissions (GHGs) are diverse and potentially very large, and probably constitute the most serious long-term environmental issue currently facing the world. This paper is prepared as task 1 of the project 'Modelling support for Future Actions - Benefits and Cost of Climate Change Policies and Measures', ENV.C.2/2004/0088, led by K.U.Leuven, Katholieke Universiteit Leuven. The paper provides a rapid review and analysis of the impacts and economic costs from climate change. The objective is to provide estimates of the benefits of climate change policy, i.e. from avoided impacts, for support to the Commission in considering the benefits and costs of mitigation efforts, and to support DG Environment in its report to the Spring Council 2005 and in future international negotiations on climate change.
Date: September 2005
Creator: Watkiss, Paul; Downing, Tom; Handley, Claire & Butterfield, Ruth
Partner: UNT Libraries

Megadrought and Megadeath in 16th Century Mexico

Description: The native population collapse in 16th century Mexico was a demographic catastrophe with one of the highest death rates in history. Recently developed tree-ring evidence has allowed the levels of precipitation to be reconstructed for north central Mexico, adding to the growing body of epidemiologic evidence and indicating that the 1545 and 1576 epidemics of cocoliztli (Nahuatl for "pest") were indigenous hemorrhagic fevers transmitted by rodent hosts and aggravated by extreme drought conditions.
Date: 2002
Creator: Acuna-Soto, Rodolfo; Stahle, David W.; Cleaveland, Malcolm K. & Therrell, Matthew D.
Partner: UNT Libraries

Preparing for Drought in the 21st Century: Report of the National Drought Policy Commission.

Description: In 1998, Congress passed the National Drought Policy Act. The Act stated that this nation would benefit from national drought policy based on preparedness and mitigation to reduce the need for emergency relief. It acknowledged that this country has no consistent, comprehensive policy driving the federal role to help reduce the impacts of drought. The Act also created the National Drought Policy Commission to advise Congress on how best to: Integrate federal drought laws and programs with ongoing state,local, and tribal programs into a comprehensive national policy to mitigate the impacts of and respond to drought. Improve public awareness of the need for drought mitigation. Achieve a coordinated approach to drought mitigation and response by governments and nongovernmental entities, including academic, private, and nonprofit interests. This document constitutes the report of the National Drought Policy Commission. (Commission members were chosen according to provisions in the Act, which required representation of federal and nonfederal government entities and the private sector.) The report presents the basis for national drought policy and calls for commitment and resolve in providing sufficient resources to achieve the policy goals.
Date: May 2000
Creator: United States. Department of Agriculture. Office of Communications.
Partner: UNT Libraries Government Documents Department

Sense of Place

Description: Lesson plan containing a collection of activities and resources regarding sense of place that meet state education standards and national sustainability standards for the 2nd grade level.
Date: August 29, 2014
Creator: Treadway, Heather
Partner: UNT Office of Sustainability

[Letter from Alice Griffin to Mary, Linnet, and Charles B. Moore, June 29, 1896]

Description: Letter from Alice Griffin to the Charles B. Moore family. She writes that she is unwell and able to do little but tend to the baby. She says that Florence Dodd is unwell and Florence and her husband Tobe are having a hard time financially. She describes her baby, Lillian Griffin. Included with the letter are swatches of fabric that she has used to make clothing.
Date: June 29, 1896
Creator: Griffin, Alice
Partner: UNT Libraries Special Collections

[Letter from Dinkie and Birdie McGee to Mary , Linnet and Charles B. Moore, August 7, 1891]

Description: Letter from Dinkie wrote about her family's health; the dry, windy weather; she went to a dinner at the Guild Smiths and was not happy with the manners of the people who showed up; she ends her part of the letter by giving an account of what they had for dinner. Birdie wrote her cousin Linnet about the shortage of water; making cider; the flower garden; and the start of school.
Date: August 7, 1891
Creator: McGee, Dinkie & McGee, Birdie
Partner: UNT Libraries Special Collections

[News Clip: Rain a blessing? Well, yes and no]

Description: Video footage from the WBAP-TV television station in Fort Worth, Texas, covering a news story by reporter Lee Elsesser about the impact of recent rain and persistent drought on cotton and pecan crops and cattle. This story is referenced by the script, "Dry," which has not yet been digitized.
Date: September 6, 1967
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

Dynamics of Stream Fish Metacommunities in Response to Drought and Re-connectivity

Description: This dissertation investigates the spatio-temporal dynamics of intermittent stream fish metacommunities in response drought-induced fragmentation and re-connectivity using both field and experimental approaches. A detailed field study was conducted in two streams and included pre-drought, drought, and post-drought hydrological periods. Fish assemblages and metacommunity structure responded strongly to changes in hydrological conditions with dramatic declines in species richness and abundance during prolonged drought. Return of stream flows resulted in a trend toward recovery but ultimately assemblages failed to fully recover. Differential mortality, dispersal, recruitment among species indicates species specific responses to hydrologic fragmentation, connectivity, and habitat refugia. Two manipulative experiments tested the effects of drought conditions on realistic fish assemblages. Fishes responded strongly to drought conditions in which deeper pools acted as refugia, harboring greater numbers of fish. Variability in assemblage structure and movement patterns among stream pools indicated species specific habitat preferences in response predation, resource competition, and desiccation. Connecting stream flows mediated the impacts of drought conditions and metacommunity dynamics in both experiments. Results from field and experimental studies indicate that stream fish metacommunities are influenced by changes in hydrological conditions and that the timing, duration, and magnitude of drought-induced fragmentation and reconnecting stream flows have important consequences metacommunity dynamics.
Date: August 2015
Creator: Driver, Lucas J.
Partner: UNT Libraries