A Survey of Landowner Attitudes Toward the Construction of Lake Ray Roberts (open access)

A Survey of Landowner Attitudes Toward the Construction of Lake Ray Roberts

Documentation of social impacts resulting from the construction of Lake Ray Roberts is to be incorporated into a two year post-impoundment study. Research objectives are to: 1) locate current residences of landowners and previous landowners who were displaced; 2) determine social impacts resulting from construction of Lake Ray Roberts; 3) document degree of satisfaction with current living conditions; 4) document landowners' degree of satisfaction associated with COE negotiations; 5) document landowners' observations. Landowners were identified by telephone and sent a mail-back questionnaire. Respondents were generally happy with current residences and communities. While courtesy and sufficient information were provided by the COE, respondents would have preferred for property settlements to be more consistent and timely.
Date: August 1991
Creator: Norris, Paula Sue
System: The UNT Digital Library
Habitat Evaluation Procedures at Ray Roberts Lake: an Analysis of the Relationship with Ecological Indicators and a Study of Observer and Temporal Variability (open access)

Habitat Evaluation Procedures at Ray Roberts Lake: an Analysis of the Relationship with Ecological Indicators and a Study of Observer and Temporal Variability

Habitat Evaluation Procedure data gathered at Ray Roberts Lake in 1989 and 1990 were analysed for temporal variability, observer variability and relationships between Habitat Units (HUs) and species density/diversity. observer variability within a group was analysed by cluster analysis and bootstrapping. Five out of 36 sites showed significant differences in Habitat Suitability Index (HSI) values within the group. A nonparametric Mann-Whitney test was used to analyze temporal variability. One of 6 sites showed a significant difference in HSI values between years. Using Spearman's Rank Correlation Coefficient, a correlation was found between indicator species density and HUs. No significant correlation was indicated between species diversity and HUs.
Date: December 1993
Creator: Wattrus, Jane M. (Jane Marie)
System: The UNT Digital Library
A Comparison of Predicted and Actual Trophic Status of Lake Ray Roberts, Texas Based on Chlorophyll A (open access)

A Comparison of Predicted and Actual Trophic Status of Lake Ray Roberts, Texas Based on Chlorophyll A

Two years before impoundment, the trophic status of Lake Ray Roberts was predicted by applying the total phosphorus input into the Organization for Economic Cooperation and Development (OECD) eutrophication model. Predicted mean summer epilimnetic (MSE) chlorophyll a of Elm Fork arm, Isle duBois arm and Main Body were in the eutrophic category of the OECD model. Observed MSE chlorophyll a two years after impoundment of Elm Fork arm, Isle duBois and Main Body had not reached their predicted means and were at the mesotrophic-eutrophic boundary of the OECD model. Six years after impoundment, observed MSE chlorophyll a for Main Body, was closer to its predicted mean and in the eutrophic category of the OECD model. Six years after impoundment, Elm Fork arm was the most productive area of Lake Ray Roberts. Observed means of chlorophyll a, total phosphates, suspended solids and turbidity were often highest in the Elm Fork arm. Wastewater effluent from Gainesville and Valley View, TX, had an impact on productivity in Elm Fork arm.
Date: May 1999
Creator: Lytle, Lili Lisa
System: The UNT Digital Library