Trinity River Research Articles

Relative Importance of Intrinsic, Extrinsic, and Anthropic Factors in the Geomorphic Zonation of the Trinity River, Texas1

Relative Importance of Intrinsic, Extrinsic, and Anthropic Factors in the Geomorphic Zonation of the Trinity River, Texas¹

Holocene sediment accretion in the Trinity River delta, Texas, in relation to modern fluvial input

Purpose This study uses sediment cores to quantify Holocene sedimentation rates in the Trinity River delta, Texas. An important question is whether modern fluvial sediment input from the Trinity River is adequate to sustain sedimentation in the delta, thereby combating subsidence and further wetland loss. Our objective was to quantify sedimentation rates within the delta in order to assess whether the delta is in- or out-of-phase with modern sediment delivery rates.

CalLite: California Central Valley Water Management Screening Model

The California Department of Water Resources (DWR) and U.S. Bureau of Reclamation Mid-Pacific Region (Reclamation) have developed a rapid, interactive screening model, named CalLite, for evaluating various Central Valley water management options. The CalLite model is being used as a computer-aided negotiations tool in a variety of stakeholder’s processes for improved understanding of water system operations and consensus-based decision making. CalLite was developed using the GoldSim system dynamics software that enables simulation of complex process through a buildup of simple object relationships, incorporates Monte Carlo stochastic methods, and includes dynamic, interactive user interfaces. The screening tool models much of the Central Valley of California that contributes flow to the Delta. The geographical coverage includes the Upper Trinity River, the Sacramento River Valley, the San Joaquin River Valley, the Sacramento–San Joaquin Delta, and the Central Valley Project and the State Water Project ser...

Faunal assemblages and multi-scale habitat patterns in headwater tributaries of the South Fork Trinity River – an unregulated river embedded within a multiple-use landscape

Headwaters can represent 80% of stream kilometers in a watershed, and they also have unique physical and biological properties that have only recently been recognized for their importance in sustaining healthy functioning stream networks and their ecological services. We sampled 60 headwater tributaries in the South Fork Trinity River, a 2,430 km2, mostly forested, multiple-use watershed in northwestern California. Our objectives were: (1) to differentiate unique headwater types using 69 abiotic and vegetation variables measured at three spatial scales, and then to reduce these to informative subsets; (2) determine if distinct biota occupied the different tributary types; (3) determine the environmental attributes associated with the presence and abundance of these biotic assemblages; and (4) using niche modeling, determine key attribute thresholds to illustrate how these biota could be employed as metrics of system integrity and ecological services. Several taxa were sufficiently abundant and widespread to use as bio-indicators: the presence and abundance of steelhead trout (Oncorhynchus mykiss), herpetofauna (reptile and amphibian) species richness, and signal crayfish (Pacifastacus leniusculus) represented different trophic positions, value as commercial resources (steelhead), sensitivity to environmental stress (amphibians), and indicators of biodiversity (herpetofauna species richness). Herpetofauna species richness did not differ, but abundances of steelhead trout, signal crayfish, and amphibian richness all differed significantly among tributary types. Niche models indicated that distribution and abundance patterns in both riparian and aquatic environments were associated with physical and structural attributes at multiple spatial scales, both within and around reaches. The bio-indicators responded to unique sets of attributes, reflecting the high environmental heterogeneity in headwater tributaries across this large watershed. These niche attributes represented a wide range of headwater environments, indicating responses to a number of natural and anthropogenic conditions, and demonstrated the value of using a suite of bio-indicators to elucidate watershed conditions, and to examine numerous disturbances that may influence ecological integrity.

Recalibrated Chronological Framework for Texas Archaeology-Geoarchaeology

Radiocarbon assays from select archaeological-geoarchaeological research projects within Texas river basins were compiled and recalibrated using the same calibration curve (i.e., INTCAL09). Chronometric data from investigations within the Nueces, San Antonio, Colorado, Brazos, and Trinity River basins were uniformly calibrated to construct a consistent chronological framework. Once calibrated, the analogous chronometric data were then used to compare drainage basins, paleoenvironmental data, and cultural chronologies across Texas and the region. These comparisons revealed four periods (Synchronous Events I–IV) in the Holocene that occurred simultaneously within all of the examined drainage basins. Synchronous Event I dating to 8,750–8,250 cal yr BP (~6800–6300 BC), Synchronous Event II dating to 7,000–6,250 cal yr BP (~5050–4300 BC), and Synchronous Event III 5,250–5,000 cal yr BP (~3300–3050 BC) are apparent periods of instability. While Synchronous Event IV occurs at 1,000–750 cal yr BP (~AD 950–1200) represents a period of stability. These events may be attributed to previously identified widespread climatic changes and seemingly coincide with several transitions in the archaeological record.

The Trinity River Corridor Project in Dallas, Texas: Enhancing an Urban Ecosystem and Reviving River and Floodplain Open Space to Create Future Sustainable Development Opportunities

The Trinity River Corridor Project in Dallas, Texas: Enhancing an Urban Ecosystem and Reviving River and Floodplain Open Space to Create Future Sustainable Development Opportunities

Demonstration Flow Assessment and 2‐D Modeling: Perspectives Based on Instream Flow Studies and Evaluation of Restoration Projects

AbstractRailsback and Kadvany (2008) make a compelling case for the use of demonstration flow assessments (DFA) for instream flow assessments as a more robust method than traditional one‐dimensional habitat simulation techniques, such as the Physical Habitat Simulation System. But, based on experience with DFAs used for instream flow assessments and evaluation of stream restoration projects, the methods presented by Railsback and Kadvany (2008) may not give reproducible results, and DFAs have significant drawbacks relative to two‐dimensional (2‐D) hydraulic and habitat modeling. Application of the DFA methodology presented in Railsback and Kadvany (2008) to assess a stream restoration project on the Trinity River, California, did not give reproducible results, with substantial disparity between replicate surveys in the total quantity and spatial distribution of habitat. As an empirical two‐dimensional habitat modeling method, DFAs have several drawbacks. Compared to 2‐D models, DFAs require interpolation and extrapolation of results from the observed flows, and lack biological realism because they use categorical (binary) habitat suitability criteria. Further, 2‐D modeling offers significant benefits over DFA in the context of adaptive management. Advantages of DFAs cited by Railsback and Kadvany (2008), namely the feasibility of assessing habitat with complex hydraulics, the ease in using mechanistic and theoretical conceptual models, and the ability to assess long reaches, also apply to 2‐D models. Modification of the DFA methods presented in Railsback and Kadvany (2008) to give reproducible results may increase the cost of DFAs or reduce the length of stream that can be assessed with DFAs to the point where 2‐D modeling may be a more cost‐effective technique than DFAs.

Predicting fractional bed load transport rates: Application of the Wilcock‐Crowe equations to a regulated gravel bed river

Bed load samples from four locations in the Trinity River of northern California are analyzed to evaluate the performance of the Wilcock‐Crowe bed load transport equations for predicting fractional bed load transport rates. Bed surface particles become smaller and the fraction of sand on the bed increases with distance downstream from Lewiston Dam. The dimensionless reference shear stress for the mean bed particle size (τ*rm) is largest near the dam, but varies relatively little between the more downstream locations. The relation between τ*rm and the reference shear stresses for other size fractions is constant across all locations. Total bed load transport rates predicted with the Wilcock‐Crowe equations are within a factor of 2 of sampled transport rates for 68% of all samples. The Wilcock‐Crowe equations nonetheless consistently under‐predict the transport of particles larger than 128 mm, frequently by more than an order of magnitude. Accurate prediction of the transport rates of the largest particles is important for models in which the evolution of the surface grain size distribution determines subsequent bed load transport rates. Values of τ*rm estimated from bed load samples are up to 50% larger than those predicted with the Wilcock‐Crowe equations, and sampled bed load transport approximates equal mobility across a wider range of grain sizes than is implied by the equations. Modifications to the Wilcock‐Crowe equation for determining τ*rm and the hiding function used to scale τ*rm to other grain size fractions are proposed to achieve the best fit to observed bed load transport in the Trinity River.

Coupling hydrodynamic modeling and empirical measures of bed mobility to predict the risk of scour and fill of salmon redds in a large regulated river

In order to assess the risk of scour and fill of spawning redds during floods, an understanding of the relations among river discharge, bed mobility, and scour and fill depths in areas of the streambed heavily utilized by spawning salmon is needed. Our approach coupled numerical flow modeling and empirical data from the Trinity River, California, to quantify spatially explicit zones of differential bed mobility and to identify specific areas where scour and fill is deep enough to impact redd viability. Spatial patterns of bed mobility, based on model‐predicted Shields stress, indicate that a zone of full mobility was limited to a central core that expanded with increasing flow strength. The likelihood and maximum depth of measured scour increased with increasing modeled Shields stress. Because redds were preferentially located in coarse substrate in shallow areas with close proximity to the stream banks, they were less likely to become mobilized or to risk deep scour during high‐flow events but were more susceptible to sediment deposition.

Linking Habitat Quality with Trophic Performance of Steelhead along Forest Gradients in the South Fork Trinity River Watershed, California

AbstractWe examined invertebrate prey, fish diet, and energy assimilation in relation to habitat variation for steelhead Oncorhynchus mykiss (anadromous rainbow trout) and rainbow trout in nine low‐order tributaries of the South Fork Trinity River, northern California. These streams spanned a range of environmental conditions, which allowed us to use bioenergetics modeling to determine the relative effects of forest cover, stream temperature, season, and fish age on food consumption and growth efficiency. Evidence of seasonal shifts in reliance on aquatic versus terrestrial food sources was detected among forest cover categories and fish ages, although these categories were not robust indicators of O. mykiss condition and growth efficiency. Consumption estimates were generally less than 20% of maximum consumption, and fish lost weight in some streams during summer low‐flow conditions when stream temperatures exceeded 15°C. Current 100‐year climate change projections for California threaten to exacerbate negative growth patterns and may undermine the productivity of this steelhead population, which is currently not listed as endangered or threatened. To demonstrate the potential effect of global warming on fish growth, we ran three climate change scenarios in two representative streams. Simulated temperature increases ranging from 1.4°C to 5.5°C during the summer and from 1.5°C to 2.9°C during the winter amplified the weight loss; estimated average growth for age‐1 fish was 0.4‐4.5 times lower than normal (low to high estimated temperature increase) in the warm stream and 0.05‐0.8 times lower in the cool stream. We conclude that feeding rate and temperature during the summer currently limit the growth and productivity of steelhead and rainbow trout in low‐order streams in the South Fork Trinity River basin and predict that climate change will have detrimental effects on steelhead growth as well as on macroinvertebrate communities and stream ecosystems in general.

A New species of Streptanthus (Brassicaceae) from Trinity County, California

Abstract Streptanthus oblanceolatus T. W. Nelson and J. P. Nelson is here described and illustrated. It is endemic to steep metavolcanic bluffs along the gorge of the Trinity River above its confluence with the New River, where three voucher specimens have been obtained.

Use of watershed factors to predict consumer surfactant risk, water quality, and habitat quality in the upper Trinity River, Texas

Surfactants are high production volume chemicals that are used in a wide assortment of “down-the-drain” consumer products. Wastewater treatment plants (WWTPs) generally remove 85 to more than 99% of all surfactants from influents, but residual concentrations are discharged into receiving waters via wastewater treatment plant effluents. The Trinity River that flows through the Dallas–Fort Worth metropolitan area, Texas, is an ideal study site for surfactants due to the high ratio of wastewater treatment plant effluent to river flow (> 95%) during late summer months, providing an interesting scenario for surfactant loading into the environment. The objective of this project was to determine whether surfactant concentrations, expressed as toxic units, in-stream water quality, and aquatic habitat in the upper Trinity River could be predicted based on easily accessible watershed characteristics. Surface water and pore water samples were collected in late summer 2005 at 11 sites on the Trinity River in and around the Dallas–Fort Worth metropolitan area. Effluents of 4 major waste water treatment plants that discharge effluents into the Trinity River were also sampled. General chemistries and individual surfactant concentrations were determined, and total surfactant toxic units were calculated. GIS models of geospatial, anthropogenic factors (e.g., population density) and natural factors (e.g., soil organic matter) were collected and analyzed according to subwatersheds. Multiple regression analyses using the stepwise maximum R 2 improvement method were performed to develop prediction models of surfactant risk, water quality, and aquatic habitat (dependent variables) using the geospatial parameters (independent variables) that characterized the upper Trinity River watershed. We show that GIS modeling has the potential to be a reliable and inexpensive method of predicting water and habitat quality in the upper Trinity River watershed and perhaps other highly urbanized watersheds in semi-arid regions.

Delivery of Trace Metals (Al, Fe, Mn, V, Co, Ni, Cu, Cd, Ag, Pb) from the Trinity River Watershed Towards the Ocean

The Trinity River (Texas, USA) contains in its watershed 23 different reservoir lakes, the largest one being Lake Livingston situated in the lower Trinity River watershed and two potentially polluting metroplexes, Dallas and Houston. In order to determine fluxes of nutrients and trace metals to Galveston Bay, a survey that included 24 discreet samples collected over a year and at various stages of discharge was carried out during 2000–2001. Geochemical (i.e., sorption by Fe oxyhydroxides), biological (i.e., seasonal uptake by sinking algae in Lake Livingston), and hydrological (i.e., dilution effects by increasing flow rates) controls were found to be mainly responsible for variations in dissolved trace metal concentrations rather than pollution sources. The Trinity River loads of suspended sediments and pollutant trace metals entering Galveston Bay at Anahuac were 96% of the pollutant trace metal load is lost to sediments.

From reclamation to restoration: Trinity River common vision for the 21st century

For most of the past 150 years, the dream for the Trinity River in north central Texas was that of a federally‐funded navigation canal with barges transporting goods more than 300 miles to and from the Gulf of Mexico. An 1898 promotional button proclaimed the dream: “Dallas ‐ The Inland Seaport of Texas.” Since then the region has grown into America's largest metropolitan region located on an inland waterway. The region's population now exceeds 6 million; its area is about 33,000 square kilometers. When the 19th‐century dream of a barge canal died in the early 1980's because of changing federal priorities, it was replaced by new local pressures to fill and reclaim significant portions of the floodplain. Studies by the US Army Corps of Engineers with the North Central Texas Council of Governments (NCTCOG) demonstrated the devastating effects that massive reclamation would have on existing properties, especially to the downstream Dallas levee system. From these important discussions emerged an unprecedented local/state/federal partnership to more comprehensively address the problems and opportunities of the river corridor and watershed towards a Trinity River Common Vision for the 21st‐century: • Safe Trinity River, with stabilization and reduction of flooding risks; • Clean Trinity River, with fishable and swimmable waters; • Enjoyable Trinity River, with recreational opportunities linked by a Trinity Trails System within a world‐class greenway; • Natural Trinity River, with preservation and restoration of riparian and cultural resources; • Diverse Trinity River, with local and regional economic, transportation, and other public needs met. This paper describes the evolution of the Trinity River Common Vision over the past 20 years, highlights successful regionwide projects to stabilize and reduce flood risks such as the innovative Corridor Development Certificate process, and shows the remarkable progress of the region's three largest cities ‐ Dallas, Fort Worth and Arlington. All illustrate the movement from reclamation to restoration, from structural to non‐structural, from a 19th‐century barge canal to a 21st‐century Trinity River Common Vision.

Hybridization between Spring‐ and Fall‐Run Chinook Salmon Returning to the Trinity River, California

AbstractIt is believed that spring‐ and fall‐run Chinook salmon Oncorhynchus tshawytscha returning to the Trinity River, California, were once reproductively isolated such that spring‐run fish spawned upstream in early fall, whereas fall‐run fish spawned further downstream in late fall. However, construction of Lewiston Dam and the Trinity River Hatchery (TRH) in 1964 resulted in extensive compression of spawning habitat and the potential for inadvertent interbreeding of the two runs. In this study, we used genetic methods and developed a simulation procedure to assess the degree to which spring‐ and fall‐run Chinook salmon returning to TRH were genetically distinct and to determine the extent of hybridization between the runs. Approximately 40 adults/week were sampled throughout the 1992 spawning season, and all individuals were genotyped at 29 polymorphic loci. Analysis with the program STRUCTURE (Pritchard et al. 2000) supported the hypothesis that the data represented two subpopulations. Individual assignments using STRUCTURE indicated that the spring‐ and fall‐run proportions among fish sampled at TRH gradually shifted through time; weekly samples taken earlier in the spawning season had a higher proportion of presumptive spring run, and those taken later in the season had a higher proportion of presumptive fall run. Comparison of observed results with simulated data suggested the occurrence of hybridization between spring‐ and fall‐run Chinook salmon returning to TRH, particularly during the transition or overlap period between fish from the two phenotypic groups. The extent to which hybridization was caused by hatchery operations or occurred prior to Lewiston Dam construction was unclear. Additional hybridization analyses of samples collected prior to dam and hatchery construction would be needed to evaluate the impacts of these facilities on hybridization. Further, studies of contemporary populations are needed to determine whether two runs currently exist despite the marked hybridization that was documented herein for the 1992 return year.

Metrics to describe the dynamical evolution of atmospheric moisture: Intercomparison of model (NARR) and observations (ISCCP)

The manuscript presents results from an exploratory study of metrics to describe the dynamical evolution of atmospheric moisture fields for interpretive studies. Specifically, we conduct diagnostic data analysis of the life cycle (initiation, growth, and decay) of instabilities of index fields of atmospheric moisture that can be related to cloudiness and rainfall from the NCEP North American Regional Reanalysis (NARR) and International Satellite Cloud Climatology Product (ISCCP) data in the southeast United States in 2000–2001. The two principal metrics consist of spatial fields of finite size Lyapunov exponents (FSLE, a measure of the growth rate of instability) and localization length (the characteristic time scale of instability, or alternatively a proxy measure of the local memory of the process). The results reveal (1) consistency among the spatial fields of the seasonal rates of instability growth (FSLE); (2) differences in the dynamical range of perturbation growth in the ISCCP observations (broad) as compared to the NARR (narrow), especially in the smaller perturbation/fast dynamics regime, which suggests stronger coupling of the physical processes in the NARR; and (3) stronger interseasonal and intraseasonal variability in the manifestation of nonlinear dynamics (e.g., strong summer/fall contrasts) in the NARR as compared to the satellite data. Larger disparities (r2 ∼ 02–0.3) occur over the ocean on the west (summer) and eastern (fall) margins of the Gulf of Mexico and over land in the Trinity river basin (Texas) and at the foothills of the Ouachita mountains where agriculture and large freshwater reservoirs (large free water surfaces) exist and where the 2000 drought attained exceptional intensity. Whereas the differences over the ocean may be attributed to the subgrid‐scale representation of warm core rings and the loop current over the Gulf of Mexico, the differences are likely associated with the representation of land‐atmosphere interactions in the model over land.

The role of organic carbon, iron, and aluminium oxyhydroxides as trace metal carriers: Comparison between the Trinity River and the Trinity River Estuary (Galveston Bay, Texas)

Concentrations of many trace elements in aquatic systems can become enriched due to anthropogenic as well as natural processes. In order to investigate particle enrichment processes from the river through an estuary, the changes in solid phase speciation and particle–water partitioning of a number of trace metals (e.g., Fe, Pb, Cd, Cu, Ni, Zn, Co, V) were evaluated from the Trinity River through Galveston Bay to the Ocean. An established way to detect anthropogenic contamination is by normalization of contaminant concentrations to Fe, Al, and/or organic carbon (OC). Particulate metal (Mn, Co, Ni, Cu, Pb, V, Ni, Zn, Cd) to Fe, Al, and metal to OC ratios were determined in waters of the Trinity River and Galveston Bay, in order to test 1) if the system is contaminated, and 2) whether Fe, Al, or organic carbon act as a master variable for determining metal concentrations. All particulate trace metals from Trinity River were present in ratios to Fe or Al similar to those from drainage basin soils, which were similar to world world-average soil. As expected, concentrations of Fe, Al and OC in particles from both the Trinity River as well as Galveston Bay were strongly correlated, from which one might conclude that Fe can be used as a reference element that is representative for all three of them. However, ratios to Fe of particle-reactive elements, such as Pb, were found to be significantly and positively correlated to the Fe content of particles from Galveston Bay, while nutrient-type elements, such as Cu, Ni, and Cd, were negatively correlated to their Fe content. Interestingly, suspended particles from the Trinity River did not exhibit any such correlations at all and only varied within a very limited range. The reason for such distinctive correlative behavior that distinguishes riverine from estuarine particles is likely caused by internal cycling of these elements within Galveston Bay, and their relationship to OC. Relationships of trace metals to OC revealed that differences in sources and cycling of OC in the estuary significantly altered the soil imprinted particle make-up. Results from selective leaching experiments of suspended particles in Galveston Bay confirmed the selective enrichment and fractionation processes for the different metals.

A new crayfish, Procambarus (Pennides) pentastylus, from southwestern Louisiana (Crustacea: Decapoda: Cambaridae), with a key to western species of the subgenus

ABSTRACT Procambarus pentastylus, a new crayfish of the subgenus Pennides, is described from the Calcasieu River drainage of southwestern Louisiana. The species formerly was confused with Procambarus dupratzi Penn, 1953 but differs in several details of the form I male pleopod, including shorter terminal elements and the presence of a large adventitious process (here termed the pentastyle) mesial to the central projection. Procambarus dupratzi as here restricted is known only from the Sabine, Neches, and Trinity River drainages in Louisiana and Texas. A key to form I males of Pennides species known from west of the Mississippi River is presented.

Antecedent alluvial morphology and sea‐level controls on form‐process transition zones in the lower Trinity river, Texas

AbstractAn important aspect of river science and management is the identification of key boundaries, transition zones and hinge points. Such critical areas are likely to be important foci or indicators of the effects of environmental change on river systems. While geological controls on such features are widely recognized in upland streams, inherited or antecedent forms may also be important controls of key transitional points or reaches in alluvial coastal plain rivers. The critical zone of the lower Trinity River, Texas marks an important transition in river channel and valley forms, dominant processes and resulting geomorphological, hydrological and ecological characteristics. Its location is not a transient result of upstream or downstream propagation of effects. Rather, the location marks the contemporary upstream extent of the effects of Holocene sea‐level rise, which in turn coincides with the point at which the Pleistocene upper Deweyville alluvial terrace surface is encountered. A more rapid rate of change and relatively sudden upstream displacement of this zone is likely when the upper Deweyville surface is flooded. Antecedent fluvial and alluvial topography inherited from previous aggradation, degradation and lateral migration episodes is likely to be an important control over modern fluvial forms and processes in other alluvial coastal plain rivers as well. Identification and mapping of such features may be extremely useful in pinpointing critical transition zones for water resource managers. Copyright © 2008 John Wiley & Sons, Ltd.

Differential Exposure toAnaplasma phagocytophilumin Rodent Species in Northern California

Anaplasma phagocytophilum is a zoonotic tick-borne rickettsial pathogen that causes granulocytic anaplasmosis (GA) in humans, horses, and dogs. In California, dusky-footed woodrats (Neotoma fuscipes) are a putative reservoir host, and Ixodes pacificus is a vector for transmission from rodents to humans, dogs, and horses. Cases are clustered in coastal and Sierra Nevada foothill regions, but not necessarily in proximity to infected woodrats. This study was designed to compare exposures and active infections of A. phagocytophilum in multiple rodents at a fine spatial scale in a hyperenzootic area and to evaluate the spatial clustering of infections. Of 331 rodents, the seroprevalence was 14.5%, with 60% in tree squirrels (Sciurus griseus and Tamiasciurus douglasii), 29% in woodrats, 14% in flying squirrels (Glaucomys sabrinus), and 5% in chipmunks (Tamias senex). No seropositive ground squirrels (Spermophilus beecheyi) were detected. The seroprevalence was significantly higher west of the Trinity River (23.1%) than east (11.8%) of the river. One Douglas squirrel and one western gray squirrel were polymerase chain reaction (PCR) positive. There was more spatial clustering among seropositive animals compared with all animals tested across the spatial scales evaluated, and this clustering was significantly greater than expected by chance alone. A significant cluster of 24 seropositive animals was found west of the Trinity River, with a population of 56 animals considered within the 50% population-at-risk, and a radius of 362.8 meters. The diversity of cricetine and sciurid rodents infected suggests that squirrels and chipmunks may be underappreciated contributors to A. phagocytophilum ecology in the western United States. The spatial clustering of exposed animals suggests interesting underlying spatially heterogeneous environmental variables that could facilitate the persistence of A. phagocytophilum in nature.