Browsing by Subject "Runoff"
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Item A Mathematical Model to Correlate Rainfall and Runoff(Texas Tech University, 1972-05) Rauschuber, Donald GeneNot Available.Item Assessing effects of highway bridge deck runoff on near-by recieving waters in coastal margins using remote monitoring techniques(Texas A&M University, 2005-02-17) Nwaneshiudu, OkeMost of the pollution found in highway runoff is both directly and indirectly contributed by vehicles such as cars and trucks. The constituents that contribute the majority of the pollution, such as metals, chemical oxygen demand, oil and grease, are generally deposited on the highways. These can become very harmful and detrimental to human health when they come in contact with our water system. The connecting tie between these harmful highway-made pollution and our water system, which includes our ground waters and surface waters, is rainfall. The main objective of this runoff study was to characterize and assess the quantity and quality of the storm water runoff of a bridge deck that discharged into a receiving water body. The bridge deck and the creek were located in the coastal margin region in the southeast area of Texas on the border of Harris and Galveston counties. Flow-activated water samplers and flow-measuring devices were installed to quantitatively determine the rate of flow of the bridge deck and determine different pollutant loading by sampling the receiving water body (Clear Creek). The collected samples were analyzed for total suspended solids, toxic metals, and other relevant constituents of concerns. The results illustrated that the runoff from the bridge deck exhibited low total suspended solids concentrations (which were highest in the creek). However, other metal constituents like the zinc and cooper concentration were high and above standards. The phosphate concentrations in the creek were the highest and exceeded EPA standards. Several nitrate concentrations were also noticeably above EPA standards.Item Characterization of bridge discharge to receiving streams(Texas Tech University, 2004-12) Nishtala, SantoshNot availableItem Comparison of Horton's, Smith's, and Green-Ampt's infiltration equations using flooding infiltrometer data in engineering applications(Texas Tech University, 1998-12) Anderson, Michael ColeThe hydrologic cycle represents the interaction of water between the earth's surface and the earth's atmosphere. Precipitation, evaporation, interception, infiltration, surface runoff, and subsurface flow make up the integral components of the hydrologic cycle (Veissman et al., 1989). The hydrologic cycle is of major interest to engineers. Many times, small, ungaged watersheds are the focus of engineering projects. The desired project outcome consists of the basin's direct runoff hydrograph because the runoff hydrograph provides a peak flow rate, time of peak flow, and a volume of direct runoff. Engineers use these values to design flood protection. Engineers are always searching for more accurate ways to model small, ungaged watersheds. The current standard practice is to use a design storm in conjunction with the Natural Resources Conservation Service (NRCS) Curve Number (CN) Procedure to predict abstractions for a storm event to produce a direct runoff hydrograph for the basin (Veissman et al., 1989). The NRCS-CN procedure is simple to use to estimate abstractions, but simplicity does not always produce the most accurate solution. The major research objective is to show that infiltration equations improve confidence in the results of a surface-runoff analysis for intense short-duration stormevents. The infiltration equations used for this research are the Horton (1933), Smith (1972), and Green-Ampt(1911) infiltration equations.Item Effects of Biochar Recycling on Switchgrass Growth and Soil and Water Quality in Bioenergy Production Systems(2012-07-16) Husmoen, Derek HowardIntensive biomass production in emerging bioenergy systems could increase nonpoint-source sediment and nutrient losses and impair surface and groundwater quality. Recycling biochar, a charcoal byproduct from pyrolysis of biomass, provides potential sources of mineral nutrients and organic carbon for sustaining biomass productivity and preserving soil and water. Yet, research is needed to verify that recycling of pyrolysis biochars will enhance crop growth and soil and environmental quality similar to black carbon or biochar derived from burning of biomass in tropical or Terra Preta soils. The experimental design of this study consisted of 3 replications and four biochar rates (0, 4, 16, and 64 Mg ha-1) incorporated in both a sandy loam and clay soil with and without fertilizer sources of N, P, and K. The sandy loam and clay soils were studied in separate experiments within a set of 24 box lysimeters seeded with switchgrass. Simulated rain was applied at 50 percent and 100 percent establishment of switchgrass for each soil type. Runoff and leachate were collected and analyzed for total and dissolved N, P, K and organic C. After the second rain event, each soil type and the accumulated switchgrass was sampled and analyzed. In the Boonville soil, biochar applied at 64 Mg ha-1 decreased switchgrass emergence from 42 percent to 14 percent when compared to soil alone. In the Burleson soil, 64 Mg ha-1 biochar had no effect (P > 0.05) on biomass production or leaf area index (LAI). Fertilizer N, P, and K had no effect (P > 0.05) on switchgrass emergence for either soil, but did increase (P < 0.001) N, P, and K uptake, biomass production, and LAI. Increasing rates of biochar increased (P < 0.001) runoff concentrations of DRP during each rain event for both the Boonville and Burleson soils. Four rates of biochar receiving supplemental N, P, and K fertilizer also resulted in greater runoff concentrations of DRP. Emergence tests under increased heat showed electrical conductivities of soil-water solutions to be as high as 600 microS cm-1, even after biochar was washed with acetone and water to remove residual oils and tars and soluble salts. Increasing biochar rates decreased soil bulk density and increased pH and SOC in the 0- to 5-cm depth of soil. As a result of high nutrient recovery during pyrolysis (58 percent of total N, 86 percent of total P and 101 percent of total K), high rates of biochar applied at 64 Mg ha-1 increased mass losses of TN, TP, and TK from both soils. Yet, the mass balance of nutrients showed a surplus of N, P, and K at 64 Mg ha-1 biochar, which suggests some nutrient inputs are not plant available and remain in soil. Careful management of biochar, especially at high rates with these high nutrient contents, is critical when trying to improve soil fertility while protecting water quality. ?Item Evaluation of the conduit sizing portion of the design procedure for storm drain networks in Texas(Texas Tech University, 2004-08) Keister, Heather RaeNot availableItem Hydrology of urban playa lakes in Lubbock, Texas(Texas Tech University, 1998-08) West, Eric LaneThe Southern High Plains region of Texas and New Mexico contains more than 20,000 small, circular depressions called playa lakes or playas. These playas create a unique physiographic phenomenon where many watersheds in the region are small closed basins in which no outlet from the watershed is present (Gustavson et al., 1994). The presence of playa lakes implies that runoff from the contributing watershed is focused into the playa lake, including chemical constituents associated with the runoff. Also, the fate of the runoff has only two possibilities, evaporation or infiltration. The chemical constituents are therefore treated naturally in playa waters, bound to playa sediments, or transported to the groundwater flow system. At one time, researchers believed that evaporation, rather than infiltration, controlled the fate of water entering playas in the High Plains. This includes work done by C V. Theis (1937) and the Texas Water Development Board (1965). However, more recent investigations are revealing that not only is infiltration significant in playa lakes, it is the primary source of recharge to the groundwater (Wood and Osterkamp, 1984b; Wood and Sanford, 1994; Wood, Rainwater, and Thompson, 1997). In an urban environment, such as the city of Lubbock, the existence of playa lakes is essential to storm drainage as well as recreation (Hertel and Smith, 1994). Little information has been collected concerning the hydrology of these urban playas, some of which have altered bed sediments due to development. In addition, rising groundwater levels and runoff quality concerns are major considerations for city engineers and administrators as well as researchers. Detailed investigations of urban playas will be a valuable tool for determining the interaction of stormwater runoff and groundwater flow systems.Item Infiltration, sediment, and erosion under grass and shrub cover in the southern high plains(Texas Tech University, 1994-12) Gutierrez-Castillo, JulianOn most rangeland watersheds, water is the limiting factor to plant production. Also, water that does not infiltrate and becomes surface runoff is the primary force for erosion on those watersheds. Arid and semiarid environments in the southwestern United States and northern Mexico have significant spatial and temporal variations in hydrologic and erosion processes. Different water and soil losses can occur at zones under plants, bare ground areas, and transition zones between plants and bare ground. Type and amount of vegetation are important factors in maintaining high infiltration rates and lower interrill erosion on rangeland watersheds. Two objectives were stated for this study: (1) to estimate spatial differences of infiltration rates, sediment concentration in runoff, and interrill erosion under grass and shrub cover in the Southern High Plains, and (2) to find soil and plant characteristics that influence infiltration, sediment concentration in runoff, and interrill erosion. The research was conducted on the rangeland portion of the Texas Tech University Campus and on the Muleshoe National Wildlife Refuge, during the summers of 1992, 1993, and 1994. Treatments included clumps of blue grama {Bouteloua gracilis [H.B.K.] Lag. ex Griffiths), clumps of sideoats grama (Boutloua curtipendula [Michx.] Torr.), coppice dunes of broom, snakeweed {Gutierrezia sarothrae [Pursh.] Shirmers), transition areas of blue grama-bare gound, sideoats grama-bare ground, and broom snakeweed-bare ground, and bare ground areas. A portable simulator was used to apply a rainfall with an intensity of 16.5 cm/hr during 40 minutes over 0.15 m^ plots. Runoff was collected at each 5-min interval, measured by volume, and transformed to runoff rates. Infiltration was estimated as the difference between applied rainfall and the collected runoff. Sediment concentration in runoff was determined in each interval by taking a sample of the collected runoff. These samples were filtered to collect sediment, oven-dried, and weighed. Interrill erosion was estimated by using the sediment concentration in runoff and plot areas, and from the amount of runoff. Finally, selected plant and soil variables were estimated before and after rainfall simulation for every plot. A split-plot design with two factors (amount of canopy cover and time) and five replications were used to find difference between treatments on infiltration rates, sediment concentration in runoff, and interrill erosion. Tukey's comparison test was used to separate treatments means. Partial correlation and multiple regression analyses were used to find soil and plant variables affecting infiltration rates, sediment concentration in runoff, and interrill erosion. In general, results showed that infiltration rates were greater in coppice dunes of broom snakeweed, foUowed by clumps of blue and sideoats grama, transition areas of blue and sideoats grama, transition areas of broom snakeweed-bare ground, and bare ground. Sediment concentration in runoff had a high variability between and within treatments, sediment concentration usually reached a greatest amount within the first 10 minutes and then decreased continuously in all treatments. Interrill erosion was lower under coppice dunes of broom snakeweed, followed by clumps of blue and sideoats grama, transition areas of blue and sideoats grama-bare ground, transition areas of broom snakeweed-bare ground, and bare ground of interspaces between plants. Results of the partial correlation and regression analyses indicated that bare ground, basal cover of grasses, cryptogams cover, sand content, clay content, and organic carbon were the most influential factors affecting infiltration rates, sediment concentration in runoff, and interrill erosion in the two shortgrasses.Item Investigating Rainwater Harvesting as a Stormwater Best Management Practice and as a Function of Irrigation Water Use(2012-02-14) Shannak, Sa'D Abdel-HalimStormwater runoff has negative impacts on water resources, human health and environment. In this research the effectiveness of Rain Water Harvesting (RWH) systems is examined as a stormwater Best Management Practice (BMP). Time-based, evapotranspiration-based, and soil moisture-based irrigation scheduling methods in conjunction with RWH and a control site without RWH were simulated to determine the effect of RWH as a BMP on a single-family residence scale. The effects of each irrigation scheduling method on minimizing water runoff leaving the plots and potable water input for irrigation were compared. The scenario that reflects urban development was simulated and compared to other RWH-irrigation scheduling systems by a control treatment without a RWH component. Four soil types (sand, sandy loam, loamy sand, silty clay) and four cistern sizes (208L, 416L, 624L, 833L) were evaluated in the urban development scenario. To achieve the purpose of this study; a model was developed to simulate daily water balance for the three treatments. Irrigation volumes and water runoff were compared for four soil types and four cistern sizes. Comparisons between total volumes of water runoff were estimated by utilizing different soil types, while comparisons between total potable water used for irrigation were estimated by utilizing different irrigation scheduling methods. This research showed that both Curve Number method and Mass-Balance method resulted in the greatest volumes of water runoff predicted for Silty Clay soil and the least volumes of water runoff predicted for Sand soil. Moreover, increasing cistern sizes resulted in reducing total water runoff and potable water used for irrigation, although not at a statistically significant level. Control treatment that does not utilize a cistern had the greatest volumes of predicted supplemental water among all soil types utilized, while Soil Moisture-based treatment on average had the least volume of predicted supplemental water.Item Limnological characteristics of the Lubbock Canyon Lakes(Texas Tech University, 1978-08) Caldwell, Thomas ReidNot availableItem A Mexican case study for world water online(2012-05) Espinoza Dávalos, Gonzalo Enrique; Maidment, David R.; McKinney, Daene C.World Water Online is a global system of hydrologic data. It is an integration of geospatial and temporal information across spatial scales: global, national, regional and local. This global water information system has no parallel, and its scope would be extended with the active participation of the global water community. Its consolidation depends on the accessibility of countries’ databases through the system. In this study, a test case using Mexican data within World Water Online is created, applying the CUAHSI framework, web services and standards. The resulting Mexican-HIS unifies the water information for the nation regardless of data provider, improving storage practices and allowing additional querying and retrieving functionalities: World Water Online is a source of information and also a supplier of web-based processing services. In the second part of this study, a precipitation-runoff analysis using the data in the system is performed.Item Natural Resources Conservation Service curve number analysis for Texas(Texas Tech University, 2001-05) Atkinson, Erin L.This study was the first step in a research project for the Texas Department of Transportation (TxDOT). The overall project was to investigate whether or not climatic adjustments need to be made to the Natural Resources Conservation Service (NRCS) runoff curve number (CN) method. An important task in the project was to compare predicted curve numbers with curve numbers calculated from measured rainfall-runoff data. The primary objective of the research reported in this thesis was to develop a procedure using a geographic information system (GIS) to compute CN. The measured rainfall-runoff data for the research project was collected from historical small watershed studies conducted by the United States Geologic Survey (USGS). A secondary objective was to compare GIS-computed CN with observed CN generated from USGS data.Item Reducing turbidity of construction site runoff via coagulation with polyacrylamide and chitosan(2012-05) Rounce, David Robert; Lawler, Desmond F.; Barrett, Michael E.The U.S. Environmental Protection Agency is in the process of developing a nationwide standard for turbidity in construction site runoff. It is widely expected that this standard cannot be met with conventional erosion and sediment control measures; consequently, innovative practices for managing sediment on construction sites must be developed. The objective of this research was to develop an understanding of how soil characteristics and polymer properties affect the amount of turbidity reduction that can be achieved through flocculation. The polymers used were PAMs, a proprietary product, and chitosan. The charge density of the PAMs ranged from 0% to 50% and the molecular weights ranged from 0.2 to 14 Mg/mol. A protocol for creating modified synthetic stormwater runoff for soil samples was developed and used on soils from seven construction sites. Particle size distributions were used to compare the modified synthetic stormwater runoff with grab samples of stormwater from one site and showed the synthetic runoff was representative of the actual runoff. Flocculation tests were performed on the synthetic runoffs with PAM and chitosan doses from 0.03 to 10 mg/L. The non-ionic PAM, proprietary product, and chitosan were found to be the most effective at reducing the turbidity of all the synthetic runoff below 200 NTU. The high molecular weight anionic PAMs were effective on only two of the seven synthetic runoff samples. Hardness tests were performed indicating interparticle bridging to be the bonding mechanism of the PAM. Electrophoretic mobility tests were performed on two of the soil suspensions and indicated the bonding mechanism of PAM to be interparticle bridging, and the bonding mechanism of chitosan to be a combination of charge neutralization and interparticle bridging. Tests showed as the charge density of the PAM increased, their effectiveness decreased.Item Simulating and Optimizing Storm Water Management Strategies in an Urban Watershed(2011-02-22) Damodaram, ChandanaLand development transforms the natural landscape and impacts in stream ecosystems and downstream communities as it alters the natural flow regime. An increase in impervious areas results in higher volumes of storm water runoff, reduced time to peak, and more frequent flooding. Best Management Practices (BMP) and Low Impact development (LID) are a few of the set of measures which are used to mitigate the impact of urbanization. Peak flow, runoff volume are few of the conventional metrics which are used to evaluate the impact and performance of these storm water management strategies on the watershed. BMP are majorly used to control the flood runoff but results in the release of large volumes of runoff even after the flood wave passed the reach and LIDs are used to replicate the natural flow regime by controlling the runoff at the source. Therefore need to incorporate a metric which includes the timing and area being inundated needs to be considered to study the impact of these strategies on the downstream. My proposed research will focus on simulating the Low Impact Development (LID) techniques like permeable pavements and rainwater harvesting on an urbanized watershed using a curve number approach to quantify the hydrologic performance of these strategies on the watershed. LID, BMPs, and combined strategies are introduced for retrofitting existing conditions and their hydrologic performance is accessed based on the peak flow and a new metric Hydrologic Footprint Residence. A simulation optimization framework would be developed which identifies cost effective LID options that maximize the reduction of peak flow from the existing condition design storms while meeting budget restrictions. Further LID and BMP placement is included in the optimization model to study the impact of the combined scenario on the storm water management plans and their performance based on different storms and corresponding budget. Therefore a tradeoff can be illustrated between the implementation cost and the hydrological impact on the watershed based on the storm water management approach of using only LID and combination of LID and BMP corresponding to varied spectrum of design storm events.Item Use of compost filter bermsfor sediment trapping: primary focus on water quality and structural stability(Texas A&M University, 2004-11-15) Raut Desai, Aditya BabuRunoff from road construction and maintenance sites is responsible for erosion and deposition of sediments in the receiving water bodies. In addition to soil particles from erosion, runoff also transports other pollutants such as rubber, toxic metals, automobile fluids, car exhausts (which settle with the rain), pesticides, fertilizers, and other debris. Compost has been used effectively as a valuable soil amendment to aid plant growth. Berms (mounds) of compost placed at the top or bottom of steep slopes can be used to slow the velocity of water and provide additional protection for receiving waters. However, a downside of the application of composted organic material is the potential degradation of runoff water quality. Overloading with nitrogen and phosphorus causes eutrophication, which reduces the suitability of waterways for beneficial uses. A field testing of the berms coupled with a laboratory analysis of the testing water will provide a basis for the impact of the compost berms on the runoff water quality. The study of the impact of compost on the runoff water quality was investigated. The objective of this study was to evaluate the performance of berms made from various materials such as dairy manure compost, yard waste compost and composted bio-solids mixed with wood chips in a ratio of 50:50 on the runoff water quality, as well as, the sediment removal efficiencies. Field tests were performed on the berms to simulate conventional rainfall runoff and the tested water was collected as time-weighted samples and analyzed in the laboratory. Several variables were investigated during this study. Results of this investigation demonstrated that the effectiveness of this application was hampered by the structural instability of the berm. A 100% failure rate was observed in the berms tested. Optimum performance was observed in yard waste compost berms, which introduced the least amount of contaminants into the water. However, some masking effect could be present due to berm failures. In fact, the actual sediment removal by the berms could not be determined. The study of compost filter berms showed some evidence of the existence of first flush effect.Item Variation in flow and flow quality from a semi-arid urban watershed.(Texas Tech University, 1975-12) Gibson, Robert MarkThis study had two major objectives. The first objective consisted for the utilization of various predictive flow models to predict the total volume and peak runoff from a gaged watershed. The predictive flow models utilized were the rational method, the Viessman and Miller method, the Viessman, Keating, and Srinivasa method, and the British Road Research Method. Using three storms of varying characteristics, the total runoff volume and peak flow from the predictive models were compared to the observed total runoff and peak flow in each case. The second major objective of the study was the utilization of regression analysis to ascertain whether or not predict relations could be derived to relate individual pollutant concentrations to dry weather flow volume; and individual dry weather flow pollutant concentrations to antecedent storm characteristics. The individual pollutant concentrations utilized were COD, BOD, total solids, suspended solids, phosphates, and nitrates. The antecedent storm characteristic consisted of duration of antecedent event, amount of antecedent event, days since antecedent event, and average intensity of antecedent event.Item Variation of urban runoff quality and quantity with duration and intensity of storms.(Texas Tech University, 1974-08) Thompson, Gary BurtonNot available