Runoff and soil loss relationships for the Texas Blackland Prairies ecoregion

Harmel, R. Daren; Richardson, C. W.; King, Kevin W.; Allen, Peter M.

doi:10.1016/j.jhydrol.2006.05.033

Cited by 57 publications

(48 citation statements)

References 22 publications

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“…These highly expansive clays, which shrink and swell with changes in moisture content, have a typical particle size distribution of 17 % sand, 28 % silt, and 55 % clay. These soils are very slowly permeable when wet (saturated hydraulic conductivity ≈ 1.5 mm/h); however, preferential flow associated with soil cracks contributes to high infiltration rates when the soil is dry Allen et al 2005;Harmel et al 2006c). …”

Section: Site Descriptionmentioning

confidence: 99%

Effects of field storage method on E. coli concentrations measured in storm water runoff

Harmel

Wagner

Martin

et al. 2016

Environ Monit Assess

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Storm water runoff is increasingly assessed for fecal indicator organisms (e.g., Escherichia coli, E. coli) and its impact on contact recreation. Concurrently, use of autosamplers along with logistic, economic, technical, and personnel barriers is challenging conventional protocols for sample holding times and storage conditions in the field. A common holding time limit for E. coli is 8 h with a 10 °C storage temperature, but several research studies support longer hold time thresholds. The use of autosamplers to collect E. coli water samples has received little field research attention; thus, this study was implemented to compare refrigerated and unrefrigerated autosamplers and evaluate potential E. coli concentration differences due to field storage temperature (storms with holding times ≤24 h) and due to field storage time and temperature (storms >24 h). Data from 85 runoff events on four diverse watersheds showed that field storage times and temperatures had minor effects on mean and median E. coli concentrations. Graphs and error values did, however, indicate a weak tendency for higher concentrations in the refrigerated samplers, but it is unknown to what extent differing die-off and/or regrowth rates, heterogeneity in concentrations within samples, and laboratory analysis uncertainty contributed to the results. The minimal differences in measured E. coli concentrations cast doubt on the need for utilizing the rigid conventional protocols for field holding time and storage temperature. This is not to say that proper quality assurance and quality control is not important but to emphasize the need to consider the balance between data quality and practical constraints related to logistics, funding, travel time, and autosampler use in storm water studies.

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Section: Site Descriptionmentioning

confidence: 99%

Effects of field storage method on E. coli concentrations measured in storm water runoff

Harmel

Wagner

Martin

et al. 2016

Environ Monit Assess

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“…USDA-ARS Riesel Watersheds is a part of the Agriculture Research Service and managed by the U.S. Department of Agriculture and has been in operation since the mid-1930s (Harmel et al, 2003;Harmel et al, 2006;Harmel et al, 2007). Riesel is 29 km southeast of Waco, TX (Figure 1) for the 47-mm filters and 82 L min À1 for the 90-mm filters, with a total of 132.48 m 3 of air sampled from midnight to midnight each day.…”

Section: Sampling Sitementioning

confidence: 99%

Urban impacts on regional carbonaceous aerosols: Case study in central Texas

Barrett

Sheesley

2014

Journal of the Air & Waste Management Association

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Rural and background sites provide valuable information on the concentration and optical properties of organic, elemental, and water-soluble organic carbon (OC, EC, and WSOC), which are relevant for understanding the climate forcing potential of regional atmospheric aerosols. Implications: Background concentration and absorption measurements are essential in determining regional potential radiative forcing due to atmospheric aerosols. Back trajectory, chemical, and optical analysis of PM 2.5 was used to determine climatic and air quality implications of urban outflow to a regional receptor site, representative of the central United States. Results indicate that central Texas organic carbon has mixed urban and rural sources, while elemental carbon is controlled by the transport of urban emissions. Analysis of aerosol absorption showed black carbon as the dominant absorber, with less brown carbon absorption than regional studies in California and the southeastern United States.

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“…Especially due to the direct consequences which provoke these extreme rainstorm events which are peak discharges, and indirect consequence as soil erosion (Braken and Kirkby, 2005). Despite the increasing number of published papers on small experimental watersheds (Regüés and Gallart, 2004;Harmel et al, 2006;Sullivan and Batten, 2007), a better understanding of processes at the watershed scale with more than one land use within the Mediterranean type of climates is needed. An improvement of these processes could shed a light on the effect of agriculture on soil erosion.…”

Section: Introductionmentioning

confidence: 99%

The impact of agriculture on solute and suspended sediment load on a Mediterranean watershed after intense rainstorms

Outeiro

Úbeda

Farguell

2010

Earth Surf Processes Landf

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The solute and suspended-sediment load following fi ve rainstorms (2005)(2006)(2007) with varied intensities were studied at the Vernegà experimental watershed, north-western Spain. Two land-use areas are located within this watershed, the upstream one (forest) with 160 ha a 100% forested area, and the downstream one (agricultural) with 97 ha being 9 ha conventional agricultural fi eld and 88 ha forest. This study investigates the capacity of each land-use to yield water, suspended sediment concentration (SSC) and dissolved solid concentration (DSC). The hypothesis is that DSC and SSC from the agricultural area are greater than DSC and SSC of the forest area. Results showed that the agriculture area produced signifi cantly greater mean DSC than in the forest area, the main contribution was the Ca 2+ (24·68 ± 46·52 mg l −1 ) ion at the agricultural area. A long-term sediment production rate at the agricultural outlet was calculated (69·1 tonnes per 100 years) based on the total sediment discharge (TSD) and the recurrence interval of the largest event of the fi ve rainstorms (October 2005). Geographic information system (GIS) spatial data layers of the watershed were produced to determine the relation of tracks, landforms, slopes and forest management to SSC yield in the forest outlet (133·89 ± 308·14 mg l −1 ) during the fi ve rainstorms. Agriculture practices are the main cause of soil erosion at the study area.

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Runoff and soil loss relationships for the Texas Blackland Prairies ecoregion

Cited by 57 publications

References 22 publications

Effects of field storage method on E. coli concentrations measured in storm water runoff

Effects of field storage method on E. coli concentrations measured in storm water runoff

Urban impacts on regional carbonaceous aerosols: Case study in central Texas

The impact of agriculture on solute and suspended sediment load on a Mediterranean watershed after intense rainstorms

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