排序方式: 共有17条查询结果,搜索用时 15 毫秒
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Jon E. Schoonover Karl W. J. Williard James J. Zaczek Jean C. Mangun Andrew D. Carver 《Water, air, and soil pollution》2006,169(1-4):303-315
The sediment filtering capabilities of giant cane (Arundinaria gigantea (Walt.) Chapm.) and forest riparian buffers were compared in a southern Illinois, USA non tile drained agricultural watershed. Giant cane, a bamboo species, serves as important wildlife habitat throughout its native range in the southeastern and lower midwestern United States. Overland flow samples were collected at the field edge and at 3.3 m, 6.6 m, and 10.0 m within the riparian buffers during 19 precipitation events over a 1-year period. On an annual basis, significant sediment reductions occurred by 3.3 m and 6.6 m in the cane and forest buffers, respectively. The giant cane buffer reduced incoming sediment mass by 94% within the first 3.3 m, while the forest buffer reduced sediment by 86% over 6.6 m. Within 10.0 m of the field edge, the cane and forest buffers reduced sediment mass by 100% and 76%, respectively. On a seasonal basis, the cane buffer outperformed the forest buffer. During each of the four seasons, the cane buffer reduced sediment masses within 3.3 m of the field edge, while the forest buffer showed initial reductions occurring at 6.6 m during the summer, fall, and winter. No detectable reductions occurred during the spring in the forested buffer. Reductions in sediment concentrations were less evident compared to mass basis, indicating that infiltration may be a more important sediment reduction mechanism than particle settling. Both the forest and giant cane buffers had relatively high measured soil infiltration rates. Study results indicate that giant cane is an appropriate species to include in riparian buffer restoration designs for sediment control. 相似文献
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R. C. Pankau J. E. Schoonover K. W. J. Williard P. J. Edwards 《Agroforestry Systems》2012,84(2):191-205
Riparian buffers in agricultural landscapes should be designed to trap pollutants in overland flow by slowing, filtering,
and infiltrating surface runoff entering the buffer via sheet flow. However, observational evidence suggests that concentrated
flow is prevalent from agricultural fields. Over time sediment can accumulate in riparian buffers forming berms that restrict
sheet flow; these berms ultimately back up surface runoff, resulting in an eventual breakthrough that concentrates overland
flow. This study examines the occurrence of concentrated flow paths (CFPs) in riparian buffers at both the field and watershed
scale. At the field scale, intensive topographic surveys were conducted at ten field sites in southern Illinois. To assess
the prevalence of CFPs at the watershed scale, three watersheds in southern Illinois were selected for walking stream surveys
along randomly selected 1,000 m reaches. CFPs were identified in all topographic surveys and all walking stream surveys. Among
field sites, concentrated flow accounted for 82.5–100% of the drainage leaving the agricultural fields. Sediment berm accumulation
was identified at all field sites and was positively correlated with CFP size. At the watershed scale, CFPs were more abundant
in agricultural areas compared to forested land. Results from this study indicate that concentrated flow was prevalent across
all study sites at both the field and watershed scale. Thus, surface water quality may suffer in areas with poorly functioning
buffers, and managers must consider the occurrence of CFPs when designing and maintaining riparian buffers to protect stream
water quality. 相似文献
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Prabisha Shrestha Karl W. J. Williard Jon E. Schoonover Logan Park 《Water, air, and soil pollution》2018,229(6):198
Literature on prevalence of concentrated flow paths (CPFs) in agricultural fields are limited at field scale with only few studies that address occurrence of CFPs at large geographic extent. This study used high-resolution Light Detection and Ranging (LiDAR) data to identify CFPs in agricultural fields and calculate the percentage of the fields drained by CFPs at a county scale. In 389 agricultural fields across Jackson County, southern Illinois, this study also investigated the association between field characteristics and CFP formation using multiple regression and CART analysis. The mean number of CFPs in a field was 5 with a minimum of 0 and maximum of 17 CFPs. The majority of the CFPs fell under the large category for CFP length and drainage area that corresponds with high mean percent (81%) of field area drained by the CFPs. Further, 85% of the fields had more than 70% of their area drained by CFPs. The multiple regression and CART analysis showed slope as an important factor influencing CFP characteristics such as number of CFPs and CFP length. Both analyses also indicated physical soil properties such as bulk density, soil erodibility factor, saturated hydraulic conductivity, LS factor, organic matter, and percent sand were also predictors of the CFP characteristics. However, these factors explained only 2 to 12% of the variation observed. The significant presence of CFP’s has important implications for water quality since current conservation practices such as riparian buffers were not designed to address concentrated flow from agricultural fields. 相似文献
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Response to Letter to the Editor: Do we have to redefine lameness in the era of quantitative gait analysis 下载免费PDF全文
S. Adair M. Baus J. Belknap R. Bell M. Boero C. Bussy F. Cardenas T. Casey J. Castro W. Davis M. Erskine R. Farr T. Fischer B. Forbes T. Ford R. Genovese R. Gottschalk M. Hoge C. Honnas G. Hunter J. Joyce A. Kaneps K. Keegan J. Kramer C. Lischer J. Marshall M. Oosterlinck P. Radue R. Redding S. K. Reed M. Rick E. Santschi M. Schoonover M. Schramme John Schumacher R. Stephenson R. Thaler J. Vedding Neilsen D. A. Wilson 《Equine veterinary journal》2018,50(3):415-417
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OBJECTIVE: To quantitatively compare 3 commonly used treatments for navicular syndrome (NS) in horses: heel-elevation shoeing alone, heel-elevation shoeing and phenylbutazone administration, heel-elevation shoeing and injection of the distal interphalangeal joint (DIPJ) with triamcinolone acetonide (TA), and all 3 treatments in combination. ANIMALS: 12 horses with NS. PROCEDURE: A force plate was used to measure baseline peak vertical ground reaction force (PVGRF) of the forelimbs. Each horse's forelimbs were shod with 3 degrees heel-elevation horseshoes; PVGRF was measured 24 hours and 14 days after shoeing. Fourteen days after shoeing (following data collection), phenylbutazone (4.4 mg/kg, i.v., q 12 h) was administered (5 treatments). Two hours after the fifth treatment, PVGRF was measured; TA (6 mg) was injected into the DIPJ of the forelimb that generated the lower baseline PVGRF Fourteen days later, PVGRF was measured. Phenylbutazone was administered as before, and PVGRF was measured. Percentage body weight of force (%BWF) was calculated from PVGRF measurements and used for comparisons. RESULTS: 14 days after shoeing, mean %BWF in both forelimbs significantly increased from baseline; additional administration of phenylbutazone significantly increased %BWF applied from the more lame forelimb. Compared with shoeing alone, there was no significant change in %BWF after injection of the DIPJ with TA in shod horses. CONCLUSIONS AND CLINICAL RELEVANCE: Heel-elevation shoeing alone and in combination with phenylbutazone administration quantitatively decreased lameness in horses with NS. Although not significant, additional DIPJ injection with TA resulted in further quantitative decrease in lameness, compared with that achieved via shoeing alone. 相似文献
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Miller Julia D. Schoonover Jon E. Williard Karl W. J. Hwang Charnsmorn R. 《Water, air, and soil pollution》2011,222(1-4):337-349
Water, Air, &; Soil Pollution - Agricultural runoff is a major non-point source pollutant and is the leading impairment of streams and rivers in the USA. This study examined the effects of... 相似文献
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Effects of tourniquet number and exsanguination on amikacin concentrations in the radiocarpal and distal interphalangeal joints after low volume intravenous regional limb perfusion in horses 下载免费PDF全文