Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/j.chemgeo.2015.05.023 |
Isotopic studies of the Upper and Middle Rio Grande. Part 2-Salt loads and human impacts in south New Mexico and west Texas | |
Szynkiewicz, Anna1,2; Borrok, David M.2,3; Ganjegunte, Girisha K.4; Skrzypek, Grzegorz5; Ma, Lin2; Rearick, Michael S.6; Perkins, George B.6 | |
通讯作者 | Szynkiewicz, Anna |
来源期刊 | CHEMICAL GEOLOGY
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ISSN | 0009-2541 |
EISSN | 1878-5999 |
出版年 | 2015 |
卷号 | 411页码:336-350 |
英文摘要 | Increasing groundwater and soil salinity is a threat to the land and water resources in arid regions. Global warming will likely increase salinity of dryland river systems. In order to characterize salt loading into the semi-arid portion of the Rio Grande in south New Mexico and west Texas, we sampled seasonally (2009-2011) the river, agricultural drains, and saline groundwater. In addition to major element chemistry, these samples were analyzed for sulfur and oxygen isotope compositions (delta S-34 and delta O-18) of dissolved SO4 and in some cases for nitrogen and oxygen isotope compositions (delta N-15 and delta O-18) of dissolved NO3. Uranium isotopes (U-234/U-238 activity ratio) were also measured for selected samples. The natural inflow of basinal brines/ground-water (d(34)S of + 8 to + 11 parts per thousand) in the semi-arid Rio Grande study area was minor in the investigated seasons and could not be detected by the delta S-34 mass balance. However, we did find localized increases of delta S-34 (+ 2 to + 5 parts per thousand) in the Rio Grande that were attributable to salt loads from the intersections of agricultural drains with the water table of a natural salt flat and associated evaporative brine (delta S-34 of + 12 parts per thousand) in the shallow subsurface. In the areas, with higher water use for land irrigation, the delta S-34 of the river and drain water was relatively consistent (from similar to 0 to + 2 parts per thousand) compared to the delta O-18 (from similar to+ 2 to + 6 parts per thousand). Most likely, this resulted from application of S-rich fertilizers (e.g., ammonium sulfates, elemental S, sulfuric acid) with low delta S-34 (-2 to + 4 parts per thousand) and high delta O-18 (+ 9 to + 16 parts per thousand). Additionally, we observed considerably lower delta O-18 (SO4) in the Rio Grande and agricultural drains (<7 parts per thousand) compared to geologic and anthropogenic SO4 sources (+ 9 to + 16 parts per thousand), which likely resulted from microbial recycling of SO4 in soil of the irrigated land related to assimilatory sulfate reduction. Shallow recharge to the Rio Grande was also inferred from the lower U-234/U-238 activity ratios (1.62 to 1.88) compared to deeper groundwater (2.54 to 2.64) and the distinctive delta N-15 and delta O-18 values of nitrates (+ 5 to + 25 parts per thousand and -5 to + 15 parts per thousand, respectively) typical for septic effluents that are undergoing denitrification. Agricultural practices during flood irrigation intensify evaporation of the Rio Grande surface water and considerably increase water salinity. This process is also important in the evolution of water chemistry toward a Na-SO4-Cl-rich composition and precipitation of secondary calcite in soil profiles. (C) 2015 Elsevier B.V. All rights reserved. |
英文关键词 | Salinity Arid Rio Grande Human impact Isotopes |
类型 | Article |
语种 | 英语 |
国家 | USA ; Australia |
收录类别 | SCI-E |
WOS记录号 | WOS:000360018300029 |
WOS关键词 | SEMIARID REGIONS ; PECOS RIVER ; AMERICAN SOUTHWEST ; CLIMATE-CHANGE ; FRESH-WATER ; SALINITY ; SULFATE ; SULFUR ; SOILS ; AQUIFER |
WOS类目 | Geochemistry & Geophysics |
WOS研究方向 | Geochemistry & Geophysics |
来源机构 | University of Western Australia |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/186461 |
作者单位 | 1.Univ Tennessee, Earth & Planetary Sci, Knoxville, TN 37996 USA; 2.Univ Texas El Paso, Geol Sci, El Paso, TX 79968 USA; 3.Univ Louisiana Lafayette, Sch Geosci, Lafayette, LA 70504 USA; 4.Texas A&M Univ Syst, Texas AgriLife Res Ctr, El Paso, TX USA; 5.Univ Western Australia, Sch Plant Biol, West Australian Biogeochem Ctr, Crawley, WA 6009, Australia; 6.Los Alamos Natl Lab, EES Earth Syst Observat 14, Los Alamos, NM 87545 USA |
推荐引用方式 GB/T 7714 | Szynkiewicz, Anna,Borrok, David M.,Ganjegunte, Girisha K.,et al. Isotopic studies of the Upper and Middle Rio Grande. Part 2-Salt loads and human impacts in south New Mexico and west Texas[J]. University of Western Australia,2015,411:336-350. |
APA | Szynkiewicz, Anna.,Borrok, David M..,Ganjegunte, Girisha K..,Skrzypek, Grzegorz.,Ma, Lin.,...&Perkins, George B..(2015).Isotopic studies of the Upper and Middle Rio Grande. Part 2-Salt loads and human impacts in south New Mexico and west Texas.CHEMICAL GEOLOGY,411,336-350. |
MLA | Szynkiewicz, Anna,et al."Isotopic studies of the Upper and Middle Rio Grande. Part 2-Salt loads and human impacts in south New Mexico and west Texas".CHEMICAL GEOLOGY 411(2015):336-350. |
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