scholarly journals Machine learning and hurdle models for improving regional predictions of stream water acid neutralizing capacity

2013 ◽  
Vol 49 (6) ◽  
pp. 3531-3546 ◽  
Author(s):  
Nicholas A. Povak ◽  
Paul F. Hessburg ◽  
Keith M. Reynolds ◽  
Timothy J. Sullivan ◽  
Todd C. McDonnell ◽  
...  
Keyword(s):  
Machine Learning ◽  
Stream Water ◽  
Acid Neutralizing Capacity ◽  
Hurdle Models ◽  
Neutralizing Capacity

Seasalt Effects on the Acid Neutralizing Capacity of Streamwaters in Southern Norway

1995 ◽  
Vol 26 (4-5) ◽  
pp. 369-388 ◽  
Author(s):  
Espen Lydersen ◽  
Arne Henriksen
Keyword(s):  
Stream Water ◽  
Base Cations ◽  
Acid Neutralizing Capacity ◽  
Neutral Salt ◽  
Exchange Reactions ◽  
Short Term ◽  
Sulphur Compounds ◽  
Neutralizing Capacity ◽  
Southern Norway

Input of neutral salt, primarily NaCl, from sea spray is an important factor for short-term acidification of surface water, primarily in already acidified areas, because Na may substitute for H+ and cationic aluminium by cation-exchange reactions in the soil. By evaluating the variation of non-marine sodium (Na*) separately it is possible to estimate the major effect of seasalt episodes on the neutralizing capacity (ANC) of stream water. At four long-term monitored Norwegian catchments, the Na* in stream water on average explained 28 ± 4% of the monthly variations of ANC in stream water at Birkenes, and 27 ± 3%, 20 ± 2% and 56 ± 5% of the correspondent variations at Storgama, Langtjern and Kaarvatn, during the respective monitoring periods. The remaining variations in acid neutralizing capacity are explained by the difference between non-marine base cations (ΣCa*,Mg*,K*) and non-marine sulphate (SO4*) and NO3. This paper also indicates that seasalt episodes are probably of greater importance for the periodic variations in ANC of stream water than commonly recognized. During the last years, extreme seasalt episodes have occurred in southern Norway, and more frequently at winter-time, which means that seasalt inputs have played a more important role for the short-term variations of ANC in stream water the last years. This tendency is also strengthened by the fact that there has been a significant decline in the input of acidic sulphur compounds and non-marine base cations in stream water during the last 10-15 years. Because the decline in soil-derived base cations in stream water is somewhat lower than the correspondent decline of sulphate, a slowly improving ANC of stream water should be expected on long-term basis. Seasalt episodes of the same magnitude as those present during the last years, will therefore most likely cause less extreme water-chemical conditions in the years to come. Because the seasalt effect seems to be a short-term effect, there is no reason to claim that these effects may cause long-term acidification, a conclusion earlier drawn from several correspondent studies.

The impact of beaver impoundments on the water chemistry of two Appalachian streams

2001 ◽  
Vol 58 (11) ◽  
pp. 2271-2283 ◽  
Author(s):  
Brian E Margolis ◽  
Mark S Castro ◽  
Richard L Raesly
Keyword(s):  
Water Chemistry ◽  
Major Ions ◽  
Stream Water ◽  
Acid Neutralizing Capacity ◽  
Discharge Temperature ◽  
Neutralizing Capacity ◽  
Beaver Impoundment ◽  
Appalachian Streams ◽  
The Impact ◽  
Strong Acids

We measured the impacts of beaver impoundments on the water chemistry of two headwater streams on the Appalachian Plateau, an unnamed tributary to Herrington Creek (HR), and Mountain Run (MT). We measured acid-neutralizing capacity (ANC), pH, conductivity, discharge, temperature, and the concentrations of major ions, dissolved organic carbon (DOC), and trace metals in stream water upstream and 1 m, 10 m, and 100 m downstream of the beaver impoundments and at two locations, 147 m apart, in a tributary to HR that did not contain a beaver impoundment. There were significant differences in water chemistry upstream and downstream of the beaver impoundments at both MT and HR, but these differences were generally confined to the summer. During the summer, both beaver impoundments generated ANC and increased pH by acting as sinks for NO3– and sources of NH4+, iron, and manganese. In addition, the beaver impoundment at MT was a sink for SO42– and the impoundment at HR was a source of DOC. The generation of ANC by beaver impoundments may be important to streams of this region where inputs of strong acids from atmospheric deposition are relatively high.

Changes in streamwater chemistry after 20 years from forested watersheds in New Hampshire, U.S.A.

2000 ◽  
Vol 30 (8) ◽  
pp. 1206-1213 ◽  
Author(s):  
C W Martin ◽  
C T Driscoll ◽  
T J Fahey
Keyword(s):  
New Hampshire ◽  
Forest Succession ◽  
Stream Water ◽  
Base Cations ◽  
Acid Neutralizing Capacity ◽  
N Saturation ◽  
Old Growth ◽  
Streamwater Chemistry ◽  
Old Growth Forest ◽  
Neutralizing Capacity

Long-term patterns of streamwater chemistry provide valuable evidence of the effects of environmental change on ecosystem biogeochemistry. Observations from old-growth forests may be particularly valuable, because patterns should not be influenced by forest succession. Water samples were collected biweekly from four streams in, and near, the old-growth forest watershed of the Bowl Research Natural Area in the White Mountains of New Hampshire from May 1973 through October 1974, and from June 1994 through June 1997. Average NO3– concentrations, which ranged from 40.8 to 46.1 µequiv.·L-1 in 1973-1974, declined significantly to averages of 14.9-20.1 µequiv.·L-1 during 1994-1997. Concentrations of the base cations, Ca2+ and Mg2+, also declined in stream water between the two sampling periods. The northeastern United States, including the study area, has been subjected to elevated atmospheric deposition of sulfur and nitrogen for more than 40 years. This observation has led to the concern that mature forest ecosystems may exhibit N saturation and depletion of Ca2+ from exchangeable soil pools. While the Bowl exhibits a pattern of elevated concentrations of NO3– throughout the year, suggestive of conditions of N saturation, concentrations have declined markedly over the last 20 years. Concentrations of Ca2+ have also declined suggesting possible depletion from the exchangeable soil pool, but the acid neutralizing capacity of stream water has remained constant or increased, indicating resistance to additional acidification.

scholarly journals Relationships between spruce plantation age, solute and soil chemistry in Hafren forest

1997 ◽  
Vol 1 (3) ◽  
pp. 627-637 ◽  
Author(s):  
P. A. Stevens ◽  
B. Reynolds ◽  
S. Hughes ◽  
D. A. Norris ◽  
A. L. Dickinson
Keyword(s):  
Stream Water ◽  
Acid Neutralizing Capacity ◽  
Forest Age ◽  
Forest Stands ◽  
Forested Catchments ◽  
Nitrate N ◽  
Neutralizing Capacity ◽  
Aluminium Speciation ◽  
Age Sequence ◽  
One Year

Abstract. Rain, throughfall, soil waters from surface peaty O horizon and deeper mineral B horizon, and stream water, were collected every four weeks for one year in a moorland catchment, and in four forested catchments. The four forested catchments represented an age sequence of first rotation Sitka spruce plantations, aged 14, 28, 37 and 53 years. All water samples were analysed for all major solutes, including dissolved organic nitrogen (DON-N); stream water and B horizon soil waters were also subjected to aluminium speciation. In each catchment, soil samples were collected on one occasion and pH was measured. Concentrations of most solutes were substantially higher in the 37 year old forest stand than in the moorland catchment, with intermediate concentrations in the two younger stands and 53 year old stand. In particular, higher nitrate-N concentrations were found in the soils and streams of the older forests, although these concentrations tended to be highest in the 37 year old stand. Acid neutralizing capacity (ANC) of soil waters was lower in the B horizon of the forest stands than in the moorland, and tended to decline with increasing forest age. Soil water from both O and B horizons was most acid in the 37 year old stand, and the water from the soil O horizon in all four forest stands was more acid than that in moorland sites. The pH of the soil itself (as measured in a deionised water slurry) was lower in the forest stands than in moorland, although trends with forest age were complex.

scholarly journals Long-term trends of water chemistry in mountain streams in Sweden – slow recovery from acidification

2014 ◽  
Vol 11 (1) ◽  
pp. 173-184 ◽  
Author(s):  
H. Borg ◽  
M. Sundbom
Keyword(s):  
Water Chemistry ◽  
Stream Water ◽  
Base Cations ◽  
Acid Neutralizing Capacity ◽  
Precipitation Trend ◽  
Run Off ◽  
Neutralizing Capacity ◽  
Recovery From Acidification ◽  
Long Term Trends

Abstract. The water chemistry of streams and precipitation in the province of Jämtland, northern Sweden has been monitored since the 1980s to study long-term trends, occurrence of acid episodes, and effects of liming. The acidity in precipitation increased in the 1970s, followed by a loss of acid neutralizing capacity (ANC) and low pH in the streams. Sulfur deposition began to decrease in the 1980s, until approximately 2000, after which the decrease levelled out. Stream water sulfate concentration followed the precipitation trend but decreased more slowly and since the late 1990s a subtle increase was observed. Sulfate concentrations in the snow typically have been higher than or equal to the stream sulfate levels. However, during the period of rapid deposition decrease and also since 2005 stream sulfate has sometimes exceeded snow sulfate, indicating desorption of stored soil sulfate, possibly because of climate-related changes in run-off routes through the soil profiles, following shorter periods of frost. From 1982 to 2000, total organic carbon (TOC) increased by approximately 0.1 mg L−1 yr−1. The mean trends in sulfate and TOC from approximately 1990 until today were generally opposite. Acidic episodes with pH 4.0 at flow peaks occurred frequently in the unlimed streams, despite relatively well-buffered waters at baseflow. To evaluate the main causes for the loss of ANC during episodes, the changes in major ion concentrations during high flow episodes were evaluated. The most important factors contributing to ANC loss were dilution of base cations (Na+, K+, Ca2+, Mg2+), enrichment of organic anions and enrichment of sulfate. Wetland liming started in 1985 after which the earlier observed extreme peak values of iron, manganese and aluminium, did not reoccur. The studied area is remote from emission sources in Europe, but the critical load of acidity is still exceeded. The long-term recovery observed in the unlimed streams is thus slow, and severe acidic episodes still occur.

Evaluation of Hemidesmus indicus root as an antacid by In vitro

2016 ◽  
Vol 5 (04) ◽  
pp. 4524
Author(s):  
Abdullah Shaikh Farooque ◽  
Md. Azharuddin Ismail Atar*
Keyword(s):  
Skin Diseases ◽  
Care Delivery ◽  
Health Care Delivery System ◽  
Acid Neutralizing Capacity ◽  
Standard Drug ◽  
Hemidesmus Indicus ◽  
Neutralizing Capacity ◽  
Loss Of Appetite ◽  
Powdered Drug

Medicinal plants are being widely used, either as single drug or in combination in health care delivery system. Indian Sarsaparilla, Hemidesmus indicus (Family: Asclepiadaceae) is a commonly known Indian Medicinal Plant, which is widely recognized in traditional systems of Medicine. It contains various phytoconstituents belonging to the category glycosides, flavonoids, tannins, sterols and volatile oils. It has been reported as useful in biliousness, blood diseases, dysentery, diarrhea, respiratory disorders, skin diseases, syphilis, fever, leprosy, leucoderma, leucorrhoea, itching, bronchitis, asthma, eye diseases, epileptic fits in children, kidney and urinary disorders, loss of appetite, burning sensation, dyspepsia, nutritional disorders, ulcer and rheumatism. Several studies are being carried towards its activities like analgesic, anti-inflammatory, antiulcer, hepatoprotective, antioxidant and helicobactericidal properties. In our study we have evaluated antacid activity of sariva (Anantmool) by using In-Vitro method, i.e. ANC (Acid Neutralizing Capacity). This evaluation was done by comparing the ANC of sariva macerated & powdered drug with water as blank & standard drug i.e. NaHCO3. Based on this In-Vitro experiment, we can conclude that, the macerated & powdered drug of sariva (Anantmool) evaluated in this study, varied in potency as measured in terms of their ANC. These results having ** i.e. P < 0.01 & Passed the normality test. However, the present study being in-vitro, the effects of antacid may vary In-Vitro; individual variations also contribute to the ultimate effectiveness of as antacid.        

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