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Chiwa, Masaaki; Kim, Do Hoon; Sakugawa, Hiroshi

doi:10.1023/a:1023946603217

Cited by 41 publications

(2 citation statements)

References 41 publications

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“…[25] Annual N deposition via throughfall plus stemflow deposition was higher than via bulk precipitation (Table 2). A positive value of NTF is considered to result from rainfall washing off dry nitrogenous pollutant deposits in the forest canopy [Parker, 1990;Fenn and Kiefer, 1999;Chiwa et al, 2003]. Net throughfall (NTF; TF + SF − BP) N deposition accounted for approximately 30% of TF + SF deposition based on a 4 year average, indicating dry N deposition in an important source of atmospheric deposition as well as wet deposition at the OEW.…”

Section: Bulk Precipitation Throughfall and Stemflowmentioning

confidence: 99%

Role of stormflow in reducing N retention in a suburban forested watershed, western Japan

et al. 2010

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[1] To evaluate the role of stormflow in reducing N retention in forested watersheds, we investigated the inorganic N budget of a Japanese suburban forested watershed for 4 years where the proportion of direct flow to precipitation is considerably high (mean is 33%; range is 25-42%). Soil net N mineralization and net nitrification were also measured at middle and lower positions of a slope within the watershed to evaluate nitrate (NO 3 − ) pool size. Annual mean N deposition via throughfall plus stemflow was 15.5 kg N ha −1 yr −1 (13.6-17.1 kg N ha −1 yr −1 ), which exceeded the threshold value to potentially induce N leaching from forested watersheds. Net nitrification at the middle position was comparable with the lower position. This suggests that the NO 3 − rich area is large, which could be partly caused by comparable soil moisture conditions with the lower position due to rising groundwater levels during storm events. Annual mean N export was 10.4 kg N ha −1 yr −1 (7.8-12.5 kg N ha −1 yr −1 ), and subsequent N retention was distinctly low 33% (12-53%). Stormflow accounted for more than 80% of total annual N export. Furthermore, N retention was lower (12 and 27%) in years with higher proportions of direct flow than in years with lower proportions (36 and 53%). Therefore, stormflow is a significant factor in reducing N retention in forested watersheds. The effect of stormflow observation on the comparison of N budgets in other watersheds with different climate and/or hydrologic conditions is discussed.Citation: Chiwa, M., R. Maruno, J. Ide, T. Miyano, N. Higashi, and K. Otsuki (2010), Role of stormflow in reducing N retention in a suburban forested watershed, western Japan,

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Section: Bulk Precipitation Throughfall and Stemflowmentioning

confidence: 99%

Role of stormflow in reducing N retention in a suburban forested watershed, western Japan

et al. 2010

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“…Urban areas might be the sources of numerous pollutants, including aliphatic and aromatic hydrocarbons, polycyclic aromatic hydrocarbons, fatty acids, and heavy metals. Composition of runoff and throughfall from forested areas is affected mostly by physiological processes occurring in plants and the dissolution of atmospheric pollutants deposited or absorbed by leaves, branches, and bark of trees (Lovett et al 2000;Balestrini et al 1998;Forti and Moreira-Nordemann 1991;Masaaki et al 2003;Hansen et al 1994;Houle et al 1999;Avila and Rodrigo 2004;Rodrigo et al 2003;Inagaki et al 1995;Bini and Bresolin 1998;Prakasa Rao et al 1995).…”

Section: Analytementioning

confidence: 99%

Determination of atmospheric pollutants in wet deposition

2011

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Water is transferred from the atmosphere to the land surface mainly via various forms of atmospheric precipitation, but the contribution of surface condensation and direct deposition (e.g., dew, hoar frost, occult precipitation, etc.) should not be neglected. Wet deposition (including surface condensation and direct deposition) scavenges pollutants from the atmosphere and contributes significantly to their transport. The composition of the runoff formed on contact with various surfaces might be further modified by the components of dry deposition collected on these surfaces or by substances leaching from the surfaces themselves. Samples of wet precipitation or direct deposition might be good indicators of the state of the atmospheric environment and can be used to trace the migration of chemicals emitted from various sources, including anthropogenic ones. This paper discusses the unique challenges present at every stage of the analytical procedures used for the determination of the pollutants in atmospheric precipitation and deposition. A brief review of the results of pollutant and toxicity determination in samples of various forms of atmospheric precipitation and (or) deposition is also included, together with a discussion of the application of chemometric techniques for data interpretation. The aim of this paper is to help interested readers discover the field of pollutant determination in wet deposition and to broaden the scope of their existing research.Résumé : Le transfert de l'eau de l'atmosphère à la surface terrestre s'effectue surtout via diverses formes de précipitations atmosphériques, mais on ne doit pas négliger la contribution de la condensation ou déposition en surface (rosée, frima, pré-cipitations occultes, etc.). La déposition humide (incluant la condensation de surface et la déposition directe) ramasse les polluants de l'atmosphère et contribue significativement à leur transport. La composition de l'écoulement formé au contact avec diverses surfaces peut être encore modifiée par des composantes de dépôts secs accumulées sur ces surfaces ou par des substances lessivées à partir des surfaces elles-mêmes. Les échantillons de dépôts directs ou précipitations humides peuvent constituer de bons indicateurs de l'état de l'environnement atmosphérique et peuvent être utilisés suivre la migration des substances chimiques émises à partir de diverses sources, incluant celles d'origine anthropique. On discute les défis uniques rencontrés aux différentes étapes des procédés analytiques utilisés pour déterminer les polluants des dépôts et des précipita-tions atmosphériques. On inclut également une brève revue des résultats de la détermination des polluants et de leur toxicité dans des échantillons de diverses formes de précipitation ou déposition, ainsi qu'une discussion de l'application des techniques chémométrique pour l'interprétation des données. Le but de cette revue vise à aider les lecteurs intéressés à prendre connaissance du champ de la détermination des polluants dans les dépositions humides et d'...

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Effects of storm flow samplings on the evaluation of inorganic nitrogen and sulfate budgets in a small forested watershed

Chiwa

Ide

Maruno

et al. 2009

Hydrological Processes

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Abstract:To investigate the effects of storm flow samplings on the evaluation of DIN and SO 4 2 budgets, we conducted storm flow samplings and discrete interval (weekly) samplings of stream water, throughfall, and stemflow. This investigation lasted for three years and took place in a small forested watershed in western Japan. Annual exports were calculated by the sum of the load (L total )-sum of the discharge (Q total ) relationships obtained by storm flow samplings. These were then compared to calculated ones that were based on LQ relationships obtained by discrete interval sampling. The results of discrete interval sampling showed that the relationships of DIN or SO 4 2 concentration to the discharge amount found in stream water differed from those of storm flow sampling. This was especially notable in years with higher annual precipitation and subsequent higher annual discharges. Also, exports of DIN and SO 4 2 during storm flow periods accounted for 83% and 78% of annual exports on 3-year averages, respectively. These results confirmed that storm flow samplings are essential for estimating annual exports of DIN and SO 4 2 . Annual exports that were calculated based on just discrete interval sampling (46% and 17%, respectively) overestimated DIN and SO 4 2 from discrete interval and storm flow samplings on a 3-year average. These overestimates were pronounced in years of higher discharge, and critically affected the rates of net-retention or export of DIN and SO 4 2 . The relationship of smaller input than output of DIN was reversed if storm flow sampling was included.

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Cited by 41 publications

References 41 publications

Role of stormflow in reducing N retention in a suburban forested watershed, western Japan

Role of stormflow in reducing N retention in a suburban forested watershed, western Japan

Determination of atmospheric pollutants in wet deposition

Effects of storm flow samplings on the evaluation of inorganic nitrogen and sulfate budgets in a small forested watershed

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