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1.
We made serial observations on acid fog at Mt. Akagi and Mt. Haruna, Japan for 5 years. The altitudes of the sampling sites were 1500 m (Mt. Akagi) and 1200 m (Mt. Haruna) above sea level, and the sites were approximately 30 km apart. The average liquid water content (LWC) at Mt. Akagi and Mt. Haruna was 74 mg m?3 and 63 mg m?3, respectively. The pH of fogwater was 2.72–7.14 (mean 3.71) at Mt. Akagi and 2.94–6.58 (mean 3.73) at Mt. Haruna. Our long-term observations indicate that there was no significant difference in the chemical components in fogwater at both sites except for ammonium ion. However, there were some cases where the chemical components of fogwater at each site were differed remarkably even in the concurrent fog event. Nitrate and sulfate ions contributed to acidification of fogwater at Mts. Akagi and Haruna and 95% of sulfate ion in the fogwater originated from air pollution. Ammonia gas in the air was the main neutralizer of acidity in fogwater. When absorption of excessive nitric acid gas over ammonia gas in the air occurred, the pH of fogwater was lowered. Our back trajectory analysis indicated that the fogwater at Mt. Akagi was mainly affected by an air mass from the Kanto Plain, including Tokyo, while the fogwater at Mt. Haruna was influenced by an air mass from large, western cities, such as Nagoya and Osaka, as well as Tokyo.  相似文献   

2.
Measurements of the chemical composition of fog water at Murododaira (altitude, 2,450 m), on the western slope of Mt. Tateyama near the coast of the Japan Sea, were performed each autumn from 2004 through 2007. Strong acidic fogs (pH?<?4) containing high concentrations of nssSO 4 2? were frequently observed in the autumn of 2005, when the air mass at Mt. Tateyama originated mainly from the polluted regions of Asia. The ratio of NO 3 ? /nssSO 4 2? in fog water was relatively high in 2004 and 2007. High concentrations of nssCa2+ derived from dust particles were detected in 2006. Background Kosa particles might have been predominant in the free troposphere and could have neutralized acidic fogs in the autumn of 2006. High concentrations of sea-salt components were also observed in October 2005. The sea-salt particles might have been transported from the Pacific Ocean by a strong typhoon, and significant Mg2+ loss was observed. Peroxides higher than 100 μM, which are seriously harmful to vegetation were sometimes detected.  相似文献   

3.
We have observed acid fog in Mt. Oyama since 1988. Fog events occur frequently in Mt. Oyama; 47% of the time the mountain top is covered with fog. The pH of fog is lower than that of rain collected at the fog sampling station by about 1 unit and the lowest pH was 1.95. We have also collected gas and aerosol components at the station and observed fog events by a video camera from the mountain base, where there is an air pollution monitoring station. The air quality at the fog sampling station was affected by not only the air quality at the base but also the wind direction, valley or mountain wind. It is ascertained by using back trajectory analyses that polluted air masses are transported to the base from the Kanto plains or other big urban areas, Osaka and Nagoya. When the base is polluted, the relative humidity increases, and the valley wind blows, acid fog is formed at the mountainside. In the acid fog, nitrate ion is the most abundant anion. Nitrate ion concentration correlates well with hydrogen ion concentration. The annual mean total ion concentration has not changed much since 1988, but the concentration ratio of nitrate ion to sulfate ion has increased in recent years. The nitric acid gas concentration in the station is comparable to that in urban areas, while other gas concentrations are much lower.  相似文献   

4.
Nitrogen emissions have grown in Spain during the last 15 years. As precipitation scavenges gases and aerosols from the atmosphere, an effect on rainwater concentrations can be expected. However, time-series studies on wet N concentrations in the Iberian Peninsula are very scarce. This paper aims to fill this gap by analysing weekly rainfall N concentrations at a set of rural sites in Catalonia (NE Spain) from 1995/1996 to 2007 and a forest site monitored from 1983 to 2007. The sites encompass a range of rural environments and climate conditions, from the inland pre-Pyrenees (Sort) to the Mediterranean coast (Begur) and from north (Sort and Begur) to central (Palautordera and La Castanya) and south Catalonia (La Senia). We found a 1-year cycle for concentrations of NH 4 + and NO 3 ? whereby higher values were reached at the end of spring–early summer, except at the easternmost coastal site of Begur. Weekly NH 4 + concentrations decreased with time at all sites (except at La Senia) whilst NO 3 ? concentrations increased at all sites during the same period. Rainfall SO 4 2? concentrations decreased with time at all sites. The opposite trends in NO 3 ? and SO 4 2? concentrations determined a shift in the relative acid contribution of those anions during the 12–13-year period. To interpret the increasing trend, mean annual NO 3 ? concentrations were regressed against NO2 Spanish emissions and to some indicators of local anthropogenic activity. The increase at Sort and Palautordera showed good correlation with local anthropogenic indicators. Wet inorganic N deposition ranged between 4.2 and 6.7 kg ha?1 year?1. When including estimates of dry deposition, total annual deposition rose up to 10–20 kg ha?1 year?1, values that have been found to initiate adverse effects on Mediterranean-type forest ecosystems.  相似文献   

5.
As acid deposition declines, recovery from acidification is delayed by the fact that the soil processes that earlier buffered against acidification are now being reversed. Monitoring of within catchment processes is thus desirable. However, soil sampling is destructive and not suitable for long-term monitoring at a single site, whereas sampling of soil water with suction lysimeters may be more suitable. In this paper we evaluate 8–11 years of soil water chemistry from E- and B-horizons in three acid forest soil plots within monitored catchments. Five years of sampling also included the C-horizon. To our knowledge, this is the first long-term lysimeter study including the E-horizon showing recovery from acidification, and one of few studies including the B-horizon. Soil water concentrations of SO4 decreased significantly between –9.5 and –1.4 μeq L-1 yr-1, with much higher rates of change at two southern sites compared to a northern site, where levels and changes of deposition were lower. The average annual bulk deposition of S ranged between 3 kg S ha-1 at the northernmost site to 11 kg S ha-1 at the southernmost site. The SO4 decline in E-horizons was smaller than the decline in deposition, which indicated leaching of SO4 from the O-horizon. At the two southern sites, a weaker decline in SO4 in the B-horizon compared to the E-horizon indicated desorption of SO4. The negative trends in SO4 were to a large extent balanced by decreases in base cations but there were also tendencies of recovery from acidification in soil solution at the southern sites by increasing pH and ANC. However, these were contradicted by increasing Al concentrations. A high influence of marine salts in the early 1990s may have delayed the recovery. Decreasing trends of the Ca/(H+)2 ratio in the soil solution, most pronounced at one of the southern sites, suggested that the soils were becoming more acidic, although the soil solution tended to recover.  相似文献   

6.
Nitrogenous air pollutants including nitrogen dioxide (NO2), nitric acid (HNO3), nitrate (NO 3 ? ), ammonia (NH3), ammonium (NH 4 + ), and nitrous acid (HONO) were characterized at an urban forested (UF) site in Hiroshima and at a suburban forested (SF) site in Fukuoka, western Japan, using an annular denuder system for 1?year from May 2006 to May 2007 to compare the concentrations and chemical species of atmospheric nitrogenous pollutants between UF and SF sites. The proximity of the urban area was reflected in higher NO2 concentrations at the UF site than at the SF site. NO2 was more oxidized at the SF site because it is farther from an urban area than the UF site, which was reflected in higher concentrations of HNO3 at the SF site than the UF site. HNO3 and acidic sulfate is neutralized by NH3, existing as ammonium nitrate (NH4NO3) and ammonium sulfate [(NH4)2SO4] at the UF site. At the SF site, acidic sulfate is neutralized by NH3, existing as (NH4)2SO4, but NH4NO3, had scarcely formed at the SF site. A much higher HONO concentration was observed at the UF site than at the SF site, especially in winter and spring at night, which could be explained by higher NO2 concentrations at the UF site because of its proximity to an urban area and stagnant meteorological conditions. Atmospheric HONO determination was critical in evaluating the possibility of damage to trees in UF areas.  相似文献   

7.
黑龙江东部山地兴安落叶松人工林对水质的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
 为了解黑龙江省东部山地落叶松人工林生态系统对水质的影响,试验用多参数水质监测仪和原子吸收法对大气降水、穿透水、树干径流和地表径流中的pH值、溶解氧、浊度、电导率、氧化还原电位、K、Na、Ca、Mg、Cu、Zn、Mn和Fe等水质指标进行测定。结果表明:在落叶松人工林生态系统中,大气降水、穿透水、树干径流和地表径流pH值的变化都不甚明显,变异系数都较低。大气降水经过林冠层后溶解氧含量降低,浊度和电导率明显增加,氧化还原电位逐渐降低,Na、Ca和Mg离子总平均浓度逐渐升高。穿透水和树干径流中K、Ca元素的淋溶量明显高于其他元素,且树干径流各元素的净淋溶和淋溶系数均高于穿透水。地表径流对水质的酸化有缓冲作用。  相似文献   

8.
The concentrations of ambient gas-phase hydrogen peroxide were measured during the summer of 1998, 1999 and 2000. The experiments were performed in the city of Wroclaw and in the vicinity of Mount Szrenica, 1362 m a.s.l., Poland. Analysis was carried out by the chemiluminescence method. Typical mean ranges of 30 min H2O2 concentrations measured were 1.4–6.0 μg m-3 at Mount Szrenica, whereas in the urban atmosphere H2O2 concentrations were in the range of 2.7–11.7 μg m-3. In the case of the urban atmosphere, H2O2 concentrations were well correlated only with solar radiation and temperature. In the mountain air, H2O2 concentrations increased along with the increase of temperature, O3, CO and the decrease of humidity. The diurnal variation was not only caused by photochemicalprocesses.  相似文献   

9.
黑龙江省东部山地樟子松人工林生态系统水化学特征   总被引:1,自引:0,他引:1  
对黑龙江省东部山地樟子松人工林(P inus sy lvestr is var.m ongolica)生态系统的大气降水、穿透水、树干径流和枯透水中的pH值、溶解氧、浊度、电导率、氧化还原电位、钾、钠、钙、镁、铜、锌、锰、铁等水质指标进行了观测,结果表明:大气降水经过林冠层后,水化学特征发生了明显变化,pH逐层降低,经过枯枝落叶层后,水质的酸化得到了缓解,说明樟子松人工林的枯枝落叶层对水质酸化有很好的缓冲作用。穿透水、树干径流和枯透水的COND变化趋势相同,且各月树干径流和枯透水的COND平均值均高于穿透水和大气降水。枯透水各月ORP的平均值明显低于大气降水和树干径流,可见樟子松人工林的枯枝落叶层对ORP值的降低有很好的作用。樟子松人工林对于增强水中微量元素F e和M n含量也有很好的作用。  相似文献   

10.
Variations in concentration and tissue distribution of mineral elements in seeds of seven quinoa cultivars from both a “natural” habitat (Patacamaya, Bolivia, 3,960 m above sea level) and a “nonnatural” habitat (Encalilla, Argentina, 1,980 m above sea level) were analyzed. Data clearly showed inter‐ and intravarietal differences in seed mineral concentrations between the two sites. Correlation analysis revealed that concentrations of major and minor dietary minerals as well as essential ultratrace elements of Encalilla seeds showed, in general, higher correlations with both seed protein and seed yield than did element concentrations of Patacamaya seeds. Results of scanning electron microscopy combined with energy dispersive X‐ray spectroscopy showed clearly differences in the contents of major mineral elements (calcium, magnesium, potassium, phosphorus, and sulfur) in the pericarp and embryonic axis (cotyledon + radicle). Obtained data could indicate that genotype × environment interactions are responsible for mineral variations occurring in quinoa cultivars. Results can also be useful for developing mineral biofortification strategies for the world's poorest regions.  相似文献   

11.
Sulfate dry deposition increases the deteriorating effects on environment. Sulfate can be deposited from atmosphere to water via both particulate (SO4 2 :sulfate)and a gas(SO 2:sulfurdioxide)form.In this research, the fluxes of gaseous(SO 2)and particulate(SO 4 2)species were measured employing a water surface sampler(WSS)and glass fiber filters(GFFs)ontheknife?edge surrogate surface(KSSs)in the campus of Uludag University and the city of Bursa, Turkey.Sampling program was conducte dinter mittently between September2004and March2005.Average to talsulfate fluxes measured with the WS Satthe Uludag University campus and in the city of Bursa were58 ± 41and235 ± 43?mgm ?2 d ?1, respectively.The to talsulfate fluxe smeasure dat Bursa were highe rand this was probably due to greater sulfur containing species in it satmosphere.The dry deposition of gas eous SO 2 flux was calculated by sub tracting the particulate flux collected with the KSS s from the total flux(particulate sulfate plus SO 2 flux)obtained by the WSS.Anautomatic SO 2 analyzer was used concurrently to measure the ambient concentration of gas eous SO 2. The average SO2 gas fluxes and ambient SO 2 concentrations were18 ± 28and54 ± 48?mgm ?2 day ?1 and11 ± 7and49 ± 14?μgm ?3 for the campus and the city, respectively.The measured gaseous SO 2 fluxes and ambient concentrations were used to calculate the mass transfer coefficient.The calculated MTC values for the campus and the city were0.8 ± 1.0and1.2 ± 1.1?cms ?1, respectively.The sevalues wereinag reement with previously reported dry deposition velocities for SO 2.  相似文献   

12.
Fog chemistry was studied for four years (April 1997–March 2001) at Mt. Rokko (altitude 931 m) in Kobe, Japan. A collection of samples was obtained at a mountainous site close to a highly industrialized area. The samples were collected by an active string-fog collector. The summer fog was dense and frequent. The geography of Mt. Rokko is linked to the seasonality of the occurrence and the thickness of the fog. Among the meteorological parameters, the relative humidity was important for the occurrence of fog. The correlation of the concentrations of the components in fog water indicated that (NH4)2SO4 and/or NH4HSO4 were involved in the process of the formation of fog drops in the atmosphere. The concentration of the components decreased with an increase in the liquid water content (LWC) of the fog, and the seasonal variation of the concentration of some components depended on the seasonal variation of the LWC. The equivalent ratio of NO3 ? to non-sea salt (nss?) SO4 2? was considerably larger than that in precipitation. Ammonium ion accounted for the largest percentage of cations, which indicates that NH4 + was an important counter cation for NO3 ? and nss-SO4 2?. A unique fog event in which the air pollutants seemed to be scavenged stoichiometrically was sometimes observed. The methodology used for collecting fog water at 60 mL intervals provided detailed information.  相似文献   

13.
三峡山地不同坡位土壤的水分特征曲线及水力学性质   总被引:2,自引:2,他引:2  
山地不同坡位的土壤水力学性质研究可为地表水文过程预测和坡地生态修复提供参考.通过采集三峡库区大老岭林区山地不同坡位的原状土样,测定饱和导水率、当量孔径、水分库容等水力学参数,利用V-G模型拟合土壤水分特征曲线,评价不同坡位土壤的渗透性能和持水能力.结果表明:坡顶土壤的入渗性能最好,平均饱和导水率为108.54 cm/d...  相似文献   

14.
Rainfall, stemflow, and throughfall were collected from 1996 to 1999 at two types of forest sites: (1) forests near the traffic roads and urban areas and (2) forests away from the urban areas at Mt. Gokurakuji, Hiroshima, western Japan in order to estimatethe effects of anthropogenic activities on atmospheric deposition. Rainfall deposition for major ions showed small differences between the sites. The NO3 - and SO4 2-concentrations in stemflow were higher at the urban-facing slope than at the mountain-facing slope. Throughfall deposition of NO3 - and SO4 2- was also higher at urban-facing slopes. Net throughfall (NTF) deposition (throughfall minus rainfall) of NO3 - and SO4 2- accounted for 77 and50% of the total throughfall deposition on urban-facing slopes, respectively, while it accounted for 44 and 23% on themountain-facing slopes, respectively. These results indicated a higher contribution from dry deposition on urban-facing slopes compared to mountain-facing slopes. Atmospheric N (NO3 - +NH4 +) deposition from throughfall was estimated to be around 17–26 kg N ha-1 yr-1 on urban-facing slopes, which was greater than the threshold of N deposition that could cause nitrogen leaching in Europe and the United States. The highload of atmospheric N deposition may be one of the factors bringing about the decline of pine forests on urban-facing slopesof Mt. Gokurakuji.  相似文献   

15.
Gillett  R. W.  Ayers  G. P.  Selleck  P. W.  Tuti  MHW  Harjanto  H. 《Water, air, and soil pollution》2000,120(3-4):205-215
Gas mixing ratios of SO2, NO2 and HNO3 and nitrate and sulfate concentrations in rainwater have beenmeasured at six sites in Indonesia. The sites, Jakarta, Serang,Cilegon, Merak and Bogor, in Java, and Bukit Koto Tabang inSumatra, provide a range of pollution regimes in Indonesia.Jakarta and Bogor are heavily polluted sites in Java, whereasBukit Koto Tabang is a clean air station in a relativelyunpopulated area on the west coast of equatorial Sumatra. At thesesites rainwater was collected daily and gas samples weeklyduring 1996. The other three sites Serang, Cilegon and Merakrepresent smaller regional towns in west Java. At these sitesrainwater samples were collected weekly from June 1991 untilJune 1992.The results show that Jakarta has the highest volume-weightedmean sulfate concentrations in rainwater while the lowest weremeasured at Bukit Koto Tabang. Volume-weighted mean nitrateconcentration was about 24 μeq L-1 at Jakarta and Bogor,significantly higher than the 0.8 μeq L-1 measured atBukit Koto Tabang.Sulfur dioxide mixing ratios ranged from 4–7 ppbv in Jakarta toan average of 1.3 ppbv at Bukit Koto Tabang. Nitrogen dioxidemixing ratio was highest in Jakarta averaging 28 ppbv comparedwith the background mixing ratio of 1.2 ppbv at Bukit KotoTabang. Using dry deposition velocities estimated during aseparate study in the similar conditions of Malaysia enabled drydeposition estimates of SO2, HNO3 and NO2.Results of estimated total acidic S and N deposition (wet anddry) were greater than 250 meq m-2 yr-1 at the Jakartaand Bogor sites compared with about 23 meq m-2 yr-1 atBukit Koto Tabang. At Jakarta and Bogor dry deposition accountedfor more than 50% of the total deposition estimates compared with about 20% at Bukit Koto Tabang. Such deposition rates arehigh when compared to critical loads estimated for Indonesia bythe RAINS-Asia model. In this model, critical loads in western Java and equatorial western Sumatra fall into one of twoclasses: 50–100 and 20–50 meq m-2 yr-1. Thus acidic deposition flux at Jakarta and Bogor wasfound to be above the predicted critical loads even for the moreacid insensitive soils.  相似文献   

16.
Temporal trends in sulfate, base cation (Ca2+ + Mg2+ + K+), and H+ ion concentrations in bulk precipitation and throughfall samples collected over a seven year period (1989-95) in four forested catchments in Finland are presented. The catchments are in remote locations and span the boreal zone (61-69 °N). The stands represent old, undisturbed forests, and are composed of varying proportions of Scots pine, Norway spruce and deciduous species (mainly Betula spp.). Monthly SO4 2- and H+ ion concentrations in bulk precipitation averaged over the study period and catchments were: 18.7 µmol L-1 and 32.3 µmol L-1. The corresponding values for throughfall were: 37.4 µmol L-1 and 32.4 µmol L-1. Sulfate and H+ ion concentrations in bulk precipitation and throughfall both showed negative linear trends, which were significant (p < 0.05) for the three southernmost catchments. Concentrations and trend slope decreased northwards (e.g., bulk precipitation SO4 2- slope estimates: -1.6 to -1.0 µmol L-1 yr-1). The decline was greater for throughfall than for bulk precipitation, indicating a proportionally greater reduction in dry deposition than wet. The sum of base cation concentrations averaged 12.1 µmol(+) L-1 in bulk precipitation and 83.1 µmol(+) L-1 in throughfall. There were no significant trends in the sum of base cations (p > 0.05). It is concluded that the reported reduction in S emissions over the study period has resulted in a significant reduction in the acidity and SO4 2- concentration of bulk precipitation, and this reduction has has been reflected in throughfall concentrations. The greatest reduction has taken place in the southern part of the country.  相似文献   

17.
[目的]研究北京山区林地凝结水的发生情况及分布特征,为该地区的水资源合理利用提供科学依据。[方法]利用首都圈森林生态定位站的大型称重式蒸渗仪对北京山区4种林地的凝结水进行2a连续观测,同时监测林地各项气象因子,分析不同林地凝结水的分布特征以及影响因子。[结果](1)北京山区非生长季凝结水出现天数和凝结水量较生长季多,非生长季月平均凝结水量约4.5mm,生长季月平均凝结水量约1.6mm;(2)4种林分年凝结水量大小关系表现为草地(38mm)栓皮栎(36mm)油松(30mm)侧柏(25mm),与年凝结水出现天数大小关系相同,灌草丛是产生凝结水的主要场所,阔叶林产生的凝结水远高于针叶林;(3)空气温度和相对湿度对凝结水的产生起到决定性作用。[结论]北京山区林地凝结水在时间上分布不均,受环境因子和植被因子的综合影响。  相似文献   

18.
Acid deposition in eastern Asia will increase and freshwaters in Japan are likely to become acidified in future. In order to make long-term predictions about freshwater acidification, it is necessary to evaluate acid neutralization mechanisms in Japanese watersheds. Ikeda and Miyanaga (1999) earlier proposed a method of separating acid-neutralization capacity into chemical weathering and cation exchange. By this means, we were able to assess the effect of hydrogeochemical properties on chemical weathering and stream water chemistry for three watersheds in Japan. On the basis of this assessment, acid-neutralization stream water chemistry was predicted using the ILWAS (Integrated Lake-Watershed Acidification Study) model. The main factors determining acidification are the thickness of weatherd profile and chemical weathering rates. The principal results are: (1) for non-acidified watersheds in Japan, acid deposition is neutralized by chemical weathering of primary minerals; (2) freshwaters in Japanese watersheds will not acidify even if acid deposition increases to the extent found in an acidified watershed in the U.S.A.  相似文献   

19.
辽宁东部山区几种主要森林植被类型水量平衡研究   总被引:13,自引:0,他引:13  
采用固定标准地观测方法 ,在对辽宁东部山区 5种主要森林类型降雨分配、植被层的蒸腾耗水及林地土壤蒸发的实际观测及对某些平衡因子 (如径流量 )通过简化水量平衡方程余项法推求基础上 ,建立森林水量平衡关系。研究表明 ,各林分类型生长季总蒸散量为 4 76 .6~ 6 5 1.3mm,以林冠的蒸发散为主 ,占同期总蒸散量的 73.5 %~ 88.6 % ,林冠下林地蒸发散为 6 9.3~ 12 6 .5 mm,占总蒸发散的 11.4 %~ 2 6 .5 % ;林地不易发生地表径流 ,生长季地下径流深 76 .6~ 2 6 3.9mm ,占同期降雨量的 10 .3%~ 35 .5 %。各林型间水量平衡分量有很大差异 ,针叶林总蒸散量明显高于阔叶林  相似文献   

20.
为了更好地推进北川羌族自治县的水土保持工作,本文总结了"长治"工程实施15年来的建设成效:不仅在水土保持生态建设、水土流失防治方面取得了丰硕的成果,而且也促进了治理县的脱贫致富和新农村的建设。同时还总结出实用的经验:强化领导、加强协调;实行体制创新、机制创新和科技创新;加强对治理成果的后续管理;加大宣传和预防监督力度;增强全民的保水观念。同时指出工作中存在的不足:小流域治理粗放、水土流失防治工作创新能力不足以及尚未全面展开水土保持的监测工作。最后对今后的工作提出了设想:调整工作思路以服务新农村建设;不断深化小流域的治理工作;强化水土保持的防治监督;注重生态修复工作。  相似文献   

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