Groundwater geochemistry in the Alisadr, Hamadan, western Iran

The chemical composition of 59 well water samples throughout the Alisadr area, Hamadan, western Iran was determined in order to describe the background ion concentration and to identify the major hydrogeochemical processes that control the observed groundwater chemistry. The hydrochemical types, Ca–HCO₃, Ca–SO₄, dominate the largest part of the groundwater followed by water types Ca–Cl and Mg–HCO₃. Total hardness indicated that 30% of groundwater samples fell in the very hard water category. Ninety-seven percent of the water samples showed nitrate ( ${\rm NO}_{3}^{-})$ concentrations above the human affected value (13 mg l^???1 ${\rm NO}_{3}^{-})$ , while 15% exceeded the maximum acceptable level (50 mg l^???1 ${\rm NO}_{3}^{-})$ according to WHO regulations. With respect to sodium adsorption ratio, the groundwater can be used for irrigation on almost all soils with little danger of the developing harmful levels of exchangeable Na^?+?. But with respect to electrical conductivity, the water quality for irrigation was low to medium, providing the necessary drainage to avoid the buildup of toxic salt concentrations. Geochemical modeling using PHREEQC enabled prediction of the saturation state of minerals and indicated the dissolution and precipitation reactions occurring in the groundwater. Groundwaters were undersaturated with respect to amorphous silica. Stability diagram indicated that the dominant cluster of groundwater samples fell into the K-feldspar field.     

Study of trace elements in wet atmospheric precipitation in Tehran,Iran

In this study, measurements of the trace metals Zn, Cd, Cr, Ni, Pb, Cu, Fe and Al were performed on 53 wet atmospheric precipitation samples (snow and rainwater) collected at a central site of Tehran. Samples were collected using a bulk sampler equipped with a high-density polyethylene funnel from November to May in 2011 and 2012 on the roof of a building in the city centre. Trace metals in the filtered samples were measured with ICP-MS. Statistical analysis of the results revealed that Al, which is principally a crustal-derived element, was the highest mean measured concentration. The pH ranged from 4.2 to 7.1 with a mean value of 5.1. Crustal enrichment factors (EF_c) related to the relative abundance of elements in crustal material was calculated using Al as reference crustal. EF_c calculations indicated that samples were not enriched with Fe and Cr but were, fairly to extremely, enriched with Zn, Cd, Ni, Pb and Cu. Factor component analysis with varimax-normalized rotation was conducted to find the probable sources of the measured species. This resulted in two factors with eigenvalues greater than unity. Factor 1 showed an anthropogenic source, mostly industrial combustion and local traffic emissions, for Zn, Cd, Ni, Pb, and Cu while factor 2 showed a crustal contribution for Al, Fe and Cr.     

Land use effects on phosphorus sequestration in soil aggregates in western Iran

Cultivating native lands may alter soil phosphorus (P) distribution and availability. The present study aimed to determine the distribution of P in soil aggregates for different long-term land management practices. The partitioned P in labile (L), Fe/Al-bound, Ca-bound, organic pools, and total P in four aggregate size fractions were determined for five land uses (forest, vineyard after 30 years, wetland, alfalfa, and wheat cultivated soil after 20 years). Both native land uses (forest and wetland) were distinguished by high and low amounts of large macro- and micro-aggregates, respectively, compared with disturbed soils (vineyard, alfalfa, and wheat soils). Labile P in large macro-aggregates were higher in native land use when compared with the other land uses, which led to increasing lability of P and accelerated water pollution. Soils under native conditions sequestered more Ca-bound P in large macro-aggregates than the soils in disturbed conditions. Conversion of native lands to agricultural land caused enhanced organic P storage in aggregates smaller than the 2 mm from 31.0 to 54.3 %. Soils under forest had 30 % total P more than the vineyard for the aggregates >2 mm after 30 years land use change. However, the amount of P in smaller (<2 mm) sized aggregates was increased by 29 % for the vineyard when compared with the forest. The P storage as bound Ca particles for the large macro-aggregates had negative correlation with the micro-aggregates.     

Fluoride pollution of atmospheric precipitation and its relationship with air circulation and weather patterns (Wielkopolski National Park, Poland)

A 2-year study (2010–2011) of fluorides in atmospheric precipitation in the open area and in throughfall in Wielkopolski National Park (west-central Poland) showed their high concentrations, reaching a maximum value of 2 mg/l under the tree crowns. These high values indicate substantial deposition of up to 52 mg/m²/year. In 2011, over 51 % of open area precipitation was characterized by fluoride concentration higher than 0.10 mg/l, and in throughfall such concentrations were found in more than 86 % of events. In 2010, a strong connection was evident between fluoride and acid-forming ions, and in 2011, a correlation between phosphate and nitrite ions was seen. Analysis of available data on F^? concentrations in the air did not show an unequivocal effect on F^? concentrations in precipitation. To find reasons for and source areas of high fluoride pollution, the cases of extreme fluoride concentration in rainwater were related to atmospheric circulation and weather patterns. Weather conditions on days of extreme pollution were determined by movement of weather fronts over western Poland, or by small cyclonic centers with meteorological fronts. Macroscale air advection over the sampling site originated in the western quadrant (NW, W, and SW), particularly in the middle layers of the troposphere (2,500–5,000 m a.s.l.). Such directions indicate western Poland and Germany as possible sources of the pollution. At the same time in the lower troposphere, air inflow was frequently from the north, showing short distance transport from local emitters, and from the agglomeration of Poznań.     

Characterization of atmospheric dust at Gurushikar,Mt. Abu,Rajasthan

The nature of atmospheric aerosols at Gurushikar, Mt. Abu, Rajasthan where a gamma ray telescope is to be installed, was investigated. Air particulate samples collected on filters were used to estimate the total suspended particulate matter (TSPM) and its elemental composition. The TSPM varied from 31 to 103 g/m³ during January to March 1994. The heighest loads were observed during the months of May and June (80–100 g/m³) and lowest during October (20–60 g/m³). The dust was also examined for size, shape and nature of the mineral matter. The particle sizes varied from 100 m to 5 m. The course particles (>50 m) are irregular shaped quartz grains. Some of the medium size (=50 m) particles were spherical and were highly conducting. These particles were rich in iron content. Correlation coefficients among various elements in the dust showed that it is made up of mainly two components-wind blown ground dust and particulate arising out of wood and coal burning.     

Leaching of nitrogen from calcareous soils in western Iran: a soil leaching column study

Nitrogen (N) leaching has become a matter of worldwide concern. The objectives of this study were: (1) to use soil columns to investigate the leaching of nitrate ( $ {\text{NO}}_3^{ - } $ ), ammonium ( $ {\text{NH}}_4^{ + } $ ), and nitrite ( $ {\text{NO}}_2^{ - } $ ) from calcareous soils that had received an average of 200?kg^?1 N?ha^?1?year^?1 for the previous 30?years and (2) to determine the relationship between soil properties and $ {\text{NO}}_3^{ - } $ , $ {\text{NH}}_4^{ + } $ , and $ {\text{NO}}_2^{ - } $ leaching. The soils used in this study ranged in texture from clay to sandy loam. Leaching experiments were conducted under saturation conditions and consisted of the collection of 1,047–2,524?mL of leachate (12 pore volumes (PVs)), which was equivalent to 534–1,286?mm from rainfall or irrigation. Losses of $ {\text{NO}}_3^{ - } $ ranged from 62 to 437?kg?ha^?1, while losses of $ {\text{NH}}_4^{ + } $ and $ {\text{NO}}_2^{ - } $ ranged from 2.5 to 19.3?kg?ha^?1 and 0.1 to 10.6?kg?ha^?1, respectively. Leaching rates differed between soil samples. The initial and secondary rate of $ {\text{NO}}_3^{ - } $ leaching was determined using an exponential model, and it ranged from 2.8 to 14.7?mg?kg^?1 PV^?1 and 0.11 to 0.32?mg?kg^?1 PV^?1. Greater leaching rates in the initial period could be due to leaching of $ {\text{NO}}_3^{ - } $ in solution, while the secondary leaching might be attributable to the diffusion-controlled transfer of $ {\text{NO}}_3^{ - } $ between mobile and immobile liquid phases. Analysis of variance indicated that the effects of soil type on total $ {\text{NO}}_3^{ - } $ leaching were highly significant (p?<?0.001). The results showed that soil $ {\text{NO}}_3^{ - } $ concentration was positively correlated with the peak concentration of $ {\text{NO}}_3^{ - } $ (r?=?0.86; p?<?0.01) and the total $ {\text{NO}}_3^{ - } $ leached (r?=?0.93; p?<?0.01). In addition, the total $ {\text{NH}}_4^{ + } $ leached was positively correlated with silt (r?=?0.67; p?<?0.05), clay (r?=?0.61; p?<?0.05), and pH (r?=?0.77; p?<?0.01), which suggests that soil parameters might be useful indicators of $ {\text{NO}}_3^{ - } $ and $ {\text{NH}}_4^{ + } $ leaching from calcareous soils. Nitrate leaching from soils could threaten groundwater supplies, so possible strategies for minimizing $ {\text{NO}}_3^{ - } $ leaching losses may need to be considered.     

Role of volcanic dust in the atmospheric transport and deposition of polycyclic aromatic hydrocarbons and mercury

The role of volcanic ash as scavenger of atmospheric pollutants, in their transport and final deposition to the ground is examined. Attention is focused on polycyclic aromatic hydrocarbons (PAHs) and on particulate mercury (Hgp). The ash-fall deposits studied belong to the 2001 and 2002 eruptive activity of Mount Etna, Southern Italy, and were investigated at three (2001) and four (2002) sites downwind of the major tephra dispersal pattern. The dry deposition of mercury and PAHs was determined, and, in particular, a downward flux to the ground of PAHs (approximately 7.29 microg m(-2) per day) and mercury (750 ng m(-2) per day) was estimated in Catania from October 26 to October 28, 2002. Finally, evidence on the anthropogenic origin of PAHs scavenged from the troposphere by volcanic ash is supported by the analysis of PAH compositions in granulometrically homogeneous fractions.     

Effect of low-molecular-weight organic acids on kinetics release and fractionation of phosphorus in some calcareous soils of western Iran

Organic acid has been related to nutrient mobilization, mainly in phosphorus (P) insoluble utilization, and therefore enhances P bioavailability. In this study, we examined the effect of low-molecular-weight organic acids (malic, citric, and oxalic acids) on P release of some calcareous soils from western Iran. Fractionation and speciation of P in the soil solution were studied at the initial and final P release. Significantly different quantities of P were extracted by the organic acids. On average the maximum (1,554.9 mg kg^-1) and the minimum (1,260.5 mg kg^-1) P were extracted by 10 mM oxalic and malic acid, respectively. Power equation described well P release. In the initial stage of P release, the solution samples in soils were supersaturated with respect to hydroxyapatite and β-TCP. At the end of P release, all solutions were undersaturated with phosphate minerals. The percentage of Fe-Al oxide fraction generally increased after P release, while carbonate and residual P fractions were decreased in all organic acids. Compared with the native soils, adding malic and citric acids had no effect on Fe-Al oxide fraction, but oxalic acid significantly reduced this fraction.     

The role of atmospheric circulation system playing in coupling relationship between spring NPP and precipitation in East Asia area

In many East Asia regions, spring (from March to May) precipitation is an important restricting factor to vegetation growth, and atmospheric circulation system may influence spring precipitation patter. It is helpful to under the response of ecosystem to climate change by studying the influence of atmospheric circulation system on the coupling relationship between spring net primary productivity and precipitation. Driving CASA (Carnegie-Ames-Stanford Approach) NPP (Net Primary Productivity) model, we estimated spring NPP for East Asia area (70 degrees E-1 70 degrees E, 10 degrees N-70 degrees N) from 1982 to 1999, and by the method of singular value decomposition we further analyzed the coupling features of spring NPP with precipitation. The result showed that the response features of NPP to precipitation were mainly embodied within the leading six NPP-precipitation paired-modes. The interpretation rates of the leading six paired-modes to the covariance of NPP-precipitation were 42.91, 23.29, 9.96, 5.60, 5.04 and 3.95%, respectively, and total to 90.75%. The temporal correlation coefficients of the leading six paired-modes were 0.830, 0.889, 0.841, 0.747, 0.912 and 0.923, respectively, and all the correlations were significant at significant level of 0.001. In some high latitude regions, there was no obviously corresponding relationship between NPP and precipitation in the leading two paired-modes, and the reason of it may be that spring temperature was the main restricting factor to NPP. In middle and low latitude regions, the effect of precipitation on NPP was relatively more notable. Nine atmospheric circulation factors in spring affected the patterns of NPP and precipitation greatly, and the regions with interpretation rate over 50% shared 60.41 and 65.58% of the whole study area, respectively.     

Ambiental dust speciation and metal content variation in TSP, PM10 and PM2.5 in urban atmospheric air of Harare (Zimbabwe)

The effects of timber harvesting on stream water quality and efficiency of alternate streamside management zones were evaluated in Pockwock Lake and Five Mile Lake watersheds in central Nova Scotia, Canada. The streamside management zone (SMZ) included a 20 m no cut, 20 m select cut and a 30 m select cut buffer strips along the stream. Water quality of eight streams, six in harvested and two in not-harvested watersheds were monitored for two years before and two years after the harvesting of timber. Nonparametric statistical tests on stream water quality showed that there was significant change in the concentration of potassium in six streams, manganese in five streams, zinc in two streams and total nitrogen in one stream after timber harvesting. There was no significant change in the quality of water in two streams used as control sites in the neighboring watersheds of similar size and hydrological characteristics. The results show that forest management practices were most favorable in streams maintained with 30 m select cut followed by 20 m no cut and 20 m select cut SMZ. The streamside zone width and treatment of select cut or no cut in the zone played an important role in filtering or retaining the minerals in surface water runoff. In buffer zones of similar width, the buffer zone with no cut or forested buffer was relatively more effective at protecting stream water quality than select cut SMZ. The vegetation in the zone may have decreased the flow velocity and increased residence time and thus increased filtration and retention of minerals in the riparian soil.     

Microscopic and chemical studies of metal particulates in tree bark and attic dust: evidence for historical atmospheric smelter emissions, Humberside, UK

Tree barks and attic dusts were examined as historical archives of smelter emissions, with the aim of elucidating the pathways of pollution associated with a plume of Sn and Pb contamination in top soils, found close to the former Capper Pass smelter, Humberside, UK. Samples were collected from three villages within the area of the contamination plume. Scanning electron microscopy (SEM) and bulk chemical analyses were used to assess particle type, number and deposition patterns. SEM analysis of dusts and bark revealed that Sn and Pb particles were present in samples from all three villages along with copper, zinc and iron particles. These were almost entirely <10 microm in diameter and occurred mostly as oxides, frequently forming clusters of sub-micron crystals. Samples further from the smelter contained considerably fewer particles. We present images of smelter derived Sn particles. Chemical assays of the barks and attic dusts demonstrated that concentrations of Sn, Pb, Cu, As, Sb and Cd diminished with increasing distance from the source. Strong positive correlations were found between Sn and Pb, As, Sb and Cd in the attic dusts. Enrichment factors (EF) were calculated for these trace elements based on topsoil element concentrations obtained from the soil survey of the study area. Decreases in these trace element concentrations and EF values with distance away from the smelter are consistent with trends found in the soil survey for Sn and Pb and are typical of deposition patterns around smelter stacks. The study demonstrates that tree bark and attic dusts can be effective archives of metal particulates deposited from large static emission sources.     

Mathematical models for accurate prediction of atmospheric visibility with particular reference to the seasonal and environmental patterns in Hong Kong

Atmospheric visibility impairment has gained increasing concern as it is associated with the existence of a number of aerosols as well as common air pollutants and produces unfavorable conditions for observation, dispersion, and transportation. This study analyzed the atmospheric visibility data measured in urban and suburban Hong Kong (two selected stations) with respect to time-matched mass concentrations of common air pollutants including nitrogen dioxide (NO(2)), nitrogen monoxide (NO), respirable suspended particulates (PM(10)), sulfur dioxide (SO(2)), carbon monoxide (CO), and meteorological parameters including air temperature, relative humidity, and wind speed. No significant difference in atmospheric visibility was reported between the two measurement locations (p > or = 0.6, t test); and good atmospheric visibility was observed more frequently in summer and autumn than in winter and spring (p < 0.01, t test). It was also found that atmospheric visibility increased with temperature but decreased with the concentrations of SO(2), CO, PM(10), NO, and NO(2). The results showed that atmospheric visibility was season dependent and would have significant correlations with temperature, the mass concentrations of PM(10) and NO(2), and the air pollution index API (correlation coefficients mid R: R mid R: > or = 0.7, p < or = 0.0001, t test). Mathematical expressions catering to the seasonal variations of atmospheric visibility were thus proposed. By comparison, the proposed visibility prediction models were more accurate than some existing regional models. In addition to improving visibility prediction accuracy, this study would be useful for understanding the context of low atmospheric visibility, exploring possible remedial measures, and evaluating the impact of air pollution and atmospheric visibility impairment in this region.     

Occurrence of organochlorine pesticides in indoor dust

Organochlorine pesticides are present in the environment and suspected of causing serious health effects. Diet has been the main exposure source, but indoor source release is gaining focus. Within a monitoring study of polychlorinated biphenyls of Danish buildings built during the 1960s and 1970s, we coincidently determined extreme levels of dichlorodiphenyltrichloroethane (DDT) levels in two of ten random samples. This raises concern and further large scale investigations are warranted to confirm this.     

Dynamics of atmospheric polychlorinated biphenyls (PCBs): concentrations, patterns, partitioning, and dry deposition level estimations in a residential site of Turkey

Air samples were collected at a residential site (Gulbahce, Bursa, Turkey) between August 2004 and April 2005 using a modified high volume air sampler. The mean of gas and particle phase concentrations of polychlorinated biphenyls (PCBs) were 468 ± 297 and 43 ± 37 pg m^???3 (average ± standard deviation, SD), respectively. The dominated PCB homologs were 3-CBs, 4-CBs, and 5-CBs. The measured PCB concentrations were higher than the values of pristine sites. In order to assess the gas/particle partitioning fate, log K _P–log $P_{\rm L}^o$ , log K _P–log K _OA and the Junge–Pankow model were applied to the data. Experimental K _P was well correlated with $\log P_{\rm L}^o$ and log K _OA at p?<?0.05. Then, dry deposition fluxes were estimated using atmospheric concentrations and dry deposition velocities obtained from literature. A correlation matrix was formed for PCB homologs including 27 congeners with concurrently measured 16 polycyclic aromatic hydrocarbons (PAHs) and meteorological parameters. Most of PAH compounds were significantly correlated with 5-CBs and 6-CBs.     

Forecasting of daily total atmospheric ozone in Isfahan

A neural network combined to an artificial neural network model is used to forecast daily total atmospheric ozone over Isfahan city in Iran. In this work, in order to forecast the total column ozone over Isfahan, we have examined several neural networks algorithms with different meteorological predictors based on the ozone-meteorological relationships with previous day's ozone value. The meteorological predictors consist of temperatures (dry and dew point) and geopotential heights at standard levels of 100, 50, 30, 20 and 10 hPa with their wind speed and direction. These data together with previous day total ozone forms the input matrix of the neural model that is based on the back propagation algorithm (BPA) structure. The output matrix is the daily total atmospheric ozone. The model was build based on daily data from 1997 to 2004 obtained from Isfahan ozonometric station data. After modeling these data we used 3 year (from 2001 to 2003) of daily total ozone for testing the accuracy of model. In this experiment, with the final neural network, the total ozone are fairly well predicted, with an Agreement Index 76%.     

Abundance, behavior, and movement patterns of western gray whales in relation to a 3-D seismic survey, Northeast Sakhalin Island, Russia

A geophysical seismic survey was conducted in the summer of 2001 off the northeastern coast of Sakhalin Island, Russia. The area of seismic exploration was immediately adjacent to the Piltun feeding grounds of the endangered western gray whale (Eschrichtius robustus). This study investigates relative abundance, behavior, and movement patterns of gray whales in relation to occurrence and proximity to the seismic survey by employing scan sampling, focal follow, and theodolite tracking methodologies. These data were analyzed in relation to temporal, environmental, and seismic related variables to evaluate potential disturbance reactions of gray whales to the seismic survey. The relative numbers of whales and pods recorded from five shore-based stations were not significantly different during periods when seismic surveys were occurring compared to periods when no seismic surveys were occurring and to the post-seismic period. Univariate analyses indicated no significant statistical correlation between seismic survey variables and any of the eleven movement and behavior variables. Multiple regression analyses indicated that, after accounting for temporal and environmental variables, 6 of 11 movement and behavior variables (linearity, acceleration, mean direction, blows per surfacing, and surface-dive blow rate) were not significantly associated with seismic survey variables, and 5 of 11 variables (leg speed, reorientation rate, distance-from-shore, blow interval, and dive time) were significantly associated with seismic survey variables. In summary, after accounting for environmental variables, no correlation was found between seismic survey variables and the linearity of whale movements, changes in whale swimming speed between theodolite fixes, mean direction of whale movement, mean number of whale exhalations per minute at the surface, mean time at the surface, and mean number of exhalations per minute during a whales surface-to-dive cycle. In contrast, at higher received sound energy exposure levels, whales traveled faster, changed directions of movement less, were recorded further from shore, and stayed under water longer between respirations.     

Estimation of Water Demand in Iran Based on SARIMA Models

The generation of synthetic, residential water demands that can reproduce essential statistical features of historical residential water consumption is essential for planning, design, and operation of water resource systems. Most residential water consumption series are seasonal and nonstationary. We employ the seasonal autoregressive integrated moving average (SARIMA) model. We fit this model to monthly residential water consumption in Iran from May 2001 to March 2010. We find that a three-parameter log-logistic distribution fits the model residuals adequately. We forecast values for 1 year ahead using the fitted SARIMA model.     

Quantitative assessment of desertification in south of Iran using MEDALUS method

The main aim of this study was the quantitative assessment of desertification process in the case study area of the Fidoye-Garmosht plain (Southern Iran). Based on the MEDALUS approach and the characteristics of study area a regional model developed using GIS. Six main factors or indicators of desertification including: soil, climate, erosion, plant cover, groundwater and management were considered for evaluation. Then several sub-indicators affecting the quality of each main indicator were identified. Based on the MEDALUS approach, each sub-indicator was quantified according to its quality and given a weighting of between 1.0 and 2.0. ArcGIS 9 was used to analyze and prepare the layers of quality maps using the geometric mean to integrate the individual sub-indicator maps. In turn the geometric mean of all six quality maps was used to generate a single desertification status map. Results showed that 12% of the area is classified as very severe, 81% as severe and 7% as moderately affected by desertification. In addition the plant cover and groundwater indicators were the most important factors affecting desertification process in the study area. The model developed may be used to assess desertification process and distinguish the areas sensitive to desertification in the study region and in regions with the similar characteristics.