Analysis of Baseline and Perimeter Air Monitoring Data from the Calaveras Dam Replacement Project (CDRP), Fremont, California

2020 ◽  
Author(s):  
Bradley Erskine ◽  
Mark Bailey
Keyword(s):  
Wind Direction ◽  
Soil Disturbance ◽  
Soil Samples ◽  
Monitoring Data ◽  
Local Source ◽  
Amphibole Composition ◽  
Calcic Amphibole ◽  
Several Variables ◽  
Index 2 ◽  
Time Of Year

<p>This paper presents the results of 810 pre-project baseline samples collected over four years (2010-2011), and 7,210 offsite (ambient) and 14,314 perimeter samples collected over 7 years (2012-2018) during the CDRP project. The principal asbestos particles were chrysotile from serpentinite, and glaucophane-winchite amphibole from blueschist. The baseline data showed that asbestos concentrations measured at each station are not representative of a regional average background, rather, they reflect contributions from several variables such as: location on or near NOA-containing units, wind direction, intensity of localized soil disturbance, and time of year. The data shows that baseline sampling prior to a project cannot be used as a measure of “background” during the project. The analysis of amphibole composition in air and rock/soil samples was applied to differentiate local source impacts from the primary CDRP asbestos emissions. Of particular value was the application of the calcic-amphibole to total amphibole ratio (Ca index) measured during ABS sampling and comparison with the ratios measured in the samples. This analysis delineated three primary amphibole sources: 1) alluvium in the Sunol Valley with a high Ca index, 2) imported road surfacing material with a moderate Ca index, and 3) blueschist with a low Ca index. When the data was sorted by wind direction, the analysis showed that the contribution of CDRP-generated asbestos to monitoring stations was significant near the point of disturbance only, and did not significantly impact offsite stations that were located at or near sensitive receptors. The asbestos measured at the offsite stations were correlated with local geologic units. The analysis verified that the CDRP emissions were well below the project-specific risk-based thresholds established for the CDRP project, documenting that the offsite receptors were not exposed to an adverse risk by CDRP activities.</p>

scholarly journals COPPER ACCUMULATION IN VINEYARD SOILS FROM NEMEA, GREECE

2017 ◽  
Vol 50 (4) ◽  
pp. 2192 ◽  
Author(s):  
E. Kelepertzis ◽  
I. Massas ◽  
G. Fligos ◽  
M. Panagiotou ◽  
A. Argyraki
Keyword(s):  
Soil Disturbance ◽  
Soil Samples ◽  
Chemical Extraction ◽  
Copper Accumulation ◽  
Deep Soil ◽  
Cu Content ◽  
Tillage Practices ◽  
Cu Accumulation ◽  
Vineyard Soils ◽  
First Time

We present for the first time the extent and magnitude of Cu accumulation in calcareous vineyard soils from Nemea, Greece, as result of intensive application of Cu-based fungicidal sprays. Surface (0-20 cm) soil samples were collected from 40 vineyard plots covering the whole agricultural region of Nemea devoted to viticulture. In 20 randomly selected vineyards, we also collected soil at 50 cm depth. Major soil properties were determined (pH, electrical conductivity, organic carbon and equivalent calcium carbonate contents, particle size distribution). Copper concentrations in Nemea vineyard soils (33.1 - 291 mg kg 1 ) were similar to those reported in the soils of vineyards in other parts of Europe. Copper has migrated down the soil profile since the levels at 50 cm depth are higher than the known background concentrations, probably as result of soil disturbance by tillage practices. We did not find differences in Cu availability between the surface and deep soil samples after applying the DTPA chemical extraction. The DTPA-extracted Cu concentrations were largely dependent on the total soil Cu content. The excessive application of Cu-based fungicides should be avoided with the aim to ensure that Cu accumulation does not reach levels that may inhibit plant growth.

Noncompetitive Effects of Johnsongrass (Sorghum halepense) on Soybeans (Glycine max)

Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 589-593 ◽  
Author(s):  
Petros C. Lolas ◽  
Harold D. Coble
Keyword(s):  
North Carolina ◽  
Glycine Max ◽  
Dry Weight ◽  
Soil Samples ◽  
Sorghum Halepense ◽  
Nutrient Concentrations ◽  
Soybean Seedling ◽  
Soybean Seedlings ◽  
Soybean Plants ◽  
Time Of Year

Studies were conducted in North Carolina to determine if johnsongrass [Sorghum halepense(L.) Pers.] rhizomes in the soil exude or produce substances that can affect soybean [Glycine max(L.) Merr.] seedling growth. Fresh and dry weights of soybean seedlings were dependent on the concentration of rhizomes present in the soil before soil samples were used for soybean growth, and on the time of year when soil samples were collected. In studies on rhizome residues, soybean seedling dry weight decreased as percent of dry, decayed rhizomes in the soil increased. For each rhizome concentration, soybean growth inhibition decreased as decay time increased. Fresh and dry weights of soybean plants were reduced by diluted fresh rhizome extract used for irrigation once a week for 3 weeks. Since no rhizomes were present in most of the soils during soybean growth and since nutrient concentrations, organic matter, and pH were not different among the soils used, it is suggested that johnsongrass rhizomes living or decaying in the soil exude, contain, or produce substances that exhibit allelopathic characteristics to soybean growth.

Eliminating soil disturbance reduces post-alfalfa summer annual weed populations

2001 ◽  
Vol 81 (4) ◽  
pp. 881-884 ◽  
Author(s):  
P. D. Ominski ◽  
M. H. Entz
Keyword(s):  
Cropping Systems ◽  
Chenopodium Album ◽  
Soil Disturbance ◽  
Amaranthus Retroflexus ◽  
Weed Ecology ◽  
Wild Mustard ◽  
No Till ◽  
Lamb’S Quarters ◽  
Time Of Year ◽  
Brassica Kaber

The influence of method (tillage vs. no-till) and time of year of alfalfa (Medicago sativa L.) termination on the population of naturally occurring weeds was assessed over three site-years in southern Manitoba. Termination method was found to be more important than timing. Populations of weeds such as green foxtail [Setaria viridis (L.) Beauv.], redroot pigweed (Amaranthus retroflexus L.), wild mustard [Brassica kaber (DC) L.C. Wheeler] and lamb’s quarters (Chenopodium album L.) were usually lower (P < 0.05) in the undisturbed (i.e., no-till) system, compared to where tillage was used. It was concluded that the combination of alfalfa in rotation and no-till management can provide significant weed control benefits to cropping systems. Key words: Weed ecology, no-till cropping, forages

Spatial Distribution and Contribution Segregation of Hg and Cd in the Soils in the Chemical Industry Park and its Surrounding Areas

2012 ◽  
Vol 610-613 ◽  
pp. 3797-3802
Author(s):  
Chun Feng Lu ◽  
Sheng Lu Zhou ◽  
Shao Hua Wu
Keyword(s):  
Spatial Distribution ◽  
Chemical Industry ◽  
Wind Direction ◽  
Surface Soil ◽  
Soil Samples ◽  
Contribution Rate ◽  
The North ◽  
Spatial Distribution Characteristics ◽  
Surrounding Areas ◽  
The Impact

This paper determined Hg and Cd contents through collecting the surface soil samples in Nanjing Liuhe Chemical Industry Park and its surrounding areas, analyzed the spatial distribution characteristics of Hg and Cd in the study area by means of ordinary Kriging, and carried out quantitative analysis for the impact of chemical industry park on the accumulation of soil heavy metals through introducing contribution rate. The results show that the chemical industry park is one of the important causes of the accumulation of Hg and Cd in the surrounding soils. In space, the closer the site is to the industrial park, the higher the accumulative content is. Wind direction has a significant effect on the diffusion of Hg, affected most greatly on the northwest, which is located downwind, with a contribution rate of 85.47%, while wind direction has no significant effect on the diffusion of Cd, affected most greatly on the north, with a contribution rate of 29.37%.

scholarly journals A homogeneous aa index: 2. Hemispheric asymmetries and the equinoctial variation

2018 ◽  
Vol 8 ◽  
pp. A58 ◽  
Author(s):  
Mike Lockwood ◽  
Ivan D. Finch ◽  
Aude Chambodut ◽  
Luke A. Barnard ◽  
Mathew J. Owens ◽  
...  
Keyword(s):  
Activity Index ◽  
Auroral Oval ◽  
Time Of Day ◽  
Hemispheric Asymmetries ◽  
Index 2 ◽  
The Difference ◽  
Time Of Year ◽  
Annual Means ◽  
Geomagnetic Activity Index ◽  
Aa Index

Paper 1 (Lockwood et al., 2018) generated annual means of a new version of the aa geomagnetic activity index which includes corrections for secular drift in the geographic coordinates of the auroral oval, thereby resolving the difference between the centennial-scale change in the northern and southern hemisphere indices, aaN and aaS. However, other hemispheric asymmetries in the aa index remain: in particular, the distributions of 3-hourly aaN and aaS values are different and the correlation between them is not high on this timescale (r = 0.66). In the present paper, a location-dependant station sensitivity model is developed using the am index (derived from a much more extensive network of stations in both hemispheres) and used to reduce the difference between the hemispheric aa indices and improve their correlation (to r = 0.79) by generating corrected 3-hourly hemispheric indices, aaHN and aaHS, which also include the secular drift corrections detailed in Paper 1. These are combined into a new, “homogeneous” aa index, aaH. It is shown that aaH, unlike aa, reveals the “equinoctial”-like time-of-day/time-of-year pattern that is found for the am index.

Estimating Population Densities of Root Lesion Nematodes, Pratylenchus spp., from Soil Samples Using Dual Active and Passive Assays

2012 ◽  
Vol 13 (1) ◽  
pp. 4 ◽  
Author(s):  
Ann E. MacGuidwin ◽  
Breann E. Bender
Keyword(s):  
Population Density ◽  
Soil Samples ◽  
Scaling Factor ◽  
The Other ◽  
Testing Methods ◽  
Population Densities ◽  
Lesion Nematodes ◽  
The Mean ◽  
Time Of Year ◽  
Root Lesion Nematodes

Root lesion nematodes are versatile parasites that move freely between root and soil habitats. Most laboratories conduct separate assays for soil or root tissue, using time-of-year as the selecting factor. We used a dual assay that simultaneously extracts nematodes from soil and root fragments in soil samples to identify the value of soil versus root tests using 920 research samples collected 1 April to 15 May, and 853 clinic samples collected year round. Nematodes were recovered from both soil and root fragments regardless of the time of year or origin of the sample. When the data were summarized by cohort, the mean percentage of nematodes recovered from root fragments was 65% for the research samples, 59% for clinic samples submitted 1 March to 15 June, 56% for clinic samples submitted 16 June to 31 July, and 49% for clinic samples submitted after 1 August. Both the incidence and population density of root lesion nematodes was underestimated if only the soil or only the root fraction was considered, indicating the need for testing methods that consider both habitats. The variability among samples for the distribution of nematodes between root and soil habitats was high, negating the option of running one assay and using a constant scaling factor to account for the other. Accepted for publication 30 October 2012. Published 20 November 2012.

Usage of computed tomography for investigation of the soil porosity in disturbed grassland 

2021 ◽  
Author(s):  
Kadri Krebstein ◽  
Tõnu Tõnutare ◽  
Kersti Vennik ◽  
Indrek Virro ◽  
Tõnis Tõnutare ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Mechanical Strength ◽  
Military Training ◽  
Soil Bulk Density ◽  
Soil Disturbance ◽  
Soil Samples ◽  
Soil Conditions ◽  
High Porosity ◽  
Undisturbed Soil ◽  
Tomography System

&lt;p&gt;Soil disturbance will remarkably alter physical properties of the soil &amp;#160;and the recovery of the structure as well as mechanical strength recovery will take &amp;#160;years. Typically deforestation works, e.g. needed for the establishment of open military training areas, seriously influences soil mechanical state. Deforestation works involve processes like felling of trees, uprooting of stumps followed by levelling of ground. For the establishment of more favourable conditions for grass cover development, tree stumps and felling residues are mixed into the soil with a rotary thriller. Therefore, the final disturbed ground &amp;#160;has low density and high porosity resulting in low mechanical strength. On the &amp;#160;contrary, military training includes high intensity movement by soldiers and trafficking by vehicles. Thus, these types of activities presume stable soil conditions with a high mechanical strength. The aim of our research was to investigate soil density status of disturbed grassland with computed tomography. The soil samples were collected from the undisturbed area and from the grassland which was treated with the rotary thriller 2 years ago. The undisturbed soil samples were collected using plastic cylinders (of 10 cm diameter and 20 cm height) in 3 repetitions. &amp;#160;For comparison, smaller soil samples (5.3 cm diameter and 4 cm height) were obtained at 0, 5, 10, 15, 20, 30 cm depths &amp;#160;for determining the soil bulk density. In the &amp;#160;laboratory, the high resolution industrial computed tomography system Yxlon FF 35 CT was used with the larger soil samples. The soil samples were analyzed using the software Volume Graphics VGSTUDIO MAX 3.2. &amp;#160;Our results indicated the possibility of determination of distribution of pores in the soil and the changes in the porosity of soils depending on the soil treatment and the type.&lt;/p&gt;

scholarly journals Quantification of CH<sub>4</sub> emissions from waste disposal sites near the city of Madrid using ground- and space-based observations of COCCON, TROPOMI and IASI

2021 ◽  
Author(s):  
Qiansi Tu ◽  
Frank Hase ◽  
Matthias Schneider ◽  
Omaira García ◽  
Thomas Blumenstock ◽  
...  
Keyword(s):  
Waste Disposal ◽  
Wind Direction ◽  
Local Source ◽  
Emission Rates ◽  
Ch4 Emission ◽  
Wind Fields ◽  
Mixing Ratios ◽  
Atmospheric Sounding ◽  
Emission Strength ◽  
Total Column

Abstract. The objective is to derive methane (CH4) emissions of the metropolitan city Madrid Spain from the CH4 enhancements seen by the space-borne and the ground-based instruments. This study applies satellite-based measurements from the TROPOspheric Monitoring Instrument (TROPOMI) and the Infrared Atmospheric Sounding Interferometer (IASI) together with measurements from the ground-based COllaborative Carbon Column Observing Network (COCCON) instruments. In 2018, a two-week field campaign for measuring the atmospheric concentrations of greenhouse gases was performed in Madrid in the framework of Monitoring greenhousE Gas EmIssions of Madrid city (MEGEI-MAD) project. Five COCCON instruments were deployed at different locations around the Madrid city center enabling the observation of total column averaged CH4 mixing ratios (XCH4). Using available wind data, the differences between CH4 columns observed at these locations allow to estimate the emissions emerging from the surrounded area. In addition, based on the dominating wind direction in the Madrid region, we calculate the difference of the satellite data maps for two opposite wind regimes (northeast – southwest, NE – SW). In the following, we refer to the resultant signal as the wind-assigned anomaly. We use TROPOMI tropospheric nitrogen dioxide (NO2) observations as a test to verify our method of wind-assigned anomaly and its implementation, taking advantage of the much better detectability of the plume due to the short lifetime and low background concentrations of NO2. Pronounced bipolar plumes are found along NE and SW wind direction, which implies that our method of wind-assigned anomaly is working as expected. The wind-assigned TROPOMI XCH4 anomaly shows much weaker symmetric plumes than NO2 due to the long lifetime of CH4 and in consequence a high accumulated background of CH4 in the atmosphere. The wind-assigned plume method is also applied to the tropospheric and upper tropospheric/stratospheric column averaged CH4 mixing ratio products (in the following referred to as TXCH4 and UTSXCH4) derived from a-posteriori merged Infrared Atmospheric Sounding Interferometer (IASI) profile and TROPOMI total column data. Based on the NE and SW wind fields, we developed a simple plume model locating the source at three waste disposal sites east of Madrid for CH4. As CH4 emission strength we estimate 7.4 × 1025 ± 6.4 × 1024 molec s−1 from the TROPOMI XCH4 data and 7.1 × 1025 ± 1.0 × 1025 molec s−1 from the TROPOMI&amp;IASI merged TXCH4 data. The COCCON observations indicate a weaker CH4 emission strength of around 3.7 × 1025 molec s−1 from local source (near to the Valdemingómez waste plant) in accordance with observations in a single day and. All emission rates estimated from the different observations are significantly larger than the emission rates provided via the official Spanish Register of Emissions and Pollutant Sources.

Relationship of Plasticity Index of Soil with Laboratory and Field Electrical Resistivity Values

2013 ◽  
Vol 353-356 ◽  
pp. 719-724
Author(s):  
Syed Baharom Syed Osman ◽  
Fahad Irfan Siddiqui ◽  
Mohammad Yaakob Behan
Keyword(s):  
Electrical Resistivity ◽  
Research Work ◽  
Soil Disturbance ◽  
Primary Objective ◽  
Soil Samples ◽  
Silty Sand ◽  
Plasticity Index ◽  
Engineering Properties ◽  
Electrical Survey ◽  
The Relationship

Borehole sampling and laboratory soil characterizations provide accurate engineering properties, yet it is time-consuming and expensive. Geo-electrical survey is an attractive tool for delineating subsurface properties without soil disturbance. The primary objective of the current research work is to investigate the relationship between electrical resistivity and plasticity index of soil. The results from electrical resistivity tests (field and laboratory) and Atterburg limit tests were analyzed to understand the relationship between electrical resistivity and plasticity index of soil. Plasticity index have a significant correlation with field and laboratory electrical resistivity values for all soil samples. It was found that silty sand soil samples are characterized by higher plasticity index and lower resistivity values whereas sandy soil samples have lower plasticity index and higher resistivity values.

Allowable pressure from loading tests on Kuwaiti soils

1985 ◽  
Vol 22 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Nabil F. Ismael
Keyword(s):  
Sandy Soils ◽  
Soil Disturbance ◽  
Empirical Methods ◽  
Soil Pressure ◽  
Overburden Pressure ◽  
Several Variables ◽  
Methods Of Calculation ◽  
Load Tests ◽  
Loading Tests ◽  
Penetration Tests

The results of recent loading tests on Kuwaiti sandy soils at seven sites are analyzed. The tests were carried out on small concrete footings ranging in size from 0.25 to 1 m. The effects of several variables on the pressure–settlement diagrams were investigated. These include footing size, overburden pressure, footing material, soil disturbance, and soil properties. The results indicate that the effect of overburden pressure and of footing material is less significant than that of the other variables. Standard penetration tests were carried out at all sites and the allowable pressures were obtained based on the different empirical methods commonly used by the practicing engineers. A comparison was made between the predicted soil pressure values and actual measurements for the purpose of determining the most suitable design methods for sandy soils. Key words: load tests, sands, footing, allowable pressure, settlement, methods of calculation, overburden pressure, soil disturbance.

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