scholarly journals Sediment type and breeding strategy of the Bank Swallow Riparia riparia in western Sweden

Ornis Svecica ◽  
2002 ◽  
Vol 12 (3) ◽  
pp. 157-163
Author(s):  
Bo-Bertil Lind ◽  
Jimmy Stigh ◽  
Lars Larsson

This paper presents an investigation of the sediment used by the Bank Swallow (Sand Martin) Riparia riparia for the construction of breeding tunnels. Grain-size distribution, bulk density and hydraulic conductivity of breeding-tunnel sediment were investigated at four localities in western Sweden. The investigation shows that the Bank Swallow was consistent in using layers composed of a narrow range of fine and medium sand. Ninety percent of the investigated breeding burrows were located in fine to medium sand (0.125–0.5 mm) and 10% in coarse sand (0.5–1.0 mm). No breeding tunnels were found in sediment finer than fine sand or coarser than coarse sand. The fine to medium sand fraction has the properties to hold stable walls and keep dry tunnels even during rainy periods with heavy infiltration. The hydraulic conductivity of the sediment was in the range of 10–4 to 10–3 m/s and the bulk density 1,510–1,575 kg/m3. In Sweden, artificially excavated slopes in gravel and sand pits have long been the dominating breeding locality for the Bank Swallow. However, during the last two decades, four major factors have led to the decrease of breeding localities: (1) a decreasing demand of aggregate resources, (2) landscaping of gravel and sand pits and stabilization of eroding slopes, including river banks and shorelines, (3) a change to quarries as a source for aggregate production, and (4) concentrating gravel and sand exploitation to fewer and larger pits. It is concluded that these factors are important for the decline of the Bank Swallow population in Sweden and possibly elsewhere in Europe and North America.

1970 ◽  
Vol 21 (1) ◽  
pp. 41-49
Author(s):  
O Adegbuyi ◽  
GP Ojo ◽  
AJ Adeola ◽  
MT Alebiosu

The physical and chemical properties of clay deposits around Isua-Akoko, Akure, Lafe and Ayadi in Ondo State southwestern Nigeria have been examined. The results have shown that Isua-Akoko, Akure and Lafe Clays are plastic fire clays while Ayadi clay is kaolinite. Grain size analysis reveals that Isua Akoko Clay contains 45% of clay, 18% silt, 12% fine sand,14% medium sand and 11% coarse sand and no gravel; Akure clay contains 42% clay, 14% silt, 13% fine sand, 20% medium sand and 8% coarse sand with 1% gravel. Lafe Clay contains 21% clay, 8% silt, 25% fine sand, 37% medium sand and 8% coarse sand with 1% gravel while Ayadi clay contains 83% clay and 17% silt. The liquid limits of these clay samples range from 41% to 73%% and plastic limits range from 18% to 26% respectively. The chemical analysis reveals that the most abundant mineral is silica (60.97%) and aluminum was next in abundance (23.69%) while other oxides are low. The results show that Isua-Akoko and Akure are residual while Lafe and Ayadi are sedimentary and transported Clays. The firing test, PH, and bleaching tests of the clays are also discussed. The chemical and physical characteristics of the clay deposits are strongly indicative of their industrial importance in the production of ceramics, refractories, paving bricks, paint and pharmaceutical products.KEYWORDS: Kaolinite, fire clay, gravel, ceramics and alumina.


2017 ◽  
Author(s):  
Miguel Ángel Martín ◽  
Yakov A. Pachepsky ◽  
Carlos García-Gutiérrez ◽  
Miguel Reyes

Abstract. The soil texture representation with the standard textural fraction triplet 'sand-silt-clay' is commonly used to estimate soil properties. The objective of this work was to test the hypothesis that other fraction sizes in the triplets may provide better representation of soil texture for estimating some soil parameters. We estimated the cumulative particle size distribution and bulk density from entropy-based representation of the textural triplet with experimental data for 6300 soil samples. Results supported the hypothesis. For example, simulated distributions were not significantly different from the original ones in 25 and 85 % of cases when the 'sand-silt-sand' and 'very coarse+coarse + medium sand – fine +very fine sand – silt+clay', were used, respectively. When the same standard and modified triplets were used to estimate the average bulk density, the coefficients of determination were 0.001 and 0.967, respectively. Overall, the textural triplet selection appears to be application- and data-specific.


Soil Research ◽  
1995 ◽  
Vol 33 (5) ◽  
pp. 851 ◽  
Author(s):  
MS Lorimer ◽  
LA Douglas

The effects of five management practices (native forest, native pasture, Phalaris pasture, crop-pasture rotation, continuous cropping), that had been in place for 18 years, on some soil physical properties of a red-brown earth near Bendigo, Victoria, were studied. Particle size distribution, bulk density and hydraulic conductivity of soil in the A and B horizons at different, management sites were measured. Where cultivation had occurred, soil in the A horizon contained less silt and clay, and more fine sand and coarse sand. The bulk density of the A horizon of soil that had produced at least six wheat crops since 1969 was greater than that of soil used for pasture or forest, while the hydraulic conductivity of soil cropped every year since 1969 was much less than that of soil under native forest. Particle size distributions for soil from the B horizons at the five management sites were found to be similar. Where pastures and crops had been established, the hydraulic conductivity of the upper B horizon was lower, and the bulk density was higher, than that of soil in the native forest (Eucalyptus spp).


2013 ◽  
Vol 1 (1) ◽  
pp. 48
Author(s):  
Junet I. S. Korwa ◽  
Esry T. Opa ◽  
Rignolda Djamaludin

Coastal area is defined as the interface point where sea and land meet. To the land the area is limited to the area influenced by the sea factors (wind, tide, and sea water infiltration), while to the sea is limited to the area influenced by the land factors. Special concern need to be addressed in regarding to the use of coastal area. As part of the coastal area, littoral zone is very dynamics due to factors of oceanography and human activities. The same fact is experienced by the littoral zone in Sindulang Satu. Physical change has been the fact in this littoral zone.  In relation to the change, it is considered of importance to describe and analysis the characteristics of the sediment and related oceanography factors.  Result of observation indicated that sediment in the littoral zone consist of fine sand, medium sand, very fine sand, coarse sand and pebbles. Silt and boulder were also found. Distribution of sediment granulometry showed that the littoral zone was dominated by fine sand material, bad sorted, asymetrical to small size and symmetrical granulometry, and mesokurtic. Tidal current is the type of current working in the littoral zone and it plays importance role in the sediment.


Solid Earth ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 159-165 ◽  
Author(s):  
Miguel Ángel Martín ◽  
Yakov A. Pachepsky ◽  
Carlos García-Gutiérrez ◽  
Miguel Reyes

Abstract. The soil texture representation with the standard textural fraction triplet sand–silt–clay is commonly used to estimate soil properties. The objective of this work was to test the hypothesis that other fraction sizes in the triplets may provide a better representation of soil texture for estimating some soil parameters. We estimated the cumulative particle size distribution and bulk density from an entropy-based representation of the textural triplet with experimental data for 6240 soil samples. The results supported the hypothesis. For example, simulated distributions were not significantly different from the original ones in 25 and 85 % of cases when the sand–silt–clay and very coarse+coarse + medium sand − fine + very fine sand − silt+clay were used, respectively. When the same standard and modified triplets were used to estimate the average bulk density, the coefficients of determination were 0.001 and 0.967, respectively. Overall, the textural triplet selection appears to be application and data specific.


2013 ◽  
Vol 1 (1) ◽  
pp. 48
Author(s):  
Junet I. S. Korwa ◽  
Esry T. Opa ◽  
Rignolda Djamaludin

Coastal area is defined as the interface point where sea and land meet. To the land the area is limited to the area influenced by the sea factors (wind, tide, and sea water infiltration), while to the sea is limited to the area influenced by the land factors. Special concern need to be addressed in regarding to the use of coastal area. As part of the coastal area, littoral zone is very dynamics due to factors of oceanography and human activities. The same fact is experienced by the littoral zone in Sindulang Satu. Physical change has been the fact in this littoral zone.  In relation to the change, it is considered of importance to describe and analysis the characteristics of the sediment and related oceanography factors.  Result of observation indicated that sediment in the littoral zone consist of fine sand, medium sand, very fine sand, coarse sand and pebbles. Silt and boulder were also found. Distribution of sediment granulometry showed that the littoral zone was dominated by fine sand material, bad sorted, asymetrical to small size and symmetrical granulometry, and mesokurtic. Tidal current is the type of current working in the littoral zone and it plays importance role in the sediment.  


2016 ◽  
Vol 27 (2) ◽  
pp. 109-120 ◽  
Author(s):  
ASM Woobaidullah ◽  
M Moklesur Rahman ◽  
M Zohir Uddin

The Pourashava area of Manikganj, located in the central part of Bangladesh is treated as arsenic hotspot in the country as the outcome of various studies concludes that almost 80% of the domestic tube wells at this area exceed arsenic level of Bangladesh standard (50 ?g/l) for drinking water. To enhance the potable water supply in the area, 15 geoelectric soundings survey using Schlumberger configuration with spreading AB/2 = 300 meters has been executed to decipher the subsurface lithology distribution and aquifers at different depths, to determine the lateral and vertical extent of aquifer at the area. Correlation of the analyzed VES results with primary and secondary borelogs, the subsurface sequence of the area is broadly divided into two geoelectric units. Firstly, the near surface geoelectric unit of resistivity less than 20.0 ?-m represents the top soil composed of silty clay to clay. The thickness of this layer varies from 1 meter to 5 meters. The second geoelectric unit represents the sand layer and is characterized by a resistivity range of 21.0 to 190.0 ?-m. This unit encompasses the very fine sand with variable thickness of 2 to 248m while resistivity is from 21.0 to 30.0 ?-m, very fine to fine sand having thickness from 174-280m and geoelectric value ranges from 31.0 to 40.0 ?-m, fine sand with resistivity from 44.0 to 50.0 ?-m, fine to medium sand having resistivity from 51.0 to 70.0 ?-m, medium sand and medium to coarse sand with resistivity value 75.0 to 110.0 ?-m, and 140.0 to 190.0 ?-m, respectively. The ultimate thickness of this unit could not be determined due to limited spread of survey but at least continues to a depth of 300 m. In the context of groundwater storage, the second geoelectric unit acts as the regional aquifer and is used for groundwater development in the Pourashava area for water supply.Bangladesh J. Sci. Res. 27(2): 109-120, December-2014


2017 ◽  
Vol 21 (2) ◽  
pp. 721-733 ◽  
Author(s):  
Lin Zhu ◽  
Huili Gong ◽  
Zhenxue Dai ◽  
Gaoxuan Guo ◽  
Pietro Teatini

Abstract. Alluvial fans are highly heterogeneous in hydraulic properties due to complex depositional processes, which make it difficult to characterize the spatial distribution of the hydraulic conductivity (K). An original methodology is developed to identify the spatial statistical parameters (mean, variance, correlation range) of the hydraulic conductivity in a three-dimensional (3-D) setting by using geological and geophysical data. More specifically, a large number of inexpensive vertical electric soundings are integrated with a facies model developed from borehole lithologic data to simulate the log10(K) continuous distributions in multiple-zone heterogeneous alluvial megafans. The Chaobai River alluvial fan in the Beijing Plain, China, is used as an example to test the proposed approach. Due to the non-stationary property of the K distribution in the alluvial fan, a multiple-zone parameterization approach is applied to analyze the conductivity statistical properties of different hydrofacies in the various zones. The composite variance in each zone is computed to describe the evolution of the conductivity along the flow direction. Consistently with the scales of the sedimentary transport energy, the results show that conductivity variances of fine sand, medium-coarse sand, and gravel decrease from the upper (zone 1) to the lower (zone 3) portion along the flow direction. In zone 1, sediments were moved by higher-energy flooding, which induces poor sorting and larger conductivity variances. The composite variance confirms this feature with statistically different facies from zone 1 to zone 3. The results of this study provide insights to improve our understanding on conductivity heterogeneity and a method for characterizing the spatial distribution of K in alluvial fans.


1959 ◽  
Vol 39 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Carol I. Dell

A mineralogical study of the fine sand fraction of unweathered tills and stratified sands chosen to represent the deposits of the major ice lobes of southern Ontario was carried out. In addition, a few analyses were made of the coarse silt and coarser sands.In general there was the same variety of minerals in all samples and they varied only in their proportions. Tills overlying Palaeozoic bedrock contained abundant carbonates and shale fragments constituting up to 70 per cent of some fine sands. In the coarse sands, carbonates and shale increased sharply. In the coarse silt and fine sand, feldspars were more abundant than quartz whereas in the medium and coarse sand the reverse was true. Quartz increased in quantity with increasing grain size and reached a maximum in the medium sand. Heavy minerals usually constituted less than 15 per cent of the fine sand. Some of the minerals present in the coarse silt and fine sand were not found in the coarser sands. Usually the order of abundance of the heavy minerals was: hornblende, garnet, micas, magnetite, pyroxenes and sphene. Epidote, rutile, apatite, tourmaline, staurolite, kyanite and others were also noted. A chart listing the plant nutrient elements found in these minerals was prepared.


2019 ◽  
Vol 68 (8) ◽  
pp. 757-768 ◽  
Author(s):  
Feikai Yang ◽  
Rajendra Prasad Singh ◽  
Dangfang Fu

Abstract Bioretention systems and selection of effective filter media are very important in implementation of sponge cities. The current study was carried out to find proper composition of filter media using locally available materials, which acclimate to the special/local climate, environmental and geographical conditions in Yangtze River Delta region. Results revealed that sand with discontinuous gradation and containing a certain amount of clay led to unsatisfactory hydraulic performance (hydraulic conductivity ranged from 423 mm/h to 1,054 mm/h, and 1,500 mm/h to 29 mm/h). In contrast, a mixture of locally available sand, which consisted of continuous gradation of coarse sand (40–70%, by mass), fine sand (0–40%, by mass), very fine sand (10–60%, by mass) and nutrient soil (0–3%, by mass), had a hydraulic conductivity ranging from 200 to 400 mm/h and relatively stable structure. During the 70 days' flooding test, the hydraulic conductivity changed in the first 20 days due to the migration of particles (mainly <0.6 mm) and then became stable; the stable value was close to the initial. Moreover, easy access and simple production processes made it easier to promote. Findings could be used as a guideline for implementation of bioretention systems and selection of locally available and effective filter material.


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