scholarly journals INCREASING THE EFFICIENCY OF WATER TRANSPORT OF THE FOREST TO INCREASE THE HYDRODYNAMIC PROPERTIES OF THE RAFT

2021 ◽  
Author(s):  
Andrey Manukovskiy ◽  
A Rubanov ◽  
N. Nedovesov
Keyword(s):  
Water Transport ◽  
Time Frame ◽  
Water Area ◽  
Hydrodynamic Resistance ◽  
Winter Period ◽  
Maximum Speed ◽  
River Bed ◽  
Hard Times ◽  
Towing Speed ◽  
Calm Weather

Of all the known modern types of water transport of the forest, the most promising is timber rafting, which, when used, has both positive and negative properties. Negative indicators include such indicators as: seasonality of work, since use in the winter period is impossible, loss of wood when unloading logs onto water and a raft, large dimensions, complexity of management, the need to unload a raft when unloading it. Passes through non-standard sections of the river bed and subsequent formations, special requirements for the dimensions of the waterway, speed limits and others. One of the most acute problems caused by huge hydrodynamic resistance to movement, which increases with an increase in towing speed, is the limitation of the speed of movement of the raft in the water area. In this regard, the maximum speed of the raft in calm weather reaches no more than 1 1.2 m / s, while two or more powerful tugs are involved. The limited time frame for rafting on wooden rafts is due to the flood period during the spring floods and floods, and they have fallen on hard times. Increasing the raft’s allowable towing speed will shorten the raft’s transport time. A decrease in hydrodynamic resistance when the raft is moving will increase the maximum allowable speed of its towing, which will have a positive effect on the efficiency of timber rafting. Based on the analysis of existing known designs of modern rafts, as well as methods of influencing the reduction of hydrodynamic resistance in the field of shipbuilding, a number of methods have been proposed for reducing the hydrodynamic resistance to the movement of the raft. Methods of reducing the resistance to the movement of the raft by changing the features of its formation by placing separate sections or beams in the streamlined material, the introduction of hydrodynamic fairings are considered. The proposed methods for reducing the hydrodynamic resistance can significantly increase the efficiency of timber rafting.

scholarly journals Image Based Surface Temperature Extraction and Trend Detection in an Urban Area of West Bengal, India

2016 ◽  
Vol 9 (3-4) ◽  
pp. 13-25 ◽  
Author(s):  
Sk Ziaul ◽  
Swades Pal
Keyword(s):  
Surface Temperature ◽  
Land Surface ◽  
Monsoon Season ◽  
Winter Season ◽  
Time Frame ◽  
Trend Detection ◽  
Winter Period ◽  
Rapid Urbanization ◽  
Post Monsoon Season ◽  
Spatio Temporal

Abstract Rapid urbanization and change of landuse/landcover results in changes of the thermal spectrum of a city even in small cities like English Bazaar Municipality (EBM) of Malda district. Monitoring the spatio-temporal surface temperature patterns is important, therefore, the present paper attempts to extract spatio-temporal surface temperature from thermal band of Landsat imageries and tries to validate it with factor based Land Surface Temperature (LST) models constructed based on six proxy temperature variables for selected time periods (1991, 2010 and 2014). Seasonal variation of temperature is also analyzed from the LST models over different time phases. Landsat TIRS based LST shows that in winter season, the minimum and maximum LST have raised up 2.32°C and 3.09°C in last 25 years. In pre monsoon season, the increase is much higher (2.80°C and 6.74°C) than in the winter period during the same time frame. In post monsoon season, exceptional situation happened due to high moisture availability caused by previous monsoon rainfall spell. Trend analysis revealed that the LST has been rising over time. Expansion and intensification of built up land as well as changing thermal properties of the urban heartland and rimland strongly control LST. Factor based surface temperature models have been prepared for the same period of times as done in case of LST modeling. In all seasons and selected time phases, correlation coefficient values between the extracted spatial LST model and factor based surface temperature model varies from 0.575 to 0.713 and these values are significant at 99% confidence level. So, thinking over ecological growth of urban is highly required for making the environment ambient for living.

scholarly journals Dynamic mechanism of an extremely severe saltwater intrusion in the Changjiang estuary in February 2014

2020 ◽  
Vol 24 (10) ◽  
pp. 5043-5056
Author(s):  
Jianrong Zhu ◽  
Xinyue Cheng ◽  
Linjiang Li ◽  
Hui Wu ◽  
Jinghua Gu ◽  
...  
Keyword(s):  
Water Level ◽  
Water Transport ◽  
River Discharge ◽  
Saltwater Intrusion ◽  
Changjiang Estuary ◽  
Maximum Speed ◽  
Residual Water ◽  
Northerly Wind ◽  
The Changjiang Estuary ◽  
Water Level Rise

Abstract. Estuarine saltwater intrusions are mainly controlled by river discharge and tides. Unexpectedly, an extremely severe saltwater intrusion event occurred in February 2014 in the Changjiang estuary under normal river discharge conditions. This intrusion cut off the freshwater input for 23 d into the Qingcaosha reservoir, which is the largest estuarine reservoir in the world, creating a severe threat to water safety in Shanghai. No similar catastrophic saltwater intrusion has occurred since records of salinity in the estuary have been kept. During the event, a persistent and strong northerly wind existed, with a maximum speed of 17.6 m s−1, lasting 9 d and coinciding with a distinct water level rise. Our study demonstrates that the extremely severe saltwater intrusion was caused by this northerly wind, which drove substantial landward net water transport to form a horizontal estuarine circulation that flowed into the northern channel and out of the southern channel. This landward net water transport overpowered the seaward-flowing river runoff and transported a large volume of highly saline water into the northern channel. The mechanisms of this severe saltwater intrusion event, including the northerly wind, residual water level rise, landward water transport and resulting horizontal circulation, etc., were systematically investigated.

scholarly journals Hydrodynamic analysis and improvement of pontoon boats

2019 ◽  
Vol XXII (1) ◽  
pp. 220-230
Author(s):  
Gürsel K. T.
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Market Share ◽  
Total Pressure ◽  
Hydrodynamic Resistance ◽  
Maximum Speed ◽  
Objective Functions ◽  
Design Features ◽  
Hydrodynamic Properties ◽  
Hydrodynamic Analysis

This study is related to the design features of pontoon boats that enjoy an increasing market share in global recreational boat industry. In this investigation, a representative pontoon boat with three cylindrical buoyancy elements was taken as the model to be studied. Afterwards, the buoyancy elements were improved to optimize hydrodynamic properties using a computational fluid dynamics package. The objective functions were the total hydrodynamic resistance of the boat and the distribution of the turbulence viscosity and total pressure on the hulls. By means of the obtained results, the powering requirements were estimated both for a service speed and for a maximum speed as well as findings were discussed.

Climate Crisis and the Democratic Prospect

2017 ◽  
Author(s):  
Frank Fischer
Keyword(s):  
Environmental Governance ◽  
Global Climate ◽  
Time Frame ◽  
States Of Emergency ◽  
The Social ◽  
Hard Times ◽  
The Media ◽  
Climate Crisis ◽  
Environmental Democracy ◽  
Political Realm

Can contemporary democratic governments tackle climate crisis? Some say that democracy has to be a central part of a strategy to deal with climate change. Others say that experience shows it not to be up to the challenge in the time frame available—that it will require a stronger hand, even a form of eco-authoritarianism. This work seeks to sort out and assess the competing answers to a question that is not easily resolved. While the book supports the case for environmental democracy, it argues that establishing and sustaining democratic practices will be difficult during the global climate turmoil ahead, especially if confronted with permanent states of emergency. This inquiry undertakes a search for an appropriate political-ecological strategy capable of preserving a measure of democratic governance during hard times. Without ignoring the global dimensions of the crisis, the analysis finds an alternative path in the theory and practices of participatory environmental governance embodied in a growing relocalization movement, and a form of global eco-localism. Although these movements largely operate under the radar of the social sciences, the media, and the political realm generally, such vibrant socio-ecological movements not only speak to the crisis ahead, but are already well established and thriving on the ground, including ecovillages, eco-communes, eco-neighborhoods, and local transition initiatives. With the help of these ideas and projects, the task is to shift the discourse of environmental political theory in ways that can assist those who will face the climate crisis in its full magnitude in real terms.

ASSESSMENT OF THE BOTTOM FAUNA BIOMASS OF THE LOWER REACHES OF THE ANGARA RIVER IN THE AREA OF THE GOREVSKY ORE MINING AND PROCESSING INDUSTRIAL COMPLEX

2018 ◽  
Vol 12 (5-6) ◽  
pp. 42-49
Author(s):  
I. V. Kosmakov ◽  
V. M. Petrov ◽  
S. P. Shulepina
Keyword(s):  
Aquatic Vegetation ◽  
Accurate Determination ◽  
Water Area ◽  
Low Flow ◽  
Bottom Fauna ◽  
Total Biomass ◽  
Industrial Complex ◽  
Biological Resources ◽  
Average Value ◽  
River Bed

In the article, the general biomass of zoobenthos is considered on the basis of the results of studies conducted during July-September 2016 in the river bed of the Angara River in the area of the water area planned for alienation. The total biomass of benthos is the main feature in the calculation of damage to aquatic biological resources. Studies were conducted in the left half of the Angara River at a distance of 40–43 km from the estuary. The results of the work were compared with the results of a comprehensive study of the Angara in its lower reaches, conducted in 1947–1948. In this work, the species composition of the zoobenthos is not considered. The aim of the work is to estimate the average total biomass for an accurate determination of the damage to aquatic biological resources. The greatest value of the total biomass of benthos was observed in September in the aquatic vegetation near the shore, represented by river mud with sand and plant remains at very low flow velocity. This value is 28.4 g/m2 , with an average value for the study period of 6.57 g/m2 . In the river bed, the greatest value of biomass (4.39 g/m2 ) was also noted in September on the shore, consisting of sand, pebbles, boulders at significant flow velocities. The average value in the river bed during the study period was 0.57 g/m2 . The average size of the total biomass of the zoobenthos in the alienation area is calculated by the ratio of the area of the coastal parts of the river bed and the river bottom, taking into account the average values of the biomass of benthos. This value is 3.86 g/m2 . The value obtained is comparable to the value determined in 1947–1948, which is 46.9 kg/ha. The previously calculated harm was 190.8 tons, with an average biomass of 68.2 kg/ha. The calculated damage is 105.5 tons.

scholarly journals RISKS ASSESSMENT OF APPLYING UNMANNED MEANS OF WATER TRANSPORT IN THE WATER AREA

2019 ◽  
Vol 11 (6) ◽  
pp. 987-1002
Author(s):  
Vladimir V. Karetnikov ◽  
◽  
Sergey V. Kozik ◽  
Artem A. Butsanets ◽  
◽  
...  
Keyword(s):  
Water Transport ◽  
Water Area ◽  
Risks Assessment

scholarly journals Analysing riverbed morphology as a response to changes of geological and neotectonic conditions: A case study of the oľšava river

2019 ◽  
Vol 38 (3) ◽  
pp. 109-122
Author(s):  
Dušan Barabas ◽  
Matúš Tkáč
Keyword(s):  
Field Measurements ◽  
Water Area ◽  
Repeated Measurements ◽  
Longitudinal Profile ◽  
Width Ratio ◽  
Morphological Parameters ◽  
Morphological Examination ◽  
River Bed ◽  
The Difference ◽  
Width Measurements

Abstract The morphological examination of the Slovak Oľšava River channel and valley parameters is based on observation of changes in the troughs’ longitudinal profile. While the relationship between valley and channel parameters has previously been researched, establishment of the diverse conditions in trough formation enables better understanding of the basin/riverbed relationship. Our research is based on field measurements of representative sections of nine segments defined by changes in the longitudinal profile. The field measurements were performed in autumn months during a low water period to ensure the best conditions for repeated measurements. Significantly, as much as 75% asymmetry of the measured flow encourages the assumption of strong tectonic influence on the riverbed formation. While the difference between the assumed continuous changes of measured parameters and the actual measured or evaluated parameters remains a matter of interpretation, the detected anomalies enable interpretation of the parameters’ relationships. The river bed and the valley morphological parameters were evaluated on the model of The Olšava River basin which drains the eastern part of the Košická kotlina Basin (the Toryská pahorkatina Upland). The location of the basin at the foot of the Slanské vrchy Mts. is an important factor in the formation of the river network asymmetries. Both the Neogene contact between the Slanské vrchy Hills neo-volcanites and the Toryská pahorkatina Upland and the neo-tectonics influenced the change in morphological parameters in the valley’s longitudinal and transverse profile and the Oľšava river bed. Our terrain works comprised length and width measurements of the bars, their positions in the river bed, the width and depth of the channel and the type of section riffle. Available maps enabled calculation of the following; ratio of valley height to width, average gradient of the section, stream gradient index, average channel segment slope, the degree of sinuosity and the highest observed correlation between slope, river segment type (0.9576) and the width and type river reach (−0.9089). High correlation coefficient values were recorded for the valley height and width ratio, the type of river section, the water area and the total river bed width and area.

scholarly journals Meander reshaping – the formation process of a wintering riverbed depression of fish

2021 ◽  
Vol 29 (4) ◽  
pp. 380-386
Author(s):  
A. A. Chemagin
Keyword(s):  
Life Cycle ◽  
Research Work ◽  
Aquatic Organisms ◽  
Water Area ◽  
Average Density ◽  
Winter Period ◽  
Channel Processes ◽  
Siberian River ◽  
Riverbed Depression ◽  
Distribution Of Fish

The study of the spatiotemporal distribution of fish is an important and poorly studied aspect of the ecology of aquatic organisms. The research work was performed using the modern hydroacoustic method and geographic information systems. A section in the lower reaches of the Irtysh, a large transboundary Siberian river (in Western Siberia, Russian Federation), was studied. It has a strong development of meandering. The merging (i.e., reshaping of closely spaced meanders and erosion-accumulating channel processes) results in development of wintering riverbed depression, which is a critical “temporal bottleneck” during the winter period of the fish life cycle. The average density of fish in the study area in summer and autumn was 8,031 and 9,194 individuals per ha, respectively. Analysis of the distribution of fish showed that the distribution in the horizontal aspect had a more aggregated character in the autumn. In the vertical aspect, it had a more surface (pelagic) character. The ichthyofauna in the water area of the riverbed depression is mainly represented by cyprinids. The loop-shaped evolution of the channel formed a section of the river with multidirectional, circulating, and counter-current flows. It also created zones with depths exceeding 20 m and aggregations of fish. These features characterize the studied water area as a wintering riverbed depression of the fish of the Lower Irtysh. This section of the river should be included in the list of protected wintering biotopes of fish in the West Siberian fishery basin, which will ensure the conservation of fish at the critical stage of the life cycle.

Hydrophysical factors of coccolithophores Emiliania huxleyi intensive bloom formation in the Abkhazian sector of the Black Sea at the end of May 2013

2019 ◽  
pp. 52-67
Author(s):  
Valeriy G. Yakubenko ◽  
Sergey V. Vostokov ◽  
Vladimir A. Silkin ◽  
Larisa A. Pautova ◽  
Anastasia S. Vostokova
Keyword(s):  
Black Sea ◽  
Elevated Temperatures ◽  
Water Area ◽  
Emiliania Huxleyi ◽  
Horizontal Distribution ◽  
Conditional Density ◽  
The Black Sea ◽  
Winter Period ◽  
The North ◽  
Seasonal Thermocline

At the end of May 2013, in the Abkhazian sector of the north-eastern part of the Black Sea, intensive blooms of Emiliania huxleyi coccolithophores of up to 4,4×106 cells/L were observed. In order to identify the necessary and sufficient hydrophysical conditions for the blooming of this alga at 15 stations of the water area, the spatial distribution of hydrophysical parameters was investigated. It is shown that the vertical distribution of temperature, salinity and density is typical for this time of year and is characterized by the presence of a sharp-gradient seasonal thermocline. The horizontal distribution of the main hydrophysical parameters on the surface water was as follows: at an average temperature of 20,209±1,027°C, the areas of elevated temperatures were located in the coastal zone, for salinity (17,585±0,556 psu) the reverse distribution was observed. Variations of conditional density were 11,477±0,516. A characteristic feature of 2013 was the renewal of the Cold Intermediate Layer (CIL) in the winter period. During the bloom period, the coccolithophores tended to be deepened along the coordinate from the center of the sea to the coast. Variations in the speed of geostrophic currents from 3,58 to 22,43 cm/s did not lead to the destruction of the bloom.

CURRENT STATE OF CASPIAN SEAL POPULATION

2017 ◽  
pp. 35-45
Author(s):  
Vasilii Vladimirovich Kuznetsov
Keyword(s):  
Caspian Sea ◽  
Ecological Monitoring ◽  
Water Area ◽  
Fishing Effort ◽  
Winter Period ◽  
The Caspian Sea ◽  
Current State ◽  
Seal Population ◽  
Ship Route ◽  
Caspian Seal

The work presents Caspian seal study review. The study gives investigation results on the current state of Caspian seal population, as well as advanced techniques of determining the number of offspring and producing females. In February 2012 during reproduction period the instrumental air-accounting survey was carried out on ice-water area in the Northern part of the Caspian Sea. For the first time in the history of the air-accounting investigations of seals in the Caspian Sea scientists used thermovision camera survey IK-scanner "Malakhit-M" which helped specify the number of white-coat seals and greatly improve deciphering methods of the obtained materials. The authors discuss the drawbacks of the earlier air-surveys of the Caspian seals (made before 2012) carried out by a group of researches. The work gives characteristics of nutrient resources of the Caspian Sea and annual food necessity of Caspian seal population. The nutrient base of seals is sound and food stocks tend to grow in the future. The work gives the reasons of decrease of seal catch since 1967; it is associated with the reduction of the fishing effort and re-orientation in winter period by the method of marine fisheries. The article shows that ship route accounting alive and dead species in different parts of the Caspian Sea which was used for ecological monitoring of the population permits to effectively control the changes of seal number, including mass epizootics. In recent years ship-route accounting has shown the stable dynamics of average concentrations of seals in the Northern, Middle and Southern parts of the Caspian Sea. Ship-route accounting presents the up-to-date total number of the seal population.

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