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Open access

Azatuhi Hovsepyan, Vahagn Muradyan, Garik Tepanosyan, Lilit Minasyan and Shushanik Asmaryan

Abstract

Lake Sevan being Armenia’s largest freshwater reservoir has a vital economic, recreational and cultural importance to both the catchment area and the nation as a whole. At present the Sevan which has seen the dramatic - some 20m drop - in water level entailing grave ecological consequences to the whole of its ecosystem, is at the stage of recovery. Hence, it is very important to study basic parameters describing the ecological status of the lake, and their annual and seasonal dynamics. The Sevan water surface temperature (WST) is a key parameter which influences all ecological processes that occur in the Lake. Declining lake level has brought to reduction of water volume and consequently to earlier warming of lake water in spring and its earlier cooling in the fall. Besides, more frequent becomes the complete surface freezing of Lake Sevan. Remotely sensed imagery makes it possible to get immediate information on a regular basis about WST across the entire surface of lakes. The purpose of this particular research was to study the space and time dynamics of Lake Sevan WST using Landsat 8 satellite imagery. The advantage of Landsat8 images is a regular frequency of capturing and availability of another thermal band that helps reduce the atmospheric refraction-induced errors/deviations. This research involved Landsat imagery for 2000-2018. The images underwent preprocessing steps (radiometric calibration, atmospheric correction, normalization etc) and then Lake Sevan WSTs and their monthly and annual changes over the mentioned periods were derived using both thermal bands (b10, b11). The research confirmed the fact, that Lake Sevan surface completely or partly freezing with periodicity of 2-3 years, whereas before the water drop the periodicity was 15-20 years. The study of spatial distribution of WST data derived from remote sensing shows that the temperature data corresponds to the overall general picture of temperature for Lake Sevan. This research has indicated that remotely sensed images and Landsat 8 imagery in particular allow derive both WST data on a regular basis and retrospective data (since 2013).

Open access

Arevik Minasyan

Abstract

Haematococcus pluvialis is a genus of green algae that keeps the high interest of the scientists for decades due to its capacity to synthesize astaxanthin. Among many others, astaxanthin is one of the most demanded natural anti-oxidant and the product of the future. It has the widest usage as source of nutrient rich food and health promoting compounds. Astaxanthin has got various applications in the nutraceuticals as immune system enhancer and anti-cancer agent, in the cosmetics as anti-aging component, as additive to food, as well as in the aquaculture industries. As a key requirement for the research in this field is to find out the better conditions and media to stimulate the H.pluvialis higher growth rate to reach in the field of microalgae economically sustainable cultivation and processing. The effect of WC versus BG-11 media to enhance growth rate of Haematococcus pluvialis has been examined. This study employed a parallel testing of stimulating effect of extra vitamins versus phosphorus. Combination of mentioned parameters with gentle shacking have been determined as multiple effectors that contribute to green algae cultures to grow to high density. Importantly, this study demonstrates that extra phosphorus contribute to growth rate of H.pluvilais positively, meanwhile addition of extra vitamins in combination with extra phosphorus impact both positively and negatively to promote cells division. Shacking influences the culture growth as either stimulator or repressor.

Open access

Georgiana Grigoraș and Bogdan Urițescu

Abstract

The aim of the study is to find the relationship between the land surface temperature and air temperature and to determine the hot spots in the urban area of Bucharest, the capital of Romania. The analysis was based on images from both moderate-resolution imaging spectroradiometer (MODIS), located on both Terra and Aqua platforms, as well as on data recorded by the four automatic weather stations existing in the endowment of The National Air Quality Monitoring Network, from the summer of 2017. Correlation coefficients between land surface temperature and air temperature were higher at night (0.8-0.87) and slightly lower during the day (0.71-0.77). After the validation of satellite data with in-situ temperature measurements, the hot spots in the metropolitan area of Bucharest were identified using Getis-Ord spatial statistics analysis. It has been achieved that the “very hot” areas are grouped in the center of the city and along the main traffic streets and dense residential areas. During the day the "very hot spots” represent 33.2% of the city's surface, and during the night 31.6%. The area where the mentioned spots persist, falls into the "very hot spot" category both day and night, it represents 27.1% of the city’s surface and it is mainly represented by the city center.

Open access

Areful Hoque

Abstract

Housing environment can influence our health in many ways. Health can be adversely affected by poor water quality, bad sanitation condition, nature of houses, housing using fuels and nature of works done by the dwellers for earning the bread. Bidi is also called poor man’s cigarette, made up of coarse uncured tobacco, tied with a string at one end. The bidi rolling is mainly a labor-intensive industry in India, coming under the category of un-organized sector, the lion share being women. The principle objective of this paper is to understand and analyze the quality of housing environment and status of health among the bidi workers. Malda district of West Bengal (India) has been selected as a study area, famous for mango cultivation and sericulture activities. The study is based on primary and secondary sources of data. Health is the most serious problems of workers in bidi industry. The working places of bidi industry are unhygienic, dingy and overcrowded, having little facilities of drinking water, even toilet facility and first aid. During the entire working time the bidi workers are exposed to tobacco fumes, thus these incidences create serious diseases (major and minor). The study also provoked that among the major diseases cough and cold diseases are mostly found (33.33 per cent) and Tuberculosis disease is at the lowest (9.00 per cent). The researchers suggested that there is an urgent need to issue the Health Card to the workers for treatment and curing of various diseases at government hospitals at subsidy rate.

Open access

Andreea-Mihaela Dunca

Abstract

Banat, a region situated in the western and south-western extremity of Romania, benefits from a defense network of meteorological stations in which a meteorological long-term monitoring activity of approximately 150 years is being carried out. Geographical position and diversity of physico-geographical conditions, under the influence of atmospheric circulation factors, determine both the major features of the climate in this region, as well as its local nuances. In order to analyze the spatial and temporal distribution of air temperature in Banat, we collected data strings and continuous meteorological observations from 14 weather stations in this area over a 35 years period (1979-2013). In Banat the air temperature regime presents a series of particularities and a patchy distribution as a result of the interaction of dynamic processes with the great diversity of these physicogeographical conditions. Analyzing the meteorological data strings one can observe that the air temperature varies in Banat, both spatially, from one meteorological station to another, and temporally from one year to another, from one semester to another, from one season to another but also from one month to the next due to the frequency and intensity of the advection of the different masses of air. The analysis of the air temperature and the thermal regime in Banat region confirms the moderate climate, with quite strong Oceanic influences from the western part of Europe and the weaker sub-Mediterranean influences, from the southwestern part of the continent. However, as a consequence of the global climate changes we are witnessing, at least in the last 50 years, there has also been a trend in Banat to increase the average annual temperature.

Open access

Md. Salauddin, Khandaker Tanvir Hossain, Istiaqe Ahmed Tanim, Md. Anisul Kabir and Mehedi Hasan Saddam

Abstract

The study attempted to assess the changes in shoreline and erosion-accretion of newly formed island at the mouth of the Meghna river estuary in Bangladesh using multi temporal satellite images and GIS techniques. The current study used NDWI an MNDWI to delineate land and water boundary to extract the shoreline and also used some overlay analysis to measure the erosion-accretion. DSAS extension is used for analyzing the shifting of the shoreline. The results (1990-2015) show that the island has 1192 hectares of land accreted during this time period, and about 1 km of its shoreline lost during this time period as it has broken in few places. Most accretion found in the northwestern part and erosion in southeastern and southwestern part. The study area was divided into four different segments and about 115 transects were constructed, of which about 74 shows the seaward movement and 44 shows landward movement. Seaward movement and rate of shoreline shifting is higher in the northwestern part where net shoreline movement (NSM) is +1897 meters and end point rate (EPR) is +73 m/year. Landward movement and the rate of shoreline shifting are higher in southeastern and southwestern part of which net shoreline movement (NSM) is about -2680 meters and end point rate (EPR) is about -129 m/year. The highest landward movement is found as -2680 meters and highest seaward movement as +1897 meters. Accretion process is dominant while erosion process discontinued the shoreline in some places.

Open access

Tayeb Sitayeb and Ishak Belabbes

Abstract

Landscape dynamics is the result of interactions between social systems and the environment, these systems evolving significantly over time. climatic conditions and biophysical phenomena are the main factors of landscape dynamics. Also, currently man is responsible for most changes affecting natural ecosystems. The objective of this work is to study the dynamics of a typical landscape of western Algeria in time and space, and to map the distribution of vegetation groups constitute the vegetation cover of this ecosystem. as well as using a method of monitoring the state of a fragile ecosystem by remote sensing to understand the processes of changes in this area. The steppe constitutes a large arid area, with little relief, covered with low and sparse vegetation. it lies between the annual isohyets of 100 to 400 mm, subjected to a very old human exploitation with an activity of extensive breeding of sheep, goats, and camels. Landsat satellite data were used to mapping vegetation groups in the Mecheria Steppe at a scale of 1: 300,000. Then, a comparison was made between the two maps obtained by a classification of Landsat-8 sensor Operational Land Imager (OLI) acquired on March 18, 2014, and Landsat-5 sensor Thematic Mapper (TM) acquired on April 25, 1987. The results obtained show the main changes affecting the natural distribution of steppe species, a strong change in land occupied by the Stipa tenacissima steppe with 65% of change, this steppe is replaced by Thymelaea microphylla, Salsola vermiculata, lygeum spartum and Peganum harmala steppe. an absence from the steppe Artemisia herba-alba that has also been replaced by the same previous steppes species. The groups with Quercus ilex and Juniperus phoenicea are characterized by a strong regression that was lost 60% of its global surface and transformed by steppe to stipa tenacissima and bare soil.

Open access

Paul Macarof, Stefan Groza and Florian Statescu

Abstract

In this paper is investigating correlation between land surface temperature and vegetation indices (Normalized Difference Vegetation Index - NDVI, Enhanced Vegetation Index 2 - EVI2 and Modified Soil Adjusted Vegetation Index - MSAVI) using Landsat images for august, the warmest month, for study area. Iaşi county is considered as study area in this research. Study Area is geographically situated on latitude 46°48'N to 47°35'N and longitude 26°29'E to 28°07'E. Land surface temperature (LST) can be used to define the temperature distribution at local, regional and global scale. First use of LST was in climate change models. Also LST is use to define the problems associated with the environment. A Vegetation Indices (VI) is a spectral transformation what suppose spatial-temporal intercomparisons of terrestrial photosynthetic dynamics and canopy structural variations. Landsat5 TM, Landsat7 ETM+ and Landsat8 OLI, all data were used in this study for modeling. Landsat images was taken for august 1994, 2006 and 2016. Preprocessing of Landsat 5/7/8 data stage represent that process that prepare images for subsequent analysis that attempts to compensate/correct for systematic errors. It was observed that the “mean” parameter for LST increased from 1994 to 2016 at approximately 5°C. Analyzing the data from VI, it can be assumed that the built-up area increased for the Iasi county, while the area occupied by dense vegetation has decreased. Many researches indicated that between LST and VI is a linear relationship. It is noted that the R2 values for the LST-VI correlations decrease from 1994 (i.g.R2= 0.72 for LST-NDVI) in 2016 (i.g.R2= 0.23 for LST-NDVI). In conclusion, these correlation can be used to study vegetation health, drought damage, and areas where Urban Heat Island can occur.

Open access

Raj Singh Bhanwar Vishvendra and Anjan Sen

Abstract

In the near future, natural resources are very rapidly diminishing all over the globe. Which is very unhealthy for land ecosystem services. In the biodiversity, Tiger is an icon of healthy wildlife which is considered as a vital factor for maintaining Universal Food Chain System. This research paper is based on “Geo-Spatial Mapping of land use and land cover changes in the Core and Periphery Area of Ranthambore Tiger Reserve, Rajasthan, India, 1975-2015, it’s a micro level Study based on primary and secondary data through GIS mapping and consider as a Socio-Economic & Physical factors to inter-connect with Tiger habitats. Especially, core and periphery LULC have been obtained from the Multispectral images from ETM and ETM+ sensors of Landsat and LISS-III and AWiFS sensors of Resourcesat-satellites. This study examines the spatial and temporal patterns of LULC change along the boundary of Ranthambhore in the Rajasthan from 1975 to 2015. Tiger Landscape change within all ecological zones will be evaluated. The Landsat TM and ETM imagery will be used to produce LULC classification maps for both areas using a hybrid supervised/unsupervised methods. LULC changes are measured using landscape metrics and change maps created by post-classification through change detection. Using all the raster maps and the final change detection of the reserve will be done through spatial analysis using the raster calculator tool in ArcGIS and Erdas and MS Excel 13. The study comes out with land use and land cover change in core and periphery areas of the reserve. The research also describes Human Encroachment, Impact on human colonization, interfere with domestic animals, Interbreeding, and the Migration in core and periphery areas, finally, the situation would be alarming for biodiversity of tiger habitat due to the high pressure of anthropogenic activities.