جستجوی مقالات مرتبط با کلیدواژه « gis » در نشریات گروه « زیست شناسی »

One of the most important concerns in fisheries management is finding suitable areas and zones to invest in aquaculture with a sustainable development approach. The use of GIS is one of the most important factors for success in aquaculture development.  Site selection of sturgeon breeding and farming locations was carried out using the facilities of GIS and data analysis was performed using fuzzy model, hierarchical analysis process and the fuzzy criteria AHP. The main criteria used in this study were ecological, climatic, natural and environmental, economic and social factors, barriers and limitations and sensitive habitats. Then, using the weighting method, a competency map was prepared and with considering the merit and applying the average of the merit value of each place, the priority of each place was determined. Combining this method with fuzzy logic and application in GIS environment and also taking into consideration the weight and relative importance of each feature and option, has increased the efficiency of this method. According to the results, the highest weight was awarded to ecological factors (0.321), the next ranks were awarded to climate (0.205), economic and social (0.179), natural (0.167) factors and barriers and restrictions (0.129), respectively. The most suitable areas for the development of sturgeon breeding and culture centers are located in the northern, northeastern and eastern regions of the Khuzestan province. The most unsuitable sites are located in the southern regions of the province.

Ecological Niche models are ways that allow approximating the area of suitability for a species, thereby allowing elaboration of conservation strategies. In order to creat a model the habitat of Onobrychis cornuta Ecological Niche Factor Analysis (ENFA) method in a Biomapper software has been used. In this study, the presence points of species used as a dependent variable and 14 environmental variables used as an independent variable. First this layers were prepared and then analyzed by Ecological Niche Factor Analysis (ENFA) method. Influential environmental variables such as A.m.t, Aspect, Ec, Slop, and TNV have been used. The results of species marginalization shows that this species tends to live in habitat of marginalization. Also, the evaluation of the model using the Cross Validation (0.8) indicate high accuracy model of Ecological Niche Factor Analysis for Onobrychis cornuta in the study area. This way of modeling could be widely used to identify appropriate areas for protecting of valuable native plant species

This research evaluates the conservation status of Lorestan newt to find new habitats and offers solutions for its protection. In this study, first by studying past researches and inquiring from local people and specialists, and then field visits and collecting information about the fauna and flora of the region and photographing, information about previous habitats as well as new habitats were obtained. Due to the dependence of Lorestan newt on rainfall, humidity, and temperature, changes in precipitation during a year and changes in temperature and humidity were studied, which could help explain the reason for the decline of Lorestan newt. Among the reasons for the decline of this species can be: a) natural threats such as floods, drought, prey, diseases, parasites, b) human threats such as financial abuse, decoration, illegal trade, unscientific research activities, tourists and mountaineers by creating noise pollution and habitat destruction, and adding detergents to water, and c) lack of applied research projects. In this study, 29 habitats were identified and surveyed. The area where the Lorestan newt is found starts from Tang Haft (Lorestan province) to Shahzade Ahmad (Khuzestan province). Habitats of Lorestan province include Tafo, Darreh Gol, Dolshali, Ab Anbar, Nargeseh or Zalazel, Kolchep Waterfall, Abkash, Choobeh, Ashk Ab, Lisaneh, Dol Nisar, Kresar, Moor Dastan, and Vejan Ab Waterfall. Habitats of Khuzestan province include Sargach, Leopard Valley, Karam Ab, Labsefid, Cheshmeh Zayd, Abshare Bozorg, Ab Zaleh, Ab Sardeh, Chenar Mengereh, Deh Sorkheh, Shahzade Ahmad, Haji Barikab, Kol Saad, and Tale Zang or Abshar Shui.  A new habitat has been identified in Haft Cheshmeh village of Poldakhtar city of Lorestan province, called Chalkel, which is located 5 km from Balmak wetland. Unlike waterfall habitats, this habitat has hot dry weather conditions.

Asalouyeh  is one of  the most important oil and gas centers in the southwest of Iran, Bushehr province and on the northern coast of the Persian Gulf. Due to the petrochemical and petroleum industries along the coast,oil derivatives leak into the sea, causing pollution of the water basin in the Asalouyeh area and neighboring areas, which is an environmental threat.The GNOME  model is a lagrangian-Eulerian model that is used to find wastewater and contaminated areas. In this paper, to assess the risk of areas affected by the petrochemical effluent contamination of the Asalouyeh coastal area,the refined  petroleum effluent diversified under 3 scenarios with Non-weathering materials, Fuel oil 4 and Fuel oil 6 and each in two volumes of 10 and 100 , set for 2018. Then,wind and flow were analyzed in the area and applied as input file to the model.Subsequently, GIS-based analyzes were used to map and estimate contaminated areas. GIS output estimates and mapping estimates showed that the highest level of contamination was  related to Non-weathering material with an area of 10.92 , which occurred in spring due to increased wind speed and consequently increased water flow. Also, Fuel oil 6 had the highest dispersion, which occurred in the spring. Final results showed that the extent of the contamination with an area of 1.31  reached to the eastern and southeastern parts of Asalouyeh, the Hala and Hara forest area of  Nayband Bay, a national protected area and national park

In general, fishing activities are considered as one of the most important environmental disturbances in increasing the vulnerability of the mangrove ecosystems due to their destructive effects on the process of sedimentation and wave currents, decreasing biodiversity, and introducing oil pollutants into these ecosystems. Therefore, investigating and mapping the intensity of fishing activities in mangrove habitats are of great needs in conducting the vulnerability assessment and providing managerial solutions and empowerment of these ecosystems to minimize and compensate the damages caused by environmental hazards. The aim of this study was to investigate, determine, and delineate and the intensity of fishing activities in the mangrove habitats of the Hormozgan province. To this end, the map of intensity of fishing activities was prepared in Khamir, Qeshm, Tiab, Sirik and Jask habitats through mapping the mangrove habitats, drawing 598 cell networks of 4 × 4 km in the coastal waters and the available geospatial data, and number of vessels in the fishing ports of the Hormozgan province. The results showed that in terms of the geographic distribution and the number of vessels in the fishing ports of the Hormozgan province, the intensity of the fishing activities in the mangrove habitats is ranked as follows: Khamir habitat> Qeshm habitat> Tiab habitat> Jask habitat> Sirik habitat. The results of this study can be used as a prerequisite for assessing the vulnerability of the mangroves of Iran.

Forests are the most important genetic reserves in the world and are considered to be the main sources of water and soil, which, in order to play their role, requires a biodiversity factor. Alborz province has an appropriate species diversity due to the special climatic conditions, diversity of topography, and a large part of its area located in the folds of Alborz Mountains. In this regard, studying its tree and shrub genetic reserves is very important. The present study was conducted in two phases of justification and detailed. In the first stage, information about tree species and shrubs in Alborz province and their districts were obtained based on valid sources. Then, the Landsat 8 satellite image (2014) was prepared for Alborz Province. After calculating the vegetation index and writing the minimum-maximum functions, fields with trees and shrubs were separated from the empty areas. Entering the arena began with recording geographic location, identifying tree species and shrub species and developing distribution maps. The results showed that in less than 3 percent of the province Rosaceae families with 49.12 percent, Cupressaceae with 24.56, Berberidaceae with 12.28, Elaeagnaceae with 5.26, Betulaceae with 3.5, Aceraceae with 1.75, Leguminosae with 1.75 and Rhamnaceae with 1.75 percent, respectively, in terms of species form tree and shrub cover.

The present study aimed to survey heavy and toxic metal pollution (lead and cadmium) in the southern Caspian Sea basin through Liza aurata</em> using geographic information system (GIS).  Samples of the gill tissue of adult Liza aurata</em> were taken in 10 stations over the southern coast of the Caspian Sea in spring and fall. Interpolation method, Kennedy density function, Moran test, and Gi* index in the GIS were used to determine the spatial distribution, density, zoning and distribution pattern of the metals. The uptake of lead and cadmium was 1.88 and 1.23 µg/g in spring, and 1.42 and 0.79 µg/g in fall, respectively. Analysis of GIS maps showed that concentration and centralization of both metals reduced from East to West. According to Moran test and Gi* index, the distribution of the metals had a strong and hot cluster pattern that reveals the accumulation and closeness of high-density polluted areas. Finally, it can be stated that the pollution of the eastern part of the Caspian Sea (Bandar Turkman and Khajeh-nafs) is higher than permissible international standard limits.

This study aimed to fulfill demands of information on aquaculture capability and to estimate ecological potential in Golestan Province. Aquaculture site selection (warm and cold water fishes) was conducted by MCE[1] method using GIS. The aquaculture suitability maps were produced by multi-criteria evaluation model (MCE), Fuzzy and Analytic Hierarchy Process (AHP) in ArcGIS 9.3. The most appropriate site for warm and cold water aquaculture was identified by improving the quality and data precision including elevation digital model map with an appropriate pixel size, rock map, agrology, water quality parameters (water temperature, acidity salinity) and etc. Results implicated the potential of the study area for aquaculture development in commercial scale. The other finding in terms of commercial aquaculture obtained in the present study was the near-by road which accelerates delivery of the fish pond products to the civil markets.