The abundance and health of scleractinian coral communities of Hormuz Island were investigated.For this purpose,we employed 20 m line intercept transects—12 in the intertidal zone and 15 subtidally to evaluate coral ...The abundance and health of scleractinian coral communities of Hormuz Island were investigated.For this purpose,we employed 20 m line intercept transects—12 in the intertidal zone and 15 subtidally to evaluate coral cover and community composition.The estimated dead coral coverage was 6.21%±0.81%,while live coral coverage was 16.93%±1.81%,considered as very poor.Totally,12 genera were recorded,of which Porites with 11.9%±1.4%live cover was the dominant,while Goniopora had the least cover(0.07%±0.08%).Based on Mann-Whitney U-test,live coral coverage,dead coral coverage,algal coverage,cover of other benthic organisms and abiotic components showed significant univariate differences between zones(p<0.05).The Spearman correlation test between the abundance of biotic and abiotic components indicated significant negative correlation of live coral and sand with zoantharian and significant positive correlation of algae and other benthic organisms with rubble.The reef health indices used for the corals indicated that,in general,the environmental conditions were not suitable,which could be attributed to both natural and anthropogenic factors,the most important of which was zoantharian’overgrowth on the scleractinian corals in this region.展开更多
One of the basic prerequisites for the development of spatial programs and policies is evaluating the land suitability for future land uses based on the principals of ecological sustainability. This analysis is critic...One of the basic prerequisites for the development of spatial programs and policies is evaluating the land suitability for future land uses based on the principals of ecological sustainability. This analysis is critical in islands due to special characteristics such as limited natural resources, interdependent and more complex ecosystems, high vulnerability to natural hazards, climate change and economic vulnerability. Accordingly, this paper based on the ecological approach and using Geographic Information System software package and Analytic Hierarchy Process and developing appropriate criteria has analyzed the land suitability of Hormuz Island. The findings clearly show the land suitability to develop industrial, agriculture, tourism land uses and can be the basis for planning the future development of the island based on the ecological sustainability.展开更多
The objective of this paper is to introduce an appropriate unidirectional wave spectrum model for the Strait of Hormuz. The research is focused on assessing performance of standard wave spectrum models in the region. ...The objective of this paper is to introduce an appropriate unidirectional wave spectrum model for the Strait of Hormuz. The research is focused on assessing performance of standard wave spectrum models in the region. By evaluating such models based on valuable measurement data recently published, the calibration procedure has been conducted on such standard models to reach a better concordance between a modified standard spectral model and observed field spectra. The calibration is performed initially with respect to four distinct directions related to four available measurement stations. So, it results in four sets of coefficients for a nominated model. Next, it is continued to reach just one model insensitive to directions. Results clearly showed that the International Towing Tank Conference （ITTC） model is more appropriate than Joint North Sea Wave Project （JONSWAP） and Pierson and Moskowitz （PM） models in this area, even without any calibration. However, modifications have been successful on improving the conformity of the model.展开更多
Profiles of salinity and temperature were measured in the strait of Hormuz（SH） during the winter of 2012, spring and summer of 2013. To investigate the double diffusion（DD） processes, Turner（TU） angle values are...Profiles of salinity and temperature were measured in the strait of Hormuz（SH） during the winter of 2012, spring and summer of 2013. To investigate the double diffusion（DD） processes, Turner（TU） angle values are calculated in all the stations in the SH. Different TU angle values correspond to salt fingering（SF）, diffusive convection（DC）and stable stratification. The distributions of the two forms of DD were plotted vertically along transects in the eastern, central and western part of the SH, and corresponding DD processes were described. The results show that both SF and DC occurred in most part of the study area. Two different water masses（the Indian Ocean surface water and the Persian Gulf water） were evident at the SH, and SF and DC were evident at the interface of two water masses. Due to evaporation, SF occurred in the surface layer of most Stations throughout the year. In the eastern part of the SH, occurrences of DC were more feasible in wintertime. SF was the main phenomenon at the end of hot season. For central part, SF occurred throughout the year in water column. In the western part,water column was stable in summer and DC happened in most part of water column in winter.展开更多
This study was carried out to investigate the Cochlodinium polykrikoides fluctuations in the north of Oman Sea during pre- and post-monsoon season in 2008. The study area was divided into 10 transects （TI-T10） from ...This study was carried out to investigate the Cochlodinium polykrikoides fluctuations in the north of Oman Sea during pre- and post-monsoon season in 2008. The study area was divided into 10 transects （TI-T10） from the Strait of Hormuz （T1） to Gwadar （TI0） which cover the whole of the Iranian waters in the Oman Sea. The results showed that at first, Cochlodinium polykrikoides appeared in the northeast part （T10） in the pre-monsoon season, then it spread to other parts of the study area. Cochlodinium polykrikoides was observed in greater abundance in the Strait of Hormuz in the post-monsoon season. The results demonstrated that T10 （transect 10） had the highest abundance in the pre-monsoon season. The Kruskal-Wallis test showed a significant difference among transects （P 〈 0.05）. The present study showed that the abundance of Cochlodinium polykrikoides increased from coastal to offshore waters in the pre-monsoon season; however, in the post-monsoon season, there was a higher abundance in coastal waters compared to the offshore zone. It could be seen that the abundance of Cochlodinium polykrikoides started in offshore waters, then increased in coastal waters. During the pre-monsoon season, water discoloration was not observed, however, the water changed to brown from T 1 to T4 （northwest） and blooms of Cochlodinium polykrikoides was recorded in the post-monsoon season.展开更多
The object-based against pixel-based image analysis approaches were assessed for lithological mapping in a geologically complex terrain using Visible Near Infrared(VNIR)bands of WorldView-3(WV-3)satellite imagery.The ...The object-based against pixel-based image analysis approaches were assessed for lithological mapping in a geologically complex terrain using Visible Near Infrared(VNIR)bands of WorldView-3(WV-3)satellite imagery.The study area is Hormuz Island,southern Iran,a salt dome composed of dominant sedimentary and igneous rocks.When performing the object-based image analysis(OBLA)approach,the textural and spectral characteristics of lithological features were analyzed by the use of support vector machine(SVM)algorithm.However,in the pixelbased image analysis(PBIA),the spectra of lithological end-members,extracted from imagery,were used through the spectral angle mapper(SAM)method.Several test samples were used in a confusion matrix to assess the accuracy of classification methods quantitatively.Results showed that OBIA was capable of lithological mapping with an overall accuracy of 86.54%which was 19.33%greater than the accuracy of PBIA.OBIA also reduced the salt-and-pepper artifact pixels and produced a more realistic map with sharper lithological borders.This research showed limitations of pixel-based method due to relying merely on the spectral characteristics of rock types when applied to high-spatial-resolution VNIR bands of WorldView-3 imagery.It is concluded that the application of an object-based image analysis approach obtains a more accurate lithological classification when compared to a pixel-based image analysis algorithm.展开更多
文摘The abundance and health of scleractinian coral communities of Hormuz Island were investigated.For this purpose,we employed 20 m line intercept transects—12 in the intertidal zone and 15 subtidally to evaluate coral cover and community composition.The estimated dead coral coverage was 6.21%±0.81%,while live coral coverage was 16.93%±1.81%,considered as very poor.Totally,12 genera were recorded,of which Porites with 11.9%±1.4%live cover was the dominant,while Goniopora had the least cover(0.07%±0.08%).Based on Mann-Whitney U-test,live coral coverage,dead coral coverage,algal coverage,cover of other benthic organisms and abiotic components showed significant univariate differences between zones(p<0.05).The Spearman correlation test between the abundance of biotic and abiotic components indicated significant negative correlation of live coral and sand with zoantharian and significant positive correlation of algae and other benthic organisms with rubble.The reef health indices used for the corals indicated that,in general,the environmental conditions were not suitable,which could be attributed to both natural and anthropogenic factors,the most important of which was zoantharian’overgrowth on the scleractinian corals in this region.
文摘One of the basic prerequisites for the development of spatial programs and policies is evaluating the land suitability for future land uses based on the principals of ecological sustainability. This analysis is critical in islands due to special characteristics such as limited natural resources, interdependent and more complex ecosystems, high vulnerability to natural hazards, climate change and economic vulnerability. Accordingly, this paper based on the ecological approach and using Geographic Information System software package and Analytic Hierarchy Process and developing appropriate criteria has analyzed the land suitability of Hormuz Island. The findings clearly show the land suitability to develop industrial, agriculture, tourism land uses and can be the basis for planning the future development of the island based on the ecological sustainability.
文摘The objective of this paper is to introduce an appropriate unidirectional wave spectrum model for the Strait of Hormuz. The research is focused on assessing performance of standard wave spectrum models in the region. By evaluating such models based on valuable measurement data recently published, the calibration procedure has been conducted on such standard models to reach a better concordance between a modified standard spectral model and observed field spectra. The calibration is performed initially with respect to four distinct directions related to four available measurement stations. So, it results in four sets of coefficients for a nominated model. Next, it is continued to reach just one model insensitive to directions. Results clearly showed that the International Towing Tank Conference （ITTC） model is more appropriate than Joint North Sea Wave Project （JONSWAP） and Pierson and Moskowitz （PM） models in this area, even without any calibration. However, modifications have been successful on improving the conformity of the model.
基金The proieect of Iranian National Institute for Oceanography and Atmospheric Science(INIOAS)in the framework of PG-GOOS cruise under contract No.391-021-01
文摘Profiles of salinity and temperature were measured in the strait of Hormuz（SH） during the winter of 2012, spring and summer of 2013. To investigate the double diffusion（DD） processes, Turner（TU） angle values are calculated in all the stations in the SH. Different TU angle values correspond to salt fingering（SF）, diffusive convection（DC）and stable stratification. The distributions of the two forms of DD were plotted vertically along transects in the eastern, central and western part of the SH, and corresponding DD processes were described. The results show that both SF and DC occurred in most part of the study area. Two different water masses（the Indian Ocean surface water and the Persian Gulf water） were evident at the SH, and SF and DC were evident at the interface of two water masses. Due to evaporation, SF occurred in the surface layer of most Stations throughout the year. In the eastern part of the SH, occurrences of DC were more feasible in wintertime. SF was the main phenomenon at the end of hot season. For central part, SF occurred throughout the year in water column. In the western part,water column was stable in summer and DC happened in most part of water column in winter.
文摘This study was carried out to investigate the Cochlodinium polykrikoides fluctuations in the north of Oman Sea during pre- and post-monsoon season in 2008. The study area was divided into 10 transects （TI-T10） from the Strait of Hormuz （T1） to Gwadar （TI0） which cover the whole of the Iranian waters in the Oman Sea. The results showed that at first, Cochlodinium polykrikoides appeared in the northeast part （T10） in the pre-monsoon season, then it spread to other parts of the study area. Cochlodinium polykrikoides was observed in greater abundance in the Strait of Hormuz in the post-monsoon season. The results demonstrated that T10 （transect 10） had the highest abundance in the pre-monsoon season. The Kruskal-Wallis test showed a significant difference among transects （P 〈 0.05）. The present study showed that the abundance of Cochlodinium polykrikoides increased from coastal to offshore waters in the pre-monsoon season; however, in the post-monsoon season, there was a higher abundance in coastal waters compared to the offshore zone. It could be seen that the abundance of Cochlodinium polykrikoides started in offshore waters, then increased in coastal waters. During the pre-monsoon season, water discoloration was not observed, however, the water changed to brown from T 1 to T4 （northwest） and blooms of Cochlodinium polykrikoides was recorded in the post-monsoon season.
文摘The object-based against pixel-based image analysis approaches were assessed for lithological mapping in a geologically complex terrain using Visible Near Infrared(VNIR)bands of WorldView-3(WV-3)satellite imagery.The study area is Hormuz Island,southern Iran,a salt dome composed of dominant sedimentary and igneous rocks.When performing the object-based image analysis(OBLA)approach,the textural and spectral characteristics of lithological features were analyzed by the use of support vector machine(SVM)algorithm.However,in the pixelbased image analysis(PBIA),the spectra of lithological end-members,extracted from imagery,were used through the spectral angle mapper(SAM)method.Several test samples were used in a confusion matrix to assess the accuracy of classification methods quantitatively.Results showed that OBIA was capable of lithological mapping with an overall accuracy of 86.54%which was 19.33%greater than the accuracy of PBIA.OBIA also reduced the salt-and-pepper artifact pixels and produced a more realistic map with sharper lithological borders.This research showed limitations of pixel-based method due to relying merely on the spectral characteristics of rock types when applied to high-spatial-resolution VNIR bands of WorldView-3 imagery.It is concluded that the application of an object-based image analysis approach obtains a more accurate lithological classification when compared to a pixel-based image analysis algorithm.
