The habitats for the wild animals are shrinking due to the clearance of forests for agriculture and industrialization.The idea of wildlife conservation begins with the identification of their acceptable habitat.Since ...The habitats for the wild animals are shrinking due to the clearance of forests for agriculture and industrialization.The idea of wildlife conservation begins with the identification of their acceptable habitat.Since this crucial information helps in the development and maintenance of the protected areas.The requirement of habitat varies with different landscapes.The bluebull(Boselaphus tragocamelus)is Asia’s largest antelope,widespread throughout the northern Indian subcontinent.Peter Simon Pallasin(1766)described it as the only member of the genus Boselaphus.The Wildlife(Protection)Act of 1972 lists it as a Schedule III animal,while the IUCN lists it as Least Concern(LC).Our goal was to design a habitat appropriateness model for blue bull so that it could reduce the conflict with farming community due to crop damage.Model will be develop using RS&GIS technique to protect the species inside the Pench Tiger Reserve(77°55’W to 79°35’E and 21°08’S to 22°00’N)the central highlands of India.The satellite data from LANDSAT-8 of 4th April 2015,Path-144,Row-45,with a ground resolution of 30 meters,were collected from the USGS website.This satellite image was then transferred in image format to ERDAS IMAGINE 2013 for further analysis.The data from satellites were gathered and analysed.The purpose of the field survey was to gather information about the presence of various ungulates.A ground truthing exercise was also carried out.For data processing and GIS analysis,ERDAS IMAGINE 13 and Arc GIS 10 were used.Analytical Hierarchy Process(AHP)was used Factors were identified who were influencing the spatial distribution of the species for conservation planning.The linear additive model was used for HSI.The results show that 242 km^(2)(29.48 percent)of Pench Tiger Reserve forest was recognized to be highly suitable for bluebull,while 196 km^(2)(23.87 percent)was moderately suitable,231 km^(2)(28.14 percent)was suitable,109 km^(2)(13.28 percent)was least suitable,and about 43 km^(2)(5.249 percent)of PTR was completely avoided by bluebull.展开更多
Habitat suitability index(HSI)models have been widely used to analyze the relationship between species abundance and environmental factors,and ultimately inform management of marine species.The response of species abu...Habitat suitability index(HSI)models have been widely used to analyze the relationship between species abundance and environmental factors,and ultimately inform management of marine species.The response of species abundance to each environmental variable is different and habitat requirements may change over life history stages and seasons.Therefore,it is necessary to determine the optimal combination of environmental variables in HSI modelling.In this study,generalized additive models(GAMs)were used to determine which environmental variables to be included in the HSI models.Significant variables were retained and weighted in the HSI model according to their relative contribution(%)to the total deviation explained by the boosted regression tree(BRT).The HSI models were applied to evaluate the habitat suitability of mantis shrimp Oratosquilla oratoria in the Haizhou Bay and adjacent areas in 2011 and 2013–2017.Ontogenetic and seasonal variations in HSI models of mantis shrimp were also examined.Among the four models(non-optimized model,BRT informed HSI model,GAM informed HSI model,and both BRT and GAM informed HSI model),both BRT and GAM informed HSI model showed the best performance.Four environmental variables(bottom temperature,depth,distance offshore and sediment type)were selected in the HSI models for four groups(spring-juvenile,spring-adult,falljuvenile and fall-adult)of mantis shrimp.The distribution of habitat suitability showed similar patterns between juveniles and adults,but obvious seasonal variations were observed.This study suggests that the process of optimizing environmental variables in HSI models improves the performance of HSI models,and this optimization strategy could be extended to other marine organisms to enhance the understanding of the habitat suitability of target species.展开更多
The habitat suitability index(HSI) model was used to identify potential sites for sustainable restoration of ark shell, Scapharca subcrenata(Lischke), in the shallow water of Xiaoheishan Island, using a geographic inf...The habitat suitability index(HSI) model was used to identify potential sites for sustainable restoration of ark shell, Scapharca subcrenata(Lischke), in the shallow water of Xiaoheishan Island, using a geographic information system framework. The seven input variables of the HSI model were sediment composition, water temperature, salinity, dissolved oxygen, water depth, p H, and ammonia. A non-linear suitability function for each variable factor was used to transform the value into a normalized quality index ranging from 0(nonsuitability) to 1(best suitability). In present study, the analysis of habitat suitability was conducted for four seasons respectively. The majority of the study area has a high HSI value(>0.6) year round, which implies a strong suitability for restoration, with the optimal habitat located on the eastern side of the island.Correspondence analysis indicated that water temperature was the main factor causing seasonal variation,while sediment composition and water depth were the two major reasons for the differences in sites. The results of this work could provide support for restoration decision making through identification of potential sites for sustainable establishment of S. subcrenata.展开更多
Based on daily average temperature,precipitation and sunshine hours during 1961-2018 from two meteorological stations of Zhaoyang District and Ludian County at Zhaolubazi,Zhaotong City,Yunnan Province,using the freezi...Based on daily average temperature,precipitation and sunshine hours during 1961-2018 from two meteorological stations of Zhaoyang District and Ludian County at Zhaolubazi,Zhaotong City,Yunnan Province,using the freezing injury index at flowering stage(Ha),climatic suitability index during expansion period(Pa),climatic suitability index during coloring period(Dy)and climatic suitability index during fruit growing period(Si),etc.,the climatic suitability of Zhaotong apple during the main growth stages was evaluated.The results showed that the annual average temperature was 11.8-12.3℃at Zhaolu Bazi in recent 60 years,and the climate was the most suitable for Fuji apple planting both in the south and north;the average annual precipitation was 674.8-852.6 mm,and the climate was suitable in the north and sub-suitable in the south;the annual average sunshine hours was between 1845.4 and 1851.1 h,and the climate was sub-suitable in both areas.The Ha was between 0.42-0.50,serious in the north and moderate in the south;the Pa was between 0.92 and 1.02,and both the south and the north were suitable areas;the Dy was between 0.95 and 1.00,and the climate in the south was suitable,while it was sub-suitable in the north;the Si was between 1.38 and 1.59,and the climate was suitable in the south and sub-suitable in the north.There was a 4-year cycle in the interannual variation of Ha,Pa,Dy and Si.After the 1980s,the Ha decreased by 0.56-0.59,the Pa,Dy and Si respectively increased by 0.10-0.16,0.14-0.15 and 0.78-0.84 with the temperature rise,and the changes of these four indexes were all favorable for Fuji apple's fruits growth.It can be seen that under the background of the global warming,the climatic conditions in Zhaolu Bazi are becoming more and more favorable for popularizing the planting of Fuji apple.展开更多
Interspecific killing is a primary reason for the low survival rates of some animal species. The giant panda(Ailuropoda melanoleuca) is an altricial eutherian mammal and thus, in comparison to other infants, panda cub...Interspecific killing is a primary reason for the low survival rates of some animal species. The giant panda(Ailuropoda melanoleuca) is an altricial eutherian mammal and thus, in comparison to other infants, panda cubs are highly vulnerable, which may significantly influence the selection of breeding sites by females. Here, we used infrared camera traps to monitor giant panda dens for 5.5 years in Foping National Nature Reserve(FNNR) to determine how interspecific factors affect den selection by wild female pandas. Results indicated that Asian black bears(Ursus thibetanus), yellow-throated martens(Martes flavigula), leopard cats(Prionailurus bengalensis), and masked palm civets(Paguma larvata) visited the dens frequently, and the presence of these species negatively influenced den selection by female pandas. Interestingly, the presence of rodents and terrestrial birds appeared to indicate den safety, and female giant pandas were not averse and even preferred dens with a high abundance index of rodents and terrestrial birds. The den suitability index(DSI) was a reliable tool for evaluating whether dens were suitable for female giant pandas to give birth to and rear cubs, with preference for dens with high DSI values. This study increases our understanding of the den selection criteria of female giant pandas and the main threats to the survival of their cubs,thus providing important guidance for the conservation and management of this species.展开更多
Finding the right balance between timber production and the management of forest-dependent wildlife species,present a difficult challenge for forest resource managers and policy makers in Okinawa,Japan.A possible expl...Finding the right balance between timber production and the management of forest-dependent wildlife species,present a difficult challenge for forest resource managers and policy makers in Okinawa,Japan.A possible explanation of this can be found in the unique nature of the forest management area which is populated with various kinds of rare and endangered species.This issue has been brought to light as a result of the nomination of northern Okinawa Island in 2018 as a candidate for World Natural Heritage site.The nomination has raised public awareness to the possibility of conflicting management objectives between timber extraction and the conservation of habitat for forest-dependent wildlife species.Managing exclusively for one objective over the other may fail to meet the demand for both forest products and wildlife habitat,ultimately jeopardizing the stability of human and wildlife communities.It is therefore important to achieve a better balance between the objective of timber production and conservation of wildlife habitat.Despite the significance of this subject area,current ongoing discussions on how to effectively manage for forest resources,often lack scientific basis to make sound judgement or evaluate tradeoffs between conflicting objectives.Quantifying the effect of these forest management activities on wildlife habitat provides useful and important information needed to make forest management and policy decisions.In this study we develop a spatial timber harvest scheduling model that incorporates habitat suitability index(HSI)models for the Okinawa Rail(Gallirallus okinawae),an endangered avian species found on Okinawa,Japan.To illustrate how the proposed coupling model assembles spatial information,which ultimately aids the study of forest management effects on wildlife habitat,we apply these models to a forest area in Okinawa and conduct a simple simulation analysis.展开更多
The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing.This study selected sea surface temperature(SST)fr...The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing.This study selected sea surface temperature(SST)from two commonly used sources,the NOAA Ocean Watch and IRI/LDEO Climate Data Library,and then constructed habitat suitability index model to evaluate the influences of SST from the two sources on the outcomes of Ommastrephes bartramii habitat models for the months of July–October in the Northwest Pacific Ocean during 1996–2012.This study examined the differences in the amount of estimated unfavourable/favourable habitat area when the SST used for model building and inference were the same or different.Dynamics in suitable habitat area calculated from SST was insensitive to the two different SST products.In the fishing season of O.bartramii,the changes of magnitude and trend of monthly suitable habitat area in August and September were similar over time,whereas there were large differences for July and October.Importantly,there is a substantial lack of consistency in the O.bartramii habitat distribution based on SST of two sources.This study considered the sources of environmental data for habitat modelling and then inferred species habitat distribution whether by the same or different data source.展开更多
Visual satisfaction of the tourists with a water body is strongly influenced by water clarity, which is in turn influenced by a number of water quality parameters. Visual satisfaction thus stands to benefit from havin...Visual satisfaction of the tourists with a water body is strongly influenced by water clarity, which is in turn influenced by a number of water quality parameters. Visual satisfaction thus stands to benefit from having a water quality management tool that results in better water clarity. A Clarity Suitability Index of Water Quality (CSIWQ), derived from clarity suitability curves of selected water quality parameters, can allow estimation of optimal values for these parameters, while ensuring high visual satisfaction among tourists. The present study used sampling and survey methodologies to investigate water clarity and quality at five tourism fishing ports;simultaneously, tourists’ visual satisfaction with a water body was assessed through a questionnaire based on their perceptions. The relationship between tourists’ visual satisfaction and water clarity was found to be positive and strong, with water clarity having predictive power of 74.2%. The study showed that DO, BOD, TP, and SS were the most critical parameters for water clarity. A continued product approach of CSIWQ was found to be most appropriate for describing the relationship between water clarity and these four parameters. This enabled a CSIWQ Index value to be calculated. With a CSIWQ value of 0.6, water clarity would be more than 2.08 m, and tourists would experience very high satisfaction. CSI curves showed that DO would preferably be 9.0 mg/L, and BOD, TP, and SS less than 0.5 mg/L, 0.12 mg/L, and 45.0 mg/L, respectively. The model thus produced valuable insights for assessing and improving water quality and ensuring high levels of visual satisfaction among tourists in tourism fishing ports. This model identified only four parameters but could be improved by ensuring that other water quality parameters were included, to encourage an increase in the number of tourists and to include monitoring of more pollutant sources.展开更多
Fisheries in Lake Victoria have been threatened by declining fish stocks and diversity, environmental degradation due to increased input of pollutants, industrial and municipal waste, overfishing and use of unapproved...Fisheries in Lake Victoria have been threatened by declining fish stocks and diversity, environmental degradation due to increased input of pollutants, industrial and municipal waste, overfishing and use of unapproved fishing <span style="font-family:Verdana;">methods, infestation by aquatic weeds especially water hyacinth, de-oxygenation</span><span style="font-family:Verdana;"> and a reduction in the quantity and quality of water. Remote sensing and GIS are essential tools in detection of fishing grounds which is important in providing fish sustainability for human beings and allows fishing grounds detection at minimal cost and optimizes effort. This research tends to identify the most favorable both environmentally and ecologically satisfactory factors which favor fish breeding and growth. The main aim of the study was to identify habitat variables that promote fish breeding and growth to maturity including the extraction of environmental variables from Landsat 8 images for the study period and using suitability index derived from fishery data. The study concentrated on establishing suitability ratings in different parts of Lake Victoria using lake surface temperature and chlorophyll-a levels. The study was conducted for months;January, May and December 2019 on Lake Victoria (limited by the availability of recent data). The factors were analysed and the favorable regions mapped satisfying the conditions for fish breeding. The output obtained illustrated the availability of suitable and habitable zones within the lake using satellite imagery and the suitability index. The fish catch data and satellite derived variables were used to determine habitat suitability indices for fish during January, May and December 2019. More than 90% of the total catch was found to come from the areas with sea surface temperature of 23.0˚C - 28.3˚C and chlorophyll-</span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">concentration between 0.72 - 1.31 mg/m</span><sup><span style="font-family:Verdana;vertical-align:super;">3</span></sup><span style="font-family:Verdana;">. The catch data was used to validate the images. This study indicated the capability of High Satellite Resolution Imageries (HSI) as a tool to map the potential fishing grounds of fish species in Lake Victoria. The variables were affected by climatic change factors like rainfall and temperature of the lake basin and other human activities around the lake and also the species ecosystem like competition or predation.</span>展开更多
It is necessary to reconstruct past changes in land use and land cover to under- stand the historical effects of humans on climate and the local environment. We collected information from historical documents on the c...It is necessary to reconstruct past changes in land use and land cover to under- stand the historical effects of humans on climate and the local environment. We collected information from historical documents on the cropland area at the county level for Heilongji- ang Province, northeast China during 1900-1910. The original records from different histori- cal documents were calibrated with each other. We then defined an agricultural suitability index quantified by the distance from settlements, the slope and complexity of the topography, and the distance from rivers. Following the order of the agricultural suitability index from high to low values, the documented areas of cropland at the county level were then allocated into 1 km x 1 km cells. The area of cropland in 2009 was then retrieved from Landsat ETM+ images and compared with the areas of cropland during 1900-1910 to determine the human-induced changes in land use and land cover. In this period, the total area of cropland was about 25,397 km2 and this mainly occurred in the mid-southern part of Heilongjiang, in particular the six counties of Hailun, Bayan, Wuchang, Hulan, Shuangcheng and Wangkui. In 2009, the total area of cropland had increased to about 163,808 km2 and had spread over the south- western part to the central and northeastern parts of Heilongjiang. The area of cropland had therefore increased by about 138,411 km2 during the 20th century. The proportion of land used as cropland increased from about 5.6% during 1900-1910 to about 36.2% in 2009, indicating that about 30.6% of the natural land surface in Heilongjiang was replaced by cropland. A total of about 44% (60,962 km2) of the cropland was converted from forest, mainly on the western edge and in the northeastern part of the present-day agricultural area. These areas of cropland reconstructed from historical records for the period 1900-1910 could be used as a basic data set to study the effects of agricultural development on climate and the local environment.展开更多
文摘The habitats for the wild animals are shrinking due to the clearance of forests for agriculture and industrialization.The idea of wildlife conservation begins with the identification of their acceptable habitat.Since this crucial information helps in the development and maintenance of the protected areas.The requirement of habitat varies with different landscapes.The bluebull(Boselaphus tragocamelus)is Asia’s largest antelope,widespread throughout the northern Indian subcontinent.Peter Simon Pallasin(1766)described it as the only member of the genus Boselaphus.The Wildlife(Protection)Act of 1972 lists it as a Schedule III animal,while the IUCN lists it as Least Concern(LC).Our goal was to design a habitat appropriateness model for blue bull so that it could reduce the conflict with farming community due to crop damage.Model will be develop using RS&GIS technique to protect the species inside the Pench Tiger Reserve(77°55’W to 79°35’E and 21°08’S to 22°00’N)the central highlands of India.The satellite data from LANDSAT-8 of 4th April 2015,Path-144,Row-45,with a ground resolution of 30 meters,were collected from the USGS website.This satellite image was then transferred in image format to ERDAS IMAGINE 2013 for further analysis.The data from satellites were gathered and analysed.The purpose of the field survey was to gather information about the presence of various ungulates.A ground truthing exercise was also carried out.For data processing and GIS analysis,ERDAS IMAGINE 13 and Arc GIS 10 were used.Analytical Hierarchy Process(AHP)was used Factors were identified who were influencing the spatial distribution of the species for conservation planning.The linear additive model was used for HSI.The results show that 242 km^(2)(29.48 percent)of Pench Tiger Reserve forest was recognized to be highly suitable for bluebull,while 196 km^(2)(23.87 percent)was moderately suitable,231 km^(2)(28.14 percent)was suitable,109 km^(2)(13.28 percent)was least suitable,and about 43 km^(2)(5.249 percent)of PTR was completely avoided by bluebull.
基金The National Key R&D Program of China under contract No.2017YFE0104400the National Natural Science Foundation of China under contract No.31772852the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)under contract No.2018SDKJ0501-2。
文摘Habitat suitability index(HSI)models have been widely used to analyze the relationship between species abundance and environmental factors,and ultimately inform management of marine species.The response of species abundance to each environmental variable is different and habitat requirements may change over life history stages and seasons.Therefore,it is necessary to determine the optimal combination of environmental variables in HSI modelling.In this study,generalized additive models(GAMs)were used to determine which environmental variables to be included in the HSI models.Significant variables were retained and weighted in the HSI model according to their relative contribution(%)to the total deviation explained by the boosted regression tree(BRT).The HSI models were applied to evaluate the habitat suitability of mantis shrimp Oratosquilla oratoria in the Haizhou Bay and adjacent areas in 2011 and 2013–2017.Ontogenetic and seasonal variations in HSI models of mantis shrimp were also examined.Among the four models(non-optimized model,BRT informed HSI model,GAM informed HSI model,and both BRT and GAM informed HSI model),both BRT and GAM informed HSI model showed the best performance.Four environmental variables(bottom temperature,depth,distance offshore and sediment type)were selected in the HSI models for four groups(spring-juvenile,spring-adult,falljuvenile and fall-adult)of mantis shrimp.The distribution of habitat suitability showed similar patterns between juveniles and adults,but obvious seasonal variations were observed.This study suggests that the process of optimizing environmental variables in HSI models improves the performance of HSI models,and this optimization strategy could be extended to other marine organisms to enhance the understanding of the habitat suitability of target species.
基金The National Natural Science Foundation of China under contract No.41206102the Program of the Key Laboratory of Marine Ecology and Environmental Science and Engineering,State Oceanic Administration under contract No.MESE-2013-01
文摘The habitat suitability index(HSI) model was used to identify potential sites for sustainable restoration of ark shell, Scapharca subcrenata(Lischke), in the shallow water of Xiaoheishan Island, using a geographic information system framework. The seven input variables of the HSI model were sediment composition, water temperature, salinity, dissolved oxygen, water depth, p H, and ammonia. A non-linear suitability function for each variable factor was used to transform the value into a normalized quality index ranging from 0(nonsuitability) to 1(best suitability). In present study, the analysis of habitat suitability was conducted for four seasons respectively. The majority of the study area has a high HSI value(>0.6) year round, which implies a strong suitability for restoration, with the optimal habitat located on the eastern side of the island.Correspondence analysis indicated that water temperature was the main factor causing seasonal variation,while sediment composition and water depth were the two major reasons for the differences in sites. The results of this work could provide support for restoration decision making through identification of potential sites for sustainable establishment of S. subcrenata.
文摘Based on daily average temperature,precipitation and sunshine hours during 1961-2018 from two meteorological stations of Zhaoyang District and Ludian County at Zhaolubazi,Zhaotong City,Yunnan Province,using the freezing injury index at flowering stage(Ha),climatic suitability index during expansion period(Pa),climatic suitability index during coloring period(Dy)and climatic suitability index during fruit growing period(Si),etc.,the climatic suitability of Zhaotong apple during the main growth stages was evaluated.The results showed that the annual average temperature was 11.8-12.3℃at Zhaolu Bazi in recent 60 years,and the climate was the most suitable for Fuji apple planting both in the south and north;the average annual precipitation was 674.8-852.6 mm,and the climate was suitable in the north and sub-suitable in the south;the annual average sunshine hours was between 1845.4 and 1851.1 h,and the climate was sub-suitable in both areas.The Ha was between 0.42-0.50,serious in the north and moderate in the south;the Pa was between 0.92 and 1.02,and both the south and the north were suitable areas;the Dy was between 0.95 and 1.00,and the climate in the south was suitable,while it was sub-suitable in the north;the Si was between 1.38 and 1.59,and the climate was suitable in the south and sub-suitable in the north.There was a 4-year cycle in the interannual variation of Ha,Pa,Dy and Si.After the 1980s,the Ha decreased by 0.56-0.59,the Pa,Dy and Si respectively increased by 0.10-0.16,0.14-0.15 and 0.78-0.84 with the temperature rise,and the changes of these four indexes were all favorable for Fuji apple's fruits growth.It can be seen that under the background of the global warming,the climatic conditions in Zhaolu Bazi are becoming more and more favorable for popularizing the planting of Fuji apple.
基金the National Natural Science Foundation of China(31622012)Key Project of the Chinese Academy of Sciences(QYZDB-SSW-SMC047)。
文摘Interspecific killing is a primary reason for the low survival rates of some animal species. The giant panda(Ailuropoda melanoleuca) is an altricial eutherian mammal and thus, in comparison to other infants, panda cubs are highly vulnerable, which may significantly influence the selection of breeding sites by females. Here, we used infrared camera traps to monitor giant panda dens for 5.5 years in Foping National Nature Reserve(FNNR) to determine how interspecific factors affect den selection by wild female pandas. Results indicated that Asian black bears(Ursus thibetanus), yellow-throated martens(Martes flavigula), leopard cats(Prionailurus bengalensis), and masked palm civets(Paguma larvata) visited the dens frequently, and the presence of these species negatively influenced den selection by female pandas. Interestingly, the presence of rodents and terrestrial birds appeared to indicate den safety, and female giant pandas were not averse and even preferred dens with a high abundance index of rodents and terrestrial birds. The den suitability index(DSI) was a reliable tool for evaluating whether dens were suitable for female giant pandas to give birth to and rear cubs, with preference for dens with high DSI values. This study increases our understanding of the den selection criteria of female giant pandas and the main threats to the survival of their cubs,thus providing important guidance for the conservation and management of this species.
基金supported by a Grant-in-Aid for Scientific Researches (No. 16K12641&17H00806) from the Ministry of Education, Culture, Sports, Science, and technology of Japan
文摘Finding the right balance between timber production and the management of forest-dependent wildlife species,present a difficult challenge for forest resource managers and policy makers in Okinawa,Japan.A possible explanation of this can be found in the unique nature of the forest management area which is populated with various kinds of rare and endangered species.This issue has been brought to light as a result of the nomination of northern Okinawa Island in 2018 as a candidate for World Natural Heritage site.The nomination has raised public awareness to the possibility of conflicting management objectives between timber extraction and the conservation of habitat for forest-dependent wildlife species.Managing exclusively for one objective over the other may fail to meet the demand for both forest products and wildlife habitat,ultimately jeopardizing the stability of human and wildlife communities.It is therefore important to achieve a better balance between the objective of timber production and conservation of wildlife habitat.Despite the significance of this subject area,current ongoing discussions on how to effectively manage for forest resources,often lack scientific basis to make sound judgement or evaluate tradeoffs between conflicting objectives.Quantifying the effect of these forest management activities on wildlife habitat provides useful and important information needed to make forest management and policy decisions.In this study we develop a spatial timber harvest scheduling model that incorporates habitat suitability index(HSI)models for the Okinawa Rail(Gallirallus okinawae),an endangered avian species found on Okinawa,Japan.To illustrate how the proposed coupling model assembles spatial information,which ultimately aids the study of forest management effects on wildlife habitat,we apply these models to a forest area in Okinawa and conduct a simple simulation analysis.
基金The National Key R&D Program of China under contract Nos 2019YFD0901401 and 2019YFD0901404the National Natural Science Foundation of China under contract No.NSFC41876141+1 种基金the Shanghai Science and Technology Innovation Program under contract No.19DZ1207502the Construction and Application of Natural Resources Satellite Remote Sensing Technology System under contract No.202101004。
文摘The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing.This study selected sea surface temperature(SST)from two commonly used sources,the NOAA Ocean Watch and IRI/LDEO Climate Data Library,and then constructed habitat suitability index model to evaluate the influences of SST from the two sources on the outcomes of Ommastrephes bartramii habitat models for the months of July–October in the Northwest Pacific Ocean during 1996–2012.This study examined the differences in the amount of estimated unfavourable/favourable habitat area when the SST used for model building and inference were the same or different.Dynamics in suitable habitat area calculated from SST was insensitive to the two different SST products.In the fishing season of O.bartramii,the changes of magnitude and trend of monthly suitable habitat area in August and September were similar over time,whereas there were large differences for July and October.Importantly,there is a substantial lack of consistency in the O.bartramii habitat distribution based on SST of two sources.This study considered the sources of environmental data for habitat modelling and then inferred species habitat distribution whether by the same or different data source.
文摘Visual satisfaction of the tourists with a water body is strongly influenced by water clarity, which is in turn influenced by a number of water quality parameters. Visual satisfaction thus stands to benefit from having a water quality management tool that results in better water clarity. A Clarity Suitability Index of Water Quality (CSIWQ), derived from clarity suitability curves of selected water quality parameters, can allow estimation of optimal values for these parameters, while ensuring high visual satisfaction among tourists. The present study used sampling and survey methodologies to investigate water clarity and quality at five tourism fishing ports;simultaneously, tourists’ visual satisfaction with a water body was assessed through a questionnaire based on their perceptions. The relationship between tourists’ visual satisfaction and water clarity was found to be positive and strong, with water clarity having predictive power of 74.2%. The study showed that DO, BOD, TP, and SS were the most critical parameters for water clarity. A continued product approach of CSIWQ was found to be most appropriate for describing the relationship between water clarity and these four parameters. This enabled a CSIWQ Index value to be calculated. With a CSIWQ value of 0.6, water clarity would be more than 2.08 m, and tourists would experience very high satisfaction. CSI curves showed that DO would preferably be 9.0 mg/L, and BOD, TP, and SS less than 0.5 mg/L, 0.12 mg/L, and 45.0 mg/L, respectively. The model thus produced valuable insights for assessing and improving water quality and ensuring high levels of visual satisfaction among tourists in tourism fishing ports. This model identified only four parameters but could be improved by ensuring that other water quality parameters were included, to encourage an increase in the number of tourists and to include monitoring of more pollutant sources.
文摘Fisheries in Lake Victoria have been threatened by declining fish stocks and diversity, environmental degradation due to increased input of pollutants, industrial and municipal waste, overfishing and use of unapproved fishing <span style="font-family:Verdana;">methods, infestation by aquatic weeds especially water hyacinth, de-oxygenation</span><span style="font-family:Verdana;"> and a reduction in the quantity and quality of water. Remote sensing and GIS are essential tools in detection of fishing grounds which is important in providing fish sustainability for human beings and allows fishing grounds detection at minimal cost and optimizes effort. This research tends to identify the most favorable both environmentally and ecologically satisfactory factors which favor fish breeding and growth. The main aim of the study was to identify habitat variables that promote fish breeding and growth to maturity including the extraction of environmental variables from Landsat 8 images for the study period and using suitability index derived from fishery data. The study concentrated on establishing suitability ratings in different parts of Lake Victoria using lake surface temperature and chlorophyll-a levels. The study was conducted for months;January, May and December 2019 on Lake Victoria (limited by the availability of recent data). The factors were analysed and the favorable regions mapped satisfying the conditions for fish breeding. The output obtained illustrated the availability of suitable and habitable zones within the lake using satellite imagery and the suitability index. The fish catch data and satellite derived variables were used to determine habitat suitability indices for fish during January, May and December 2019. More than 90% of the total catch was found to come from the areas with sea surface temperature of 23.0˚C - 28.3˚C and chlorophyll-</span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">concentration between 0.72 - 1.31 mg/m</span><sup><span style="font-family:Verdana;vertical-align:super;">3</span></sup><span style="font-family:Verdana;">. The catch data was used to validate the images. This study indicated the capability of High Satellite Resolution Imageries (HSI) as a tool to map the potential fishing grounds of fish species in Lake Victoria. The variables were affected by climatic change factors like rainfall and temperature of the lake basin and other human activities around the lake and also the species ecosystem like competition or predation.</span>
基金National Natural Science Foundation of China, No.42171217 No.41471171
文摘It is necessary to reconstruct past changes in land use and land cover to under- stand the historical effects of humans on climate and the local environment. We collected information from historical documents on the cropland area at the county level for Heilongji- ang Province, northeast China during 1900-1910. The original records from different histori- cal documents were calibrated with each other. We then defined an agricultural suitability index quantified by the distance from settlements, the slope and complexity of the topography, and the distance from rivers. Following the order of the agricultural suitability index from high to low values, the documented areas of cropland at the county level were then allocated into 1 km x 1 km cells. The area of cropland in 2009 was then retrieved from Landsat ETM+ images and compared with the areas of cropland during 1900-1910 to determine the human-induced changes in land use and land cover. In this period, the total area of cropland was about 25,397 km2 and this mainly occurred in the mid-southern part of Heilongjiang, in particular the six counties of Hailun, Bayan, Wuchang, Hulan, Shuangcheng and Wangkui. In 2009, the total area of cropland had increased to about 163,808 km2 and had spread over the south- western part to the central and northeastern parts of Heilongjiang. The area of cropland had therefore increased by about 138,411 km2 during the 20th century. The proportion of land used as cropland increased from about 5.6% during 1900-1910 to about 36.2% in 2009, indicating that about 30.6% of the natural land surface in Heilongjiang was replaced by cropland. A total of about 44% (60,962 km2) of the cropland was converted from forest, mainly on the western edge and in the northeastern part of the present-day agricultural area. These areas of cropland reconstructed from historical records for the period 1900-1910 could be used as a basic data set to study the effects of agricultural development on climate and the local environment.