Bangladesh, situated in tropical and subtropical regions, receives significant amount of solar energy, making it an ideal location for solar energy production. However, determining suitable sites in the country for so...Bangladesh, situated in tropical and subtropical regions, receives significant amount of solar energy, making it an ideal location for solar energy production. However, determining suitable sites in the country for solar based power plant establishment turns out to be a difficult task given its dense population. This study aims to the identification of such a potential site by assessing the stability of the Jamuna river Island to be proposed as a site for developing solar based power plant. The research concentrates on Fulchhari union of Gaibandha district, one of the three major islands in the Jamuna river, utilizing two GIS-based multi-criteria decision-making (MCDM) techniques. One is Digital Shoreline Analysis System (DSAS) for stability analysis, and another is Analytical Hierarchy Process (AHP) for suitability evaluation. For the stability analysis of the island, Landsat satellite imagery of 1990, 1995, 2000, 2005, 2010, 2015 and 2020 covering a long term of 30 years period were investigated. Based on average change rates, the bankline of the island was divided into 2 accretion zones in the south and south-eastern direction, and 8 erosion zones. Along with the bankline changes, climatological, geomorphological, and environmental factors have been adopted to modeling process for suitability analysis. The optimal locations for solar based power plants have been demonstrated by a suitability map, where high and standard potential area is about 60% of the area of Fulchhari union. Production may be enhanced up to 5 times more with the consideration of utilizing the moderate optimum zone.展开更多
Under the support of the remote sensing and geographical information system(GIS) techniques,we acquire the land use data in 1990 and 2008 regarding 6 inhabited islands,namely Longxue Island,Hengmen Island,Weiyuan Isla...Under the support of the remote sensing and geographical information system(GIS) techniques,we acquire the land use data in 1990 and 2008 regarding 6 inhabited islands,namely Longxue Island,Hengmen Island,Weiyuan Island,Qi'ao Island,Hengqin Island and Gaolan Island in Pearl River Estuary.By using dynamic degree of land use,land use change intensity,relative change rate and other indicators,we conduct quantitative description,and thus quantitatively and qualitatively analyse characteristics of temporal evolution and law of spatial pattern change concerning land use of each island.The study indicates that in the period 1990-2008,the area of construction land and water in 6 islands increased,while the area of agricultural land and unused land increased in some islands and decreased in others.The land use change shows spatial disparity;the holistic land use change degree in Hengmen Island is higher than that of other islands;the dynamic degree of land use,intensity of land use,and relative change rate differ in different islands.展开更多
We examined the impact of various coastal developments on mangrove cover along the Kilim River, Langkawi Island, Malaysia between 1996 and 2008. We analysed images from Systeme Probatoire d＇Observation de la Tarre （...We examined the impact of various coastal developments on mangrove cover along the Kilim River, Langkawi Island, Malaysia between 1996 and 2008. We analysed images from Systeme Probatoire d＇Observation de la Tarre （SPOT） of Kilim River using supervised classification and Principal Component Analysis （PCA）. Over 8% （176.83 ha] of mangrove cover was degraded along the Kilim River from its total area of 2153.07 ha during the past 14 years. We identified several causes of mangrove degradation, including mangrove clearing （38%）, mangrove conversion to commercial area （21%）, residential area （19%）, agriculture （12%）, aquaculture （12%） and wake current （6%）. Langkawi is one of the main tourism islands in Malaysia. Tthe pace of coastal development throughout the entire island including Kilim River had suppressed the mangroves propagation over the years. Long term monitoring of mangrove ecosystems is essentials to ensure the survival and sustainability of mangrove associated biodiversity.展开更多
传统旱涝评估多从单一因素角度来研究,而忽略了下垫面的特性如农业用地对旱涝事件形成的影响。基于昌化江流域内20个气象站点1970—2019年逐日降雨数据,结合遥感提取的30 m DEM和遥感解译的土地利用数据,应用降水Z指数对流域内的旱涝等...传统旱涝评估多从单一因素角度来研究,而忽略了下垫面的特性如农业用地对旱涝事件形成的影响。基于昌化江流域内20个气象站点1970—2019年逐日降雨数据,结合遥感提取的30 m DEM和遥感解译的土地利用数据,应用降水Z指数对流域内的旱涝等级进行划分。运用下垫面数据修正分析结果,评估流域旱涝面积时空变化特征,分别划分流域的易旱、易涝区。结果表明:流域冬春季节干旱问题较其它季节突出,但整体上干旱面积呈明显下降趋势;流域内夏秋季雨涝问题较为严重,且总体雨涝面积呈上升趋势。全年干旱易发区与秋季雨涝易发区较为集中分布于流域下游;总体昌化江流域旱涝灾害有逐年缓解趋势。展开更多
基于SRTM DEM 30m数据和ArcGIS软件,提取台湾岛的水系和流域盆地,计算得到台湾岛的地貌参数(坡度、地形起伏度和面积-高程积分(HI)值),并分析台湾岛水系分布对活动断裂的响应情况,得到以下结论:1)台湾岛河流受构造活动控制,以中央山脉...基于SRTM DEM 30m数据和ArcGIS软件,提取台湾岛的水系和流域盆地,计算得到台湾岛的地貌参数(坡度、地形起伏度和面积-高程积分(HI)值),并分析台湾岛水系分布对活动断裂的响应情况,得到以下结论:1)台湾岛河流受构造活动控制,以中央山脉为分水岭,西侧河流的南部水系为纵向流动,北部水系为横向流动,中央山脉以东的河流均为东西流向;2)台湾岛的HI值整体上呈现中间高、两边低的趋势,与海拔大体上呈正相关关系,沿逆冲断层边界,不同构造地质单元的HI值东西两侧差异明显;3)HI值可以反映台湾岛造山带的生成时序,流域盆地受构造抬升运动影响时间越长,HI值越大。展开更多
Based on non-radiance-calibrated DMSP/OLS nighttime light imagery from 1992 to 2003, urban land area statistical data, meteorological data and land surface temperature data retrieved by MODIS and NOAA/AVHRR data, the ...Based on non-radiance-calibrated DMSP/OLS nighttime light imagery from 1992 to 2003, urban land area statistical data, meteorological data and land surface temperature data retrieved by MODIS and NOAA/AVHRR data, the influence of urbanization on regional climatic trend cf temperature in the Yangtze River Delta （YRD） was analyzed. Conclusions are as follows： 1） There is a significant urbanization process from 1992 to 2003 in the YRD. Four city clusters of Nanjing-Zhenjiang-Yangzhou, Suzhou-Wuxi-Changzhou, Shanghai and Hangzhou Bay form a zigzag city belt. The increase rate of annual mean air temperature in city-belt is 0.28-0.44℃/10a from 1991 to 2005, which is far larger than that of non-city-belt. 2） The urban heat island （UHI） effect on regional mean air temperature in different seasons is summer〉autumn〉spring〉winter. 3） The UHI intensity and the urban total population logarithm are creditably correlated. 4） The UHI effect made the regional annual mean air temperature increased 0.072℃ from 1961 to 2005, of which 0.047℃ from 1991 to 2005, and the annual maximum air temperature increased 0.162℃, of which 0.083℃ from 1991 to 2005. All these indicating that the urban expansion in the YRD from 1991 to 2005 may be regarded as a serious climate signal.展开更多
The Boao coastal system along the eastern coast of Hainan Island is a dynamic delta-tidal inlet-barrier formed during the late Holocene. The delta developed inside a shallow lagoon barred by a sandy barrier with a nar...The Boao coastal system along the eastern coast of Hainan Island is a dynamic delta-tidal inlet-barrier formed during the late Holocene. The delta developed inside a shallow lagoon barred by a sandy barrier with a narrow, shallow tidal inlet opening. Two major distributary channels separated by small islands characterize the delta. The lagoon is silting up receiving and trapping sediments from both the river and, in minor measure during storms, through the tidal inlet opening and barrier washovers. The barrier at the tidal inlet is highly dynamic and changes its form, accreting (migrating spit) against the inlet during fair-weather conditions and being eroded during storms and river floods. The delta has almost completely filled the lagoon and major concerns exist on the effect that ongoing large development plans may have on the environment. These concerns include the effect on floods and rate of siltation once banks of the islands have been stabilized and floodwater and sediment load are impeded from spreading over the lowlands, and the effect of increasing pollutant loads from the new facilities on the ecosystems of the increasingly restricting lagoon water and on the seashores.展开更多
Physical profile is significant reference to in addressing areas at risk due to fluvial processes and in establishing the physiographic maps especially in protected areas. Calbiga is one of the major rivers inside the...Physical profile is significant reference to in addressing areas at risk due to fluvial processes and in establishing the physiographic maps especially in protected areas. Calbiga is one of the major rivers inside the Samar Island Natural Park (SINP). The source of Calbiga river was traced at the foot of Mt. Huraw of San Jose de Buan, Samar. The area is at the center of the Samar Island with an elevation of 850 meter above sea level (MASL). The river stretches 36.4 kilometers, with an average span of 44.57 meters, and average depth of 2.6 meters. The average height of the river bank is 7.67 meters, with rage of 5 - 10 meters. Generally, the substrate was sand. On fluvial dynamics, the average water velocity is 0.20 mps with the average water flow of 18.64 m<sup>3</sup>/sec. The floodplain ranged from 10 - 15 meters and 5 to 7 meters high. The river control measures are making a positive impact, though it could be reviewed to address the low elevation of the midstream. Rehabilitation measures at the watershed should be considered, parallel to the policy implementation of Disaster Risk Reduction Management (DRRM) measures.展开更多
The islands and associated back channels on the Ohio River, USA, are believed to provide critical habitat features for several wildlife species. However, few studies have quantitatively evaluated habitat quality in th...The islands and associated back channels on the Ohio River, USA, are believed to provide critical habitat features for several wildlife species. However, few studies have quantitatively evaluated habitat quality in these areas. Our main objective was to evaluate the habitat quality of back and main channel areas for several species using habitat suitability index (HSI) models. To test the effectiveness of these models, we attempted to relate HSI scores and the variables measured for each model with measures of relative abundance for the model species. The mean belted kingfisher (Ceryle alcyon) HSI was greater on the main than back channel. However, the model failed to predict kingfisher abundance. The mean reproduction component of the great blue heron (Ardea herodias) HSI, total common muskrat (Ondatra zibethicus) HSI, winter cover component of the snapping turtle (Chelydra serpentina) HSI, and brood-rearing component of the wood duck (Aix sponsa) HSI were all greater on the back than main channel, and were positively related with the relative abundance of each species. We found that island back channels provide characteristics not found elsewhere on the Ohio River and warrant conservation as important riparian wildlife habitat. The effectiveness of using HSI models to predict species abundance on the river was mixed. Modifications to several of the models are needed to improve their use on the Ohio River and, likely, other large rivers.展开更多
文摘Bangladesh, situated in tropical and subtropical regions, receives significant amount of solar energy, making it an ideal location for solar energy production. However, determining suitable sites in the country for solar based power plant establishment turns out to be a difficult task given its dense population. This study aims to the identification of such a potential site by assessing the stability of the Jamuna river Island to be proposed as a site for developing solar based power plant. The research concentrates on Fulchhari union of Gaibandha district, one of the three major islands in the Jamuna river, utilizing two GIS-based multi-criteria decision-making (MCDM) techniques. One is Digital Shoreline Analysis System (DSAS) for stability analysis, and another is Analytical Hierarchy Process (AHP) for suitability evaluation. For the stability analysis of the island, Landsat satellite imagery of 1990, 1995, 2000, 2005, 2010, 2015 and 2020 covering a long term of 30 years period were investigated. Based on average change rates, the bankline of the island was divided into 2 accretion zones in the south and south-eastern direction, and 8 erosion zones. Along with the bankline changes, climatological, geomorphological, and environmental factors have been adopted to modeling process for suitability analysis. The optimal locations for solar based power plants have been demonstrated by a suitability map, where high and standard potential area is about 60% of the area of Fulchhari union. Production may be enhanced up to 5 times more with the consideration of utilizing the moderate optimum zone.
基金Supported by Guangdong 908 Special Plan(GD908-01-02)The Marine Science and Technology Director Foundation of South China Sea Branch (0871)
文摘Under the support of the remote sensing and geographical information system(GIS) techniques,we acquire the land use data in 1990 and 2008 regarding 6 inhabited islands,namely Longxue Island,Hengmen Island,Weiyuan Island,Qi'ao Island,Hengqin Island and Gaolan Island in Pearl River Estuary.By using dynamic degree of land use,land use change intensity,relative change rate and other indicators,we conduct quantitative description,and thus quantitatively and qualitatively analyse characteristics of temporal evolution and law of spatial pattern change concerning land use of each island.The study indicates that in the period 1990-2008,the area of construction land and water in 6 islands increased,while the area of agricultural land and unused land increased in some islands and decreased in others.The land use change shows spatial disparity;the holistic land use change degree in Hengmen Island is higher than that of other islands;the dynamic degree of land use,intensity of land use,and relative change rate differ in different islands.
基金funded by Mangrove Cluster Research under Institute of Oceanographic and Maritime Studies (INOCEM), International Islamic University Malaysia
文摘We examined the impact of various coastal developments on mangrove cover along the Kilim River, Langkawi Island, Malaysia between 1996 and 2008. We analysed images from Systeme Probatoire d＇Observation de la Tarre （SPOT） of Kilim River using supervised classification and Principal Component Analysis （PCA）. Over 8% （176.83 ha] of mangrove cover was degraded along the Kilim River from its total area of 2153.07 ha during the past 14 years. We identified several causes of mangrove degradation, including mangrove clearing （38%）, mangrove conversion to commercial area （21%）, residential area （19%）, agriculture （12%）, aquaculture （12%） and wake current （6%）. Langkawi is one of the main tourism islands in Malaysia. Tthe pace of coastal development throughout the entire island including Kilim River had suppressed the mangroves propagation over the years. Long term monitoring of mangrove ecosystems is essentials to ensure the survival and sustainability of mangrove associated biodiversity.
文摘传统旱涝评估多从单一因素角度来研究,而忽略了下垫面的特性如农业用地对旱涝事件形成的影响。基于昌化江流域内20个气象站点1970—2019年逐日降雨数据,结合遥感提取的30 m DEM和遥感解译的土地利用数据,应用降水Z指数对流域内的旱涝等级进行划分。运用下垫面数据修正分析结果,评估流域旱涝面积时空变化特征,分别划分流域的易旱、易涝区。结果表明:流域冬春季节干旱问题较其它季节突出,但整体上干旱面积呈明显下降趋势;流域内夏秋季雨涝问题较为严重,且总体雨涝面积呈上升趋势。全年干旱易发区与秋季雨涝易发区较为集中分布于流域下游;总体昌化江流域旱涝灾害有逐年缓解趋势。
文摘基于SRTM DEM 30m数据和ArcGIS软件,提取台湾岛的水系和流域盆地,计算得到台湾岛的地貌参数(坡度、地形起伏度和面积-高程积分(HI)值),并分析台湾岛水系分布对活动断裂的响应情况,得到以下结论:1)台湾岛河流受构造活动控制,以中央山脉为分水岭,西侧河流的南部水系为纵向流动,北部水系为横向流动,中央山脉以东的河流均为东西流向;2)台湾岛的HI值整体上呈现中间高、两边低的趋势,与海拔大体上呈正相关关系,沿逆冲断层边界,不同构造地质单元的HI值东西两侧差异明显;3)HI值可以反映台湾岛造山带的生成时序,流域盆地受构造抬升运动影响时间越长,HI值越大。
基金Concentrated fund item of national science and technology foundation work, No.2005DKA31700-06-20 Jiangsu Natural Science Foundation, No.BK2005163 Climate change special foundation of China Meteoro logical Administration, No.CCSF2006-32
文摘Based on non-radiance-calibrated DMSP/OLS nighttime light imagery from 1992 to 2003, urban land area statistical data, meteorological data and land surface temperature data retrieved by MODIS and NOAA/AVHRR data, the influence of urbanization on regional climatic trend cf temperature in the Yangtze River Delta （YRD） was analyzed. Conclusions are as follows： 1） There is a significant urbanization process from 1992 to 2003 in the YRD. Four city clusters of Nanjing-Zhenjiang-Yangzhou, Suzhou-Wuxi-Changzhou, Shanghai and Hangzhou Bay form a zigzag city belt. The increase rate of annual mean air temperature in city-belt is 0.28-0.44℃/10a from 1991 to 2005, which is far larger than that of non-city-belt. 2） The urban heat island （UHI） effect on regional mean air temperature in different seasons is summer〉autumn〉spring〉winter. 3） The UHI intensity and the urban total population logarithm are creditably correlated. 4） The UHI effect made the regional annual mean air temperature increased 0.072℃ from 1961 to 2005, of which 0.047℃ from 1991 to 2005, and the annual maximum air temperature increased 0.162℃, of which 0.083℃ from 1991 to 2005. All these indicating that the urban expansion in the YRD from 1991 to 2005 may be regarded as a serious climate signal.
文摘The Boao coastal system along the eastern coast of Hainan Island is a dynamic delta-tidal inlet-barrier formed during the late Holocene. The delta developed inside a shallow lagoon barred by a sandy barrier with a narrow, shallow tidal inlet opening. Two major distributary channels separated by small islands characterize the delta. The lagoon is silting up receiving and trapping sediments from both the river and, in minor measure during storms, through the tidal inlet opening and barrier washovers. The barrier at the tidal inlet is highly dynamic and changes its form, accreting (migrating spit) against the inlet during fair-weather conditions and being eroded during storms and river floods. The delta has almost completely filled the lagoon and major concerns exist on the effect that ongoing large development plans may have on the environment. These concerns include the effect on floods and rate of siltation once banks of the islands have been stabilized and floodwater and sediment load are impeded from spreading over the lowlands, and the effect of increasing pollutant loads from the new facilities on the ecosystems of the increasingly restricting lagoon water and on the seashores.
文摘Physical profile is significant reference to in addressing areas at risk due to fluvial processes and in establishing the physiographic maps especially in protected areas. Calbiga is one of the major rivers inside the Samar Island Natural Park (SINP). The source of Calbiga river was traced at the foot of Mt. Huraw of San Jose de Buan, Samar. The area is at the center of the Samar Island with an elevation of 850 meter above sea level (MASL). The river stretches 36.4 kilometers, with an average span of 44.57 meters, and average depth of 2.6 meters. The average height of the river bank is 7.67 meters, with rage of 5 - 10 meters. Generally, the substrate was sand. On fluvial dynamics, the average water velocity is 0.20 mps with the average water flow of 18.64 m<sup>3</sup>/sec. The floodplain ranged from 10 - 15 meters and 5 to 7 meters high. The river control measures are making a positive impact, though it could be reviewed to address the low elevation of the midstream. Rehabilitation measures at the watershed should be considered, parallel to the policy implementation of Disaster Risk Reduction Management (DRRM) measures.
文摘The islands and associated back channels on the Ohio River, USA, are believed to provide critical habitat features for several wildlife species. However, few studies have quantitatively evaluated habitat quality in these areas. Our main objective was to evaluate the habitat quality of back and main channel areas for several species using habitat suitability index (HSI) models. To test the effectiveness of these models, we attempted to relate HSI scores and the variables measured for each model with measures of relative abundance for the model species. The mean belted kingfisher (Ceryle alcyon) HSI was greater on the main than back channel. However, the model failed to predict kingfisher abundance. The mean reproduction component of the great blue heron (Ardea herodias) HSI, total common muskrat (Ondatra zibethicus) HSI, winter cover component of the snapping turtle (Chelydra serpentina) HSI, and brood-rearing component of the wood duck (Aix sponsa) HSI were all greater on the back than main channel, and were positively related with the relative abundance of each species. We found that island back channels provide characteristics not found elsewhere on the Ohio River and warrant conservation as important riparian wildlife habitat. The effectiveness of using HSI models to predict species abundance on the river was mixed. Modifications to several of the models are needed to improve their use on the Ohio River and, likely, other large rivers.
