Bailongjiang watershed in southern Gansu province, China, is one of the most landslide-prone regions in China, characterized by very high frequency of landslide occurrence. In order to predict the landslide occurrence...Bailongjiang watershed in southern Gansu province, China, is one of the most landslide-prone regions in China, characterized by very high frequency of landslide occurrence. In order to predict the landslide occurrence, a comprehensive map of landslide susceptibility is required which may be significantly helpful in reducing loss of property and human life. In this study, an integrated model of information value method and logistic regression is proposed by using their merits at maximum and overcoming their weaknesses, which may enhance precision and accuracy of landslide susceptibility assessment. A detailed and reliable landslide inventory with 1587 landslides was prepared and randomly divided into two groups,(i) training dataset and(ii) testing dataset. Eight distinct landslide conditioning factors including lithology, slope gradient, aspect, elevation, distance to drainages,distance to faults, distance to roads and vegetation coverage were selected for landslide susceptibility mapping. The produced landslide susceptibility maps were validated by the success rate and prediction rate curves. The validation results show that the success rate and the prediction rate of the integrated model are 81.7 % and 84.6 %, respectively, which indicate that the proposed integrated method is reliable to produce an accurate landslide susceptibility map and the results may be used for landslides management and mitigation.展开更多
Mountains in western China, hosted rich biodiversity and millions of people and inhabitant with vital ecosystem services, had experienced the most serious biodiversity loss with fragile ecological problems. Even thoug...Mountains in western China, hosted rich biodiversity and millions of people and inhabitant with vital ecosystem services, had experienced the most serious biodiversity loss with fragile ecological problems. Even though increasing attentions had been paid to this issue, we still lacked efficient methods to assess the change of plant biodiversity at medium/large scale due to the poor data and co-existing multiple habitat types. This study proposed an integrated method combining InVEST-habitat quality model, NPP and landscape pattern indexes to analyze the spatial heterogeneity of plant biodiversity and its spatiotemporal change on raster cell scale. The results indicated that plant biodiversity service was high in Bailongjiang watershed with obvious spatial pattern variations. The land area containing higher plant biodiversity were 3161 km2, which mainly distributed in the National Nature Reserve and forestry area. While the areas with lower plant biodiversity accounted for 37.67% and mainly distributed in the valleys between Zhouqu-Wudu-Wenxian County, the valley of Minjiang in Tanchang County and alpine mountain snow-covered regions. During 1990–2010, plant biodiversity level tended to increase and the higher plant biodiversity area increased from 14.13% to 17.15% due to ecological restoration and afforestation, while plant biodiversity decreased in the area with intensive human activities, such as cultivated land, urban and rural land. The results showed that combining InVEST-habitat quality model, NPP and landscape pattern indexes can effective reveal mountain plant biodiversity change. The study was useful for plant biodiversity conservation policy-making and human activity management for the disaster-impacted mountainous areas in China.展开更多
净生态系统生产力(NEP)是估算区域植被碳源、碳汇的重要指标。以甘肃白龙江流域为研究区,结合MODIS与气象数据对2000—2013年的流域净生态系统生产力时空变化进行了研究,并探讨了典型地形因子对NEP的影响。结果表明:(1)2000—2013年甘...净生态系统生产力(NEP)是估算区域植被碳源、碳汇的重要指标。以甘肃白龙江流域为研究区,结合MODIS与气象数据对2000—2013年的流域净生态系统生产力时空变化进行了研究,并探讨了典型地形因子对NEP的影响。结果表明:(1)2000—2013年甘肃白龙江流域单位面积NEP平均为226.65 g C m^(-2)a^(-1),碳汇区主要分布在白龙江上游两岸、岷江西岸、白水江南岸、大团鱼河两岸的山地林区,碳源区主要分布在武都区、迭部县北缘的高寒草甸区等。(2)从不同植被类型上看,常绿阔叶林、常绿/落叶阔叶混交林单位面积NEP最高,高寒草地单位面积NEP最小,且耕地单位面积NEP增加最明显,常绿/落叶阔叶混交林单位面积NEP降低最明显。(3)2000—2013年研究区单位面积NEP总体上呈增加的趋势,增加明显的地区分布在流域的中部和西北部,4—9月为流域碳汇季节。(4)地形因子对甘肃白龙江流域NEP有明显影响,海拔4200 m以下多为碳汇区;陡坡区的碳汇能力的增长趋势低于缓坡区;阴坡的碳汇能力高于阳坡区。展开更多
基金supported by the Project of the 12th Five-year National Sci-Tech Support Plan of China(2011BAK12B09)China Special Project of Basic Work of Science and Technology(2011FY110100-2)
文摘Bailongjiang watershed in southern Gansu province, China, is one of the most landslide-prone regions in China, characterized by very high frequency of landslide occurrence. In order to predict the landslide occurrence, a comprehensive map of landslide susceptibility is required which may be significantly helpful in reducing loss of property and human life. In this study, an integrated model of information value method and logistic regression is proposed by using their merits at maximum and overcoming their weaknesses, which may enhance precision and accuracy of landslide susceptibility assessment. A detailed and reliable landslide inventory with 1587 landslides was prepared and randomly divided into two groups,(i) training dataset and(ii) testing dataset. Eight distinct landslide conditioning factors including lithology, slope gradient, aspect, elevation, distance to drainages,distance to faults, distance to roads and vegetation coverage were selected for landslide susceptibility mapping. The produced landslide susceptibility maps were validated by the success rate and prediction rate curves. The validation results show that the success rate and the prediction rate of the integrated model are 81.7 % and 84.6 %, respectively, which indicate that the proposed integrated method is reliable to produce an accurate landslide susceptibility map and the results may be used for landslides management and mitigation.
基金National Natural Science Foundation of China,No.41771196,No.41761039,No.41271199
文摘Mountains in western China, hosted rich biodiversity and millions of people and inhabitant with vital ecosystem services, had experienced the most serious biodiversity loss with fragile ecological problems. Even though increasing attentions had been paid to this issue, we still lacked efficient methods to assess the change of plant biodiversity at medium/large scale due to the poor data and co-existing multiple habitat types. This study proposed an integrated method combining InVEST-habitat quality model, NPP and landscape pattern indexes to analyze the spatial heterogeneity of plant biodiversity and its spatiotemporal change on raster cell scale. The results indicated that plant biodiversity service was high in Bailongjiang watershed with obvious spatial pattern variations. The land area containing higher plant biodiversity were 3161 km2, which mainly distributed in the National Nature Reserve and forestry area. While the areas with lower plant biodiversity accounted for 37.67% and mainly distributed in the valleys between Zhouqu-Wudu-Wenxian County, the valley of Minjiang in Tanchang County and alpine mountain snow-covered regions. During 1990–2010, plant biodiversity level tended to increase and the higher plant biodiversity area increased from 14.13% to 17.15% due to ecological restoration and afforestation, while plant biodiversity decreased in the area with intensive human activities, such as cultivated land, urban and rural land. The results showed that combining InVEST-habitat quality model, NPP and landscape pattern indexes can effective reveal mountain plant biodiversity change. The study was useful for plant biodiversity conservation policy-making and human activity management for the disaster-impacted mountainous areas in China.
文摘净生态系统生产力(NEP)是估算区域植被碳源、碳汇的重要指标。以甘肃白龙江流域为研究区,结合MODIS与气象数据对2000—2013年的流域净生态系统生产力时空变化进行了研究,并探讨了典型地形因子对NEP的影响。结果表明:(1)2000—2013年甘肃白龙江流域单位面积NEP平均为226.65 g C m^(-2)a^(-1),碳汇区主要分布在白龙江上游两岸、岷江西岸、白水江南岸、大团鱼河两岸的山地林区,碳源区主要分布在武都区、迭部县北缘的高寒草甸区等。(2)从不同植被类型上看,常绿阔叶林、常绿/落叶阔叶混交林单位面积NEP最高,高寒草地单位面积NEP最小,且耕地单位面积NEP增加最明显,常绿/落叶阔叶混交林单位面积NEP降低最明显。(3)2000—2013年研究区单位面积NEP总体上呈增加的趋势,增加明显的地区分布在流域的中部和西北部,4—9月为流域碳汇季节。(4)地形因子对甘肃白龙江流域NEP有明显影响,海拔4200 m以下多为碳汇区;陡坡区的碳汇能力的增长趋势低于缓坡区;阴坡的碳汇能力高于阳坡区。
