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Spatial-temporal Evolution and Determinants of the Belt and Road Initiative: A Maximum Entropy Gravity Model Approach 被引量:8
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作者 HUANG Qinshi ZHU Xigang +3 位作者 LIU Chunhui WU Wei LIU Fengbao ZHANG Xinyi 《Chinese Geographical Science》 SCIE CSCD 2020年第5期839-854,共16页
The spatial interaction model is an effective way to explore the geographical disparities inherent in the Belt and Road Initiative(BRI) by simulating spatial flows. The traditional gravity model implies the hypothesis... The spatial interaction model is an effective way to explore the geographical disparities inherent in the Belt and Road Initiative(BRI) by simulating spatial flows. The traditional gravity model implies the hypothesis of equilibrium points without any reference to when or how to achieve it. In this paper, a dynamic gravity model was established based on the Maximum Entropy(MaxEnt) theory to estimate and monitor the interconnection intensity and dynamic characters of bilateral relations. In order to detect the determinants of interconnection intensity, a Geodetector method was applied to identify and evaluate the determinants of spatial networks in five dimensions. The empirical study clearly demonstrates a heterogeneous and non-circular spatial structure. The main driving forces of spatial-temporal evolution are foreign direct investment, tourism and railway infrastructure construction, while determinants in different sub-regions show obvious spatial differentiation. Southeast Asian countries are typically multi-island area where aviation infrastructure plays a more important role. North and Central Asian countries regard oil as a pillar industry where power and port facilities have a greater impact on the interconnection. While Western Asian countries are mostly influenced by the railway infrastructure, Eastern European countries already have relatively robust infrastructure where tariff policies provide a greater impetus. 展开更多
关键词 spatial interaction model the Belt and Road Initiative(BRI) maximum entropy(maxent)gravity model spatial pattern China
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基于MaxEnt和GARP的阿蒙森海域南极磷虾(EUPHAUSIA SUPERBA)的分布区预测 被引量:5
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作者 刘璐璐 赵亮 +1 位作者 蔺诗颖 冯建龙 《海洋与湖沼》 CAS CSCD 北大核心 2023年第2期399-411,共13页
南极磷虾是南大洋生态系统的关键物种,在南极碳汇过程中起到重要作用,近年来受到越来越多的关注。针对位于南大洋太平洋扇区的阿蒙森海域,运用最大熵模型(maximum entropy modeling,MaxEnt)和预设规则的遗传算法(genetic algorithm for ... 南极磷虾是南大洋生态系统的关键物种,在南极碳汇过程中起到重要作用,近年来受到越来越多的关注。针对位于南大洋太平洋扇区的阿蒙森海域,运用最大熵模型(maximum entropy modeling,MaxEnt)和预设规则的遗传算法(genetic algorithm for rule-set production,GARP)两种生态位模型,基于已采集的南极磷虾分布点的数据,对其在阿蒙森海域的潜在分布区进行了预测和分析,并采用受试者工作特征曲线(receiver operating characteristic curve,ROC)下的面积(area under curve,AUC)和真实技巧统计法(true skill statistic,TSS)对模型结果进行评估。结果表明:MaxEnt模型中的高适生区刻画细致,GARP模型预测的高适生区分布范围更广。为克服单个模型的不确定性得到更佳结果,将两个模型的预测结果进行集合。集合后的结果模拟精度显著提高(AUC为0.946,TSS为0.78),达到了极好的预测效果。磷虾的高适生区集中分布在65°~73°S,占总面积的6.2%,中适生区占总面积的5.7%。海冰、平均海平面气压最小值和纬向流速最大值是MaxEnt中贡献最高的3个变量,3个变量贡献达81.3%。相较于MaxEnt模型,GARP模型中各个变量遗漏误差相对较平均。研究表明,集合的结果能够提高物种分布预测的准确性,阿蒙森海域南极磷虾的分布预测结果可以为磷虾保护、利用提供科学参考。 展开更多
关键词 南极磷虾 最大熵模型(maximum entropy modeling maxent) 预设规则的遗传算法(genetic algorithm for rule-set production GARP) 阿蒙森海域
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Predicting changes in the suitable habitats of six halophytic plant species in the arid areas of Northwest China
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作者 YANG Ao TU Wenqin +9 位作者 YIN Benfeng ZHANG Shujun ZHANG Xinyu ZHANG Qing HUANG Yunjie HAN Zhili YANG Ziyue ZHOU Xiaobing ZHUANG Weiwei ZHANG Yuanming 《Journal of Arid Land》 SCIE CSCD 2024年第10期1380-1408,共29页
In the context of changes in global climate and land uses,biodiversity patterns and plant species distributions have been significantly affected.Soil salinization is a growing problem,particularly in the arid areas of... In the context of changes in global climate and land uses,biodiversity patterns and plant species distributions have been significantly affected.Soil salinization is a growing problem,particularly in the arid areas of Northwest China.Halophytes are ideal for restoring soil salinization because of their adaptability to salt stress.In this study,we collected the current and future bioclimatic data released by the WorldClim database,along with soil data from the Harmonized World Soil Database(v1.2)and A Big Earth Data Platform for Three Poles.Using the maximum entropy(MaxEnt)model,the potential suitable habitats of six halophytic plant species(Halostachys caspica(Bieb.)C.A.Mey.,Halogeton glomeratus(Bieb.)C.A.Mey.,Kalidium foliatum(Pall.)Moq.,Halocnemum strobilaceum(Pall.)Bieb.,Salicornia europaea L.,and Suaeda salsa(L.)Pall.)were assessed under the current climate conditions(average for 1970-2000)and future(2050s,2070s,and 2090s)climate scenarios(SSP245 and SSP585,where SSP is the Shared Socio-economic Pathway).The results revealed that all six halophytic plant species exhibited the area under the receiver operating characteristic curve values higher than 0.80 based on the MaxEnt model,indicating the excellent performance of the MaxEnt model.The suitability of the six halophytic plant species significantly varied across regions in the arid areas of Northwest China.Under different future climate change scenarios,the suitable habitat areas for the six halophytic plant species are expected to increase or decrease to varying degrees.As global warming progresses,the suitable habitat areas of K.foliatum,S.salsa,and H.strobilaceum exhibited an increasing trend.In contrast,the suitable habitat areas of H.glomeratus,S.europaea,and H.caspica showed an opposite trend.Furthermore,considering the ongoing global warming trend,the centroids of the suitable habitat areas for various halophytic plant species would migrate to different degrees,and four halophytic plant species,namely,S.salsa,H.strobilaceum,H.glomeratus,and H.capsica,would migrate to higher latitudes.Temperature,precipitation,and soil factors affected the possible distribution ranges of these six halophytic plant species.Among them,precipitation seasonality(coefficient of variation),precipitation of the warmest quarter,mean temperature of the warmest quarter,and exchangeable Na+significantly affected the distribution of halophytic plant species.Our findings are critical to comprehending and predicting the impact of climate change on ecosystems.The findings of this study hold significant theoretical and practical implications for the management of soil salinization and for the utilization,protection,and management of halophytes in the arid areas of Northwest China. 展开更多
关键词 HALOPHYTES climate change global warming maximum entropy(maxent)model soil salinization suitable habitats Northwest China
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Potential distribution of Haloxylon ammodendron in Central Asia under climate change
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作者 CHEN Zhuo SHAO Minghao +2 位作者 HU Zihao GAO Xin LEI Jiaqiang 《Journal of Arid Land》 SCIE CSCD 2024年第9期1255-1269,共15页
Understanding the spatial distribution of plant species and their dynamic changes in arid areas is crucial for addressing the challenges posed by climate change.Haloxylon ammodendron shelterbelts are essential for the... Understanding the spatial distribution of plant species and their dynamic changes in arid areas is crucial for addressing the challenges posed by climate change.Haloxylon ammodendron shelterbelts are essential for the protection of plant resources and the control of desertification in Central Asia.Thus far,the potential suitable habitats of H.ammodendron in Central Asia are still uncertain in the future under global climate change conditions.This study utilised the maximum entropy(MaxEnt)model to combine the current distribution data of H.ammodendron with its growth-related data to analyze the potential distribution pattern of H.ammodendron across Central Asia.The results show that there are suitable habitats of H.ammodendron in the Aralkum Desert,northern slopes of the Tianshan Mountains,and the upstream of the Tarim River and western edge of the Taklimakan Desert in the Tarim Basin under the current climate conditions.The period from 2021 to 2040 is projected to undergo significant changes in the suitable habitat area of H.ammodendron in Central Asia,with a projected 15.0% decrease in the unsuitable habitat area.Inland areas farther from the ocean,such as the Caspian Sea and Aralkum Desert,will continue to experience a decrease in the suitable habitats of H.ammodendron.Regions exhibiting frequent fluctuations in the habitat suitability levels are primarily found along the axis stretching from Astana to Kazakhskiy Melkosopochnik in Kazakhstan.These regions can transition into suitable habitats under varying climate conditions,requiring the implementation of appropriate human intervention measures to prevent desertification.Future climate conditions are expected to cause an eastward shift in the geometric centre of the potential suitable habitats of H.ammodendron,with the extent of this shift amplifying alongside more greenhouse gas emissions.This study can provide theoretical support for the spatial configuration of H.ammodendron shelterbelts and desertification control in Central Asia,emphasising the importance of proactive measures to adapt to climate change in the future. 展开更多
关键词 Haloxylon ammodendron potential suitable habitats climate change DESERTIFICATION maximum entropy(maxent)model Central Asia Aralkum Desert
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