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新疆南部风灾的空间格局和年际变化特征
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作者 荆海亮 牟欢 王军 《绿洲农业科学与工程》 2021年第1期68-74,共7页
利用1980—2019年新疆南部48个县/市风灾的出现次数、死亡人数、倒塌房屋数、倒塌棚圈数、牲畜死亡数和受灾面积等6个灾情要素数据,采用比值权重法和无量纲化线性求和法构建风灾灾损指数,根据灾损指数的伽玛分布函数,将每个县/市和每年... 利用1980—2019年新疆南部48个县/市风灾的出现次数、死亡人数、倒塌房屋数、倒塌棚圈数、牲畜死亡数和受灾面积等6个灾情要素数据,采用比值权重法和无量纲化线性求和法构建风灾灾损指数,根据灾损指数的伽玛分布函数,将每个县/市和每年出现的风灾强度定量划分为一般、较重、严重和特重四个等级。分析结果表明,新疆南部风灾集中发生在4月至5月,较重等级以上风灾主要集中在吐鲁番地区、阿克苏地区、克孜勒苏柯尔克孜自治州、和田地区和哈密地区发生,其中特重等级风灾主要集中在吐鲁番市、阿克苏市、沙雅县、洛浦县和乌什县发生。1980—2019年新疆南部风灾强度呈分段式线性增强趋势,1986年、1999年和2001年分别为风灾发生特重年份。 展开更多
关键词 风灾 灾损指数 等级划分 时间和空间变化
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水文变量时空正交展开的Excel实现
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作者 魏义长 王纪军 +2 位作者 张芳 张立平 刘小强 《水力发电》 北大核心 2010年第12期4-7,共4页
水文变量时空正交展开是一种使用特征技术的统计方法,能够将变量场时间和空间变化分离,并用尽可能少的模态表达出主要的时间和空间变化。利用Excel的数据透视表功能对原始数据进行筛选、分类汇总,运用ExcelVBA矩阵和线性代数计算插件对... 水文变量时空正交展开是一种使用特征技术的统计方法,能够将变量场时间和空间变化分离,并用尽可能少的模态表达出主要的时间和空间变化。利用Excel的数据透视表功能对原始数据进行筛选、分类汇总,运用ExcelVBA矩阵和线性代数计算插件对水文变量时空正交函数进行展开。结果表明,Excel的数据透视表可快速合并和对大量数据进行比较,建立源数据的不同汇总,显示感兴趣区域的明细数据;Excel VBA矩阵和线性代数计算插件在计算实对称矩阵的特征值和特征向量方面,其计算结果既和专业SAS软件计算的结果完全一致,又具有专业软件快捷直观的优点,同时又具有普通办公软件方便和实用等特点。 展开更多
关键词 水文变量 时空 正交展开 Excel Empirical ORTHOGONAL Function 时间和空间变化 数据透视表 计算插件 线性代数 矩阵的特征值 计算结果 感兴趣区域 专业软件 正交函数 原始数据 统计方法 特征向量 特征技术 分类汇总 办公软件
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Geographic distribution of archaeological sites and their response to climate and environmental change between 10.0–2.8 ka BP in the Poyang Lake Basin, China 被引量:4
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作者 徐佳佳 贾玉连 +4 位作者 马春梅 朱诚 吴立 李育远 王鑫浩 《Journal of Geographical Sciences》 SCIE CSCD 2016年第5期603-618,共16页
The temporal-spatial geographic distribution of archaeological sites and its feature between 10.0-2.8 ka BP (ka BP= thousands of years before 0 BP, where "0 BP" is defined as the year AD 1950) were determined, bas... The temporal-spatial geographic distribution of archaeological sites and its feature between 10.0-2.8 ka BP (ka BP= thousands of years before 0 BP, where "0 BP" is defined as the year AD 1950) were determined, based on GIS spatial analysis in the Poyang Lake Basin. The relationship between geographic distribution of sites of different periods under subsis- tence existence of ancient civilizations, climate and environmental change was investigated. The results revealed numerous archaeological sites of the Neolithic Age (10.0-3.6 ka BP). The sites were mainly located in the northern part of the Poyang Lake Basin, a hilly and mountainous area with many river terraces suitable for the development of human civilization. The number of archaeological sites rapidly increased during the Shang and Zhou dynasties (3.6-2.8 ka BP) and spread widely on the floodplains of the middle and lower reaches of Ganjiang River and onto the west, south, and southeast beach areas of the Poyang Lake. Holocene records of climate change suggested that it was possible that climate fluctuations had a great impact on human evolution in the study area. Before 3.6 ka BP, westward and northward expansion of Neolithic cultures in the Poyang Lake watershed occurred under the background of climate amelioration (becoming warmer and wetter). The ancient people lived in the hilly areas with high elevation. The simple mode of a fishing and gathering economy was mostly suited to this area in the early Neolithic Age. The scope of human activities was expanded and cultural diversity developed in the late Neolithic Age. However, with population growth and increasing survival pressure in a dry-cold climatic stage after 3.6 ka BP, this sim-pie living mode had to be abandoned, and various forms of economy, the majority being ag- riculture, were developed on flood plains of the lower reaches of numerous rivers around Poyang Lake. This promoted flourishing of the Bronze culture of South China. 展开更多
关键词 Poyang Lake Basin archaeological sites temporal-spatial distribution climate and environmentalchange Shang and Zhou dynasties
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