基于高分影像光谱特征快速估算综合雨量径流系数的方法探索——以嘉兴海绵城市示范区为例

依据综合雨量径流系数计算公式,提出了一种基于高分影像光谱特征的综合雨量径流系数快速估算方法。结合面向对象的影像分割分类技术及阴影区再分类方法,获取了试验区覆被分类信息,从而达到了快速估算综合雨量径流系数的目的,并以嘉兴海绵城市示范区为例,对比嘉兴市地理国情普查成果,验证本文方法的可行性。     

BDS／GPS 组合 RTK 定位性能分析

针对单系统RTK存在可见卫星数少等问题,文中研究BDS/GPS站间单差的RTK算法模型,该模型采用二次型函数部分最小化及LAMBDA方法联合搜索模糊度。利用该模型分析BDS/GPS组合RTK的定位性能,通过短基线实测数据分析表明:站间单差RTK模型与双差模型是等价的;BDS/GPS组合系统相比于单一系统,明显提高定位的稳健性和精度,改善模糊度固定的成功率。     

A Comparison Study on the δD Value of Polycyclic Aromatic Hydrocarbons in Hydrous Pyrolysate of Herbaceous Peat with Different Water Medium

To investigate the influence of diagenetic water media on the hydrogen isotopes of individual sedimentary aromatic compounds, a series of hydrous pyrolyses were conducted on herbaceous peat. Polycyclic aromatic hydrocarbons (PAHs) in hydrous pyrolysed samples and their hydrogen isotopic composition characteristics were studied. The aqueous medium demonstrated a significant influence on the hydrogen isotopic composition of the individual PAHs generated during pyrolysis. The results showed that the PAHs formed after pyrolysis in the presence of a saltwater medium with high δD value from a salt lake had a heavy hydrogen isotopic composition. The PAHs formed after pyrolysis in the presence of a fresh water medium with low δD value from a swamp had a light hydrogen isotopic composition. The difference in the average PAH δD value between the two hydrous experiments varied from –174‰ to –109‰, suggesting that the hydrogen isotopic composition of individual sedimentary PAHs can reflect the source of the diagenetic water medium. In addition, a comparative study found that the hydrogen isotopes of PAHs were superior to those of n-alkanes in the same sample for diagenetic water indications. The results indicated that the exchange of water-derived inorganic hydrogen and organic hydrogen was more intensive in freshwater experiments than in saltwater experiments. With an increase in the simulation temperature, the average δD value of PAHs generated in the hydrous simulation experiments showed an increasing trend, reflecting that the δD value of sedimentary PAHs formed with the participation of diagenetic water media was still closely related to the thermal maturity of organic matter. Comparative studies showed that the δD values of different types of organic compounds produced by hydrous pyrolysis of peat were in the order, PAHs > n-alkanes > methane.     

Planning of Water-Saving Green Space System Based on GIS Technology and Archydrodata Model

Water Resources - Following sponge city concept, taking Qunli New District as study object, and planning water-saving green space system (WGSS) that can use rainwater resources. GIS and ArcHydro...     

3D Anisotropic P- and S-Mode Wavefields Separation in 3D Elastic Reverse-Time Migration

Surveys in Geophysics - In 2D anisotropic media, non-stationary filters and low-rank approximation methods are classical strategies to compute the decomposition operators, but they suffer from...     

基于MongoDB的地震风险评估综合地情数据服务平台设计与实现

本文介绍了基于MongoDB的地震风险评估综合地情数据服务平台,以灵活的文档结构存储与查询为目标,使用Web Service技术,采用前后端分离的开发方式,给出了系统的总体设计以及关键技术和功能,实现了全国区县级地震风险评估综合地情数据更灵活地上传、编辑、查询等功能。通过建立全国统一的地震风险评估综合地情数据服务平台,对数据进行可视化展示,提高了全国综合地情数据的利用率和服务能力。     

安徽省含山县土地整理耕地质量评价及其变化研究

土地整理是改善土地利用条件,提高土地质量的有效措施,对土地整理后的耕地质量进行评价是土地整理重要工作之一。从耕地质量的内涵和土地整理项目的基本要求出发,选取耕地自然条件和耕地利用条件2个基本因素和12个影响因子,将特尔斐法与层次分析法相结合,确定各因子权重,构建基于土地整理的耕地质量评价指标体系。以安徽省含山县铜闸镇土地整理项目为例,采用传统的土壤调查与3S技术相结合的方法,分析土地整理复垦过程中耕地质量时空格局变化,得出整理前、后耕地质量的级别变化。研究结果表明,通过土地整理,研究区的耕地质量空间分布和级别发生了很大变化,整理后一级、二级、三级质量的土地比整理前分别增加了7.20%,11.95%和0.65%,四级、五级则分别减少了15.65%和4.16%,整理后的耕地质量总体水平是整理前的1.291倍。     

1960—2008年新疆哈密地区的气温变化分析

通过对哈密地区6个气象站1960-2008年气温观测数据的统计整理,利用回归分析、求相关和t检验、对比分析等方法,研究了哈密地区季、年气温的变化特征.结果表明:近49 a来,哈密地区气温明显上升,1987年以来上升明显;春、夏、秋三季和年均气温每10 a平均最大值均出现在21世纪初期,最小值多出现在20世纪70年代;季...