我国海岛开发与保护的战略思考

我国海岛开发保护虽取得显著成效,但问题亦十分突出。海岛开发保护对我国经济社会长远发展具有重大的战略意义。文章基于可持续发展视角,借鉴国际经验,从战略层面对我国海岛开发保护的进一步发展进行研究和思考,尝试提出可行的海岛开发保护战略目标、思路和对策建议。     

Homo erectus pekinensis''''s age and environment——with discussion on the relationship among Homo erectus from Beijing,Nanjing and Chenjiawo

This paper inspects the relationship between Homo erectus from Beijing, Nanjing and Chenjiawo on the viewpoint of environmental variations. Pieces of evidence show that Nanjing and Chenjiawo Homo erectus lived in glacial age at the Marine Oxygen Isotope Stage (MIS) 16, while Homo erectus pekinensis in major interglacial age at MISs 15-13. It is also recovered that the cave deposits in Tangshan, Nanjing, and Zhoukoudian, Beijing, as well as the deposits at the Homo erectus site in Chenjiawo, have undergone some similar development process. All of them originated from early-middle Middle Pleistocene, and have gone through the test of the major glacial age at MIS 16 and the major interglacial period at the paleosol stage S5. At the same time, they were also closely connected with some environment events, such as the uplift of the Qinghai-Xizang Plateau, the formation of glaciations and the loess accumulations.     

New characteristics of weighted GDOP in multi-GNSS positioning

In positioning, navigation and timing applications of multi-GNSS (global navigation satellite system) constellations, the geometric dilution of precision (GDOP) offers an important index for selecting satellites and evaluating positioning accuracy. However, GDOP assumes that the measurement errors of all the tracked satellites are independent and have the same accuracy level, which is impossible in practice, especially when the tracked satellites are from various constellations. Through introducing a weighted matrix describing the measurement errors of different satellites into a common GDOP, we focus on new characteristics of weighted GDOP (WGDOP) in two aspects. First, we compare the sizes of WGDOP and the common GDOP based on the range of the weights of different satellites, i.e., the diagonal elements of the weighted matrix. In addition, when the weights of different satellites increase, the change of WGDOP with the weights is also derived. Moreover, a closed-form formula for calculating WGDOP is also presented. The theoretical derivations demonstrate that the closed-form can reduce the computation burden effectively. Furthermore, numerical tests verify these analyses.     

激光扫平仪在线自动检测系统

介绍了一种新型的激光扫平仪在线自动检测系统,主要用于激光扫平仪倾斜误差β、锥角误差γ和补偿误差δ的高精度在线自动检测。     

海南岛鹿回头造礁珊瑚的14C年代及珊瑚礁的发育演化

通过2002年7月沿鹿回头珊瑚礁坪断面方向,在原生滨珊瑚(Porites)礁表面进行系统采样,并进行C测年和年代校正,初步划分出全新世以来珊瑚礁演化的5个阶段珊瑚礁繁盛期(7 300-6000cal.aBP)、珊瑚礁发育停滞期Ⅰ(6 000-4 800cal.aBP)、珊瑚礁发展期(4 800-3000 cal.aBP)、珊瑚礁发育停滞期Ⅱ(3 000-1000 cal.aBP)和现代珊瑚礁发育期(1 000cal.aBP以来).鹿回头珊瑚礁在7 300-000cal.aBP处于发育的繁盛期,己基本上形成了现代珊瑚礁的地貌格局.后来不同时期珊瑚礁是在此时期形成的礁塘或礁坑等低洼地中形成,并在鹿回头半岛两侧向外发展,现代珊瑚礁则发育于全新世珊瑚礁的外礁坪或礁前斜坡带.     

微波与光学遥感协同反演旱区地表土壤水分研究

土壤水分是水文循环中的关键因素,尤其对旱区的生态环境具有十分重要的意义。微波遥感是反演土壤水分的有效手段,而植被是影响土壤水分反演精度的重要因素。因此,对土壤水分的反演需要考虑植被的影响。本文以内蒙古乌审旗为研究区,利用Radarsat-2雷达数据与TM光学数据,对旱区稀疏植被覆盖地表土壤水分反演进行研究。利用TM数据,分别选取NDVI和NDWI指数对植被含水量进行反演,通过水云模型消除植被层对土壤后向散射系数的影响;在此基础上,根据研究区地表植被特性,提出一种基于AIEM 模型的反演土壤水分的改进算法,反演了不同粗糙度参数、不同极化（VV极化和HH极化）条件下的研究区土壤水分。反演结果与野外实测数据的对比结果表明,本文提出的基于地表植被特性的土壤水分改进算法,具有更好的适应性;土壤水分反演模式\begin{array}{c}M{v}_{\mathit{\sigma vv}\left(1\right)}^{\mathit{lh}}\end{array}（VV极化方式下采用NDVI去除植被影响的反演模式）更适合于旱区考虑稀疏植被覆盖影响的地表土壤水分的反演。     

暴雨强度计算系统及其应用

用数值逼近和最小二乘法来推算暴雨强度公式中的参数值。在此基础上 ,设计出数学模型 ,采用结构化、模块化的编程原则 ,开发研制了暴雨强度计算系统     

基于梯度变换的浅水湖泊围网区遥感提取算法

获取并掌握浅水湖泊围网养殖区域的时空分布信息对合理规划围网养殖进而提升湖泊水质具有重要意义.本文以长江下游典型的围网养殖浅水湖泊——阳澄湖作为研究区,利用资源三号(ZY-3)高分遥感影像,针对围网区与非围网区的光谱空间变化特征,采用梯度变换方法,尝试提出一种浅水湖泊围网区的遥感提取算法;并以人工解译结果作为参考,对提取结果进行验证.研究结果发现该算法对浅水湖泊围网养殖区的提取精度为90.66%,可进一步用于开展长时序的浅水湖泊围网区动态变化研究,进而为湖泊环境的政府部门制定湖泊水质提升和围网区合理规划政策提供决策依据.     

北京市地质环境监测现状及对策研究

分析了北京市开展地质环境监测的必要性,介绍了北京市地勘局对北京市地质环境监测工作战略:"首都地质资源环境承载能力监测预警平台建设工程",总结了北京市地质环境监测现状及存在的不足,对未来北京市地质环境监测工作提出了编制北京市地质环境监测规划、做好监测网络技术支撑工作、逐步建设和完善北京市地质环境监测体系的对策。     

华南陆地时变重力观测数据质量评估

陆面时变微重力观测常用于监测地壳内部物质变化.仪器不确定性是影响数据质量的重要因素.本文以华南地区2015年至2018年的时变重力观测数据为研究对象,分别从相对重力仪的非线性漂移特征、格值系数变化入手,引入贝叶斯分析方法,量化不确定性来源,并以网内绝对重力观测结果进行交叉检验,评估时变重力数据产品质量.研究表明:华南2...