任意曲线曲面上重磁位场转换的B样条函数法

提出用B样条函数求解曲线、曲面上重磁位场的向上延拓,水平、垂向导数计算,磁异常分量互换的方法。该方法的特点是:原理简明,程序通用性强,计算精度高。     

沙漠地区春季近地层气象要素分布规律的观测研究

利用2005年1月至2006年4月朱日和地区20 m气象塔的风向、风速、气温、相对湿度的观测资料,分析沙漠地区春季近地层气象要素的分布规律。结果表明: 春季温度回升,风速最大,相对湿度最小,利于起沙,故沙尘天气频繁。风速满足幂指数率分布规律,并且幂指数m能够很好的反映出风速梯度的变化情况;在沙尘暴、扬沙、背景、浮尘的天气条件下,春季近地面层风速梯度依次增大,湍流动量、热量交换系数依次减小;风向以西南为主。浮尘、扬沙天气各气层平均增温率分别大于或小于同时段的背景大气;沙尘暴期间温度下降,平均降温率为0.61 ℃\5h-1。春季相对湿度的平均递减率(递增率)与平均增温率(降温率)的大小正相关。浮尘天气相对湿度的平均递减率大于同时段的背景大气;扬沙天气相对湿度的平均递减率小于同时段的背景大气;沙尘暴天气相对湿度增大,平均增大率为2.80%\5h-1。     

滇西思茅盆地景谷地区曼岗组石英颗粒表面特征及其指示意义

石英具有硬度大和化学稳定性高的特点,其颗粒表面特征能很好的反映沉积环境,通过扫描电镜观察石英表面微细特征是判别沉积环境行之有效的方法。思茅盆地白垩系曾一度被认为是陆相水成沉积,笔者通过野外识别及室内基础研究发现,景谷地区下白垩统曼岗组具有风成沉积特征,需对该套地层开展石英颗粒表面特征的系统研究来进一步确定其沉积相,研究结果表明:研究区曼岗组石英颗粒表面具有明显的风成特征,磨圆度高,普遍发育典型的蝶形撞击坑、新月形撞击坑、毛玻璃化表面,存在沙漠漆,极易与水成特征相区别;而其较强的溶蚀作用与沉淀作用则显示了当时干旱炎热的气候条件。在风成沉积确定的基础上,笔者再结合典型沉积构造,粒度分析、岩性特征等沉积特征进行综合分析,认为研究区曼岗组应属沙漠沉积。     

Bias estimation and correction for triangle-based surface area calculations

The calculation of surface area is meaningful for a variety of space-filling phenomena, e.g., the packing of plants or animals within an area of land. With Digital Elevation Model (DEM) data we can calculate the surface area by using a continuous surface model, such as by the Triangulated Irregular Network (TIN). However, just as the triangle-based surface area discussed in this paper, the surface area is generally biased because it is a nonlinear mapping about the DEM data which contain measurement errors. To reduce the bias in the surface area, we propose a second-order bias correction by applying nonlinear error propagation to the triangle-based surface area. This process reveals that the random errors in the DEM data result in a bias in the triangle-based surface area while the systematic errors in the DEM data can be reduced by using the height differences. The bias is theoretically given by a probability integral which can be approximated by numerical approaches including the numerical integral and the Monte Carlo method; but these approaches need a theoretical distribution assumption about the DEM measurement errors, and have a very high computational cost. In most cases, we only have variance information on the measurement errors; thus, a bias estimation based on nonlinear error propagation is proposed. Based on the second-order bias estimation proposed, the variance of the surface area can be improved immediately by removing the bias from the original variance estimation. The main results are verified by the Monte Carlo method and by the numerical integral. They show that an unbiased surface area can be obtained by removing the proposed bias estimation from the triangle-based surface area originally calculated from the DEM data.     

塔里木盆地河水氢氧同位素与水化学特征分析

塔里木盆地是内陆地区重要的能源战略基地,研究其地表水的氢氧同位素和水化学特征对于区域水资源研究有重要意义.分析了塔里木盆地主要河流的河水样品δD-δ18O之间的关系以及主要离子与C1-之间的变化关系,得出如下认识:天山南麓和盆地西南部河水样品的δD、δ180值之间的差异主要是由同位素的高程效应引起的,昆仑山北坡河水样品的δD、δ180值之间的差异是同位素的高程效应和大陆效应共同作用的结果;渭干河、阿克苏河、喀什噶尔河、和田河中Na+主要来源于河水对蒸发盐石盐的溶解,K+主要来自于矿物的风化过程,喀什噶尔河流域中Ca2和SO42-主要来自于石膏的溶解,渭干河、阿克苏河、和田河流域中的Ca2和SO42-不来源于高溶解度的矿物.     

塔河油田地面工程信息系统的设计与探讨

着重探讨了塔河油田地面工程信息系统的建设思路和实现方法,针对油田的实际,以当前先进的组件式地理信息系统软件MAPGIS和可视化编程工具Microsoft Visual Studio构架的技术体系为基础,开发一套方便实用的油田地面工程信息系统。本系统建设为集原油集输、天然气和油田伴生气集输、道路、输供电线路为一体的可视化数据平台,实现了整个油田数据采集、管线图绘制,以及信息的浏览、查询统计、综合管理等功能。     

基于大炮初至的近地表层析反演方法研究及应用

详细研究了射线追踪、层析反演方法原理以及层析反演数值求解算法,提出了利用大炮初至直接建立初始地震模型,由小折射和微测井进行约束的层析反演近地表速度模型的处理流程,提出了基于多次回溯的高精度快速射线追踪算法和层析反演数值求解算法。采用双重网格技术提高正演模拟计算精度和层析反演的成像质量,另外,充分考虑多种质量控制方案,确保最终的反演速度模型精确。设计了10种不同地表地质条件的理论模型,进行模型试算,并在实际生产中应用,理论模型试算和实际资料反演结果证明了本文方法的正确性。     

FIO-ESM气候模式北太平洋海表温度和降水的季节性预报技巧评估

The seasonal prediction of sea surface temperature(SST) and precipitation in the North Pacific based on the hindcast results of The First Institute of Oceanography Earth System Model(FIO-ESM) is assessed in this study.The Ensemble Adjusted Kalman Filter assimilation scheme is used to generate initial conditions, which are shown to be reliable by comparison with the observations. Based on this comparison, we analyze the FIO-ESM 6-month hindcast results starting from each month of 1993–2013. The model exhibits high SST prediction skills over most of the North Pacific for two seasons in advance. Furthermore, it remains skillful at long lead times for midlatitudes. The reliable prediction of SST can transfer fairly well to precipitation prediction via air-sea interactions.The average skill of the North Pacific variability(NPV) index from 1 to 6 months lead is as high as 0.72(0.55) when El Ni?o-Southern Oscillation and NPV are in phase(out of phase) at initial conditions. The prediction skill of the NPV index of FIO-ESM is improved by 11.6%(23.6%) over the Climate Forecast System, Version 2. For seasonal dependence, the skill of FIO-ESM is higher than the skill of persistence prediction in the later period of prediction.     

基于Modis地表温度的横断山区气温估算及其时空规律分析

横断山区气象观测站稀少且多分布在河谷之中,气温资料极度匮乏,严重影响山区地理与生态研究。随着遥感技术的发展,热红外遥感数据,结合地面观测数据,可以用来推测山区气温。本文通过对横断山区2001 年-2007 年间64 个气象台站的多年月平均气温数据(Ta) 与Modis地表温度多年月平均值(Ts) 进行了时序分析和回归分析,并取得如下研究结果：(1) Ts 与Ta 具有非常好的线性相关关系,89%的台站的决定系数高于0.5;95%的台站的标准误差都低于3 oC,84.4%的台站标准误差低于2.5 oC;12 个月份的Ts 与Ta 的决定系数R²在0.63~0.90 之间,标准误差在2.22~3.05 oC之间。(2) 研究区内月均气温的变化范围在-2.25~15.64 oC之间;生长季(5-9 月份) 的月均气温变化范围为：10.44~15.64 oC。(3) 等温线的海拔高度自山体外围向内部逐渐升高,与山体效应的增温效应相吻合;0 oC等温线自10 月份从海拔4700±500 m左右逐渐降低,至1月份降至最低点,约在3500±500 m左右,此后,逐渐回升,至次年5 月份再次达到4700±500 m左右,也就是说横断山区5200 m以下的广大山区全年至少有6~12 个月的气温在0 oC以上。研究表明：可以利用Modis月均地表温度结合地面观测台站的数据较精确的估算山区月均气温。