利用ICESat激光测高数据确定极地冰盖高程变化     

黄海兰  王正涛  金涛勇  超能芳 《武汉大学学报(信息科学版)》2012,37(10):1221-1223,1251

对比研究了Shepard方法和连续曲率张力样条法及Kriging法在高程观测值稀疏和空缺区域中的插值效果,然后基于精化的ICESat数据集,利用连续曲率张力样条法建立了两极冰盖的格网时间序列模型,给出了极地冰盖高程的变化速率分布,并与卫星交叉点差值方法得到的相应值进行了对比分析。  相似文献   

Catastrophic groundwater pollution in a karst environment: a study of phosphorus sludge waste liquid pollution at the Penshuidong Cave in Yunnan,China   总被引：2，自引：1，他引：1  

Zhengtao Shi  Xinyou Liu  Yong Liu  Ying Huang  Haiying Peng 《Environmental Earth Sciences》2009,59(4):757-763

Due to a humid climate, karst areas in south China have an abundance of groundwater. With the development of agriculture, industry, and mining, the potential factors that may result in catastrophic groundwater pollutions are increasing. A phosphorus groundwater pollution event and its subsequent emergency treatment at Penshuidong Cave in Songming, Yunnan Province on February 24, 2008 were analyzed in addition to water quality monitoring in the region. The results showed that concentrations of phosphates, fluoride, cyanides and volatile phenols in phosphorus sludge waste liquid to be 11,532, 252, 224, 200 times higher than that of the Environmental quality standards for surface water (GB 3838-2002) III, respectively. The element phosphorus concentration was 16,510 times higher than the limit set by the Water quality standard for fisheries (GB11607-1989). The addition of quicklime and water to the phosphorus sludge waste liquid dumping pit clearly decreased pollutant concentrations, which indicates that the quicklime can remove the phosphorus from the waste liquid. Peak values of pollutant concentration decreased along the flow direction, which suggests the highly concentrated polluted water mass may be diluted during its movement. After treatment with water, a pollutant concentration peak appears at the groundwater outlet indicating that washing may accelerate the moving speed of the pollutants in groundwater. Element phosphorus concentrations, however, remained at a high and stable range(46–65 times higher than the limit set by the Water quality standard for fisheries).  相似文献   

Groundwater Storage Change in the Jinsha River Basin from GRACE,Hydrologic Models,and In Situ Data     

Nengfang Chao  Gang Chen  Jian Li  Longwei Xiang  Zhengtao Wang  Kunjun Tian 《Ground water》2020,58(5):735-748

Groundwater plays a major role in the hydrological processes driven by climate change and human activities, particularly in upper mountainous basins. The Jinsha River Basin (JRB) is the uppermost region of the Yangtze River and the largest hydropower production region in China. With the construction of artificial cascade reservoirs increasing in this region, the annual and seasonal flows are changing and affecting the water cycles. Here, we first infer the groundwater storage changes (GWSC), accounting for sediment transport in JRB, by combining the Gravity Recovery and Climate Experiment mission, hydrologic models and in situ data. The results indicate: (1) the average estimation of the GWSC trend, accounting for sediment transport in JRB, is 0.76 ± 0.10 cm/year during the period 2003 to 2015, and the contribution of sediment transport accounts for 15%; (2) precipitation (P), evapotranspiration (ET), soil moisture change, GWSC, and land water storage changes (LWSC) show clear seasonal cycles; the interannual trends of LWSC and GWSC increase, but P, runoff (R), surface water storage change and SMC decrease, and ET remains basically unchanged; (3) the main contributor to the increase in LWSC in JRB is GWSC, and the increased GWSC may be dominated by human activities, such as cascade damming and climate variations (such as snow and glacier melt due to increased temperatures). This study can provide valuable information regarding JRB in China for understanding GWSC patterns and exploring their implications for regional water management.  相似文献   

利用卫星测高数据研究海面高月异常变化与厄尔尼诺现象的相关性   总被引：1，自引：0，他引：1  

王正涛  李建成  晁定波  姜卫平 《武汉大学学报(信息科学版)》2004,29(8):699-703

利用美国宇航局和法国空间局联合公布的T/P数据 (1994年、1996年和 1997年 )、欧洲空间局的ERS1数据 (1992～ 1993年 )和ERS2数据 (1996年、1997年 )以及美国海军的Geosat精密重复任务数据 (1987年、1988年 ) ,由共线法计算了热带太平洋及东、西赤道太平洋洋域海平面高月变化 ,进而研究了 1987年、1991～ 1992年、1994年、1997年四次厄尔尼诺现象与该地区海面高月变化的相关性。测高数据采用最新编辑标准编辑 ,同时进行了逆气压等各项物理改正 ,得出了与 1987年、1992～ 1993年、1994年、1997年厄尔尼诺现象有联系的热带太平洋及东、西赤道太平洋逐月的海面高变化异常图 ,利用正常年 1988年、1996年海平面高月变化作为基准 ,计算出相对于正常年的海平面高变化的异常值  相似文献   

海洋重力似大地水准面与区域测高似大地水准面的拟合问题   总被引：3，自引：0，他引：3  

王正涛  李建成  晁定波 《武汉大学学报(信息科学版)》2005,30(3):234-237

研究了将陆地重力似大地水准面与GPS水；住似大地水准面拟合的处理方法推广到海洋的问题．首先从理论上证明了当存在海面地形．则海洋大地水准面与似大地水准面不重合．导出了在海洋上大地水；住面差距与高程异常之间差值的公式．由此给出了求定平均海面相对于区域高程基准的正常高以及测高似大地水准面的计算公式。由于测高平均海面与GPS大地高有相近的精度．提出了将海洋重力似大地水准面与区域测高似大地水准面拟合的处理方法．并利用当前最新的海面地形模型和测高平均海面模型做了数值估计。  相似文献   

Swarm系列卫星非差运动学厘米级精密定轨     

张兵兵  牛继强  王正涛  徐丰  田坤俊 《测绘学报》2021,50(1):27-36

采用2015年5月24日—30日的Swarm星载GPS双频观测数据,基于Melbourne-Wübbena(MW)和消电离层线性组合,在精密单点定位技术的基础上,采用批处理最小二乘估计法对不同轨道高度的Swarm系列卫星进行非差运动学精密定轨。利用星载GPS相位观测值残差、与欧空局发布的简化动力学轨道对比,以及SLR检核3种方法对Swarm系列卫星非差运动学定轨结果进行精度评估。结果表明:①Swarm系列卫星星载GPS相位观测值残差RMS为6~7 mm;②与欧空局发布的简化动力学轨道进行求差,径向、切向及法向轨道差值RMS为2~4 cm;③与欧空局发布的运动学轨道进行求差,径向、切向及法向轨道差值RMS为1~2 cm;④SLR检核结果表明Swarm-A/B/C卫星轨道精度为3~4 cm。因此,采用非差运动学定轨方法与本文提供的定轨策略进行Swarm系列卫星精密定轨是切实可行的,定轨精度为厘米级。  相似文献   

论自然灾害经济损失评估研究的重要性   总被引：1，自引：1，他引：0  

李宁  张正涛  陈曦  冯介玲 《地理科学进展》2017,36(2):256-263

本文就当前国内外对灾害经济损失的认识、损失评估在灾害管理中的重要作用、灾害直接经济损失和间接经济损失评估存在的问题进行了综合分析,论证了灾害损失评估研究的重要性,区分了直接损失和间接损失的差异,阐述了间接损失评估的必要性和可行性。研究结果表明,直接损失和间接损失的评估同等重要、通过合理的评估方法得到的直接和间接损失的评估结果既是防灾减灾的迫切需求,也有利于提高防灾减损的管理水平。灾害学与经济学相结合是有效改进评估方法并提高灾害经济损失评估水平的有效途径。  相似文献   

基于GOCE梯度的地球引力场恢复(英文)     

SHEN Wenbin LI Jin LI Jiancheng WANG Zhengtao NING Jinsheng CHAO Dingbo  Dept. of Geophysics  School of Geodesy  Geomatics  Wuhan University  Luoyu Road  Wuhan  China  The Key Laboratory of Geospace Environment  Geodesy  Wuhan University  Luoyu Road  Wuhan  China. 《地球空间信息科学学报》2008,(4)

Given the second radial derivative Vr r ( P ) |S of the Earth’s gravitational potential V ( P ) on the surface S corresponding to the satellite altitude, by using the fictitious compress recovery method, a fictitious regular harmonic field rrVr r( P )* and a fictitious second radial gradient field Vr *r ( P) in the domain outside an inner sphere K i can be determined, which coincides with the real field Vr r( P ) in the domain outside the Earth. Vr *r ( P)could be further expressed as a uniformly convergent expansion series in the domain outside the inner sphere, because rrVr r( P )* could be expressed as a uniformly convergent spherical harmonic expansion series due to its regularity and harmony in that domain. In another aspect, the fictitious field V * ( P) defined in the domain outside the inner sphere, which coincides with the real field V ( P ) in the domain outside the Earth, could be also expressed as a spherical harmonic expansion series. Then, the harmonic coefficients contained in the series expressing V * ( P) can be determined, and consequently the real field V ( P ) is recovered. Preliminary simulation calculations show that the second radial gradient field Vr r( P ) could be recovered based only on the second radial derivative Vr r ( P )| S given on the satellite boundary. Concerning the final recovery of the potential field V ( P ) based only on the boundary value Vr r ( P )|S, the simulation tests are still in process.  相似文献   

粤东靖海湾海岸地貌动力演变及其工程影响   总被引：1，自引：0，他引：1  

姬泓宇  陈沈良  雷亚平  郭晓娟  朱正涛 《海洋工程》2016,34(5):57-64

受人为工程的影响,相对稳定的岬湾海岸地貌常经历显著的动态调整。本文以粤东靖海湾典型岬湾海岸为例,运用Mc Laren模型、波浪动力场数值模拟、等深线对比、冲淤计算等多种方法,从海岸地貌动力学角度,对人为岬角工程前后岬湾海岸地貌动力过程和冲淤演变进行综合分析。结果表明:1)海岸地貌动力系统内常存在负反馈机制以维持系统的稳定。岬角工程后上岬角防波堤沿SSW延伸,ESE和E向浪经过防波堤时发生绕射,波能削减,湾顶动力减弱,海滩沉积物从下岬角向湾顶反向运移;2)海滩的蚀积状态在工程前后发生了转换,工程前遮蔽段侵蚀、开敞段堆积;工程后遮蔽段堆积、开敞段侵蚀;3)海湾水下地形对岬角工程的响应敏感,工程后海湾水下地形冲淤剧烈。  相似文献   

联合Jason-1与GRACE卫星数据研究全球海平面变化   总被引：3，自引：2，他引：1  

蒋涛  李建成  王正涛  金涛勇  陈明 《测绘学报》2010,39(2):135-140

海平面变化主要由海水质量变化和比容海平面变化组成。联合GRACE时变重力场与Jason-1卫星测高数据分别研究了全球平均海平面及其质量分量与比容分量的季节性变化(2002-09—2008-04),联合两种卫星数据所得平均海平面变化在周年振幅和相位上与WOA05海洋模型结果具有一致性。估算出研究时间段内全球平均海平面变化及其两个主要分量的长期性趋势,在超过6.5a的时间尺度上,全球平均海平面以+2.0±0.4mm/a的速率上升,其中海水质量变化分量的贡献为+1.4±0.4mm/a,比容变化分量的贡献为+0.5±0.3mm/a。  相似文献