WV-3遥感数据在滇西矿产资源开发与地质灾害调查中的应用     

胡官兵  党伟  金梦迪 《江苏地质》2022,46(2):199-206

选择云南三江中南段高黎贡山之南作为研究对象,利用WorldView-3卫星数据高空间分辨率的特点,基于Skyline软件构建三维模拟场景,从不同视域范围、远近尺度、方位视角对解译目标进行全方位展示,获取了不同矿山开发及地质灾害的典型识别标志,进行矿产资源开发状况精细识别及地质灾害详细信息提取,解译出区内建筑石料用灰岩等5种非金属矿以及滑坡等3种类型地质灾害,为矿山管理及地质灾害调查提供快速精准的目标,提升工作效率和质量。  相似文献   

Avalanche in Tuban: a hazard with no defense   总被引：1，自引：0，他引：1  

Xiang-Zhou Xu  Guo-Dong Song  Jie Liu  Wei-Qin Dang  Hang Gao  Zhen-Yi Liu  Hong-Wu Zhang 《Natural Hazards》2015,79(3):2181-2187

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乌兰布和沙漠东南缘白沙蒿(Artemisia sphaerocphala)灌丛沙堆形态特征与固沙能力     

高永  党晓宏  虞毅  汪季  王珊  原伟杰  张惜伟 《中国沙漠》2015,(1):1-7

白沙蒿(Artemisia sphaerocphala)灌丛沙堆是乌兰布和沙漠最为广泛分布的典型荒漠灌丛沙堆之一。本研究对白沙蒿灌丛的灌丛形态参数、沙堆形态参数进行了野外测定,探讨沙堆形态发育及固沙能力与白沙蒿灌丛形态的关系。结果表明:白沙蒿灌丛高度随着灌丛半径的增加而呈对数曲线增加,在灌丛较小时灌丛高度增长较快,随后渐趋于稳定,其水平方向发育速度大于垂直方向;白沙蒿灌丛沙堆半径及高度随灌丛半径和高度增加而增加,二者呈显著线性关系,沙堆水平方向发育受到灌丛冠幅的影响,沙堆垂直方向的发育水平取决于灌丛高度;随白沙蒿地上部分鲜重的增加,灌丛沙堆底面积、高度、沙堆体积和固沙效率均呈极显著线性增加(p0.01);白沙蒿灌丛越大其固积沙堆也越大,固沙率越高,不同大小灌丛白沙蒿间的固沙效率差异显著(p0.05);白沙蒿灌丛背风侧的积沙宽度(y)与积沙距离(x)显著相关(R2=0.9917),其线性回归方程为y=-19.654x+122.41,在距离灌丛背风面6~7倍高度的地方,积沙接近消失。  相似文献   

Improved initialization conditions and single impulsive maneuvers for \hbox {J}_{2}-invariant relative orbits     

Zhaohui Dang  Zhaokui Wang  Yulin Zhang 《Celestial Mechanics and Dynamical Astronomy》2015,121(3):301-327

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Downscaling large-scale climate variability using a regional climate model: the case of ENSO over Southern Africa   总被引：1，自引：1，他引：0  

Damien Boulard  Benjamin Pohl  Julien Crétat  Nicolas Vigaud  Thanh Pham-Xuan 《Climate Dynamics》2013,40(5-6):1141-1168

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Observed and simulated sea breeze characteristics over Rayong coastal area, Thailand   总被引：1，自引：0，他引：1  

Tung Thanh Phan  Kasemsan Manomaiphiboon 《Meteorology and Atmospheric Physics》2012,116(3-4):95-111

This work presents the detailed characterization of sea breeze (SB) over the Rayong coastal area, one of the most rapidly developed and highly industrialized areas during the last decade in Thailand, using observation data analysis and fine-resolution (2?km) mesoscale meteorological modeling with incorporation of new land cover and satellite-derived vegetation fraction data sets. The key characteristics considered include frequency of SB occurrence, sea-breeze day (SBD) identification, degree of inland penetration, and boundary layer development. It was found that SBs occur frequently in the winter due mainly to relatively large land–sea temperature contrasts and minimally in the wet season. Monthly mean SB onset and cessation times are at around 12–15 local time (LT) and 18–21 LT, respectively, and its strength peaks during the early- to mid-afternoon. Monthly SB hodographs generally exhibit clockwise rotations, and SB inland penetration (at PCD-T tower) ranges widely with the monthly means of 25–55?km from the coast. Mesoscale MM5 modeling was performed on two selected SBDs (13 January and 16 March 2006), on which the SBs are under weak and onshore strong influences from background winds, respectively. Simulated near-surface winds and temperature were found to be in fair-to-acceptable agreement with the observations. The SB circulation along the Rayong coast is clearly defined with a return flow aloft and a front on 13 January, while it is enhanced by the onshore background winds on 16 March. Another SB along the Chonburi coast also develops separately, but their fronts merge into one in the mid-afternoon, resulting in large area coverage by the SB. Simulated planetary boundary layer height over the land area is significantly affected by a thermal internal boundary layer (TIBL) induced by an SB, which is found to be low near the coast and increases toward the front (up to 800–1,000?m along the Rayong coast).  相似文献   

Microscopic morphology and size distribution of particles in PM<Subscript>2.5</Subscript> of Guangzhou City     

Xidan Feng  Zhi Dang  Weilin Huang  Longyi Shao  Weijun Li 《Journal of Atmospheric Chemistry》2009,64(1):37-51

Samples of airborne PM_2.5 particles in Guangzhou urban area were collected during the autumn of 2006 and the spring of 2007. The morphologies and elemental compositions of individual particles were determined by Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectrometer (SEM-EDX). The obtained images were further analyzed for size distribution by an image analysis system. Based on the morphology, particles in PM_2.5 were classified into four groups: soot aggregates, minerals, fly ash and others. The amount of soot aggregates and minerals were higher than that of fly ashes. The distributions of particles by number and size in two seasons were bimodal with 90% less than 1.0 μm in diameter. The primary peak from the autumn samples was in the size range of 0.4 ~ 0.5 μm, and 0.3 ~ 0.4 μm for the spring samples. More soot aggregates (36.1%) and minerals (61.5%) were found than fly ash (2.4%) in autumn, but soot aggregates (89.9%) was the dominant particle type in spring. The size distribution of particles according to the volume was generally opposite to that according to the number. Particles less than 1.0 μm were as high as 89.5% in number but contributed only 18.9% in volume, indicating that fine particles contributed relatively little in volume although existing in large numbers.  相似文献   

甘肃省夏季层状云微物理特征个例分析   总被引：4，自引：2，他引：2  

党娟  王广河  刘卫国 《气象》2009,35(1):24-36

对2004年6月12日甘肃河西地区一次降水性层状云的云物理飞机探测结果进行了分析,通过对云中粒子的浓度、直径、二维图像以及谱型变化地研究,并结合宏观观测记录,详细分析了云系的垂直和水平微物理特征.观测资料分析表明:此次云系为Ac-Sc结构,上层Ac云为纯冷云,下层Sc云为纯暖云,两层云之间存在较厚的干层.云中微物理量的垂直和水平变化均具有明显的不均匀性,整个探测过程中,FSSP-100所测云粒子的浓度和平均直径变化范围分别为0.1～-232.6cm-3和3.5～45.5μm,OAP-2D-GA2所测云粒子浓度及平均直径变化范围分别为0.01～116.7cm-3和32.2～995.7μm.粒子二维图像表明,上层高积云中冰相粒子的凇附、粘连现象普遍,说明云中存在较多的过冷水.图像及谱型分析表明,6000m以上某些区域有冰晶高浓度区存在,大量冰晶的成长消耗了云中过冷水,不利于大云粒子的形成和成长;这次降水雨滴主要由纯暖性Sc云中暖云成雨过程形成,冷云过程只在Sc云顶附近有一定作用,本次降水主要机制为下层层积云中的暖云过程.  相似文献   

Black carbon decomposition under varying water regimes   总被引：1，自引：0，他引：1  

Binh Thanh Nguyen  Johannes Lehmann 《Organic Geochemistry》2009,40(8):846-853

The stability of biomass-derived black carbon (BC) or biochar as a slow cycling pool in the global C cycle is an important property and is likely governed by environmental conditions. This study investigated the effects of water regimes (saturated, unsaturated and alternating saturated–unsaturated conditions) and differences in BC materials, produced by carbonizing corn residues and oak wood at two temperatures (350 °C and 600 °C) on BC degradation at 30 °C over 1 year in a full factorial experiment. Effects of water regime on C loss and potential cation exchange capacity (CECp at pH 7) significantly depended on biomass type. Corn BC was both mineralized (16% C loss for the first year) and was oxidized [1000 mmole(+) kg^?1 C] significantly faster under unsaturated conditions than under other water regimes, whereas oak BC mineralized most rapidly (12%) under alternating saturated–unsaturated conditions with similar oxidation, irrespective of water regime. Over 1 year of saturated incubation, the O/C ratio values did not significantly (P > 0.05) increase even though BC was mineralized by 9% and CECp increased by 170 mmole(+) kg^?1 C, in contrast to unsaturated and alternating saturated–unsaturated conditions. While mineralization and oxidation significantly decreased at higher charring temperature for corn, no difference was observed for oak (P > 0.05). Unsaturated and alternating conditions increased carboxylic and OH functional groups, while they decreased aliphatic groups. The pH increased by about one unit for corn BC, but decreased by 0.2 units for oak BC, indicating strong mineral dissolution of corn BC. Carbon loss strongly correlated with changes in O/C values of both corn BC and oak BC, indicating that oxidation of BC was most likely the major mechanism controlling its stability. However, under saturated conditions, additional mechanisms may govern BC degradation and require further investigation.  相似文献   

Effects of riverbed incision on the hydrology of the Vietnamese Mekong Delta     

Doan Van Binh  Sameh A. Kantoush  Tetsuya Sumi  Nguyen Phuong Mai  Trieu Anh Ngoc  La Vinh Trung  Tran Dang An 《水文研究》2021,35(2):e14030

The hydrogeomorphology of the Vietnamese Mekong Delta (VMD) has been significantly altered by natural and anthropogenic drivers. In this study, the spatiotemporal changes of the flow regime were examined by analysing the long-term daily, monthly, annual and extreme discharges and water levels from 1980 to 2018, supported by further investigation of the long-term annual sediment load (from the 1960s to 2015), river bathymetric data (in 1998, 2014 and 2017) and daily salinity concentration (from the 1990s to 2015) using various statistical methods and a coupled numerical model. Then, the effects of riverbed incision on the hydrology were investigated. The results show that the dry season discharge (i.e., in March–June) of the Tien River increased by up to 23% from the predam period (1980–1992) to the postdam period (1993–2018) but that the dry season water level at My Thuan decreased by up to −46%. The annual mean and monthly water levels in June at Tan Chau and in January and June–October at My Thuan in the Tien River decreased statistically, even though the respective discharges increased significantly. These decreased water levels instead of the increased discharges were attributed to the accelerated riverbed incision upstream from My Thuan, which increased by more than three times, from a mean rate of −0.16 m/year (−16.7 Mm³/year) in 1998–2014 to −0.5 m/year (−52.5 Mm³/year) in 2014–2017. This accelerated riverbed incision was likely caused by the reduction in the sediment load of the VMD (from 166.7 Mt/year in the predam period to 57.6 Mt/year in the postdam period) and increase in sand mining (from 3.9 Mm³ in 2012 to 13.43 Mm³ in 2018). Collectively, the decreased dry season water level in the Tien River is likely one of the main causes of the enhanced salinity intrusion.  相似文献