Future hydro-meteorological drought of the Johor River Basin,Malaysia, based on CORDEX-SEA projections     

Mou Leong Tan  Liew Juneng  Fredolin T. Tangang  Ngai Weng Chan  Sheau Tieh Ngai 《水文科学杂志》2019,64(8):921-933

Water scarcity issues in the Johor River Basin (JRB) could affect the populations of Malaysia and Singapore. This study provides an overview of future hydro-meteorological droughts using climate projections from an ensemble of four Coordinated Regional Climate Downscaling Experiments – Southeast Asia (CORDEX-SEA) domain outputs under the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios for the 2021–2050 and 2071–2100 periods. The climate projections were bias corrected using the quantile mapping approach before being incorporated into the Soil and Water Assessment Tool (SWAT) hydrological model. The Standardized Precipitation Index (SPI) and Standardized Streamflow Index (SSI) were used to examine the meteorological and hydrological droughts, respectively. Overall, future annual precipitation, streamflow, and maximum and minimum temperatures are projected to change by about ?44.2 to 24.3%, ?88.7 to 42.2%, 0.8 to 3.7ºC and 0.7 to 4.7ºC, respectively. The results show that the JRB is likely to receive more frequent meteorological droughts in the future.  相似文献   

福建石牛山水蚀花岗岩石蛋地貌特征及成因研究   总被引：2，自引：0，他引：2  

梁诗经  文斐成  陈斯盾  揭育金  魏勇  胡祚林 《福建地质》2006,25(2):65-74

石牛山主峰出露晚白垩世石牛山组晚期侵入相钾长花岗斑岩,山体浑厚壮观,石蛋千姿百态。石蛋、石堡及崖壁上分布着深浅不一的石脊、石槽及大小不同的石臼、石盆、石穴等微地貌,构成独具特色的“水蚀花岗岩石蛋地貌”。经研究,钾长花岗斑岩是形成水蚀花岗岩石蛋的物质基础,风化剥蚀、大气降水击蚀及其流水侵蚀是形成石脊、石槽、石臼、石盆、石穴的主要外动力地质作用。  相似文献   

安徽省休宁—歙县整装勘查区晚侏罗世逆冲推覆构造特征及其与成矿作用关系     

翁望飞  王德恩  胡召齐  朱强  汪启年  吴冀明  唐国强  张鹏飞 《吉林大学学报(地球科学版)》2020,50(5):1518-1538

通过野外地质调查结合大地电磁测深综合构造解释,在休宁—歙县金多金属矿整装勘查区及邻区厘定出发育于晚侏罗世的较大规模逆冲推覆构造,其由逆冲断层、逆冲岩席、原地岩系、构造窗及伴生的牵引褶皱等组成。该逆冲推覆构造发育于"屯溪—休宁"红层盆地南缘,表现为晚元古代浅变质火山-碎屑岩系逆冲推覆于中侏罗统洪琴组碎屑岩之上。逆冲推覆构造由一系列分支逆断层组成,以前展式叠瓦状逆冲为特征,断层前缘陡立,向下变缓。逆冲推覆构造呈北东走向展布,勘查区内延伸可达40 km,推覆体面积大于600 km²。构造窗出露位置结合钻探、物探揭示,逆冲位移为2.0~8.0 km。根据逆冲断层时空配套以及岩浆活动与波及的沉积地层,判断晚侏罗世逆冲推覆构造活动时间为163.5~149.0 Ma。通过逆冲断层擦痕观察及古应力场分析,认为该期逆冲推覆构造形成于华南板块向北强烈挤压的区域动力学环境。逆冲推覆构造为成矿前构造,其与之后发生的伸展构造对岩浆的侵入及含矿热液的流通起着重要的作用,控制了整装勘查区内金、银、铅锌等中低温元素的分布与富集成矿。  相似文献   

Urban heat island monitoring and analysis using a non-parametric model: A case study of Indianapolis   总被引：1，自引：0，他引：1  

Umamaheshwaran Rajasekar  Qihao Weng 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(1):86-96

A procedure for the monitoring an urban heat island (UHI) was developed and tested over a selected location in the Midwestern United States. Nine counties in central Indiana were selected and their UHI patterns were modeled. Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) images taken in 2005 were used for the research. The images were sorted based on cloud cover over the study area. The resulting 94 day and night images were used for the modeling. The technique of process convolution was then applied to the images in order to characterize the UHIs. This process helped to characterize the LST data into a continuous surface and the UHI data into a series of Gaussian functions. The diurnal temperature profiles and UHI intensity attributes (minimum, maximum and magnitude) of the characterized images were analyzed for variations. Skin temperatures within any given image varied between 2–15 ^°C and 2–8 ^°C for the day and night images, respectively. The magnitude of the UHI varied from 1–5 ^°C and 1–3 ^°C over the daytime and nighttime images, respectively. Three dimensional (3-D) models of the day and night images were generated and visually explored for patterns through animation. A strong and clearly evident UHI was identified extending north of Marion County well into Hamilton County. This information coincides with the development and expansion of northern Marion County during the past few years in contrast to the southern part. To further explore these results, an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) 2004 land use land cover (LULC) dataset was analyzed with respect to the characterized UHI. The areas with maximum heat signatures were found to have a strong correlation with impervious surfaces. The entire process of information extraction was automated in order to facilitate the mining of UHI patterns at a global scale. This research has proved to be promising approach for the modeling and mining of UHIs from large amount of remote sensing images. Furthermore, this research also aids in 3-D diachronic analysis.  相似文献   

基于典型事例推理的路径规划方法研究(英文)     

翁敏  魏秀琴  瞿嵘  蔡忠亮 《地球空间信息科学学报》2009,12(1):66-71

Case-based reasoning is an AI technique in which the previous solutions are stored for future use. People are used to guiding themselves according to those routes that are stored in their memories and have been used by them before. It is just based on people’s preference to familiar routes, which are gained through the study of the cognitive activities. We propose to apply the intelligent method based on the case reasoning to path planning. It is impossible for a case base to store all the solutions to all the shortest paths; therefore, part of them should be stored. However, which routes should be stored and which should not be? How do we adapt the cases that have already been stored and how do we acquire the shortest route based on them? All these issues need to be explained by integrating knowledge of the network on account of case-based reasoning techniques. This paper suggests the case-based reasoning in another point. This means finding some irreplaceable links on the basis of the complete analysis of the problems space, which are called the must_be_passed link between the source and destination. Merely compute the shortest path case from those best exit/entry nodes of the grids to the irreplaceable links, and then add them into the case base storing for future use. This method is based on case-based reasoning technique and completely considers the properties of the problem space. In addition to the use of knowledge of the natural grid in the route network, this method is more efficient than existing algorithms on computing efficiency.  相似文献   

TOVS资料的变分处理方法在青藏高原地区的数值试验   总被引：16，自引：2，他引：14  

翁永辉  徐祥德 《大气科学》1999,23(6):703-712

首次在测站稀少的高原地区引入经变分技术处理的TOVS资料,使用MM5数值模式对高原地区降水数值预报难点进行了研究。探讨了解决高原地区测站少、数值预报模式初始场信息误差大的技术关键问题,提出了采用TOVS资料在高原地区增加初始场信息的构思。数值试验结果表明,应用变分法处理后的TOVS资料,可显著地提高高原初始场信息的可靠性。考虑夏季高原地区是对流多发区特点,本文采用非静力MM5模式,并在模式初始场中增加了TOVS资料,弥补了测站稀少的高原地区使用非静力模式的不足之处。研究结果表明,本文采用的TOVS资料技术方案可能是高原区域数值模式降水预报的有效途径,并为开拓卫星资料的应用领域提供了技术思路与理论分析依据。  相似文献   

基于三峡秭归井水位和GNSS观测特征的地震活动性研究     

翁骋  王杰  鲁小飞  涂先新  吴海波  林俊 《中国地震》2023,39(2):325-333

三峡水库蓄水后,秭归盆地内部仙女山断裂北端邻近区域内发生多次3.5级以上地震,该地区的地震活动备受关注。本研究分析了该区域秭归井动水位的变化、水化学特征以及同期GNSS形变数据,结果显示:①秭归井水位的快速变化主要受该区域构造应力变化的影响,前期以拉张应力为主,后期区域应力变为挤压状态;②GNSS应变场特征显示面膨胀率高值区位于三峡库区周边及其南部,极高值区恰好位于仙女山断裂北部,且GNSS时间序列与秭归井水位的涨落存在较好的同步性;③2020年10月初开始的震群与该地区持续6个月的挤压状态有关,表明研究区应力积累已经超过岩层抗剪强度,岩层发生破裂。  相似文献   

1978-2018年中国旅游业发展的地理格局     

张城铭  翁时秀  保继刚 《地理学报(英文版)》2020,30(3):487-507

Since the reform and opening-up policy launched in 1978,the number of inbound tourists increased from 1.8 million in 1978 to 139.5 million in 2017,and that of domestic tourists increased from 344 million in 1991 to 5 billion in 2017.This article conducts research on how the geographical pattern of China’s tourism has evolved in the last four decades on the national-scale and regional-scale,for rare studies before could focus on such an extended date and utilize inbound and domestic tourism data simultaneously.Grounded on viable datasets and multiple vibrant data analysis approaches(including the Gini coefficient,primacy index analysis,hot spot analysis and Pearson correlation analysis),this article unpacks triple vital realities.(1)The overall geographical pattern of China’s tourism development can arguably summarize as“high in the eastern and low in the western part,high in the southern and low in the northern part.”Meanwhile,China’s inbound tourism has long shown a pattern of polarized distribution;While,domestic tourism has experienced a shift from the polarized distribution to the equilibrium distribution.(2)According to the features and characteristics,China's tourism development can be divided into four stages.They are precisely the initial modern tourism stage(1978–1988),the domestic tourism cultivating stage(1989–1996),the rapid development stage(1997–2007)and the new normal stage(2008–present).(3)This article also identified multiple factors underlying the inbound and domestic tourism development in China,including policies,management systems,tourism demand,tourist attractions,economic level,consumption level,industrial development,investment status,traffic conditions,accommodation services,intermediary services and degree of openness.  相似文献   

重金属对日本对虾仔虾存活及代谢酶活力的影响   总被引：13，自引：0，他引：13  

李少菁  王桂忠  翁卫华  汤鸿  林琼武 《台湾海峡》1998,(2)

本研究测定了铜、锌、镉对不同盐度下日本对虾仔虾的24hLC50、48hLC50、96hLC50,三种金属毒性大小依次为Cd2＋＞Cu2＋＞Zn2＋。对次致死浓度下仔虾的碱性磷酸酶（AKP）、酸性磷酸酶（ACP）、谷丙转氨酶（GPT）、及谷草转氨酶（GOT）的活性的测定结果表明：重金属对AKP、GPT、GOT活性有不同程度的抑制作用;且随着浓度的增高,抑制作用越明显。但对ACP活性有激活作用,且随着浓度的增高,激活作用越明显。  相似文献   

热带西太平洋暖池及其与南方涛动和副热带高压关系     

翁学传  张启龙  颜廷壮 《海洋科学集刊》1998,(40):35-41

热带西太平洋暖池是全球大洋表面温度最高的区域,也是全球海-气能量交换年总量最大的海域。它的维持和变化不仅对El Nifio的发生、发展起着重要作用,而且对中高纬度大气环流的变化也有重要影响。近年来国内外对热带西太平洋暖池进行了许多实验和研究,取得了一些有意义的结果(王世平,1989; Wyrtki,1989;黄荣辉,1994;董敏,1994;Wajsowicz,1994)。但是这些研究多偏重于暖池对大气环流和东亚气候的影响方面,对暖池本身的主要特征及其变异方面的研究相对较少,而后者却是进一步了解发生在暖池区的海-气相互作用的过程,研究暖池在全球气候变化中的作用所不可缺少的。本文在分析1951-1990年间的SST资料和137°E,155°E,165°E断面观测结果的基础上,结合有关研究成果(符淙斌,1990),对暖池的形态、高温中心和热含量这三个主要特征及其变异特点进行了研究,并初步找出了暖池表面面积与南方涛动指数和副热带高压面积指数间的关系。  相似文献