涪江流域径流变化趋势及其对气候变化的响应

采用Mann-Kendall非参数检验方法分析了涪江流域实测径流量的变化趋势,根据假定的气候变化情景和HADCM3预估的气候情景,利用考虑融雪的水量平衡模型(SWBM模型)分析了径流对气候变化的响应。结果表明:涪江流域径流量总体呈现递减趋势,但非汛期的个别月份有增加趋势,实测年径流变化主要是由于气候要素变化引起的,流域内的水电开发对径流量的季节分配存在一定的影响。SWBM模型对涪江流域月流量过程具有较好的模拟效果,实测与模拟径流量总体较为吻合,只有个别年份峰值模拟误差相对较大。气温变化固定的情况下,降水变化与径流变化之间的关系接近线性;在降水变化相同的情况下,单位气温变幅引起的径流量变化幅度也基本相当。尽管不同排放情景下涪江流域径流量的变化有一定差异,但总体来看,未来水资源可能以偏少为主,特别是2030年以后,多年平均偏少量将可能超过5%。     

中更新世早中期以来黄河上游与三峡库区滑坡形成机理与气候变化关系研究

气候变化对滑坡的影响关系研究是近年来滑坡灾害研究的热点问题之一。本研究以我国中更新世早中期以来黄河上游和三峡库区的滑坡为研究对象,分析了其发育期与气候变化的对应关系以及气候演变对滑坡发育的作用机理。研究认为: 1）大型古滑坡在时空分布上具有明显的多期性和时段性,大区域滑坡的广泛发育与全球古环境变化的暖湿间冰期之间呈现良好的对应关系。2）黄河上游龙羊峡-刘家峡段干流区内共发育有3期滑坡,其中早期滑坡多披覆于黄河Ⅲ～Ⅳ级阶地,光释光年龄显示其发生于MIS3时期;  晚期滑坡多披覆于黄河Ⅱ级阶地,发育于MIS1时期;  现代滑坡披覆于黄河Ⅰ级阶地,多为早期滑坡前缘因人类工程活动诱发的次级滑坡。3）三峡库区中更新世早中期以来主要发育了3期古滑坡,并以深海氧同位素的MIS5和MIS3为最多,尤其是中更新世晚期以来,滑坡数量明显增加,延续时间明显增长。     

An Examination of the Predictability of Tropical Cyclone Genesis in High-Resolution Coupled Models with Dynamically Downscaled Coupled Data Assimilation Initialization

Predicting tropical cyclone(TC) genesis is of great societal importance but scientifically challenging. It requires fineresolution coupled models that properly represent air-sea interactions in the atmospheric responses to local warm sea surface temperatures and feedbacks, with aid from coherent coupled initialization. This study uses three sets of highresolution regional coupled models(RCMs) covering the Asia-Pacific(AP) region initialized with local observations and dynamically downscaled coupled data assimilation to evaluate the predictability of TC genesis in the West Pacific. The APRCMs consist of three sets of high-resolution configurations of the Weather Research and Forecasting-Regional Ocean Model System(WRF-ROMS): 27-km WRF with 9-km ROMS, and 9-km WRF with 3-km ROMS. In this study, a 9-km WRF with 9-km ROMS coupled model system is also used in a case test for the predictability of TC genesis. Since the local sea surface temperatures and wind shear conditions that favor TC formation are better resolved, the enhanced-resolution coupled model tends to improve the predictability of TC genesis, which could be further improved by improving planetary boundary layer physics, thus resolving better air-sea and air-land interactions.     

基于SRTM天气雷达净空环境评估算法误差分析

采用航天飞机雷达地形测绘使命(SRTM)高程数据对天气雷达净空环境进行评估,可有效提高雷达选址评估效率。利用人工测量数据和SRTM数据进行天气雷达净空环境评估对比试验,结果表明基于该数据的天气雷达净空环境评估算法总体与人工测量方法具有较好的一致性。采用方位矫正和距离矫正算法后,基于该数据的天气雷达净空环境评估算法精度明显提高。     

塔里木盆地沙尘气溶胶的柱质量密度特性

气溶胶质量密度是气溶胶重要的参数,它影响着大气中复杂的化学反应,也与气溶胶的传输过程和空间分布息息相关.基于MERRA-2再分析资料提供的气溶胶柱质量密度数据,研究了我国塔里木盆地1980—2018年长时间序列的沙尘气溶胶柱质量密度的时空分布特征.结果表明,沙尘气溶胶和沙尘PM_2.5气溶胶柱质量密度有很大的变化范围,平均值分别为0.33和0.086 g/m²,同时具有明显的年际、月和季节变化特征.沙尘气溶胶和沙尘PM_2.5气溶胶柱质量密度的年平均值在0.24~0.41和0.06~0.11 g/m²范围内变化;春季最大,其平均值分别为0.47和0.12 g/m²,冬季最小,其平均值分别为0.13和0.04 g/m²;月平均值最大出现在5月,分别为0.57和0.14 g/m²,最小在1月,分别为0.1和0.03 g/m².     

Carbon and strontium isotopes and global correlation of Cambrian Series 2-Series 3 carbonate rocks in the Keping area of the northwestern Tarim Basin, NW China

One hundred and ten carbon and nineteen strontium isotopic values of outcropping Cambrian Series 2 and Series 3 carbonate rocks in the Penglaiba section of the Keping area were analyzed. Effective isotopic data with little influence of diagenesis were used to address the global correlation. The δ¹³C values exhibit two major positive excursions (peaking at 3.1‰ and 3.3‰) and three major negative excursions (peaking at −3.0‰, −4.2‰ and −3.2‰). The carbon isotope excursions (peaking at −3.0‰ and −4.2‰) across the Cambrian Series 2-Series 3 boundary show good correlations with similar variations reported in Siberia, Laurentia, North China and South China. In contrast, the other three carbon isotope excursions (peaking at 3.1‰, 3.3‰ and −3.2‰) do not have a fairly good global correlation because of the lack of biostratigraphic data. With respect to the ⁸⁷Sr/⁸⁶Sr ratios, they show good correlation with those reported for Laurentia, and further support the global δ¹³C comparison. On the basis of these new data, it is showed that the combination of δ¹³C curves and ⁸⁷Sr/⁸⁶Sr variations serves as a powerful tool for correlation and subdivision of Cambrian strata in the Tarim Basin of northwest China, and provides new data for global correlation.     

都汶路恢复重建中的主要地震次生山地灾害与明洞工程

"5·12"汶川地震次生灾害中,有两类山地灾害至今仍对公路运营安全影响很大,其一是高高堆积在坡体之上且规模较大的松散(动)危岩体,其二是与岷江大致正交的泥石流沟泥石流.它们共同的特点是危险物源分布相对位置高、体量大、来势凶猛、冲击破坏性极强,加上它们发生的时间或空间的不确定性,致使常规防治措施无能为力并极易遭到破坏.复式明洞工程则是针对上述灾害专门提出的公路实用性防护工程.经过前期运行,已明显体现出这类工程的优越性,同时也凸显出一些尚需进一步改进的地方.     

Paleoenvironmental Characteristics of Paleogene Lacustrine Source Rocks in the Western Bozhong Sag, Bohai Bay Basin, China: Evidence from Biomarkers, Major and Trace Elements

The organic matter (OM) enrichment mechanisms and depositional environment characteristics of lacustrine source rocks in the western Bozhong Sag, Bohai Bay Basin in Northeast China remain controversial. To address these issues, based on Rock-Eval pyrolysis, kerogen macerals, H/C and O/C ratios, GC-MS, major and trace elements, the Dongying Formation Member (Mbr) 3 (E3d3), the Shahejie Formation mbrs 1 and 2 (E2s1+2), and the Shahejie Mbr 3 (E2s3) source rocks in the western Bozhong Sag were studied. The above methods were used to reveal their geochemical properties, OM origins and depositional environments, all of which indicate that E2s1+2 and E2s3 are excellent source rocks, and that E3d3 is of the second good quality. E3d3 source rocks were formed under a warm and humid climate, mainly belong to fluvial/delta facies, the E3d3 sediments formed under weakly oxidizing and freshwater conditions. Comparatively, the depositional environments of E2s1+2 source rocks were arid and cold climate, representing saline or freshwater lacustrine facies, and the sediments of E2s1+2 belong to anoxic or suboxic settings with large evaporation and salinity. During the period of E2s3, the climate became warm and humid, indicating the freshwater lacustrine facies, and E2s3 was characterized by freshwater and abundant algae. Moreover, compared with other intervals, the OM origin of E3d3 source rocks has noticeable terrestrial input. The OM origin of the E2s1+2 and E2s3 are mainly plankton and bacteria. Tectonic subsidence and climate change have affected the changes of the depositional environment in the western Bozhong Sag, thus controlling the distribution of the source rocks, the geochemical characteristics in the three intervals of lacustrine source rocks have distinct differences. Overall, these factors are effective to evaluate the paleoenvironmental characteristics of source rocks by biomarkers, major and trace elements. The established models may have positive implications for research of lacustrine source rocks in offshore areas with few drillings.     

新疆库车坳陷西段膏盐层沉积、 地球化学特征及找钾方向

库车坳陷西段深部(5141～5218 m埋深)已有古近纪固体钾石盐矿(化)层的发现,但对该区域的膏盐层特征及成钾条件、找钾方向仍需做进一步的系统研究.以油气钻井深部膏盐层岩屑为主要对象,对库车坳陷西段膏盐层的沉积、岩石学特征以及钾、溴氯系数、Sr和S同位素等地球化学特征进行研究,并对该区盐构造特征及演化进行分析.结果表...