积雪在El Niño影响东亚夏季气候异常中的作用

本文利用1948-2010年Global Land Data Assimilation System（GLDAS）NOAH陆面模式资料、GPCC月平均降水资料和NCAR/NCEP全球月平均再分析资料,采用滤波、距平合成和线性相关等方法,分析了El Niño成熟位相冬季欧亚大陆积雪异常的分布特征,研究了关键区积雪融化对后期春、夏季土壤湿度、土壤温度以及大气环流与降水的影响,揭示了El Niño事件通过关键区积雪储存其强迫信号并影响东亚夏季气候异常的机制和过程.主要结论如下：El Niño成熟阶段冬季伊朗高原、巴尔喀什湖东北部和青藏高原南麓区域是雪深异常的三个关键区,这些区域的雪深、雪融和土壤湿度有明显的正相关;这三个关键区雪深异常通过春季融雪将冬季El Niño信号传递给春、夏季局地土壤湿度,通过减少感热通量和增加潜热通量对大气环流产生影响;春末夏初伊朗高原土壤湿度异常对东亚夏季气候异常的影响最大,其引起的降水异常与El Niño次年夏季降水异常分布基本一致,春夏季青藏高原南麓和巴尔喀什湖附近土壤湿度也都明显增加,均会对中国华北降水增加有显著正贡献.总之,在利用El Niño事件研究和预测东亚夏季气候异常时,还应考虑关键区雪深异常对El Niño信号的存储和调制作用.     

利用水位资料反演华北地区构造应力场变化

本文选取华北地区观测条件较好的63口水位观测井资料, 运用小波分析法去除各井水位资料中的短期高频信息, 提取出能反映水位多年动态变化的趋势信息, 并利用各井水位趋势变化数据反演出华北地区多年构造应力场变化图像, 结合其它水文资料, 探讨了华北地区近年来的构造应力场变化特征。     

Preliminary Interlaboratory Trial for ISO/DIS 12010: Determination of Short Chain Polychlorinated Alkanes (SCCP) in Water

A first preliminary interlaboratory trial was planned to prepare ISO/DIS 12010: Water quality – determination of short chain polychlorinated alkanes (SCCP) in water – method using GC/MS and electron capture negative ionisation (ECNI). The task was to determine the sum of short chain polychlorinated n‐alkanes with carbon chain lengths of C₁₀–C₁₃ and a chlorine content between 49 and 67% in water by GC‐ECNI‐MS and quantification by multiple linear regression described in ISO/DIS 12010 as the compulsory method. Distributed samples were obtained from a real water extract spiked with a target concentration of 0.4 µg/mL sum of SCCP, i.e. the environmental quality target level according to the Water Framework Directive. The interlaboratory trial included the calibration, a column chromatographic clean up, a concentration step and an integration of chromatographic unresolved humps as well as the quantification with multiple linear regression. Reproducibility standard deviations between 21.5 and 22.9% were achieved by 17 participating laboratories from four countries. The method outlined no significant difference of the results between the standard solution and a real water matrix extract. On the basis of this succeeded preliminary interlaboratory trial the final interlaboratory trial for validation of ISO 12010 was prepared in autumn 2010.     

新30号泉水流量观测资料的初步分析

在系统清理新疆温泉地震台新30号泉水流量20多年的观测资料的基础上,发现新30号泉在中强地震前泉水流量有明显的异常变化,对附近的小震以同震响应或震后效应为主。因此,深入研究泉水流量的动态类型,有效地排除各种干扰,包括人为因素等,将会显著地增强泉水流量动态监测的映震效能,有助于提高温泉地震台地震短临预测能力。     

Assessing the feasibility of integrating remote sensing and in-situ measurements in monitoring water quality status of Lake Chivero,Zimbabwe

This work investigates the likelihood of integrating the cheap and readily-available broadband multispectral MODIS data and in-situ measurements in quantifying and monitoring water quality status of an inland lake within Upper Manyame Catchment in Zimbabwe. Specifically we used MODIS images to quantify inland lake chlorophyll_a concentrations, as a proxy for predicting lake pollution levels. The findings of this study show a high chlorophyll_a concentration of 0.101 ± 0.128 μg/L within the Lake. The results further demonstrated that the chlorophyll_a concentration levels did not significantly vary (p = 0.788) between sites, except among depths (p = 0.05). Further, prediction results based on the relationship between observed and predicted chlorophyll_a produced a high R² value of 0.89 and a root mean square error (RMSE) value of 0.003 μg/L. Moreover, the derived landuse maps of Upper Manyame Catchment indicated a significant variation in the percentage settlement in 1985, 1994 and 2010 change from 1985 to 2010. For instance, 8% increase in settlement in the period between 1994 and 2010 and over 12% increase from 1985 to 2010 and a decline in percent forest coverage (i.e. 9.8% in 1985 to 2.0% in the year 2010) in the catchment was observed. Overall, the findings of this study highlights the importance of free and readily-available satellite datasets (such as the multispectral MODIS and Landsat) in quantifying and monitoring water quality across inland lakes especially in data-scarce areas like Sub-Saharan Africa.     

Water ecological function zoning in Heihe River Basin,Northwest China

Rapid urbanization coupled with increase in population growth rate in recent years has accelerated economic pressure on the ecological environment leading to a gradual deterioration of global and regional environment. This has particularly resulted into water contamination and shortage of water resources thus posing a great threat to human survival. How to guaranteeing sustainable use of basin water resources has attracted more and more attentions. The Heihe River Basin is the secondary longest river inland China and the significantly water source of Hexi Corridor, the problem of water pollution, ecological environment deterioration and the shortage of water has seriously threatened the ecological system of the Heihe River Basin. In this study, through depicting the characteristics of natural environment, human activities, water ecosystem services and other factors in Heihe River Basin we delineated the water ecological function in Heihe River using the principal components analysis and the K-means clustering method. In the study, Heihe River Basin is divided into 3 primary level areas and 8 secondary level sub-areas. Water ecological characteristics analysis showed that the spatial distribution of the water ecological function of Heihe River Basin was not uniform, which are mainly showed in three aspects, function of windproof and sand fixation, function of soil erosion prevention and function of water sources conservation. The results of this study can provide effective and scientific theoretical references for the integrated water sources management and the ecological function optimization of the Heihe River Basin.     

Rates of rockwall slope erosion in the upper Bhagirathi catchment,Garhwal Himalaya

Rockwall slope erosion is defined for the upper Bhagirathi catchment using cosmogenic Beryllium-10 (¹⁰Be) concentrations in sediment from medial moraines on Gangotri glacier. Beryllium-10 concentrations range from 1.1 ± 0.2 to 2.7 ± 0.3 × 10⁴ at/g SiO₂, yielding rockwall slope erosion rates from 2.4 ± 0.4 to 6.9 ± 1.9 mm/a. Slope erosion rates are likely to have varied over space and time and responded to shifts in climate, geomorphic and/or tectonic regime throughout the late Quaternary. Geomorphic and sedimentological analyses confirm that the moraines are predominately composed of rockfall and avalanche debris mobilized from steep relief rockwall slopes via periglacial weathering processes. The glacial rockwall slope erosion affects sediment flux and storage of snow and ice at the catchment head on diurnal to millennial timescales, and more broadly influences catchment configuration and relief, glacier dynamics and microclimates. The slope erosion rates exceed the averaged catchment-wide and exhumation rates of Bhagirathi and the Garhwal region on geomorphic timescales (10³−10⁵ years), supporting the view that erosion at the headwaters can outpace the wider catchment. The ¹⁰Be concentrations of medial moraine sediment for the upper Bhagirathi catchment and the catchments of Chhota Shigri in Lahul, northern India and Baltoro glacier in Central Karakoram, Pakistan show a tentative relationship between ¹⁰Be concentration and precipitation. As such there is more rapid glacial rockwall slope erosion in the monsoon-influenced Lesser and Greater Himalaya compared to the semi-arid interior of the orogen. Rockwall slope erosion in the three study areas, and more broadly across the northwest Himalaya is likely governed by individual catchment dynamics that vary across space and time. © 2019 The Authors. Earth Surface Processes and Landforms Published by John Wiley & Sons, Ltd.     

陇东黄土高原下垫面不均匀性指标的建立及其对大孔径闪烁仪(LAS)观测感热通量的影响

目前定量研究下垫面不均匀性对大孔径闪烁仪(LAS)、涡动相关仪(ECS)观测感热通量差异的影响还比较少.本文利用黄土高原庆阳观测站2012年6、7月典型晴天两主风向范围E-SE和SW-W的陆面过程数据,在建立了下垫面不均匀性定量化指标的基础上,分析了下垫面不均匀性与地表温度变率的关系及其对LAS、ECS观测感热通量差异的影响.结果表明:庆阳站下垫面不均匀性大小η和地表温度变率г具有很好的相关性,相关系数达到0.566以上,证明了新建立指标的合理性.下垫面不均匀性大小η和LAS、ECS观测的感热通量差异HLAS-HECS具有很好的一致性,相关系数达到0.634.下垫面不均匀性对LAS和ECS的感热通量差异影响显著,下垫面越不均匀LAS和ECS测量的感热通量差异越大.对两主风向分别进行分析,在E-SE风向范围η和HLAS-HECS的相关系数为0.430,HLAS和HEC拟合的线性趋势系数为1.279,在SW-W风向范围η和HLAS-HECS的相关系数为0.680,HLAS和HEC拟合的线性趋势系数为1.297.下垫面不均匀性的影响程度越大,LAS和ECS观测的感热通量差异越大.