采用不同样本集合同化地面观测对一次飑线过程的影响

针对夏季黄淮地区一次飑线过程,利用WRF (Weather Research and Forecasting) 模式及其Hybrid ETKF-3DVAR同化系统,考察不同生成方案的样本对同化地面观测的影响。集合样本创建方式包括3类:扰动初始背景场的方案 (RCV)、使用不同的物理参数化方案 (PPMP) 以及前两者集成方案 (BLE)。基于增量场分析,同化地面观测主要调整850 hPa以下水平风和水汽混合比的空间结构,其中RCV方案侧重于改变水平风的空间分布,PPMP方案侧重于改变水汽混合比的空间结构,BLE方案兼具二者特征。同化地面观测可以间接改善6 h降水预报,其中PPMP试验的降水预报最好,尤其是对降水位置和强度的预报。对比雷达回波观测,RCV试验和BLE试验对弓状回波模拟得较好,BLE试验的模拟较多体现RCV特征。PPMP试验和RCV试验还可改变冷池的位置和强度,同时影响飑线出现和消亡时间,相对而言,PPMP试验影响更大。     

关于发展人工影响天气数值模式的一些问题

人工影响天气的学科基础是中小尺度天气动力学与云降水物理学,需要将天气-动力-云降水物理耦合为一体。考虑到目前将天气动力学性质的基础数值模式用于人工影响天气中的问题,从数值模式动力方程、模式分辨率、云物理过程、数值求解方案、初边值条件等方面系统地探索了发展人工影响天气数值模式中一些需要重点解决、且不可忽视的特色问题,并举例对相关问题提出了解决思路和方法。期望提出的问题有助于构思更适合于人工影响天气数值模式,使数值模式功能真正向满足人工影响天气的要求靠近一步。     

不同同化方案在一次梅雨锋暴雨预报中的应用研究

基于ATOVS辐射率资料和GTS常规观测资料融合,通过不同化任何观测资料的控制试验、3DVAR同化试验和ETKF-3DVAR混合同化试验,对2013年7月4—5日一次梅雨锋暴雨天气过程进行模拟分析。结果表明:混合同化方案能够明显地提高暴雨预报准确率,且有效改善了风场、温度场和相对湿度场等各个气象要素的初始场结构,而这些气象要素对于暴雨的预报准确性具有重要作用。且混合同化方案对于中低层大气改进效果较为明显。在数值积分过程中,随着时间的推移,混合同化方案的优势逐渐减弱。     

物联网在人工影响天气装备弹药管理中的应用

本研究以物联网技术为基础,利用条码、二维码和射频电子标签标识、射频扫码技术、声光电自动感应技术、GPS/GIS技术进行信息采集,建立人工影响天气装备弹药物联网管理系统,实现人工影响天气装备弹药从生产、验收、转运、仓储到发射作业的全程监控。在北京、陕西、贵州、河南4个地区进行试点开发研究,根据有源/无源射频识别(RFID)、二维码/条形码、火箭弹/高炮炮弹以及信息采集技术分别开展不同技术模式的应用试验,将弹药信息按照统一格式汇集至国家级物联网系统,有效提高了全国人工影响天气装备弹药信息采集的准确性和时效性,并结合有效传感器、无线通信技术,解决了大范围内的作业数据自动化采集及地面作业信息实时监控,提高人工影响天气作业安全管理的科技水平和业务信息化现代化程度,对全国开展人工影响天气装备物联网建设工作具有较强的参考价值。     

Complementing coal seam gas facies modelling workflows with decompaction based processes

Differential compaction plays a key role in influencing the palaeogeographic organisation of many depositional systems. In the Jurassic Walloon Subgroup, Surat Basin, Eastern Australia, the process of compensational stacking contributes significantly to the complex coal layer architecture and is documented in mine exposure, borehole and seismic datasets. Despite this understanding, current best-practices do not formally consider the mechanics of compensational stacking when populating palaeogeography facies in coal seam gas (CSG) reservoir models. To address this limitation, a hybrid modelling workflow was developed in which numerical rules representing the process of differential compaction are used explicitly to condition an iterative workflow containing traditional geostatistical facies modelling algorithms. The workflow is facilitated by a newly developed open source plugin which allows grid decompaction in Schlumberger PETREL™ 2015. Application of the workflow was tested in a CSG production area containing closely spaced wellbores and a 3D seismic survey. In this area, facies models were constructed using both traditional geostatistical approaches and the newly developed hybrid methodology. Comparison of these models suggests that facies models constructed via unconstrained geostatistical approaches often result in unrepresentative realisations, inconsistent with coal seam architectures as observed in seismic and outcrop. The hybrid geostatistical-forward modelling approach developed during this study was better able to reproduce complex alluvial stacking patterns, particularly with respect to coal seam amalgamation, bifurcation and washout.     

新疆相对资源承载力评估模型构建及其实证分析

在分析了区域人地关系系统基础上构建区域PRED系统,相对资源承载力模型进行了4方面改进：（1）基于人地关系理论和可持续发展理论构建区域PRED系统模型,将人口、资源、环境、社会和经济各子系统相对资源承载力进行整合。（2）在自然资源子系统中加入了林业用地面积和建设用地面积两个重要指标,在环境资源子系统中加入了环境污染治理投资总额,并在社会资源了系统中加入了全社会固定资产投资总额这一指标。（3）提出了加权平方平均相对资源承载力模型,并利用该模型对新疆维吾尔自治区（以下简称新疆）2000-2014 年相对资源承载力进行。（4）结合脱钩理论对相对资源综合承载力与资源环境、社会经济因子之间的关系进行研究。结果表明：采用改进后的相对资源承载力模型得出评价结果更符合资源匹配度较差地区的实际情况;新疆各要素相对资源承载力平均水平由大到小的顺序是：平均自然资源承载力、平均综合承载力、平均环境资源承载力、平均社会资源承载力、平均经济资源承载力。研究期间一直处于富余状态,自然资源优势相对突出,但是环境资源、经济资源、社会资源劣势也很明显,新疆综合承载力与资源环境、经济社会要素的矛盾十分突出。     

BFA-CM最优化测井解释方法

最优化测井解释方法能充分利用各种测井资料及地质信息,可以有效地评价复杂岩性油气藏.优化算法的选择是最优化测井解释方法的关键,影响着测井解释结果的准确性.细菌觅食算法(BFA)是新兴的一种智能优化算法,具有较强的全局搜索能力,但在寻优后期收敛速度较慢.复合形算法(CM)局部搜索能力极强,将其与BFA算法相结合构成BFA-CM混合算法,既提高了搜索精度又提高了搜索效率.利用BFA-CM最优化测井解释方法对苏里格致密砂岩储层实际资料进行了处理,计算结果与岩心及薄片分析资料吻合得很好.     

CEC比值法在凝灰质砂岩储层测井评价中的应用——以海-塔盆地X凹陷凝灰质砂岩储层为例

凝灰质砂岩储层一直是测井评价中的难点.凝灰质的存在使储层的孔隙结构和物性变化都很大,其含量直接影响储层参数的求取,对储层饱和度的影响不容忽视.本文以海-塔盆地X凹陷的凝灰质砂岩储层为例进行测井评价研究.基于泥质和凝灰质的测井响应差异利用粒子群和细菌觅食的混合优化算法计算储层中两者的含量,然后通过阳离子交换量(CEC)的实验数据验证了凝灰质具有导电性,进而利用CEC与电阻率之间的关系得到凝灰质电阻率的计算方法,并且应用到饱和度的计算,最终得到了一种新的计算凝灰质砂岩储层饱和度的方法——CEC比值法,并取得了良好的应用效果.     

Riparian responses to reduced flood flows: comparing and contrasting narrowleaf and broadleaf cottonwoods

Abstract

To enable assessment of risks of water management to riparian ecosystems at a regional scale, we developed a quantile-regression model of abundance of broadleaf cottonwoods (Populus deltoides and P. fremontii) as a function of flood flow attenuation. To test whether this model was transferrable to narrowleaf cottonwood (Populus angustifolia), we measured narrowleaf abundance along 39 river reaches in northwestern Colorado, USA. The model performed well for narrowleaf in all 32 reaches where reservoir storage was <75% of mean annual flow. Field data did not fit the model at four of seven reaches where reservoir storage was >90% of mean annual flow. In these four reaches, narrowleaf was abundant despite peak flow attenuation of 45–61%. Poor model performance in these four reaches may be explained in part by a pulse of narrowleaf cottonwood expansion as a response to channel narrowing and in part by differences between narrowleaf and broadleaf cottonwood response to floods and drought.

Editor Z.W. Kundzewicz; Guest editor M. Acreman

Citation Wilding, T.K., Sanderson, J.S., Merritt, D.M., Rood, S.B., and Poff, N.L., 2014. Riparian responses to reduced flood flows: comparing and contrasting narrowleaf and broadleaf cottonwoods. Hydrological Sciences Journal, 59 (3–4), 605–617.     

Effect of soil depth on inelastic seismic response of structures

Effect of depth of soil stratum on estimated inelastic displacement of three typical structures, viz. a four storey building, a continuous bridge, and a tower, is studied and adequacy of the site amplification models of the current design codes and available empirical relationships is examined. The structures are assumed to be located on well-defined sites with varying bedrock depths, and effect of depth on elastic response spectrum, site amplification factor, displacement modification factor and inelastic displacement is studied, numerically, for two values of PGA. It is observed that soil depth has a significant effect on elastic as well as inelastic response of the structures; however, the effect of soil amplification on inelastic response is not as pronounced as in case of elastic response. Therefore, use of empirical site amplification models based on elastic response may be too conservative, for estimating inelastic response.