Multivariate Standardized Drought Index: A parametric multi-index model

Defining droughts based on a single variable/index (e.g., precipitation, soil moisture, or runoff) may not be sufficient for reliable risk assessment and decision-making. In this paper, a multivariate, multi-index drought-modeling approach is proposed using the concept of copulas. The proposed model, named Multivariate Standardized Drought Index (MSDI), probabilistically combines the Standardized Precipitation Index (SPI) and the Standardized Soil Moisture Index (SSI) for drought characterization. In other words, MSDI incorporates the meteorological and agricultural drought conditions for overall characterization of drought. In this study, the proposed MSDI is utilized to characterize the drought conditions over several Climate Divisions in California and North Carolina. The MSDI-based drought analyses are then compared with SPI and SSI. The results reveal that MSDI indicates the drought onset and termination based on the combination of SPI and SSI, with onset being dominated by SPI and drought persistence being more similar to SSI behavior. Overall, the proposed MSDI is shown to be a reasonable model for combining multiple indices probabilistically.     

A drought index for Rainfed agriculture: The Standardized Precipitation Crop Evapotranspiration Index (SPCEI)

A drought index is one of the main methods used for measuring drought and represents the basis of drought monitoring, early warning, and classification. On the basis of an analysis of the advantages and limitations of the Standardized Precipitation Evapotranspiration Index (SPEI), the Standardized Precipitation Crop Evapotranspiration Index (SPCEI), which is a drought index of rainfed agriculture, was constructed in this study. The applicable conditions of the SPCEI were then investigated, and the results showed that the SPCEI was suitable for dryland crops under non‐irrigated conditions in arid and semi‐arid areas. The difference between the SPEI and SPCEI is analysed. Compared with the SPEI, the SPCEI considers crop evapotranspiration and the crop growth stage and was found to be more suitable for monitoring agricultural drought. Qigihar, which is located in a semi‐arid area in western Heilongjiang Province, China, was then analysed as an example. The characteristics of the spatial and temporal variability of regional agricultural drought were analysed based on maize and soybean in dryland areas. The results for the different growth stages of maize and soybean showed that drought intensity is more serious in the initial stage in the middle part. In crop development, mid‐season and late season stage, the drought conditions gradually increased from north to south. The drought degree of the two crops at the initial stage gradually increased, and the drought degree at the crop development stage gradually decreased. The main reason is that precipitation gradually increases during the crop development stage.     

Compositional time series analysis for Air Pollution Index data

The increasing importance of understanding the structure of Air Pollution Index (API) makes it necessary to come out with a compositional of API based on its pollutants. This will be more comprehensible for the public and easier to cooperate with authorities in reducing the causes of air pollution. Since five pollutants contribute in determining the API values, API can be shown as a compositional data. This study is conducted based on the data of API and its pollutants collected from Klang city in Malaysia for the period of January 2005 to December 2014. The proportion of each pollutant in API is considered as a component with five components in a compositional API. The existence of zero components in some pollutants, that have no effect on API, is a serious problem that prevents the application of log-ratio transformation. Thus, the approach of amalgamation has been used to combine the components with zero in order to reduce the number of zeros. Also, a multiplicative replacement has been utilized to eliminate the zero components and replace them with a small value that maintains the ratios of nonzero components. Transforming the compositional data to log-ratio coordinates has been done using the additive log ratio transformation, and the transformed series is then modeled by using a VAR model. Four criteria are used to determine the number of lags p of VAR(p) and these are: the Akaike Information, the Schwartz, the Hannan–Quinn and the Final Prediction Error criteria. Based on the results, A VAR (1) model with no constants or trend is considered as the best fitted model and it is used to forecast 12 months ahead. In addition, API values are mainly determined by PM₁₀ that has a proportion close to one most of the time during study period. Therefore, authorities and researchers need to study the sources of PM₁₀ and provide the public with useful information and alternatives in term of reducing the air pollution.     

辽宁省重力异常指标体系研究

以辽宁省近年来流动重力观测数据为基础,统计监测区内主要地震事件(灯塔M5.1;朝阳M4.6;海城M4.4)与重力变化的对应关系,通过分析重力时变特征,提取重力异常判定指标,构建定量指标体系,提高重力学科在地震监测中的预报效能。研究结果从定性和定量两方面完整的给出了辽宁省M5.0±0.5震级档重力异常判定指标,同时对M6.0以上强震预判提供了科学参考。     

论期刊指数分析及排序

通过对期刊方阵构成，科学指数数据库的介绍，认识科技期刊引证及评价指标；了解地球科学类期刊的划分排序及中国地震局数据中心的科学查新。     

Solar-Activity Index for the E-Layer Critical Frequency at Middle Latitudes

Geomagnetism and Aeronomy - Based on an analysis of data from the midlatitude ionospheric stations, it is found that the P = 0.5(F1 + F81) index is an optimal solar-activity index for the daily...     

Vegetation Index Methods for Estimating Evapotranspiration by Remote Sensing

Evapotranspiration (ET) is the largest term after precipitation in terrestrial water budgets. Accurate estimates of ET are needed for numerous agricultural and natural resource management tasks and to project changes in hydrological cycles due to potential climate change. We explore recent methods that combine vegetation indices (VI) from satellites with ground measurements of actual ET (ET_a) and meteorological data to project ET_a over a wide range of biome types and scales of measurement, from local to global estimates. The majority of these use time-series imagery from the Moderate Resolution Imaging Spectrometer on the Terra satellite to project ET over seasons and years. The review explores the theoretical basis for the methods, the types of ancillary data needed, and their accuracy and limitations. Coefficients of determination between modeled ET_a and measured ET_a are in the range of 0.45–0.95, and root mean square errors are in the range of 10–30% of mean ET_a values across biomes, similar to methods that use thermal infrared bands to estimate ET_a and within the range of accuracy of the ground measurements by which they are calibrated or validated. The advent of frequent-return satellites such as Terra and planed replacement platforms, and the increasing number of moisture and carbon flux tower sites over the globe, have made these methods feasible. Examples of operational algorithms for ET in agricultural and natural ecosystems are presented. The goal of the review is to enable potential end-users from different disciplines to adapt these methods to new applications that require spatially-distributed ET estimates.     

水生生物监测质量保证、质量控制与标准化:动态与展望

水生生物监测是流域水生态状况评价的重要基础,监测数据的准确性和可靠性直接影响水生态环境质量评价与流域水生态管理成效。目前我国水生生物监测质量保证和质量控制体系尚处于持续完善的阶段,关键环节的控制要求和质控目标等亟待明确和细化。本文总结了欧美发达国家水生生物监测质量保证与质量控制体系建设中的经验,通过梳理我国水生生物监测工作基础与进展,较为系统地提出了适合我国现状的水生生物监测质量保证与质量控制体系标准化建设对策建议,包括实验室内部和外部质量保证与质量控制、水生生物监测质控数据库、人工智能识别和环境DNA新技术质控要点等标准化建议,为实现水生生物监测业务化运行,准确评估我国流域水生态质量状况的变化提供技术支撑。     

地电扰动指数GEI研究

本文应用中国大陆地区11个地电场台站5.5年（2012-01-01—2017-05-31）中磁静日和磁扰日的观测数据,并联系地电场变化敏感响应地下介质非均匀性和空间电磁活动的特点,发展了地电扰动指数,即消除静日地电变化的幅值比地电指数（GEI）.对比各台站的地电指数与地磁指数,87.43%的单台地电指数D与单台地磁指数K在数值上完全相同或相差1,93.75%的单台平均地电指数Ds与单台平均地磁指数[K+0.5]（四舍五入）相同或仅相差1,说明地电指数能用于量化界定地电扰动水平,如同地磁指数量化界定磁扰水平.地电指数将服务于地球电磁环境监测、科学研究等领域,同时也可以用来评估地电场观测数据的质量.     

MSCTE评价Crohn病活动度指数与Harvey-Bradshaw指数的相关性研究?

目的：探讨MSCTE评价克罗恩病（Crohn）活动指数（CDII）与Harvey-Bradshaw指数（HBI）的相关性。方法：选取2014年7月至2016年3月两家医院病理证实的30例CD患者为研究对象,HBI评分后行MSCTE检查并根据CD影像指数评分表评价Crohn病活动指数,比较CDII与HBI在CD活动度分级差异及相关性。结果：CDII与HBI在CD各分级中比较差异无统计学意义（P>0.05）。Spearman相关分析得出CDII和HBI在CD活动度各级中均有显著相关性。结论：CDII与HBI呈显著相关性,具有较高临床价值。     

An Improved Analytic Signal Technique for the Depth and Structural Index from 2D Magnetic Anomaly Data

This paper presents a new inversion method for the interpretation of 2D magnetic anomaly data, which uses the combination of the analytic signal and its total gradient to estimate the depth and the nature (structural index) of an isolated magnetic source. However, our proposed method is sensitive to noise. In order to lower the effect of noise, we apply upward continuation technique to smooth the anomaly. Tests on synthetic noise-free and noise corrupted magnetic data show that the new method can successfully estimate the depth and the nature of the causative source. The practical application of the technique is applied to measured magnetic anomaly data from Jurh area, northeast China, and the inversion results are in agreement with the inversion results from Euler deconvolution of the analytic signal.     

Research of the Differential Uplifting in the Palongzangbu Region Based on the Synthesis of the Watershed Index and Seismic Data

Research on the differential uplifting in the Palongzangbu region is crucial to understanding the tectonic deformation mechanism and establishing the model of the faulted blocks in the region of the east structural knot. In this paper, based on the ASTER-30m DEM, we calculate the hypsometry index (HI) of 19 watersheds in the Palongzangbu region, and study the differential uplifting in this region combining with seismic data, the ground deposition and erosion process. The result shows that the spatial distribution of the HI value can reflect the differential uplifting in the study area. Differential uplifting exists within different zones, and there are 2 relative strong uplifting centers. One center is near the east structural knot, and the other lies between the Lhari fault and Nujiang fault at their converging segment. Also, the watershed evolution, seismic activity, and ground deposition and erosion process are closely related to each other, and they constitute a chain of evidence which reveals the whole process from the tectonic movement underground to the landform evolution on the surface.     

基于损伤的累积滞回耗能与延性系数

从地震损伤评价出发, 通过分析与推导, 建立了基于位移延性系数的损伤评价模型。 采用四个柱的破坏性试验数据, 运用推导出来的模型进行了柱的损伤程度评价。 考虑到延性系数计算的困难以及其与累积滞回耗能的关系, 通过分析建立起累积滞回耗能与位移延性系数的关系曲线。     

地震电磁辐射前兆异常特征和异常指标关系研究

根据收集的地震电磁类资料, 总结分析了地震电磁异常特征及震例的异常指标间的关系。据统计, 一般对M≥ 3.0地震, 电磁异常平均出现在震前10～45天, 异常的平均传播距离为100～600 km, 震级越大, 异常提前出现的时间越早, 异常传播的距离越大; 一定范围内, 震级和异常提前出现的时间、 震级和异常传播的距离存在简单的线性关系。地震发生在异常出现后两个月之内的概率达93.5%。有88%的地震发生在异常结束后或异常结束当天, 有98%的地震发生在异常结束后20天以内。     

Index of the Long-Term Influence of Sporadic Solar Activity on Cosmic Ray Modulation

Coronal mass ejections (CMEs) not only produce Forbush effects but contribute to long-term modulations of cosmic rays. That makes coronal ejections the main sporadic manifestations of the solar activity, which should be considered in modulation models. In this paper, a new version of the CME-index is proposed based on a comparison of the data from satellite coronographs with Forbush effects and long-term variations of cosmic rays.     

张渤带形变预测指标分析

根据张渤带震例研究成果, 系统清理1966年以来张渤带5级以上地震前形变异常变化的各项特征, 初步归纳出张渤带的形变预测指标。 主要指标为: 张渤带5.6~6.2级地震异常相对集中, 异常主要集中在110~270 km范围; 潮汐类、 突变类异常数量相对较少; 破年变类异常较多, 异常主要对应4.5~5级和6~6.5级地震, 异常对应范围主要为100~300 km; 趋势转折类异常主要对应5.5~6.5级地震, 且异常时间在4.5~6.5级范围内有随震级增大而增加的趋势。     

基于NPP-VIIRS数据的夜间灯光指数变化分析——以夏河MS5.7地震为例

夜间灯光数据具有反映人类活动的特点,其数据变化与电力设施运行情况、建筑物和其他发光物体息息相关,因此近年来被广泛应用于各类科学研究中。本文从夜间灯光数据特点出发,以夏河M_S5.7地震灾区为研究区,利用多时相NPP-VIIRS夜间灯光数据,经过数据预处理后获得三种灯光指数,从而分析灾区的夜间灯光变化,为地震应急救援工作提供一种震后灾情信息获取的途径和方法,为甘肃县级尺度的地震应急工作提供另一种思路。     

山东地区水化学短临跟踪标志体系的研究

在系统整理山东地区水化学观测资料的基础上,对山东菏泽５．９级地震、苍山５．２级地震及大同６．１级地城才南黄海５．３级地震前的地震异常特征了分析和总结,认为水化学多组分的同步异常变化,反映了震源应力场孕育过程,具有统一的物理力学机制,是震前源兆异常的重要标志。这异常基本同步出现,相互印证,增强了异常的可信度,为短临异常的判定提供了较为充分的依据。某一井孔水化学多组分出现同步异常变化,预示位于井孔同     

山西省及邻区洞体形变异常指标的研究

利用山西省及部分邻区近几年的洞体形变观测资料,分析了在几次中强地震前观测数据的分量均值、倾斜矢量、潮汐因子变化等不同指标的异常特征,找出了区域地震前倾斜的共性异常特征和个体异常特征,并与数字观测资料进行了对比研究,指出了数字观测资料在今后地震预报中的应用前景。     

地震应急评估与决策指标体系的构建

Loss assessment and decision-making are essential for earthquake emergency rescues,and for scientific prediction of seismic damage and determination of rescue objectives.In practice,however,there exist some problems,such as basic data not being precise and rich enough and decision making not having systematic and complete criteria.This paper tries to solve these problems using the method of data indexation by constructing an index system for earthquake emergency loss assessment and decision-making.