基于权重赋值法与灰色聚类法评价虾蛏串联养殖池塘的生态修复效果

水产养殖业的尾水排放已成为水域生态环境的污染源之一,为探究凡纳滨对虾-缢蛏串联养殖模式的生态修复效果,对凡纳滨对虾-缢蛏串联养殖池塘的水生态进行周年跟踪测定,并采用权重赋值法与灰色聚类法对其生态修复效果进行评价.结果 显示:串联模式下浮游植物的丰度介于6.8× 105～2.5×108 cell/L,生物量为2.04～6...     

城市群协同发展的灰色关联分析与成因模型

综合运用灰色关联技术和协同学方法,以江西省城市群为例,在对其城市群协同发展进行了灰色关联分析的基础上,建构了城市群协同演进的非线性微分成因模型,并通过数值模拟得到其系统发展的序参量。灰色关联分析发现,江西省城市群作为一个非线性的复杂大系统,其形成与演化受到众多因素的共同作用,而且它们之间不是简单的因果线性关系,具有相关性、非均匀性、不可逆性等;因子模型进一步揭示,对江西省城市群协同演化起支配作用的序参量是工业化率、城镇固定资产投资占全社会固定资产投资比重和单位面积的公路通车里程数,它们是城市群形成与演化中的关键动力因子。显然,模拟结果比较符合江西省城市群发展的实际,因此,这种非线性的综合处理方法可以进一步推广。     

博尔塔拉河、精河流域绿洲土壤空间异质性研究

对博尔塔拉河、精河流域绿洲土壤的理化性状进行了分析,认为该区土壤肥力整体水平并不高,并且较20 a前普遍有所下降。之后,用Kriging进行插值,对研究区土壤综合肥力分布的规律进行了研究,结果表明,东南方向上土壤的综合肥力较高,西北方向上土壤的综合肥力较低。然后,利用灰色方法找寻了导致研究区土壤异质性的驱动因子,年蒸发量与灾害性天气日数是首要的自然驱动力,耕地面积和化肥施用量则是人文驱动力,并且以人文因素驱动作用占主导。     

Climatic Characteristics of Binary Tropical Cyclones in the Northwest Pacific Ocean

Based on typhoon best track data of China Meteorological Administration and NCEP global reanalysis data, this study analyzed the characteristics of binary tropical cyclones (TC) in the Northwest Pacific Ocean during 1951 to 2014 by using the objective determine standard. When the distance between the two TCs d≤ 1 800 km, they are defined as binary tropical cyclones or binary typhoons. And binary typhoons are divided into two different types which are typical binary typhoons and atypical binary typhoons. The climatic characteristics of binary tropical cyclones are as follows: There were 699 pairs of binary typhoons in Northwest Pacific Ocean during 1951 to 2014. In these cases, there were 446 pairs of typical binary typhoons and 253 pairs of atypical cases, occupying 63.8% and 36.2%, respectively. The proportion of typical cases increased with the shortest distance decreasing, while the proportion of atypical cases decreased with the shortest distance decreasing. When the speed of typical binary typhoons moving towards each other reached the peak, binary typhoons mainly showed the east to west direction. At this time, typhoons were controlled by easterly stream of the southern edge of the subtropical high. In this situation, the east typhoon moved toward the west typhoon quickly. When the anticlockwise angular velocity of typical binary typhoons reached the peak, binary cases distributed northeast to southwest or east-northeast to west-southwest, appearing in west and southwest edge of the subtropical high and mainly being controlled by southeasterly stream, thus benefiting the anticlockwise rotation between the typical binary typhoons.     

基于灰色关联和相关向量机的隧道地表沉降预测

基于灰色关联算法确定与地表沉降有直接重要关联的主要影响因子,构建高斯核函数和多项式核函数的加权核函数,利用遗传算法优化模型参数,建立相关向量机地表沉降预测模型。实验结果表明,灰色关联算法能定量地反映系统影响因子与地表沉降变化的关联程度,有效处理不是完全明确的灰色系统信息;加权核函数的合理组合可较好地通过低维空间线性不可分映射变换到高维特征空间线性可分;遗传算法具有计算过程简单和自适应迭代寻优特点;相关向量机模型可极大地减少核函数的计算量,计算过程和结果均具有概率解释。该模型预测结果的多项精度指标值均优于BP神经网络和GR-SVM方法。     

秦岭北麓现代泥石流灾害活动周期的灰色预测

本文应用灰色系统理论,在对控制泥石流形成的内、外营力要素灰色关联度进行分析的基础上,分别建立了秦岭北麓现代泥石流灾害活动周期的长期、短期及近期灰色动态时间序列预测模型(GM),并进行了灰色灾变预测。结果表明,影响本区泥石流活动的主要因素是雨量强度,其次为地震活动性。并预测出本世纪后半叶泥石流灾害出现的年份为:1962,1966,1982,1988,1994～1995,前四次已与泥石流实际活动年份相符。近期泥石流活动期的预测,对泥石流灾害的预防有实用意义。     

软基沉降的BP神经网络和灰色系统联合预测

使用BP神经网络插值方法对灰色数据进行了预处理,进而建立了预测软基沉降量的BP神经网络和灰色系统联合模型.实例分析表明,该模型短期沉降预测结果的最大相对误差小于2%,最终沉降预测结果的相对偏差小于5%,且灰色预测时取后期沉降瘦导颇算结果准确度高于取前期沉降数据的计算结果准确度.     

山区地震数据采集方法的技术难点与对策

山区地形复杂,浅层地震地质条件变化较大,成孔形式不一,数据采集困难。通过对岩石出露区、坡积物堆积区及黄土覆盖区进行试验分析,采用了封孔、压孔、组合炮及特殊观测系统等手段,有效地压制了干扰,提高了信噪比,使目的层反射波明显,得到了较理想的野外原始数据。     

水下生产系统在海洋石油开发中的应用

水下生产系统是一种将全部或部分油气集输设备放置于海底，低成本开发海洋石油的先进方法。对这一方法的研究在我国仅是近几年的事情。本文根据我国海洋油田的具体情况，提出了多种开发边际油田的方案，可供设计、生产部门参考。     

INTEGRATED FRACTIONS SKILL SCORE FOR THE ASSESSMENT OF PRECIPITATION

Traditional skill scores (e.g., the threat score) used in the high-resolution verification of precipitation are affected by a “double penalty” caused by slight spatial or temporal displacements, which can lead to misleading evaluations. The fractions skill score (FSS) is a popular spatial verificaiton measure that can be used to solve these problems. It can determine useful and skillful scores by neighborhood analysis, which can be used to monitor the performance of operational forecasts. However, the FSS provides different scores at each spatial scale and it is difficult to obtain a definite score for the assessment of precipitation to analyze the temporal variabilities of daily forecasts. We previously reported a modified FSS assessment method and showed that a particular analysis scale had a significant advantage in the verification of operational forecasts of precipitation. To compensate for the lack of artificial definition in the analysis scale, we report here a new integrated score that satisfies a Gaussian weight function to average the FSS over all scales. We describe the advantages of the new score in the verification of forecasts of daily and hourly precipitation, taking forecast products from the GRAPES regional model and quantitative precipitation estimation products from the National Meteorological Information Center during June and July 2017 and investigating the differences between these results and those obtained with the traditional category score. We found that a value of 0.5 can be used as a standard for the skillful FSS in the forecast of heavy rainfall. The integrated score can maintain all the advantages seen in previous studies in the verification of daily and hourly precipitation and show excellent application prospects. The long-term verification including different seasons also find that the score can effectively improve the identification characteristics of the assessment.