基于SAVEE方法的海岛地下水开采适宜性评价

对海岛地下水资源情况加以准确评估是合理开发利用的前提。采用SAVEE方法评估海岛地下水开采,消极因子和积极因子的影响都可以直接体现。同时SAVEE方法中各因子迭加采用了概率论中关于可信度的运算方法,使本方法中影响因子的迭加更接近于人类专家的判断。文中利用SAVEE方法对在南长山岛上设置的3个水井位置进行了评估,通过因子选取、数据标准化、迭加运算3个步骤,得出了位于海岛中部的水井位置最佳的结论。这一评估结论与之前其他学者相关研究结论一致,说明SAVEE方法可以作为海岛地下水开采适宜性评估的一种有效方法。     

GRP文件格式到MIF格式的实现

为将ＧＲＰ文件格式转换成ＭＩＦ文件格式，提供一种数据不变，而文件存储方式改变的数据转换方法和实例。     

Impact factors identification of spatial heterogeneity of herbaceous plant diversity on five southern islands of Miaodao Archipelago in North China

Herbaceous plants are widely distributed on islands and where they exhibit spatial heterogeneity. Accurately identifying the impact factors that drive spatial heterogeneity can reveal typical island biodiversity patterns. Five southern islands in the Miaodao Archipelago, North China were studied herein. The spatial distribution of herbaceous plant diversity on these islands was analyzed, and the impact factors and their degree of impact on spatial heterogeneity were identified using CCA ordination and ANOVA. The results reveal 114 herbaceous plant species, belonging to 94 genera from 34 families in the 50 plots sampled. The total species numbers on different islands were significantly positively correlated with island area, and the average α diversity was correlated with human activities, while the β diversity among islands was more affected by island area than mutual distances. Spatial heterogeneity within islands indicated that the diversities were generally high in areas with higher altitude, slope, total nitrogen, total carbon, and canopy density, and lower moisture content, pH, total phosphorus, total potassium, and aspect. Among the environmental factors, pH, canopy density, total K, total P, moisture content, altitude, and slope had significant gross effects, but only canopy density exhibited a significant net effect. Terrain affected diversity by restricting plantation, plantation in turn influenced soil properties and the two together affected diversity. Therefore, plantation was ultimately the fundamental driving factor for spatial heterogeneity in herbaceous plant diversity on the five islands.     

化探背景异常划分的多背景变差衬度法

针对化探背景异常划分问题,在考虑岩性背景、随机误差与结构异常关系基础上,提出了多背景变差衬度法。该方法是对研究区样品按地质背景分类求背景上限,再针对每一个样品,利用其临近同类样品元素含量和所属类别的背景上限值求变差衬度值,从而获得单个样品的异常相对强度,实现消除岩性影响,突出低弱异常的目的。研究区实例的处理结果表明,这种新方法适用于岩性复杂地区异常受岩性影响严重的元素的背景异常划分。方法的特点是符合地质理论、计算相对简单、异常结果清晰。     

断层上方第四系覆盖层中氡气运移规律的数值模拟

在前人研究的基础上,建立了稳定条件下断层上方第四系覆盖层中氡气的运移方程,给出了相应的边界条件,对断层上方覆盖层中的氡浓度分布进行了数值模拟,并对其影响因素进行了讨论.结果表明,断层上方第四系覆盖层中存在明显的氡浓度异常,其分布与覆盖层的厚度、断层的宽度、氡的扩散系数和对流速度等因素有关.     

氡气测量在佳木斯城市地下热水普查的应用

在佳木斯城区地下热水调查中,运用了水中氡活度浓度测量和土壤氡活度浓度测量综合方法,有效地克服了城市地热地质调查中的不利因素.通过对水中氡活度浓度及土壤氡活度浓度测量值的正态化变换以及原始氡活度浓度异常分析,明确了氡活度浓度异常对地下热水控制构造的指示作用.通过对氡活度浓度测量值的趋势分析,提取局部异常,综合各种异常信息,确定了城区地下热水的有利远景区.     

SIMULATION OF BOUNDARY LAYER EFFECTS ON A HEAVY RAINFALL EVENT CAUSED BY A MESOSCALE CONVECTIVE SYSTEM OVER THE YELLOW RIVER MIDSTREAM AREA

A heavy rainfall event caused by a mesoscale convective system (MCS), which occurred over the Yellow River midstream area during 7–9 July 2016, was analyzed using observational, high-resolution satellite, NCEP/NCAR reanalysis, and numerical simulation data. This heavy rainfall event was caused by one mesoscale convective complex (MCC) and five MCSs successively. The MCC rainstorm occurred when southwesterly winds strengthened into a jet. The MCS rainstorms occurred when low-level wind fields weakened, but their easterly components in the lower and boundary layers increased continuously. Numerical analysis revealed that there were obvious differences between the MCC and MCS rainstorms, including their three-dimensional airflow structure, disturbances in wind fields and vapor distributions, and characteristics of energy conversion and propagation. Formation of the MCC was related to southerly conveyed water vapor and energy to the north, with obvious water vapor exchange between the free atmosphere and the boundary layer. Continuous regeneration and development of the MCSs mainly relied on maintenance of an upward extension of a positive water vapor disturbance. The MCC rainstorm was triggered by large range of convergent ascending motion caused by a southerly jet, and easterly disturbance within the boundary layer. While a southerly fluctuation and easterly disturbance in the boundary layer were important triggers of the MCS rainstorms. Maintenance and development of the MCC and MCSs were linked to secondary circulation, resulting from convergence of Ekman non-equilibrium flow in the boundary layer. Both intensity and motion of the convergence centers in MCC and MCS cases were different. Clearly, sub-synoptic scale systems in the middle troposphere played a leading role in determining precipitation distribution during this event. Although mesoscale systems triggered by the sub-synoptic scale system induced the heavy rainfall, small-scale disturbances within the boundary layer determined its intensity and location.     

气象服务在促进内蒙古政策性农业保险事业发展中的作用

文章在分析国内外农业保险发展现状的基础上,结合内蒙古农业气象观测站网建设和气象为农服务业务开展现状,阐述了气象服务在农业保险业务发展中的作用和优势,为我区各级气象部门开展政策性农业保险服务业务提供了思路。     

一次副热带高压边缘突发性暴雨的锋生及水汽特征分析

针对2010年7月31日夜间山西西南部一次业务模式出现较大预报偏差的西太平洋副热带高压(下称副高)边缘突发性暴雨天气过程,利用常规和降水加密观测资料、FY-2E卫星TBB数据以及中尺度模式WRF高分辨率数值模拟结果,诊断分析了暴雨的发生发展、锋生及锋生过程中的水汽演变特征。结果表明:此次突发性暴雨是由高空槽后干冷空气推动副高边缘暖湿气流所导致的一次锋生型强降水,β中尺度对流系统(meso-βcircular convective system,MβCCS)是造成暴雨的直接影响系统,低层β中尺度涡旋的形成和发展为MβCCS的维持提供了有利的水汽辐合条件,地面冷锋及其附近中尺度辐合线是对流触发因子。锋生诊断表明,低层辐合、中层辐散的垂直结构导致对流层低层水平锋生、中层水平锋消,而低层强烈的上升运动使得强不稳定层结高度升高,从而引起对流层中层强垂直锋生发展,垂直锋生与水平锋生同时产生,且垂直锋生较水平锋生大一个量级,中低层强锋生和次级环流圈的出现与强降水的发生时间和位置对应较好,比较而言,倾斜项对总锋生贡献最大,辐合项贡献最小。中低层锋生的加强有利于低层水汽的辐合抬升,锋生过程中深厚的水汽饱和层的出现以及水汽含量向高空的凸起,对局地强降水的预报有明显的指示意义。另外,高空冷空气的强度、移动路径以及MβCCS的发展对判断此类强降水的发生和暴雨落区具有重要作用。