西北干旱区乡村性评价及驱动机制研究——以甘肃武威为例

基于武威市1949~2013年65 a的社会经济统计数据,以县域为基本单元构建乡村性指标体系,通过测算各县区乡村性指数和分异指数来分析乡村性的时间演变和空间分异,并从社会经济和技术经济两个维度探讨了乡村性演变的影响因素。结果表明：① 1949~2013年间武威市各县区乡村性指数总体呈减弱趋势,但减弱幅度和速度存在差异。② 各县区乡村性分异指数呈波动增长趋势,2000年以后乡村性分异指数急剧增长,表明各县区乡村性差异越来越大。③ 社会经济和技术经济是影响乡村性变动的两大动因,各因素的发展致使城乡差距缩小、乡村性水平减弱、城乡一体化发展趋势明显。     

Simulation of rainfall-runoff and watershed convergence process in the upper reaches of Heihe River Basin, July 2002

The watershed flow concentration scheme in the distributed hydrology-soil- vegetation model (DHSVM) is coupled with the mesoscale atmospheric model MM5 version 3.5, in which the Oregen States University land surface model (OSULSM) was involved. The flood event which happened in July 2002 in the upper reaches of Heihe river basin is simulated and the surface flow convergence process is shown with this coupled model. It has been concluded that times water head reaches each place of the basin are different. Water amount at each point is split-flow proportionally as the drops in elevation between it and neighbor points. Large part of the water amount pass away in greater slope direction and small part pass away in smaller slope one.Adding of the slope convergence makes the atmospheric model redistributes the surface water laterally.     

地电化学法在豫西崤山黄土覆盖区找矿中的应用——以洛宁县石龙山预查区为例

豫西崤山北部沟壑纵横,第四系黄土广泛覆盖,地表植被发育。为探讨地电化学法在豫西崤山黄土覆盖区寻找金矿的有效性,选择了隐伏于黄土下的石寨沟金矿开展找矿可行性试验,并在其邻区石龙山金多金属矿预查区南部开展地电化学找矿研究。研究发现,石寨沟Au矿床上部发育地电化学综合异常,异常规律明显,元素相关性较好,具有很好的套合和分带关系。对石龙山预查区地电提取的微量元素含量特征(分形、变异系数、地电提取比)进行分析,发现其与石寨沟Au矿床具有相近的地电异常规律。进一步利用Surfer软件绘制等值线异常图,结合前人研究成果在异常套合较好的02号线45～47测点初步经过地表工程验证,确定了一条品位较好的工业金矿体,侧面证明实测、推测断层F1-1和F20确实存在。该成果为石龙山地区深部及石寨沟矿床外围找矿提供地电化学理论基础,也为崤山黄土覆盖区找矿提供了新的思路。     

区域气候模式RegCM砾石参数化方案在青藏高原不同区域土壤水分输送的模拟分析

在耦合CLM4.5的区域气候模式RegCM4.7中分别应用原始土壤水热参数化方案与改进后的砾石参数化方案在青藏高原西部、中部与东南部区域进行模拟,并根据砾石分布特征在每个区域选取单点分析了两种方案模拟结果存在差异的原因.在此基础上利用中国陆面融合再分析数据(CRA-40)检验了砾石参数化方案在高原不同区域对于土壤含水量...     

Global Land Surface Climate Analysis Based on the Calculation of a Modified Bowen Ratio

A modified Bowen ratio(BRm),the sign of which is determined by the direction of the surface sensible heat flux,was used to represent the major divisions in climate across the globe,and the usefulness of this approach was evaluated. Five reanalysis datasets and the results of an offline land surface model were investigated. We divided the global continents into five major BRm zones using the climatological means of the sensible and latent heat fluxes during the period 1980–2010:extremely cold,extremely wet,semi-wet,semi-arid and extremely arid. These zones had BRm ranges of(-∞,0),(0,0.5),(0.5,2),(2,10) and(10,+∞),respectively. The climatological mean distribution of the Bowen ratio zones corresponded well with the K ¨oppen-like climate classification,and it reflected well the seasonal variation for each subdivision of climate classification. The features of climate change over the mean climatological BRm zones were also investigated. In addition to giving a map-like classification of climate,the BRm also reflects temporal variations in different climatic zones based on land surface processes. An investigation of the coverage of the BRm zones showed that the extremely wet and extremely arid regions expanded,whereas a reduction in area was seen for the semi-wet and semi-arid regions in boreal spring during the period 1980–2010. This indicates that the arid regions may have become drier and the wet regions wetter over this period of time.     

2014—2016年拉萨市大气环境质量分析及评价

本文对2014—2016年拉萨市6种空气污染物SO2、NO2、PM10、PM25、CO、O3的浓度变化进行了分析和评估。结果表明：①拉萨市区大气污染物以PM10为主,其次是O3;②拉萨市区大气环境中SO2、CO的含量逐年下降,但是,NO2含量逐年上升;③拉萨市大气环境中的PM25与PM10比值明显偏低,表明拉萨市大气环境质量主要的影响因素为自然因素。     

CEOF ANALYSIS OF ATMOSPHERIC LOW FREQUENCY OSCILLATION IN LOWER LATITUDE REGION AND FREQUENCY MODULATION PHENOMENA OF LOW FREQUENCY SIGNALS

The low frequency oscillation of the low level atmospheric circulation in lower latitudes region is studied by usingthe CEOF method and other normal spectral analysis methods.It is found that in the atmospheric motion frequencyspectrum,there exist certain frequency bands with relatively-concentrated energy among low frequency bands,andthere is nonlinear interaction of frequency modulation among peak signals.It is this modulating action that leads to thechange of the temporal-spatial features of frequency and phase of these low frequency signals.In the paper,the propa-gation picture of low frequency waves modulated and its influence on midium-range variation of summer monsoon arealso discussed.     

川西义敦地区的斧石矿及其矿床地质特征

川西义敦某地发现罕见的斧石矿床,产于黑云母二长花岗岩与中下三叠统图姆沟组外接触 的矽卡岩中,为中高温、中温热液接触交代形成。其形成时代为早第三纪。矿物呈紫色,透明至半透明,据化学成份确定为锰铁斧石。其晶粒粗大,颜色鲜艳夺目,无裂纹,可作为中高档宝石原料,具有较高的经济价值。