EN型测风数据处理仪故障分析及处理

分析了EN型测风数据处理仪在商丘站使用13年来出现的一些故障原因,并提出了故障处理方法.     

L波段雷达发生丢球的原因及解决办法

由于L波段雷达波束宽度（≤6°）比59—701型二次测风雷达波束宽度（垂直波瓣≤10°,水平波瓣≤11．5°）要窄,测角精度比较高。这样也给我们的操作人员在遇到丢球时找回目标带来了困难．不能像59—701那样根据四条亮线就能把球迅速找回来,必须结合L波段雷达的新特点进行抓球,做到快而准。以免造成资料缺测或重放球。     

近50年中国干湿气候界线波动及其成因初探

文中在 10a际尺度上详细分析了中国干湿气候界线波动与气候的干湿变化 ,得出 :过去 5 0a中国干湿气候界线波动显著 ,区域差异大 ,呈现出整体移动和东西、南北相异波动的特征。 2 0世纪 6 0～ 70年代中国干湿气候存在一次突变 ,由较湿润变为干旱 ,但各地干旱程度不同。干湿气候界线波动与气候的干湿变化具有显著的年代际特征。在此基础上分析了气候界线波动的可能原因 ,中国干湿气候界线的波动与气候的干湿变化是西太平洋副热带高压强度位置导致的东南季风、孟加拉湾暖流所导致的西南季风以及高原季风、中纬度西风环流等综合作用的结果。中国各地区干湿位相变化不一致 ,区域差异大 ,是不同环流以及环流的不同强弱组合所致。东南季风、西南季风、高原季风、中纬度西风环流、西太平洋副热带高压的年代际变化是过去 5 0a中国干湿气候界线波动与气候干湿变化年代际变化的根本原因。 2 0世纪 6 0～ 70年代的干湿突变 ,是整个北半球大气环流异常的结果     

延安国家基本气象站迁站对比观测数据分析

通过对延安国家基本气象站(53845)新、旧站2013年1—12月气压、空气温度、空气湿度、风向风速、降水、地温等观测资料的对比分析,发现新站气压、气温、湿度、平均地温、极端日最低地温低(小)于旧站,降水、风速以及地面日极端最高温度大部高(大)于旧站。并从海拔高度、两站周围环境差异等方面分析了新、旧站各气象要素差异的形成原因,为延安站资料的序列延续和订正提供依据。     

关于湖泊沉积物磷释放及其测定方法的雏议

湖水位下降是近期我国西北地区湖泊一种普遍现象,由于该地区湖泊多属闭合流域,湖泊水位下降往往导致湖水浓缩咸化,进而给湖体及湖周带来一系列的生态环境问题,本文根据近几十年来岱海的湖区气候,湖泊集水域的入湖径流特征分析,以及湖泊水量平衡计算,分辨出１９５５－１９９５年３．８５ｍ,的水位降幅中,人为影响的贡献为３．１７ｍ,占８２％,自然因素的贡献为０．６８ｍ,占１８％,说明岱海湖水位下降主要是集水域内人类     

金矿勘探中的"测不准"现象及原因分析

赋存于花岗岩中的金矿体,在勘探中的钻探结果被证实对矿体的控制偏差很大,这种"测不准"现象是由于花岗(斑)岩角砾硬度较大,含矿岩石破碎,含金硫化物在钻探过程中因硬度较小常被磨碎,并被泥浆带出钻孔,导致矿化段样品被严重贫化,从而失去探矿价值.应注意施工方法及管理,尽可能地以坑道作为这类矿体的首选勘探手段,慎用"以钻代坑".     

上海滨海湿地退化原因及生态修复措施研究

滨海湿地是上海的重要自然资源之一,在维持生态系统中发挥着重要作用。随着城市发展,上海滨海湿地面临面积缩小、功能减弱、生物多样性下降等严重胁迫,在人为活动的干扰下生态系统结构趋于破碎化,生态服务的调节能力减弱。本文探讨了其退化的自然因素和人为因素等原因,人工围滩造地加剧、滨海湿地资源过度发展、工业活动等导致了滩涂面积缩小、湿地退化甚至丧失的现象,分析了近自然生态恢复的修复方式,进一步针对外来物种管控措施、减缓湿地退化措施以及建立健全相关法制和管理体系等方面提出建议,可为滨海湿地修复的相关研究和实践提供参考。     

安徽阜南综合观测井水位大幅度下降异常原因探讨

安徽省阜南综合观测井(下文简称阜南井)水位于2015年4月20日开始出现大幅度下降变化,至2015年10月9日累计下降1.8 m,之后在低值波动.2016年5月29日,该井水位再次出现下降变化,安徽省地震局随即开展了异常现场核实及相关分析,获得以下认识.     

Spatiotemporal characteristics,patterns and causes of land use changes in China since the late 1980s简

Land-use/land-cover changes （LUCCs） have links to both human and nature inter- actions. China＇s Land-Use/cover Datasets （CLUDs） were updated regularly at 5-year inter- vals from the late 1980s to 2010, with standard procedures based on Landsat TM／ETM＋ im- ages. A land-use dynamic regionalization method was proposed to analyze major land-use conversions. The spatiotemporal characteristics, differences, and causes of land-use changes at a national scale were then examined. The main findings are summarized as fol- lows. Land-use changes （LUCs） across China indicated a significant variation in spatial and temporal characteristics in the last 20 years （1990-2010）. The area of cropland change de- creased in the south and increased in the north, but the total area remained almost un- changed. The reclaimed cropland was shifted from the northeast to the northwest. The built-up lands expanded rapidly, were mainly distributed in the east, and gradually spread out to central and western China. Woodland decreased first, and then increased, but desert area was the opposite. Grassland continued decreasing. Different spatial patterns of LUC in China were found between the late 20th century and the early 21st century. The original 13 LUC zones were replaced by 15 units with changes of boundaries in some zones. The main spatial characteristics of these changes included （1） an accelerated expansion of built-up land in the Huang-Huai-Hai region, the southeastern coastal areas, the midstream area of the Yangtze River, and the Sichuan Basin; （2） shifted land reclamation in the north from northeast China and eastern Inner Mongolia to the oasis agricultural areas in northwest China; （3） continuous transformation from rain-fed farmlands in northeast China to paddy fields; and （4） effective- ness of the ＂Grain for Green＂ project in the southern agricultural-pastoral ecotones of Inner Mongolia, the Loess Plateau, and southwestern mountainous areas. In the last two decades, although climate change in the north affected the change in cropland, policy regulation and economic driving forces were still the primary causes of LUC across China. During the first decade of the 21st century, the anthropogenic factors that drove variations in land-use pat- terns have shifted the emphasis from one-way land development to both development and conservation. The ＂dynamic regionalization method＂ was used to analyze changes in the spatial patterns of zoning boundaries, the internal characteristics of zones, and the growth and decrease of units. The results revealed ＂the pattern of the change process,＂ namely the process of LUC and regional differences in characteristics at different stages. The growth and decrease of zones during this dynamic LUC zoning, variations in unit boundaries, and the characteristics of change intensities between the former and latter decades were examined. The patterns of alternative transformation between the ＂pattern＂ and ＂process＂ of land use and the causes for changes in different types and different regions of land use were explored.