淀山湖水量的初步研究

分析了淀山湖水量的主要补给来源及淀山湖水量受潮沙影响的泄流规律,并用1988年的实测资料研究枯水年型的淀山湖水量平衡。计算结果表明:淀山湖区在1988年降水稀少,但它可获取邻近河湖及长江等水体的水源补给,使湖水量达到年内基本平衡。     

基于ArcGIS的山东地震台站空间分布特征研究

本文以ArcGIS为平台,通过对山东省地震台站与行政区划图、活动断裂带图、地震峰值加速度区划图等进行叠加分析及缓冲区分析来研究山东省地震台站的空间分布特点。得出山东省地震台站在空间上分布具有不均匀性,近半数位于活动断裂旁6km范围内,绝大部分位于25km范围内,位于地震烈度Ⅶ度区区划内的数量超过了60%。     

Evaporation in the Atacama Desert: An empirical study of spatio-temporal variations and their causes

The Atacama Desert is hyper-arid, and areas where adequate moisture exists for evaporation are spatially highly restricted. Nevertheless, water resources exist and their evaluation requires knowledge of this elusive but important component of the hydrological cycle. Evaporation may occur in four typical areas: rivers and associated riparian zones, localized springs, large playas and extensive areas of bare soil after infrequent precipitation events. Transpiration is locally possible where moisture is sufficiently close to the surface to allow phreatophytes or scarce grass cover to grow, but virtually no information is available for quantification. Pan evaporation data from 11 stations for the period 1977–1991 is analyzed and complemented by analysis of an evaporation study conducted in the Salar de Atacama during 1987/1988. The results show that pan evaporation, and hence maximum potential evaporation may be considered largely a function of maximum temperature and elevation as well as density of the evaporating fluid. Actual evaporation is limited by available moisture and diminishes rapidly as the level of soil moisture saturation drops below the soil surface, extinguishing at ca. 2 m depth. Evaporation is greatest during the summer, but at higher elevations convective cloudiness develops during January and February reducing evaporating rates at a time when significant precipitation may occur. Inter-annual variations in pan evaporation are considerable and weakly correlated with ENSO, but variations in actual evaporation are damped by comparison. Regression equations are developed which have widespread applicability and may be used to estimate evaporation in areas where no site-specific data exists.     

重震反演中国东北地壳上地幔三维密度结构

本文利用重力和地震P波到时数据反演得到了中国东北地区地壳上地幔三维密度结构.与单一的重力或地震反演相比,重震反演一方面有效地克服了重力反演结果垂向分辨率低的问题,另一方面也提高了地震反演结果的可靠性.结果显示:中国东北地区的地壳及上地幔剩余密度异常分布与构造单元具有明显的相关性,造山带对应低密度异常,盆地对应高密度异常;区域内火山下方有明显的低密度体存在,可能是由于太平洋板块俯冲进入上地幔并部分滞留,在滞留板块深部脱水和软流圈热物质共同作用下产生了上涌岩浆,喷发后形成了火山.     

Sources of polyfluoroalkyl compounds in the North Sea, Baltic Sea and Norwegian Sea: Evidence from their spatial distribution in surface water

The spatial distribution of 15 polyfluoroalkyl compounds (PFCs) in surface water was investigated in the North Sea, Baltic Sea and Norwegian Sea. In addition, an interlaboratory comparison of the sampling techniques and analysis was conducted. Highest concentration in the North Sea was found near the coast, whereas the ∑PFC concentration decreased rapidly from 18.4 to 0.07 ng l⁻¹ towards the open North Sea. The river Elbe could identify as a local input source for PFCs into the North Sea, whereas perfluorobutanoic acid (PFBA) was transported into the sampling area with the easterly current. In contrast to the North Sea, the distribution of PFCs in the Baltic Sea was relatively homogenous, where diffuse sources dominated. In general, the composition profile was influenced from local sources caused by human activities, whereas atmospheric depositions of here analysed PFCs were negligible, but it could have possibly an influence on low contaminated sites like the open North Sea or Norwegian Sea.     

太湖水体遥感反演参数的空间异质性

空间异质性的存在,会导致水质参数遥感反演中的尺度效应,影响反演精度,因此通过分析水质参数空间异质性,对于选择适当分辨率的遥感影像,提高反演精度具有重要意义.通过2008年10月在太湖布置的3个样方,利用GIS地统计学原理和分形维数的方法,对水质遥感反演中的三要素浓度,包括叶绿素a(Chl.a)、总悬浮物(TSM)和溶解有机碳(DOC)的空间异质性及其可能产生的尺度效应进行了研究.结果表明:太湖水体的三要素浓度在不同样方单元中变异系数相差较大,存在着明显的尺度效应;三个样方内Chl.a变异函数曲线斜率在变程范围内变化都较为剧烈,分形维数较高,说明太湖水体Chl.a受到某种起主导作用的生态过程的影响和控制;Chl.a和TSM的空间结构比例都在90%左右,有较强的空间相关性,表明其空间异质性的产生主要是由于结构性因素引起的,随机性因素作用微弱;DOC空间结构比例较小,说明随机性因素对其空间异质性的产生起了主导作用.三个样方中Chl.a的变程分别为147.3m、129.3m和115.0m,TSM的变程分别为1131.7m、130.6m、149.1m,因此在遥感反演中可选择TM影像,选择5×5窗口,以150m×150m作为基本单元;而DOC的变程分别为34.3m、38.5m、26.4m,表明其自相关距离较小,建议直接选择分辨率为30m的TM影像,使实际测量值与遥感影像最小单元相对应,消除反演过程中的尺度效应带来的误差.该研究也表明,MODIS的像元尺寸(250、500、1000m)明显偏大,在太湖水体三要素反演过程中,由于空间异质性引起的尺度效应,会造成一定的误差.     

Analysis of spatial water quality and stream networks in the southern Cotswolds during and after the drought of 1976

A study of water chemistry changes and stream network changes during and immediately after the 1976 drought is made in an area to the north and east of Bristol. In particular, contrasts are made between the Cotswold Limestone dip slope and the Severn Clay Vale. Immediately following the end of the drought a solute flushing effect was observed on the clay streams, whilst network extension on limestone streams incorporated new source areas and maintained higher solute concentrations throughout the post-drought period investigated.     

一种通过地形指数提取流域自由水蓄水容量空间分布的方法

对于分布式水文模型而言,如何获得参数的空间分布是模型应用的重点和难点问题.本文将分水源参数中的敏感参数——自由水蓄水容量为研究对象.建立地形指数与自由水蓄水容量的函数关系,以此提取流域内的自由水蓄水容量空间分布.最后利用本方法提取了陕西省陈河流域的自由水蓄水容量空间分布,并将之作为栅格型新安江模型的参数进行洪水模拟演算.应用结果表明本文提出的方法得到了理想的模拟结果.该方法以物理规律为基础能较为准确地计算出流域内自由水蓄水容量的空间分布,为分布式模型的发展奠定了坚实的基础.     

基于TRMM卫星多传感器资料揭示的亚洲季风区雷暴时空分布特征

利用16年（1998-2013）的热带降水测量任务卫星（TRMM）降水雷达和闪电成像仪等多传感器观测资料,分析了亚洲季风区内雷暴和强雷暴的空间分布、季节变化及日变化等气候特征.文中取闪电数大于1的雷达降水特征为雷暴,并将闪电频数在前10%的雷暴定义为强雷暴.结果表明：雷暴活动主要集中在陆地及近海区域,陆地与海洋上的雷暴密度之比约为4.4：1,强雷暴密度之比约为7.4：1.0-10°N纬度带内雷暴数占总雷暴的比例最大（占总数的31.7%）,而强雷暴则在20°N-30°N区间最为活跃（34.5%）.雷暴与闪电密度的空间分布在低纬度区域（0-30°N）较为一致,但在中纬度地区（30°N-36°N）呈现出不同的分布特征,即从西部的青藏高原向东部的江淮流域,雷暴密度逐渐减少但闪电密度逐渐增加;而强雷暴与闪电密度的空间分布基本一致.受亚洲夏季风活动影响,低纬度地区强雷暴更容易发生在春季,强中心位于喜马拉雅山南麓东端,次中心位于中南半岛,而中纬度地区在夏季最为活跃,强中心和次中心则分别位于喜马拉雅山南麓西端和中国江淮流域.陆地上雷暴主要集中在午后至傍晚,少数区域受局地环流和气象条件的影响夜雷暴活动频繁,而海洋上雷暴更易发生在午夜至清晨.

     

浙江千岛湖深水区大型底栖动物时空变化格局

2007-2008年对浙江千岛湖深水区底栖动物群落进行了研究.共调查到8种底栖动物,其中寡毛类7种,线形动物门1种.群落类型不存在季节差异,优势种为霍甫水丝蚓和正颤蚓.群落年均密度和生物量分别为594.6ind./m~2和0.54g/m~2.双因素方差分析表明,密度和生物量无季节变化,但存在显著的空间差异,两者均是上游中游下游.密度和生物量与水深、透明度显著负相关,前者与水柱混合水样的TN和TP、与底部局部水样的TP显著正相关,后者与水柱混合水样的TP显著正相关.逐步回归分析表明,水深是密度和生物量的唯一最优解释因子,随水深增加密度和生物量均呈指数式下降.     

太湖蚌类现存量及空间分布格局

于2016年10月和2017年10月对太湖全湖8个湖区129个样点的蚌类进行调查,分析蚌类的物种组成、现存量、空间分布及历史变化.共采集到蚌类704个个体,隶属8属14种.全湖蚌类平均生物量和密度分别为4.169±9.337 g/m²和0.164±0.386 ind./m²;各湖区蚌类平均生物量和密度差异较大,东部沿岸区生物量和密度最高,分别为14.975±16.743 g/m²和0.577±0.758 ind./m²;湖心区生物量和密度最低,仅为0.727±1.622 g/m²和0.029±0.071 ind./m².扭蚌（Arconaia lanceolata）、圆顶珠蚌（Unio douglasiae）和背角无齿蚌（Anodonta woodiana woodiana）为太湖现阶段的优势种.基于蚌类平均密度的聚类分析,8个湖区分为3类.与历史数据相比,太湖蚌类资源呈明显衰退趋势,现状不容乐观,需加强对太湖蚌类的保护和资源的有效管理.     

Scenario-based water resources planning for utilities in the Lake Victoria region

Urban areas in the Lake Victoria (LV) region are experiencing the highest growth rates in Africa. As efforts to meet increasing demand accelerate, integrated water resources management (IWRM) tools provide opportunities for utilities and other stakeholders to develop a planning framework comprehensive enough to include short term (e.g. landuse change), as well as longer term (e.g. climate change) scenarios. This paper presents IWRM models built using the Water Evaluation And Planning (WEAP) decision support system, for three towns in the LV region – Bukoba (Tanzania), Masaka (Uganda), and Kisii (Kenya). Each model was calibrated under current system performance based on site visits, utility reporting and interviews. Projected water supply, demand, revenues and costs were then evaluated against a combination of climate, demographic and infrastructure scenarios up to 2050. Our results show that water supply in all three towns is currently infrastructure limited; achieving existing design capacity could meet most projected demand until 2020s in Masaka beyond which new supply and conservation strategies would be needed. In Bukoba, reducing leakages would provide little performance improvement in the short-term, but doubling capacity would meet all demands until 2050. In Kisii, major infrastructure investment is urgently needed. In Masaka, streamflow simulations show that wetland sources could satisfy all demand until 2050, but at the cost of almost no water downstream of the intake. These models demonstrate the value of IWRM tools for developing water management plans that integrate hydroclimatology-driven supply to demand projections on a single platform.     

Impact of climate change on water resources in southern Taiwan

This study investigates the impact of climate change on water resources in southern Taiwan. The upstream catchment of Shin-Fa Bridge station in the Kao-Pen Creek basin was the study area chosen herein. The historical trends of meteorological variables, such as mean daily temperature, mean daily precipitation on wet days, monthly wet days, and the transition probabilities of daily precipitation occurrence in each month, at the Kao-Hsiung meteorological station, near the catchments were detected using a non-parametric statistical test. The trends of these meteorological variables were then employed to generate runoff in future climatic conditions using a continuous rainfall–runoff model. The analytical results indicate that the transition probabilities of daily precipitation occurrence significantly influence precipitation generation, and generated runoff for future climatic conditions in southern Taiwan was found to rise during the wet season and decline during the dry season.     

面向地震风险评估的中国大陆区县级人口总量时空预测方法研究

以中国大陆区县级历史人口数据为基础, 研究人口总量和人口增长率的时间序列变化规律, 并综合运用阻滞模型、 指数模型、 对数模型、 线性模型等拟合方法, 得到相当精度的拟合预测模型, 获得了经验证较可靠的中国大陆未来区县级总人口预测结果。 同时, 以2020年预测人口为例, 定量分析了2010—2020年人口空间分布格局, 各区县未来人口增减变化情况, 其能够较准确的表达未来人口空间分布。 本研究旨在为地震风险评估对人口在时间变化和空间分布上的未来预测需求提供可靠数据。     

主磁场梯度的空间分布和长期变化特征

根据GUFM1和IGRF11模型,计算1590—2010年主磁场总强度F、水平分量H和磁倾角I三个要素的水平梯度和垂直梯度,分析了它们的空间分布和长期变化特点.结果表明:F和H的垂直梯度与其磁场的空间分布类似,水平方向的梯度以及磁倾角I在3个方向的梯度都与其磁场分布有明显差异.H的3个方向的梯度分布清楚地指示出南磁极的位置.梯度的长期变化表明,北半球磁场梯度漂移缓慢,南半球磁场梯度变化较快.磁倾角的垂直梯度显示,中太平洋负异常周围的正异常在围绕该负异常旋转.近赤道的梯度异常带在60°W附近的转折是由印度洋异常向非洲方向移动所致.     

抚仙湖浮游甲壳动物群落结构与空间分布

云南抚仙湖是我国典型的高原深水湖泊,为揭示湖中浮游甲壳动物对生态系统变化的响应,研究了其群落结构与空间分布特征.2005年6-7月在抚仙湖共采集浮游甲壳动物8种,平均密度为27.6ind./L,优势类群为桡足类.桡足类优势种为舌状叶镖水蚤(Phyllodiaptomus tunguidus Shen et Tai),枝角类优势种为角突网纹涵(Ceriodaphnia cornuta Sars)和象鼻溞(Bosmina sp.).浮游甲壳动物主要分布在0-30m水层,密度随水深增加而下降;0-10m水层,枝角类和无节幼体占优势,大于10m水层,桡足类占优势.浮游甲壳动物密度南区大于北区(P<0.01),而沿岸区与湖心区之间、沉水植物区与非沉水植物区之间无显著性差异(P>0.05).相关分析表明:浮游甲壳动物密度的垂直分布与藻类密度和水体理化凼子相关关系显著,而水平分布与藻类密度和水体理化因子相关关系不显著.与20世纪80年代相比,抚仙湖浮游甲壳动物优势种发生了演替,西南荡镖水蚤(Neutrodiaptomus mariadviagae mariadviagae (Brohm))消失,被舌状叶镖水蚤代替,可能与太湖新银鱼(Neosalanx taihuensi Chen)引入有关;浮游甲壳动物密度表现出增加趋势,但仍处于较低水平,与水体营养水平的提高及太湖新银鱼的捕食压力有关.     

主磁场梯度的空间分布和长期变化特征

根据GUFM1和IGRF11模型,计算1590—2010年主磁场总强度F、水平分量H和磁倾角I三个要素的水平梯度和垂直梯度,分析了它们的空间分布和长期变化特点.结果表明:F和H的垂直梯度与其磁场的空间分布类似,水平方向的梯度以及磁倾角I在3个方向的梯度都与其磁场分布有明显差异.H的3个方向的梯度分布清楚地指示出南磁极的位置.梯度的长期变化表明,北半球磁场梯度漂移缓慢,南半球磁场梯度变化较快.磁倾角的垂直梯度显示,中太平洋负异常周围的正异常在围绕该负异常旋转.近赤道的梯度异常带在60°W附近的转折是由印度洋异常向非洲方向移动所致.     

The distribution of daily snow water equivalent in the central Italian Alps

The statistical distribution of the daily Snow Water Equivalent (SWE) is investigated for a network of gauging stations in the Alpine part of Lombardia region, in the central Italian Alps. An event based data analysis is carried out using a 14 year long data set dating back to 1989. SWE is estimated when the new snow depth is greater than 6 cm. The SWE sample average in time is shown to be related to physiographic attributes of the gauging area, thus not being homogeneous in space. The values of SWE scaled by their average, or index value, instead show well approximated homogeneity of the second order moment, or coefficient of variation, in space. This suggests the use of a regional approach for frequency estimation of SWE. The frequency of occurrence of the normalized values of SWE is evaluated and tentatively accommodated by four probability distributions, often adopted in statistical modeling of hydrological variables. The Lognormal distribution shows the best performance. Single site distribution fitting is then carried out using the regional distribution, providing satisfactory results.     

Temporal and spatial distribution of dam failure events in China

Reservoirs play a vital role in economic development and flood control. Nevertheless, both human and natural factors may lead to dam failures with catastrophic consequences. Analyzing the data of dam failure events from 1954 to 2003 and using the method of energy spectrum analysis, this paper studies the periodicity of dam failures. The rate of failure of different dam ages is analyzed. The climate is the main factor affecting the rate of dam failure. Climate diagrams are used to analyze the spatial distribution of dam failure events in China. High rate of dam failure occurs with 25-year and 12.5-year periods. The distribution of the percentage of dam failure shows an L-shape as a function of service age. The first 5 years of operation is known as the ＂infant period＂, during which, the probability of dam failure is much higher than during any other periods. The failure rate in areas near or north to the 400 mm annual isopluvial line is notably higher than other areas. In areas with high temperature difference among seasons have a high annual average dam failure rate.     

鄱阳湖枯水期延长背景下越冬水鸟群落结构、丰富度及其空间分布格局

鄱阳湖是我国最大的淡水湖,也是具有国际意义的候鸟越冬地.本研究于2015和2016年越冬期对鄱阳湖越冬水鸟的群落结构、丰富度和空间分布进行了系统的调查,分别记录到水鸟494033和388017只,隶属于6目13科68种.雁形目和鸻形目鸟类种类最多,其次是鹳形目和鹤形目;从生态型来看,游禽32种,涉禽36种.雁鸭类相对丰富度最高,是鄱阳湖越冬水鸟的优势类群,其次是鸻形目鸟类,而2015和2016年鹤形目鸟类数量仅占当年总数量的2.6%和1.4%.在鄱阳湖湿地的不同区域,越冬水鸟种类组成差异较大.从空间分布来看,越冬水鸟主要集中在鄱阳湖自然保护区、九江湿地和南昌湿地.开展鄱阳湖越冬水鸟的种群数量调查,摸清越冬水鸟群落结构和种群丰富度现状,对于有针对性地开展越冬水鸟保护具有重要意义.