亚热带喀斯特水库桡足类和枝角类动物群落季节变化——以贵州红枫湖、百花湖、阿哈水库为例

2008年至2009年对贵州红枫湖(HF)、百花湖(BH)、阿哈水库(AH)的桡足类和枝角类动物进行4次采样调查,共发现桡足类5科11属19种,其种包含一未定种。枝角类5科9属14种。三个水库中都存在的桡足类优势种为绿色近剑水蚤、叶片剑水蚤、短尾温剑水蚤;枝角类的优势种为长刺溞、长额象鼻溞;角突网汶溞。桡足类和枝角类的总密度在红枫湖为春季最高,秋季次之,夏季最低;在百花湖为夏季最高,秋季次之,冬季最低;在阿哈水库为春季最高,秋季次之,夏季最低。三个水库季节生物多样性比较:春季的多样性是AHBHHF;夏季和冬季是BHAHHF;秋季是AHHFBH。季节性气候变化和污染是影响桡足类和枝角类动物群落变化的重要因素。     

面向水平衡测试的北方城镇生活用水规律研究

利用昌图县2011年和朝阳县2010年生活用水数据,分析居民生活用水量周、年内变化特征,并根据各个月份北方生活用水特点划分了北方生活用水季节,同时,结合滑动平均、经验模态分析和小波分析方法计算了城市生活用水水平衡测试周期。主要结论：一周初始生活用水量最低,周末用水量最高;一年中11-3月用水量最高,为生活用水冬季,6-8月为夏季,用水量次之,4-5月为春季,9-10月为秋季,春秋季用水量较少;城市生活用水水平衡测试的最佳周期为7天。     

辽宁省气温变化趋势中的城市化影响研究

利用1961 - 2017年逐日平均、 最低、 最高气温资料、 DMSP/OLS卫星夜晚灯光数据, 定量分析了城市化对辽宁省平均气温和极端气温指数趋势变化的影响。研究表明： 辽宁省气温呈显著增加趋势, 城市站增温速率明显快于乡村站; 平均最低气温增温率最快, 平均气温次之, 平均最高气温相对较慢; 四季增温速率依次为： 冬季>春季>秋季>夏季; 最低气温的城市化影响贡献率最大, 平均气温次之, 最高气温相对较小; 城市站最低气温的明显升高和最高气温增幅较小, 必将导致日较差明显减小和日较差城市化影响贡献率的增大。城市化加剧了辽宁省极端低温事件的显著减少和极端高温事件的明显增加, 城市化对极端气温事件影响显著。与冷事件有关的极端气温指数的城市化影响均为负值, 与暖事件有关的均为正值; 相对指数的城市化影响贡献率较大, 持续时间指数次之, 除气温日较差以外的绝对指数相对较小。基于最低气温的极端气温指数比基于最高气温的极端气温指数受城市化影响更显著, 其原因可能是城市热岛强度的非对称性以及城市站和乡村站气溶胶浓度之间的差异, 导致最高气温的增加没有最低气温的增加显著。     

地形对天山积雪冻融变化的影响分析

天山积雪是新疆水资源的重要来源,地形对积雪的空间分布和消融有重要影响,分析地形对天山积雪冻融过程的影响具有重要的理论意义.基于2005-2014年的MODIS/Terra积雪8 d合成数据（MOD10A2）与数字高程模型（DEM）数据,分析了天山积雪覆盖随高程、坡度和坡向的季节变化规律.分析结果表明：（1）在不同季节里,不同高程中的融雪和积雪过程同步发生,其中在春季和冬季,雪盖变化较大的区域主要分布在低海拔和高海拔地区;而在夏、秋两季,雪盖变化较大的区域主要分布在中海拔地区.（2）在不同季节,不同坡度的积雪冻融过程也同步进行,但春季和冬季积雪呈线性变化,在缓坡和陡坡地区变化明显;夏季和秋季积雪变化缓慢,在中坡变化显著.（3）天山积雪变化随坡向具有对称性和周期性.积雪变化呈现北坡大、南坡小,春、冬季大,夏、秋季小的特点.在波动周期内,夏秋季积雪变化波动较大,变化趋势与春、冬季相反.研究结果可为融雪型洪水预报提供科学依据.     

Algal blooms in a shallow lake with a special reference to lake (Loch) Lindores: Scotland

Algal blooms are frequently observed in eutrophic lakes; a typical example of which is Lake Lindores, where two species of algal blooms were observed during the studied period. The first bloom of Asterionella formosa occured in spring, with a second occurence of the bloom observed in late winter and autumn when the water temperature was fairly low. At a higher water temperature, of more than 15°C, an unwanted blue-green algal bloom of Anabaena flosaquae occured. The blue-green algal bloom normally occured in summer and early autumn.     

祁连山云和空中水汽资源的季节分布与演变

祁连山云和空中水汽资源具有明显的季节变化特征：总云量春季最多，夏季次之，低云量夏季最多，春季次之。近45年中的春季和夏季，总云量在减少，低云量在增加，对应降水也在增加；秋季三者都为减少趋势；冬季总云量和降水在增加，但低云却呈减少趋势。相关分析表明，总云和降水在夏季、秋季呈显著正相关，低云和降水在春季、夏季及秋季呈正相关；值得注意的是冬季低云和降水在祁连山的中东段呈负相关，但通不过信度检验。空中水汽主要沿两条路径输送到祁连山，平均状况下祁连山存在较强的水汽辐合，且东段辐合（-0.1～-0.05 kg/(m2·s）)强于中西段（-0.05～0 kg/(m2·s））。地中海、黑海、里海、咸海、阿拉伯海和孟加拉湾是祁连山的水汽输送源地，但各个季节又有所不同。祁连山区域的水汽收支表明，春季净水汽通量在1979年以后一直为正且呈增加趋势，夏季整个区域基本上是个“水汽汇”，秋季和冬季则一直为负。分析认为祁连山春、夏两季空中云水资源具有较好的开发潜力。     

天山南坡科其喀尔冰川表碛区小气候特征研究

利用天山南坡科其喀尔冰川3号观测站2009年全年的气象观测资料,分析研究了科其喀尔冰川表碛区的小气候特征. 结果表明：总辐射和净辐射夏秋季较高、冬春季较低;反射辐射和地表反照率反之. 与其他地区不同,该区主要受积雪物理性质和下垫面状况的影响,冬春季地表反照率日变化表现为由大到小的变化过程,夏秋季表现为倒U型. 温度年变化表现为夏秋季高、冬春季低,最高月均值出现在8月,为9.4℃,最低月均值出现在1月,为-9.6℃. 受山谷风和冰川风的影响,全年的风向以西北风和西北偏西风为主,风向的日变化以11：00为界发生转向. 受降水和冰川消融等的影响,比湿夏秋季月均值较大,冬春季月均值较小.     

The impact of sulfate reduction on the distribution of methylmercury in reservoirs in the city of Guiyang

In this paper, the relationship between sulfate reduction potential and mercury methylation potential was studied in the Aha, Baihua and Hongfeng reservoirs from Guiyang City. The methylmercury (MeHg) concentrations of lake water in the Aha Reservoir were greatly elevated as compared to those of the Hongfeng and Baihua reservoirs, which was correlated with its distinctly high SRB abundance, SO42-, and S2- concentrations. Among the three reservoirs, however, the highest MeHg was observed in in the top several centimenters of pore water profile in the Hongfeng Reservoir where the lowest S2- in pore water occurred. The distributions of MeHg in lake water and pore water showed the highest methylation potential occurred at water-sediment surface for the Aha Reservoir and the in the top several centimenters of sediments for the Hongfeng Reservoir. It is guessed that the highest mercury methylation only occurs at the sites with certain sulfide concentrations.     

峰丛洼地表层岩溶动力系统季节变化规律

峰丛洼地表层岩溶动力系统与土壤CO₂密切相关.土壤CO₂体积分数变化受气温和降雨影响, 其季节变化特征表现为: 冬季的波谷、夏季的波峰交替出现, 秋季出现次波谷和次波峰.受降雨影响, 表层岩溶动力系统运行强度春、夏季较强, 秋、冬季较弱.从冬至夏, 在土壤CO₂逐渐增多时, 系统溶解、转移碳的能力也逐渐增强.在土壤CO₂和温度双重支配下, 系统由冬季的沉积趋势转为春、夏季的溶解趋势.      

青海高原不同生态功能区气候突变时间的比较分析

根据地理位置和地貌特征将青海省划分为东部农业区、 环青海湖区、 三江源区和柴达木盆地4个生态功能区, 利用这4个生态功能区1961-2010年的月平均气温和降水量资料, 对年和四季的平均气温及总降水量进行了突变检测.结果表明: 4个生态功能区年平均气温和四季气温都呈显著的上升趋势, 其中冬季气温上升最明显, 其次为秋季, 春季和夏季相对较小.气温突变时间检测表明, 年平均气温为柴达木盆地的突变时间最早, 其次为东部农业区和环湖区, 三江源区突变时间最晚.不同生态功能区四季气温突变时间不尽相同.年降水量除柴达木盆地上升趋势明显外, 其余三个地区变化趋势都不明显; 四季降水量变化趋势除冬季降水量变化明显(除东部农业区)外, 其余三季变化趋势基本不明显.降水量突变信号较气温突变信号弱, 只有个别地区的个别季节降水量发生了突变.     

Phytoplankton and particulate matter in Carlingford Lough, Ireland: An assessment of food availability and the impact of bivalve culture

In an attempt to assess the impact of bivalve culture in Carlingford Lough, Ireland, the seasonal cycles of nutrients, particulate matter, chlorophylla, and phytoplankton in the lough was investigated in 1992. Chlorophyll levels showed an increase in April, corresponding to the annual spring bloom, and levels remained relatively high (2–12 mg m^?3) throughout the summer before dropping to a winter minimum by December. Throughout the summer the phytoplankton community was dominated by diatoms, with microflagellates becoming an increasingly larger fraction of the biomass in autumn and winter. Dinoflagellates were only present on occasion in low numbers during the summer months. Seasonal variations in nitrate, phosphate, and silicate concentrations at all stations showed characteristic winter maxima and summer minima. Nitrate concentrations had reached a minimum undetectable level by June, at a time when the main freshwater input from the Clanrye River had dropped to <0.3 m³ s^?1. Particulate organic carbon (POC) composed approximately 5% of the suspended matter, with highest values in winter due to resuspension. Levels of biologically available POC, as determined by a modified BOD technique, were greatest in summer, and an inverse relationship was observed between total POC and its fraction that was biologically available. Most of the labile fraction was considered to be phytoplankton, and remineralization during the summer is suggested as a mechanism for maintaining high productivity during the summer months. Although the phytoplankton biology was uncoupled with that outside the lough, it is concluded that there is scope for expansion of the local bivalve mariculture industry without altering the ecosystem of the lough. The upper limit on such expansion would be set by practical considerations such as availability of space and site suitability due to water quality.     

Seasonal variations in sulfur isotopic composition of dissolved SO<Subscript>4</Subscript><Superscript>2−</Superscript> in the Aha Lake,Guiyang and their implications

The Aha Lake is a seasonal anoxic water system in the southwest of Guiyang City, Guizhou Province, China. Seasonal variations in SO42- concentrations and their isotopic compositions in lake water as well as in the tributaries were investigated in this study. The results showed that sulfate concentrations in river water range from 0.94 to 6.52 mmol/L and their δ34S values range from -14.9‰ and 0.9‰, while lake water has sulfate concentrations ranging from 1.91 to 2.79 mmol/L, and δ34S values from -9.8‰ to -5.9‰. It is suggested that coal mining drainage is the major source of SO42- in the Aha Lake. Rainfall, sewage discharge, sulfide oxidation and gypsum dissolution have made only limited contributions. Different depth-dependent distributions of dissolved SO42- and δ34S were de-veloped for both DB and LJK in summer and winter. Due to water overturn, δ34S values display homogenous vertical distributions in winter and spring. While in summer and autumn, significant positive shifts of δ34S were clearly ob-served in epilimnion and bottom strata as a result of water stratification. High δ34S values in epilimnion may result from the retention of rainwater during water stratification. Dissimilatory sulfate reduction by bacteria was thought to be responsible for the increase of δ34S value in hypolimnion.     

1980-2009年西藏地区水汽输送的气候特征

利用1980-2009年NCEP/NCAR月平均再分析格点资料, 分析了近30 a来西藏地区水汽输送的气候特征. 结果表明: 1)西边界和南边界为水汽流入边界, 北边界和东边界为水汽流出边界; 夏季水汽总输入量最大, 冬季最小且季节差异显著; 春季水汽总输出量最大, 冬季最小且季节差异不明显; 春、 冬季为净水汽支出, 夏、 秋季为净水汽收入; 2)无论是年还是不同季节平均, 近30 a来西边界水汽输入量、 北边界水汽输出量基本呈现增加趋势或弱的减少趋势, 东边界水汽输出量、 南边界水汽输入量基本呈现减少趋势; 总水汽输入、 输出量均呈现减少趋势; 年、 夏季、 秋季净收入量呈现减少趋势, 春季、 冬季净支出量呈现增加趋势; 3)西藏地区冬、 春、 秋季的水汽主要来自中纬度西风带水汽输送, 夏季水汽主要来自阿拉伯海、 孟加拉湾、 南海和西太平洋地区, 夏季南边界的水汽输送状况对西藏地区降水起着决定性作用.