三峡山地沟谷不同坡位土壤水分特征及对降雨过程的响应

土壤水分是影响地表植被生长发育及分布格局的重要因子，也是岩石圈-水圈-生物圈-大气圈水分循环的重要环节，其动态变化能够反映土壤水文过程的信息。基于高分辨率时域反射水分探针和小型气象站连续定位监测，获取2018~2019年三峡大老岭地区典型沟谷内坡上、坡中、坡下部位0~80 cm范围内各土层含水量及大气降水数据，分析了不同坡位土壤水分在月尺度，日尺度和小时尺度的变化特征及其对降雨过程的响应。结果表明：（1）月尺度上，土壤水分含量季节性差异明显，春夏季节（5~7月）是土壤水分储蓄期，土壤平均含水率为38.40%，夏秋季节（8~10月）是水分消耗期，剖面土壤平均含水率仅为35.04%。（2）日尺度和小时尺度，不同层次土壤水分含量对降水响应存在差异。0~40 cm深度土壤对降雨响应较快（响应时间<0.5 h），土壤水分与降雨量变化趋势相似；60~80 cm深度土壤对降雨响应存在明显的滞后现象（响应时间滞后0.5~3.0 h），且随深度加深，滞后时间呈阶梯式延长。（3）不同降雨条件下，土壤水分对降水的响应差异明显。随降雨量级由中雨增至大暴雨，土壤水分对降雨的响应加快，含水量变化曲线与降雨过程同步性增强，响应深度也逐层增加，土壤水分增量变大。（4）不同坡位对土壤水分的影响存在差异，上坡位对中雨、大雨响应平稳，中、下坡位对降水响应强烈，土壤水分增加迅速。产生不同坡位间响应差异的原因是各点微地形差异导致集水面积不同。     

Climatic signal in radial increment of conifers in forest-steppe of southern Siberia and its dependence on local growing conditions

Radial increments have been studied in Siberian larch (Larix sibirica Ledeb.) and Scots pine (Pinus sylvestris L.) growing in the forest-steppe zone of southern Siberia in areas with different landscapes and levels of soil moisture supply but uniform climatic conditions. It has been shown that the radial increment significantly depends on climatic factors, primarily temperatures in April to July and September, sums of precipitation in April to July and September to November, and hydrothermal coefficient in May. The climatiC response in the wood of conifers in the forest-steppe zone differs depending on their species-specific features and local growing conditions.     

鄱阳湖流域叶面积指数时空变化特征及其与气候因子的关系

利用1982~2001年NOAA/AVHRR NDVI数据,根据简单生物模型SiB2的方法计算鄱阳湖流域叶面积指数LAI,分析不同植被类型LAI年内和年际变化及其与降水、气温的关系。结果显示：在年内,LAI从1月开始减小,至3月降到最小,之后开始迅速增大,7月达到最大值,然后又开始减小;各植被覆盖类型LAI与前3月降水和前1月平均气温相关性较强,并且全部通过95％的显著性检验。在年际上,各植被覆盖类型LAI在20 a间无明显整体增大或减小趋势,但每隔2~3 a呈锯齿状增大减小交替变化,其中常绿针叶林LAI变幅较大,在23~35之间,而林地草原LAI变化较平缓,在05~09之间;植被LAI年际变化受流域内5~7月降水年际变化的影响较大。在空间上,植被LAI在春、冬季整体较小,空间分布差异也较小,仅在流域边缘山区林地覆盖区稍大,其余大片区域LAI值很低,且分布比较均一;夏、秋季LAI较大,空间分布差异也较大,其空间分布主要与流域内土地覆盖类型有关     

Estimation of the Relationship between Environment Heterogeneity and Distribution of Birds in Western Siberia

The results of censuses of 335 bird species and estimation of environmental factors in 1163 habitats located in undeveloped areas of the Western Siberian Plain were analyzed. The data for analysis were obtained from the databank of the Laboratory of Zoological Monitoring of the Institute of Animal Ecology and Systematics (Siberian Division, Russian Academy of Sciences). The material was collected in the first half of summer (between May 16 and July 15) in 1936–1938 and 1959–1999 (mostly beginning from 1967). A learning sample (863 variants) was used to approximate the abundance of each species with respect to each factor (including calculation by the principal-component method), and the approximation was integrated with respect to all these factors. The approximation coefficients were used to make a prognosis of species abundance based on the values of environmental factors in the control sample (300 variants). For the 50 most prevalent species, accounting for more than 80% of total bird abundance, the values of explained variances of approximation and prognosis averaged 53.5 (r = 0.73) and 47% (r = 0.68), respectively.     

长江中下游流域旱涝急转时空演变特征分析

基于长江中下游流域75个雨量站1960~2012年的日降水资料,通过定义长、短周期旱涝急转指数,全面地分析了长江中下游流域旱涝急转的趋势变化和时空分布特征。研究结果表明:(1)长周期旱涝急转表现为以涝转旱事件为主,且存在由旱涝急转事件向全旱或全涝事件过渡的趋势,短周期的旱涝急转发生频率较高的也是涝转旱事件;(2)长江中下游北岸多发生旱转涝事件,南岸则多发生涝转旱事件;(3)1998年和2011年6~7月短周期高强度旱转涝事件发生在长江北岸,涝转旱事件发生在南岸地区;5~6月与7~8月旱涝急转事件强度分布则呈相反状态;(4)总体来说,长、短周期涝转旱频次呈现不断减小的趋势,旱转涝有轻微增加的趋势。7~8月则较为特殊,湘江流域涝转旱有增加的趋势,洞庭湖地区涝转旱显著增加,此研究结果可以为长江中下游流域防洪抗旱工作提供一定的依据。     

Reconstruction of May–June precipitation in the territory of Bashkiria based on Scots pine tree-ring data from the Bugulma–Belebey Upland

The relationship between Scots pine (Pinus sylvestris L.) tree-ring width and temperature and precipitation was analyzed in pine forests on the Bugulma–Belebey Upland, Bashkiria. A close correlation between tree-ring width and the current spring–summer precipitation was revealed. On this basis, a reconstruction of May–June precipitation in the period from 1860 to 1994 was made.     

长江流域极端降水过程事件的年内分布特征

使用长江流域142个站1960～2009年逐日降水量资料,通过定义度量极端降水过程时空聚集程度的参数--极端降水过程事件聚集度和聚集期,并采用主成分分析、Morlet小波分析方法,研究了长江流域极端降水过程事件的年内分布特征。结果表明：长江流域上游极端降水过程事件主要聚集在7月上旬,出现相对比较集中,且聚集度和聚集期年际变化小;中下游则主要聚集在5月中旬至6月下旬,出现比较分散,聚集度和聚集期年际变化相对较大。极端降水过程事件聚集度和聚集期的主要空间异常模态分别表现为东南与西北反向和南北反向的变化特征;其区域平均序列分别呈上升和下降趋势,并分别在13 a和10 a尺度上周期震荡明显,表明长江流域极端降水过程事件的发生有趋于集中和提早趋势     

1961～2018年河南省暴雨初终日和暴雨日数的时空变化规律分析

利用1961～2018年河南省111个气象站逐日降水资料,采用气候倾向率、相关分析和多元逐步回归等数理统计方法,分析了河南省暴雨初终日和暴雨日数的时空变化规律。结果表明:(1)河南省各站平均暴雨初日为5月19～7月16日,最早暴雨初日为1月28日～5月25日,均由南向北明显推迟,由西向东明显提前,由平原向山区明显推迟。(2)河南省各站平均暴雨终日为8月5日～8月30日,最晚暴雨终日为9月9日～11月29日,均由南向北明显日期提前,由西向东明显推迟,由平原向山区最晚暴雨终日明显提前。(3)河南省各站年平均暴雨日数为0.7～4.3天,由南向北明显减少,由西向东明显增多,由平原向山区明显减少。(4)河南省平均暴雨初日和平均暴雨终日均有提前趋势,气候倾向率分别为1.2和0.2 d·(10 a)~(-1);平均暴雨日数呈阶段性变化,特别是2000年以后呈明显减少趋势;各站暴雨初日、暴雨终日和暴雨日数的气候倾向率分别在-9.3～9.3、-2.4～5.4和-3.0～3.2 d·(10 a)~(-1)之间,但仅有少数站点通过显著性水平检验。     

金华旱涝趋势统计分析

根据对旱涝自身变化及其与太阳黑子活动，厄尔尼诺事件关系的分析，，得出了金华旱涝趋势的几点认识：（1）在未来的十几年之内，金华站将从涝年占优势的阶段转入旱年占优势的阶段；（2）在太阳黑子活动22年的磁周期转变年前后，金华站3年平均年降水量明显偏多；（3）在春季型厄尔尼诺事件的当年和夏季型厄尔尼诺事件的次年，金华站年降水量偏多；（4）厄尔尼诺事件的结束时间若超过5月1日，那么次年金华站年降水量偏多；（5）厄尔尼诺事件的强度越大，对金华站年降水量的影响也越大；（6）在太阳黑子活动22年磁周期转变年前后的厄尔尼诺事件的次年，金华站年降水量明显偏多。这些认识对长期及超长期的旱涝趋势预测具有重要的现实意义。     

Climate changes and overstory recruitment of larch at the northern timberline in the Yamal Peninsula

Studies on overstory recruitment of the Siberian larch (Larix sibirica Ledeb.) in open larch forests depending on the time of seedling establishment (1880–1980) have been performed in the northern timberline ecotone on the Yamal Peninsula. Two periods of active larch establishment have been revealed: from 1900 to 1935 and from 1950 to 1970. A comparison of these data with the results of instrumental observations on temperature and precipitation has shown that the overstory recruitment of larch in valleys of northern rivers is largely dependent on July air temperatures in the first years of tree life, when seedlings grow 10–20 cm high.     

江汉平原小麦开花前降水分布特点及同期渍害的产量效应

江汉平原小麦生长期易受渍害导致减产。在系统分析1983~2012年江汉平原腹地荆州市小麦生育期降水分布特点的基础上,于2011~2012年度及2012~2013年度,以郑麦9023为试验材料,通过田间试验与盆栽试验相结合的方法,分别在拔节期及孕穗期进行渍水处理,探讨其对株高、旗叶光合速率、叶片黄化进程的影响及其与干物质积累量和籽粒产量的关系。结果表明：江汉平原1983~2013年小麦拔节期至孕穗期1/3以上年份同期降水量在802 mm以上,极限降雨量达1944 mm,即较多年份有渍害风险;进一步研究表明拔节期渍水和孕穗期渍水均导致旗叶光合速率降低,叶片黄化进程加快,其中孕穗期渍水对以上指标的影响大于拔节期;拔节期渍水和孕穗期渍水均导致株高降低、干物质积累量降低,最终籽粒产量显著降低,其中拔节期渍水处理成熟期籽粒产量比对照降低163%,孕穗期渍水处理籽粒产量比对照降低218%。在本试验条件下,拔节期渍水处理和孕穗期渍水处理均导致小麦植株各种光合指标降低,最终干物质积累量和籽粒产量均显著降低,且孕穗期渍水处理对产量等的影响大于拔节期渍水处理     

Comparative studies on the concentrations of some elements in the urban air particulate matter in Lodz City of Poland and in Milan,Italy

Urban air particulate matter (APM) was collected at two sampling sites in the city of Lodz, Poland in March, May and July 2001. The concentrations of several trace elements (TEs) as well as heavy metals were determined by neutron activation analysis (NAA). It was found that for many elements, the contribution of the blank values arising from the filtering material is very high, especially for glass fiber filters. The results obtained for Lodz were compared to those obtained for Milan, Italy. The data of Lodz are, in general, lower than those found in Milan downtown in the winter season. The influence of three coal-fired power plants located within the city of Lodz on the concentration of trace elements in APM was also considered.     

Population status of Indian Chinkara in Cholistan Game Reserve,Punjab, Pakistan

A population study of Indian Chinkara Gazella bennettii was conducted during September 2006 to July 2007 in Cholistan Game Reserve. The estimated population density was 0.16 Chinkara/km². The observed group size varied from 1 to 16 heads. The observed male to female sex ratio during September/October, February/March and July was 1: 1.15, 1: 2.31, 1: 2.33 respectively.     

Growth and potential reproduction of <Emphasis Type="Italic">Poa crymophila</Emphasis> in response to season precipitation shortage in the Eastern Tibetan Plateau,China

The growing season in 2006 existed a quite less precipitation than previous years in the eastern of Tibetan Plateau, China. In order to explore the response strategies of the grass to drought year, the variations of growth and potential reproduction of Poa crymophila between rich (2005) and poor rainfall year (2006) were studied. Reproductive shoot biomass, above- and below-ground biomass pronounced decreased in the poor rainfall year, but the ratio of above-/below-ground biomass and vegetative shoot biomass increased. Carbon content in inflorescence increased significantly in 2006, but decreased significantly in root. Nitrogen contents and the C/N ratios in plant components were not significantly different. Sexual reproduction in 2005 and 2006 was not different. Season precipitation shortage could result in the higher mortality of vernal budding shoots or tillers. The results suggested that P. crymophila response to poor rainfall year (drought) by a smaller plant body, allocating more proportional biomass to above-ground, altering more carbon to inflorescence, and altering its reproductive way to sexual.     

Radioactivity in surface air and precipitation in Japan after the Chernobyl accident

Radioactive plumes from the Chernobyl reactor accident first passed over Japan on 3 May 1986. Measurements of ¹⁰³Ru, ¹³¹I and ¹³⁷Cs in rainfall and airborne dust collected at Chiba near Tokyo show that, in fact, at least two or more kinds of plume arrived during May. Their altitudes were calculated to be about 1500 m in early May and 6300 m in late May.Radionuclides detected in 33 precipitation samples collected by the network of prefectural radiation monitoring stations from 1 to 22 May were ⁷Be, ⁸⁹Sr, ⁹⁵Sr, ⁹⁵Zr, ⁹⁵Nb, ¹⁰³Ru, ¹⁰⁶Ru, ^110mAg, ¹²⁵Sb, ^129mTe, ¹³¹I, ¹³²Te, ¹³²I, ¹³⁴Cs, ¹³⁶Cs, ¹³⁷Cs, ¹⁴⁰Ba, ¹⁴⁰La, ¹⁴¹Ce and ¹⁴⁴Ce, the measurements being made using germanium detectors and low-background GM counters after radiochemical separation. The radiation was characterized by higher levels of the volatile nuclides, such as ¹⁰³Ru (in the form of RuO₂), ¹³²Te, ¹³¹I and ¹³⁷Cs, than fallout levels in nuclear weapons testing, and by activity ratios of 0·48 and 14 for, respectively, ¹³⁴Cs/¹³⁷Cs and ⁸⁹Sr/⁹⁰Sr, as on 26 April. The fallout activity was higher in northwestern Japan, the average depositions of ⁹⁰Sr and ¹³⁷Cs in Japan from 1 May (or 30 April) to 22 May being 1·4 Bq m⁻² and 95 Bq m⁻², inventories which are 14 and 550 times higher than the pre-Chernobyl values.     

2016年湖北省梅雨期暴雨特征及灾情影响分析

通过对2016年湖北省梅雨期降雨量特征及其与灾情之间的关系进行分析,得到承灾体与雨量的关系及暴雨致灾阈值。结果表明,梅雨期6轮降水灾度均在3以上,6月30～7月6日的暴雨过程灾度高达8。不同承灾体（受灾人口、倒损房屋、受灾面积）与直接经济损失均为正相关,其中倒损房屋最高,达0.9以上。灾情发生阈值日最大降雨量和过程雨量分别为35 mm和50 mm。过程降雨量和有效降雨指数与灾情的相关性较好,大于0.5。承灾体中死亡人口集中区域与降水量大值区对应,分散区域与局地短时强降雨有关;而农作物绝收面积在降雨强度指数相当或偏低时,降雨叠加效应会促使其占比增加。 关键词： 梅雨期;暴雨;过程降雨量;灾情     

成都未来气候变化趋势的R/S分析

运用R/S分析法,对1951～2002年成都的平均值气温、极端气温值及降水累积值进行了计算分析。研究表明,成都未来气候变化趋势与过去50年来的变化趋势有着很好的自相似性。今后成都将继续变暖。依平均气候倾向率,未来10年,年平均气温将升高0.25°C,年平均最低气温将升高0.14 °C,年平均最高气温将升高0.04 °C,年极端最低气温将升高0.54 °C,年极端最高气温将升高0.13 °C。其中,年平均气温、年平均最低气温和年平均最高气温升高趋势的持续性强度很强。成都未来降水量将继续减少。未来10年的年降水量将减少45.2 mm,并且这种减少趋势具有很强的持续性强度。     

Modeling Carbon and Water Budgets in the Lushi Basin with Biome-BGC

Abstract

In this article, annual evapotranspiration (ET) and net primary productivity (NPP) of four types of vegetation were estimated for the Lushi basin, a subbasin of the Yellow River in China. These four vegetation types include: deciduous broadleaf forest, evergreen needle leaf forest, dwarf shrub and grass. Biome-BGC—a biogeochemical process model was used to calculate annual ET and NPP for each vegetation type in the study area from 1954 to 2000. Daily microclimate data of 47 years monitored by Lushi meteorological station was extrapolated to cover the basin using MT-CLIM, a mountain microclimate simulator. The output files of MT-CLIM were used to feed Biome-BGC. We used average ecophysiological values of each type of vegetation supplied by Numerical Terradynamic Simulation Group (NTSG) in the University of Montana as input ecophysiological constants file. The estimates of daily NPP in early July and annual ET on these four biome groups were compared respectively with field measurements and other studies. Daily gross primary production (GPP) of evergreen needle leaf forest measurements were very close to the output of Biome-BGC, but measurements of broadleaf forest and dwarf shrub were much smaller than the simulation result. Simulated annual ET and NPP had a significant correlation with precipitation, indicating precipitation is the major environmental factor affecting ET and NPP in the study area. Precipitation also is the key climatic factor for the interannual ET and NPP variations.     

Importance of atmospherically deposited nitrogen to the annual nitrogen budget of the Neuse River estuary,North Carolina

Wet deposition of nitrogen, as NH(4)(+), NO(3)(-), and organic N, contributes up to 50% of the total externally supplied or 'new' N flux to the Neuse River Estuary (North Carolina). Excessive nitrogen (N) loading to N-sensitive waters such as the Neuse River Estuary has been linked to changes in microbial and algal community composition and function (harmful algal blooms), hypoxia/anoxia, and fish kills. In a 4-year study from July 1996 to July 2000, the weekly wet deposition of NH(4)(+), NO(3)(-), and dissolved organic N was calculated, based on concentration and precipitation measurements, at 11 sites on a northwest-southeast transect in the watershed. Data from this period indicate that the annual mean total wet atmospherically deposited (AD)-N flux was 11 kg ha(-1) year(-1). Deposition was fairly evenly distributed between nitrate, ammonium, and organics (32%, 32%, and 36%, respectively). Seasonally, the summer (June-August) months contained the highest weekly wet total N deposition; this trend was not driven by precipitation amount. Estimates of watershed N retention and in-stream riverine processing revealed that the AD-N flux contributed an estimated 20% (range of 15-51%) of the total 'new' N flux to the estuary, with direct deposition of N to the estuary surface accounting for 6% of the total 'new' N flux. This study did not measure the dry depositional flux, which may double the contribution of AD-N to the estuary. The AD-N is an important source of 'new' N to the Neuse River Estuary as well as other estuarine and coastal ecosystems downwind of major emission sources. As such, AD-N should be included in effective nutrient mitigation and management efforts for these N-sensitive waters.     

基于MODIS叶面积指数的大渡河流域作物生态需水研究

利用大渡河流域30年的气象资料,采用FAO最新修订的Penman Monteith方程计算流域参考作物腾发量。同时获取大渡河流域2007年内45期MODIS LAI数据,根据叶面积指数与作物系数的经验关系得到作物系数2007年年内的变化情况,利用GIS中的Zonalmean函数对大渡河流域平均作物生态需水量年内变化进行估算。在根据年干燥度进行干湿区划的基础上,对作物生态需水来源进行分析。结果表明：大渡河流域2007年内生态需水总量为6188 mm,月平均值为516 mm。其中作物生态需水量年内变化过程为夏季最高,占全年总需水量的357%,春季、秋季、冬季生态需水量逐渐减少分别占全年总量的304%、201%和138%。在雨季,降水完全可以满足流域生态需水量,降水是这一时期生态需水的主要来源。在旱季,半干旱区的生态需水来源受区域干燥度的影响较大,越干燥的地区降水占作物生态需水百分比就越高;半湿润区作物生态需水来源仍以降水为主,但降水占作物生态需水百分比除了受区域干燥度影响之外,可能还受到其它因素如：陡坡耕地占耕地总面积的比例的影响。