长江中下游流域旱涝急转事件特征分析及其与ENSO的关系

基于长江中下游流域75个雨量站1960-2015年的日降水资料,通过对原有的旱涝急转指数加以改进,定义了日尺度旱涝急转指数（Dry-Wet Abrupt Alternation Index, DWAAI）,全面分析长江中下游流域夏季（5-8月）旱涝急转事件的时空演变特征,并讨论了旱涝急转事件与事件发生前太平洋海表温度的关系。结果表明：① 改进的DWAAI综合考虑了事件前后期旱涝差异与急转快慢程度,筛选事件更加全面。② 总体来说,自20世纪60年以来,流域内发生旱涝急转事件的区域范围越来越广,事件频率和强度均具有逐年增长趋势。旱涝急转事件主要发生在5月和6月,且汉江水系、中游干流区间、洞庭湖水系北部和鄱阳湖水系西北部地区为事件高发区。③ 旱涝急转事件与事件发生前Nino 3.4区域海温持续异常偏低存在一定关系。在发生时间上,La Ni?a现象具有一定的先兆作用,41.04%的事件发生在La Ni?a现象衰亡期或现象结束后8个月内;在事件强度上,流域内站点的DWAAI与事件发生前第1~6个月的Nino 3.4区域海温异常值存在显著的负相关性,尤其是在鄱阳湖水系和中游干流区间,二者负相关性最强。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。     

基于气象旱涝指数的旱涝急转事件识别方法

基于长江流域212个气象站点1961-2017年的日降水资料,借助标准化加权平均降水指数（SWAP）,结合多门槛游程理论,提出一种识别旱涝急转事件的新方法。方法应用于旱涝急转事件高发的长江流域,分别从典型站点旱涝事件分析、区域典型旱涝急转事件分析、旱涝急转事件时空分布规律分析等角度,探讨了长江流域1961-2017年旱涝急转事件规律。结论显示：①SWAP指数对于旱涝事件具有良好的识别能力。②聚类方法可聚合相似旱涝急转事件,2011年长江中下游旱涝急转事件中干旱事件占主导地位,持续时间远长于洪涝事件。③ 长江流域旱涝急转事件呈现明显的区域规律：上游发生频率较低,中下游偏高;此外,长江流域多数分区近期旱涝急转事件发生频率呈现上升趋势。研究结果表明,基于SWAP指数并结合多门槛游程理论的方法能够比较准确地识别旱涝急转事件,可进一步应用于旱涝急转事件的预测及评估中。     

长江中下游阻隔性河段作用机理初步研究（英文）

Alluvial channel has always adjusted itself to the equilibrium state of sediment transport after it was artificially or naturally disturbed.How to maintain the equilibrium state of sediment transport and keep the river regime stable has always been the concerns of fluvial geomorphologists.The channel in the middle and lower reaches of the Yangtze River is characterized by the staggered distribution of the bifurcated river and the single-thread river.The change of river regime is more violently in the bifurcated river than in the single-thread river.Whether the adjustment of the river regime in the bifurcated river can pass through the single-thread river and propagate to the downstream reaches affects the stabilities of the overall river regime.Studies show that the barrier river reach can block the upstream channel adjustment from propagating to the downstream reaches;therefore,it plays a key role in stabilizing the river regime.This study investigates 34 single-thread river reaches in the middle and lower reaches of the Yangtze River.On the basis of the systematic summarization of the fluvial process of the middle and lower reaches of the Yangtze River,the control factors of barrier river reach are summarized and extracted:the planar morphology of single-thread and meandering;with no flow deflecting node distributed in the upper or middle part of the river reach;the hydraulic geometric coefficient is less than 4;the longitudinal gradient is greater than 12‰,the clay content of the concave bank is greater than 9.5%,and the median diameter of the bed sediment is greater than 0.158 mm.From the Navier-Stokes equation,the calculation formula of the bending radius of flow dynamic axis is deduced,and then the roles of these control factors on restricting the migration of the flow dynamic axis and the formation of the barrier river reach are analyzed.The barrier river reach is considered as such when the ratio of the migration force of the flow dynamic axis to the constraint force of the channel boundary is less than 1 under different flow levels.The mechanism of the barrier river reach is such that even when the upstream river regime adjusts,the channel boundary of this reach can always constrain the migration amplitude of the flow dynamic axis and centralize the planar position of the main stream line under different upstream river regime conditions,providing a relatively stable incoming flow conditions for the downstream reaches,thereby blocking the upstream river regime adjustment from propagating to the downstream reaches.     

泾河流域气候变化及其与ENSO的关系

ENSO(厄尔尼诺-南方涛动)常引起大气环流的改变并导致气候异常,探讨区域气候变化与ENSO的关系有助于理解区域水文等各方面的变化.通过Mann-Kendall、相关性检验和小波分析等方法.研究了1960-2005年泾河流域气候变化及其与ENSO的关系.结果表明,1960-2005年,泾河流域气候趋向暖干,且这种趋势在90年代以来愈加显著.气候变化与ENSO有显著的关系.降水对ENSO的响应程度强于温度;降水可能受南方涛动的影响比较大,而温度可能受海表温度的影响较多;ENSO暖事件对泾河流域气候变化的影响可能大于冷事件.     

宁夏降水变化及其与ENSO事件的关系

分析1959~2001年的月降水数据发现:20世纪60~80年代宁夏降水有较明显的干旱趋势,但90年代降水较80年代有所增加。功率谱分析表明,ENSO和宁夏降水具有一致的变化周期,即14年、3.75年、准2年和1.5年。宁夏降水对EL Nino事件达到最显著响应需要滞后2~4个月,而对LA Nina事件的响应比对EL Nina迅速,只需滞后1~2个月便达到最显著响应。ENSO对宁夏不同季节降水的影响差异很大。EL Nino发生4个月后,春、夏、秋三个季节降水都偏少,但冬季降水却是增加了。LA Nina发生1个月后,夏、秋、冬三个季节降水都偏多,但春季降水减少了。EL Nino事件发生期间,宁夏年降水偏少28 mm,占常年降水量的10%,而LA Nina发生期间,年降水偏多24 mm,占年降水量9%。     

长江中下游流域自然保护地空间分布及其与人类活动强度关系研究

以2015年土地利用类型数据为基础,计算长江中下游流域人类活动强度,采用最邻近指数、地理集中指数和不均衡指数分析研究区自然保护区、风景名胜区等六类国家级自然保护地分布特征,并定量揭示保护地空间分布与人类活动强度的关系,旨在为长江中下游流域建立基于人类活动强度的各类自然保护地管控策略提供科学依据。结果表明：1）人类活动高、较高、中、较低和低强度带在研究区的占比分别为3.74%、9.83%、14.98%、30.81%和40.63%;高等级强度带主要分布在长江三角洲平原、江汉平原等平原区,低等级强度带主要分布在秦岭山区、武陵山区等山地丘陵区。2）湿地公园、森林公园、风景名胜区和地质公园的空间分布类型为均匀型,水利风景区和自然保护区为凝聚型;六类保护地在各人类活动强度带空间分布不均衡。3）湿地公园、森林公园、水利风景区、自然保护区、风景名胜区和地质公园分别在中、较高、高、低、较低和低强度带密度最大;在高等级强度带“人地”矛盾更突出,应加强对自然保护地的保护力度和人类活动管控,尤其针对湿地公园、森林公园和水利风景区。     

ENSO事件与山西气候的关系

通过搜集和整理1955-2008年大同、河曲、原平、太原、阳泉、介休、离石、长治、临汾、运城等地的气象资料,分析了山西的降水量、气温与ENSO事件的关系,研究了ENSO事件对山西气候的影响。结果表明,1955-2008年ENSO事件呈现出起伏波动的特点,1980年以后波动趋势更为剧烈;大致可分为两个阶段:1955-1980年为第1阶段,ENSO冷事件的频次略高于暖事件,但强度更大;1981-2008年为第2阶段,ENSO暖事件的频次和强度均高于冷事件。ENSO事件对山西降水量的影响表现十分明显,ENSO暖事件当年降水量明显偏低,次年降水量明显增加或达到最高趋势明显。ENSO冷事件年全省降水量均明显增加。ENSO事件对山西气温的影响也十分显著,ENSO暖事件年大多表现为气温偏高或升温,ENSO冷事件年一般表现为气温偏低或降温。     

1901–2013年中亚季节降水时空变化特征及其与ENSO的关系（英文）

The vulnerable ecosystem of the arid and semiarid region in Central Asia is sensitive to precipitation variations. Long-term changes of the seasonal precipitation can reveal the evolution rules of the precipitation climate. Therefore, in this study, the changes of the seasonal precipitation over Central Asia have been analyzed during the last century(1901–2013) based on the latest global monthly precipitation dataset Global Precipitation Climatology Centre(GPCC) Full Data Reanalysis Version 7, as well as their relations with El Ni?oSouthern Oscillation(ENSO). Results show that the precipitation in Central Asia is mainly concentrated in spring and summer seasons, especially in spring. For the whole study period, increasing trends were found in spring and winter, while decreasing trends were detected in summer and fall. Inter-annual signals with 3–7 years multi-periods were derived to explain the dominant components for seasonal precipitation variability. In terms of the dominant spatial pattern, Empirical orthogonal function(EOF) results show that the spatial distribution of EOF-1 mode in summer is different from those of the other seasons during 1901–2013. Moreover, significant ENSO-associated changes in precipitation are evident during the fall, winter, spring, and absent during summer. The lagged associations between ENSO and seasonal precipitation are also obtained in Central Asia. The ENSO-based composite analyses show that these water vapor fluxes of spring, fall and winter precipitation are mainly generated in Indian and North Atlantic Oceans during El Ni?o. The enhanced westerlies strengthen the western water vapor path for Central Asia, thereby causing a rainy winter.     

洞庭湖流域降水同位素与ENSO关系研究

基于洞庭湖流域内长沙市2010年1月至2012年12月降水事件、GNIP(Global Network for Isotopes in Precipitation)长沙站1988~1992年月降水同位素资料及ENSO（厄尔尼诺/拉尼娜和南方涛动）的2个常用指标（南方涛动指数SOI和Nino3区海面温度SST）,分析了流域降水同位素与ENSO关系。结果表明：洞庭湖流域降水中δ¹⁸O与降水量、气温在日、月尺度上均呈负相关且只有月度上与降水量的负相关不显著。洞庭湖流域降水中δ¹⁸O与ENSO的SST指标则呈显著正相关。ENSO对洞庭湖流域降水同位素的影响机制可能如下：春季,La Nina年源自西太平洋的东南风强盛,其转向为西南风的区域达到印度洋,而El Nino年,东南风转向为西南风的发生区域位于印度洋以东,前者有利于挟带印度洋远源水汽向中国东部区域输送,进而造成降水同位素的贫化;夏季,La Nina年印度洋水汽输送在中国南海转为经向继而向北延伸,而El Nino年,源自印度洋的水汽沿纬向穿过南海,在东海转向往北延伸,后者有利于挟带西太平洋的近源水汽输送到中国东部季风区,进而引起降水同位素的富集。     

1368-1911年宝鸡地区旱涝灾害链的时空演变特征分析（英文）

Based on the collation and statistical analysis of flood and drought information in Baoji area from 1368 to 1911, and in the context of climate change, we investigated the spatio-temporal evolution characteristics of drought and flood disaster chains in this area during the Ming and Qing dynasties using the methods of moving average, cumulative anomaly and wavelet analysis. The results are as follows:(1) We found a total of 297 drought and flood events from 1368 to 1911 in Baoji. Among these events, droughts and floods occurred separately 191 and 106 times, which accounted for 64.31% and 35.69% of the total events, respectively.(2) We observed distinct characteristics of flood and drought events in Baoji in different phases. The climate was relatively dry from 1368 to 1644. A fluctuant climate phase with both floods and droughts occurred from 1645 to 1804. The climate was relatively wet from 1805 to 1911. Moreover, we observed a pattern of alternating dry and wet periods from 1368 to 1911. In addition, 3 oscillation periods of drought and flood events occurred around 70 a, 110 a and 170 a, which corresponded to sunspot cycles.(3) We also observed an obvious spatial difference in drought and flood events in Baoji. The northern and eastern parts of Weihe River basin were regions with both frequent droughts and floods.(4) The sequential appearance of drought and flood disaster chains in Baoji from 1368 to 1911 was in response to global climate change. Since the 1760s, global climatic deterioration has frequently led to extreme drought and flood events.     

拉市海流域生境质量空间变化及其评价（英文）

生境质量变化监测与评价对于生物多样性保护意义重大。为探明云南省拉市海流域的生境变化情况,本文基于SPOT卫星影像提取云南拉市海流域2000年与2015年两期土地利用数据,运用InVEST模型对流域生态退化度、生境质量和生境稀缺性进行评价,采用空间统计方法定量分析了2000–2015年的空间动态变化。结果表明:在研究的15年间,拉市海地区生境退化区总体较少,数量上明显减少,生态退化度呈阶梯式下降;总体上生境质量保持良好并有所提升,少部区域生境质量降低;耕地生境稀缺性增加,人地矛盾突出。拉市海生境质量提升的原因可归结为三个方面:1)当地自2000年起实行的退耕还林政策得到了很好的落实并取得了显著成效,伐木毁林等森林破坏基本杜绝,生态环境得到了恢复;2)较高的林地占比,赋予当地较高生境适宜性本底;3)当地旅游经济的发展,使生态优势转化为经济优势,大幅提高了居民经济收入水平和生活水平;同时生态资源红利的持续发挥,增加了居民生态保护的积极性,保障了森林、湿地及珍贵动植物资源保护,使生态退化减弱,生境质量提升。同时,必须注意到当地人地矛盾的加剧。为持续减轻生态退化,促进生境质量的提升,还需推动生态经济发展,进一步提高居民收入水平,减少生产生活对第一产业的依赖,缓解人地矛盾,从而使流域经济和生态协同发展,保障可持续发展目标。     

藏南羊卓雍错流域水化学状况及其形成机制（英文）

The hydrochemistry of alpine lakes reflects water characteristic and its response to climatic change. Over 300 water samples had been collected from 52 sites of 5 lakes and 7 inflowing rivers in the Yamzhog Yumco Basin, South Tibet, during 2009–2014, basing which the hydrochemical regime and its mechanism were analyzed along with the adoption of hydrological investigations in 1979 and 1984 as well. Results revealed that the waters were hard with weak alkalinity for the Yamzhog Yumco Basin. Most of them were fresh, and the rest were slightly saline. The hydrochemical types of 5 lakes(i.e., Lake Yamzhog Yum Co, Puma Yum Co, Bajiu Co, Kongmu Co, and Chen Co) were SO_4~(2–)–HCO_3~––Mg~(2+)–Na~+, HCO_3~–– SO2–2+4–Mg~(2+)–Ca, SO_4~(2–)–Mg~(2+)–Na~+, SO_4~(2–)–HCO_3~––Ca~(2+), and SO_4~(2–)–Na~+–Mg~(2+)–Ca~(2+), respectively. As for rivers, HCO_3~– and SO_4~(2–) were the major anions, and Ca~(2+) was the dominant cation. Lake Yamzhog Yum Co, the largest lake in the basin, exhibited remarkable spatial variations in hydrochemistry at its surface but irregular changes with depth. The weathering of evaporates and carbonates, together with evaporation and crystallization, were the major mechanisms controlling the hydrochemistry of waters in the Yamzhog Yumco Basin. Global warming also had significant impacts on hydrochemical variations.     

实施流域生态管理的长江中下游湿地保护探讨

长江中下游地区湿地分布广泛且类型多样,是我国淡水湖泊分布最集中和最具有代表性的地区。为了从根本上解决长江中下游湿地利用面临的问题,实现湿地资源的可持续利用,保护湿地环境,解决区内上、下游用水的供需矛盾,实现水资源的优化配置,调动区域湿地保护的积极性和主动性,有必要遵循湿地流域分布规律,应用流域生态学最新理论与实践成果,进行流域生态管理。一方面,要从流域角度处理好几大江湖关系、蓄泄关系、湖垸关系和山湖(河)关系等;另一方面,在流域内建立统一协调机制,对流域湿地进行保护与合理利用、合理布局和统一规划;同时在保护的前提下,科学合理地利用长江中下游湿地资源,开拓新的生产力。     

黑河流域气温的稳定性与长程相关性（英文）

Air temperature(AT) is a subsystem of a complex climate.Long-range correlation(LRC) is an important feature of complexity.Our research attempt to evaluate AT’s complexity differences in different land-use types in the Heihe River Basin(HRB) based on the stability and LRC.The results show the following:(1) AT’s stability presents differences in different land-use types.In agricultural land,there is no obvious variation in the trend throughout the year.Whereas in a desert,the variation in the trend is obvious: the AT is more stable in summer than it is in winter,with Ta ranges of [8,20]°C and SD of the AT residual ranges of [0.2,0.7],respectively.Additionally,in mountainous areas,when the altitude is beyond a certain value,AT’s stability changes.(2) AT’s LRC presents differences in different land-use types.In agricultural land,the long-range correlation of AT is the most persistent throughout the year,showing the smallest difference between summer and winter,with the Hs range of [0.8,1].Vegetation could be an important factor.In a desert,the long-range correlation of AT is less persistent,showing the greatest difference between summer and winter,with the Hs range of [0.54,0.96].Solar insolation could be a dominant factor.In an alpine meadow,the long-range correlation of AT is the least persistent throughout the year,presenting a smaller difference between summer and winter,with the Hs range of [0.6,0.85].Altitude could be an important factor.(3) Usually,LRC is a combination of the Ta and SD of the AT residuals.A larger Ta and smaller SD of the AT residual would be conducive to a more persistent LRC,whereas a smaller Ta and larger SD of the AT residual would limit the persistence of LRC.A larger Ta and SD of the AT residual would create persistence to a degree between those of the first two cases,as would a smaller Ta and SD of the AT residual.In addition,the last two cases might show the same LRC.     

长江经济带经济增长与资源环境的协同效应及其驱动力分析（英文）

基于人口、资源、环境与经济、社会协调发展的视角,引入生态系统服务价值评价方法构建资源环境成本核算模型以及经济增长与资源环境的协调发展度、相对协调发展度模型,对长江经济带区域经济增长与资源环境的协同效应进行分析、并以偏最小二乘回归方法对其驱动因素进行解析。计算出1983–2012年长江经济带7省2市资源环境成本由4736.55×1012元攀升至15 359.45×1012元、占全国同期比重由31.1%降至19.7%,协调发展度由0.295升至1.506,各时段相对协调发展度均高于全国平均水平;1983、1993、2003年3个时段驱动长江经济带区域经济增长与资源环境协调发展的主要因素是资源环境成本相对较低,研究区对推动我国经济、社会协调发展均做出较大贡献;2012年以后随着我国第一、三产业增加值整体上持续增加,长江经济带的比较优势趋于弱化。未来,长江经济带有关省市应积极完善主体功能区规划实施细则,抓住机遇持续推进产业结构调整,通过各个层面实施生态恢复补偿、提高资源利用效率、降低环境损失成本等提高经济发展质量,进一步促进区域经济增长与资源、环境协调发展。     

北京城区交通时间可达性测度及其空间特征分析（英文）

Construction of road infrastructure is fundamental to city operation and development, as well as an important pathway and focus in physical urban-rural integration. The long-term implementation of a system of ring roads plus radiating roads in Beijing has strongly impacted urban infrastructure construction and space-time accessibility. Particularly, recent rapid growth of private car ownership in Beijing has imposed greater loads on its road system, seriously hampering urban commuting efficiency and negatively impacting quality of life. To address such challenges and enhance the rapid development of transport infrastructure, Beijing has accelerated rail transit construction since 2008 in an effort to improve commuting capacity. This paper aims to measure time accessibility and its spatial characteristics in urban areas of Beijing by applying a comprehensive method that combines vector and raster attribute data generated from road network and subway transport infrastructure. By using a dual index of accessibility and road density, the study further reveals the features of and differences in spatial accessibility and the construction of road systems in urban areas of the northern and southern parts of Beijing. The findings of this study can provide a scientific basis for future urban planning and road system construction both in general and with respect to Beijing, given its aspirations to become a world city.     

洞庭湖流域各季节旱涝及其与大气环流和关键区海温的关系

利用逐月降水数据和NCEP/NCAR再分析数据,分析了洞庭湖流域春、夏、秋季57年来旱涝异常的年际变化以及典型旱涝异常年份的全球海温分布形势,并利用降尺度和趋势分析方法探究气象因子对ENSO和关键区海温的响应,以加强对流域旱涝前期影响因素的认识.结果表明:1)流域在春、秋季旱涝变化趋势不明显,在夏季较明显地变湿.2)前...     

基于GIS的长江中下游岩浆岩成矿核心时空聚集特征分析及其指示意义

岩浆岩地球化学数据作为地质学研究的重要依据,对于指示元素特征、研究成矿规律至关重要。该文以构建的长江中下游成矿带岩浆岩地球化学数据库为基础,以岩浆岩成矿3个地质时期及其成矿岩体的地理空间分布特征为依据,利用GIS的Ripley′s K函数对不同时期成矿岩体的空间格局进行多距离空间聚类分析,获取成矿岩体的空间聚集尺度,进而利用GIS的核密度分析工具求取3个地质时期的成矿核心及其时空演化特征,并以控矿元素Cu、Au为例展开空间分析,进一步揭示成矿核心区对于成矿预测及科学找矿的重要意义。研究结果表明:1)长江中下游成矿带安徽段3个成矿时期(124～148Ma)的岩浆岩成矿核心呈动态变化,形成一强多弱相结合的成矿核心空间分布格局,空间上成矿核心由铜陵、安庆—贵池矿集区向庐枞、宁芜盆地方向扩展,时间上成矿聚集程度逐渐变弱;2)以铜金成矿为主的第一时期,铜金等成矿岩体及其形成的重要多金属矿床受长江深断裂构造控制,安徽段主要集中于长江深断裂以南4～28km处的铜陵、安庆—贵池等断隆区,其Cu、Au含量高值位于成矿核心东、西两侧的扇形带上,该区域是铜金等多金属矿床找矿的有利地段。     

火山爆发与ENSO事件的联系

ENSO(EI Nino/Southern Oscillation)现象是海洋与大气相互作用的一个突出表现。ENSO 事件发生时,赤道东太平洋海表温度异常增高,南方涛动指数迅速下降,同时带来全球气候和海洋环境的异常。由于这一事件的出现常常带来严重的气候灾害和世界经济的巨大损失,所以越来越受到气象学家和海洋学家的重视。现在以 ENSO 为中心的海气相互作用的研究已成为当前地球科学中发展最快的领域之一。