Floristic Study of Vascular Plants in Typical Plant Communities in the Middle and Upper Reaches of the Yarlung Zangbo River

[Objective] Species composition and flora of vascular plants in the middle and upper reaches of the Yarlung Zangbo River were analyzed,to provide scientific basis for the estimation and protection of plant diversity,construction of ecological security shelter for the Tibetan Plateau.[Methods] In the middle and upper reaches of the Yarlung Zangbo River,quadrat (line transect) method was applied to investigate the phytocoenoses in sample plots,and relative literature was used to analyze the floristic composition and floristic element of vascular plants in the middle and upper reaches of the Yarlung Zangbo River.[Results]① There are 96 species (including subspecies and variations),69 genera of 35 vascular plant families,accounting for 16.83%,5.48%,1.66% and 11.63%,2.02%,0.31% of total vascular plant families,genera and species in Tibet and China.② There are 24 monotypic-genus families,accounting for 68.57% of the total family number in the local area;22 monotypic-species families,accounting for 62.86% of the total family number in the local area.Local flora shows the characteristics of ancient relict,such as Euphorbiaceae,Rubiaceae,Liliaceae and Ranunculaceae,they are all ancient primitive groups of the third flora and the fourth flora.③ Local vascular plant genera fall into 10 areal types and 8 variations.④ Temperate elements are much more than tropical elements,R/T is 0.19,indicating that vascular plants have typical temperate nature and residual tropical nature.There are only a few endemic genera,but more endemic species to the local area,and these species are closely related,of which there are some transitional species,indicating that local flora is too young to experience more differentiation and specialization.⑤ There are 24 Chinese endemic species,accounting for 25% of total number of species in the local area;among which there are 12 endemic species to Tibet,accounting for 50% of endemic species to China,12.5% of total number of species in the local area.Four key wild plant species are included in the second batch of national key protection.[Conclusions]① There are scarce plant groups in the local area.② Among the obvious advantages,single-genus (species) families possess the absolute advantage,and the flora has ancient origins.③ The local flora has diversified distribution types,and the complicated geographical elements.④ Temperate species possess obvious advantages,and the flora is young.⑤ Rich unique and rare species have high species diversity protection and research value.

Analysis on Landscape Pattern in the Upper and Middle Reaches of Yarlung Zangbo River:Taking Zhongba County,Angren County, Rikaze City as Example

Taking Zhongba County, Angren County, Rikaze City located at the Upper and Middle Reaches of Yarlung Zangbo River as landscape units , this paper studied the difference of the landscape pattern under various degrees of human disturbance in the three areas. The results showed that： the three areas all reflected the same characteristic of landscape pattern in Qinghai-Tibet Plateau, the natural landscapes were in the absolute dominant position. However, from Zhangba to Rikaze, with human disturbance intensity increasing, anthropogenic features of landscapes became more and more outstanding, In Zhongba, the landscape structure appeared to be simpler with coarse grains and a less rich diversity, Conversely, in Rikaze, the landscape showed a complicated shape with finer grains and a relatively richer diversity, This reflected that the impact of human activities to natural landscape behaved a gradually-growing trend from the upper reach to the middle one of Yarlung Zangbo River Basin.

Unsteadiness of COD in the Upper and Middle Reaches of Minjiang River

This paper explores and identifies the rules of the unsteady evolution of COD in the upper and middle reaches of Minjiang River through multi-scale analysis on the weekly COD data for the last six years provided by the Water Quality Monitoring Station,Minjiang River Bridge,Leshan City,Sichuan Province.The results of the wavelet analysis indicate that the COD index oscillates alternatively and differently at each time-scale in an oneyear cycle,and the density of COD,subjected to the runoff volume,the effects of Wenchuan Earthquake and agricultural seeding and industrial construction,etc.,is high in winter and spring,mild in summer and autumn.

The SIA method for spatial analysis of precipitation in the upper-middle reaches of the Yangtze River

Using geographic information system (GIS) techniques and the newest seasonal and annual average precipitation data of 679 meteorological stations from 1971 to 2000, the multiple regressions equations of the precipitation and topographical variables are established to extract the effect of topography on the annual and seasonal precipitation in the upper-middle reaches of the Yangtze River. Then, this paper uses a successive interpolation approach (SIA), which combines GIS techniques with the multiple regressions, to improve the accuracy of the spatial interpolation of annual and seasonal rainfall. The results are very satisfactory in the case of seasonal rainfall, with the relative error of 6.86%, the absolute error of 13.07 mm, the average coefficient of variation of 0.070, and the correlation coefficient of 0.9675; in the case of annual precipitation, with the relative error of 7.34%, the absolute error of 72.1 mm, the average coefficient of variation of 0.092, and the correlation coefficient of 0.9605. The analyses of annual mean precipitation show that the SIA calculation of 3-5 steps considerably improves the interpolation accuracy, decreasing the absolute error from 211.0 mm to 62.4 mm, the relative error from 20.74% to 5.97%, the coefficient of variation from 0.2312 to 0.0761, and increasing the correlation coefficient from 0.5467 to 0.9619. The SIA iterative results after 50 steps identically converge to the observed precipitation.

ANALYSIS OF THE MICROPHYSICAL STRUCTURE OF RADIATION FOG IN XUANEN MOUNTAINOUS REGION OF HUBEI,CHINA

Based on data of radiation fog events in Xuanen, Hubei province, 2010, this paper analyzes the microphysical process and evolution characteristics of radiation fogs with complicated substrate in the upper and middle reaches of the Yangtze River, and compares them with findings in other areas. Results are as follows: radiation fog in Xuanen is evidently weaker in droplet number concentration and liquid water content than land fogs in other areas. Its liquid water content fluctuates obviously, 0.01g/m3 with visibility of 1,000 meters, which is quite different from that in urban areas, but similar to the Nanling Mountains. Bi-modal droplet distribution is likely to occur in Xuanen mountain radiation fog(MRF) events. Statistical analysis shows that the observed droplet size distribution can be piecewise described well by the Gamma distribution. There is a positive correlation between liquid water content, fog droplet concentration and mean radius, especially in the development and dissipation stage. Condensation growth and droplet evaporation are major processes of Xuanen MRF. The dissipation time coincided with the time when the grass temperature reached the peak value, which indicated that dew evaporation is a key role in maintaining Xuanen MRF. In the early stage of dense fog's growth, droplets with diameter of over 20 micrometers can be observed with visibility of800-1,000 m, which might be caused by the transportation of low cloud droplets to earth's surface by turbulence. Big droplets in the initial stage correspond to higher water content, leading to the higher observed value of water content of Xuanen MRF.

长江中上游重要渔业水域环境质量评估

为准确评估长江中上游重要渔业水域水环境质量现状及变化趋势,提高水质评价效率,本研究基于11个水质参数,采用水质指数法(water quality index,WQI)对2006-2021年长江中上游三个重要渔业水域水质进行了综合评价,建立WQI min综合评价模型。结果显示:(1)长江中上游重要渔业水域的水温和高锰酸盐指数呈上升趋势;基于地表水环境质量标准(GB38338-2002),单因素水质评价结果表明监测水域内整体水质处于地表水Ⅴ类水标准,部分年份达劣Ⅴ类,主要污染指标为总氮。(2)通过综合评价方法分析,长江中上游重要渔业水域整体为“良”;2006~2021年长江中上游重要渔业水域水质质量呈逐年改善的趋势,且上游保护区的改善较大。(3)基于WQI方法,确定了长江中上游重要渔业水域的关键水质参数为:总氮、高锰酸盐指数、汞、溶解氧、氨氮、悬浮物以及水温,分别构建了上游保护区、中华鲟保护区以及四大家鱼保护区的WQI_(min)模型;考虑权重和不考虑权重的WQI min模型对比分析表明,考虑权重的WQI min模型的水质评价结果更加准确,该方法可有效评估长江中上游重要渔业水域的水质变化特征并可扩展用于其他水域。

基于水光电力系统时序生产模拟模型的水光优化配比研究

基于考虑系统负荷、新能源发电出力等时序变化特性的时序生产模拟法,建立了水光电力系统时序生产模拟模型;从系统结构性、经济性、灵活性与可靠性方面综合确定最佳水光容量配比,并通过金沙江上游川藏段水光系统验证了模型的合理性。金沙江上游川藏段光伏电站与水电站出力具有较好的年内、日内互补特性;对于2030年水平年,考虑枯期水电留存,913.6万kW水电配套400万kW光伏的方案综合性能更优,其新增非水可再生电量约60亿kW·h。

金沙江上游沙丁麦大型古滑坡发育特征与稳定性评价

沙丁麦古滑坡位于金沙江上游,金沙江断裂的德工—射胆断裂从滑体前部通过,岩体结构破碎,加上区域降雨、人类活动影响,滑坡变形强烈,坡体存在失稳滑动的风险,严重威胁到当地居民生命财产以及金沙江上游重要交通设施等。为探究沙丁麦古滑坡的发育特征及滑坡稳定性等关键问题,本文对沙丁麦古滑坡开展了遥感解译、InSAR形变监测、降雨量数据分析以及滑坡稳定性数值模拟计算等研究,揭示滑坡目前的变形特征,并探讨不同数值模拟工况下的滑坡稳定性。结果表明,沙丁麦古滑坡长约2100 m,宽约1300 m,平均厚度15~20 m,体积为2180×10^(4)~2900×10^(4)m^(3),属于特大型堆积层滑坡。空间上可划分为古滑坡后缘区(I)、古滑坡堆积区(Ⅱ)和强变形区(Ⅲ)三个区域,其中强变形区中包含两个复活变形区(Ⅲ_(1)、Ⅲ_(2))。沙丁麦古滑坡以拉张裂缝、房屋开裂、下错陡坎、局部滑塌等变形现象为主。基于小基线集合成孔径雷达干涉测量(SBAS-InSAR)的监测结果显示,沙丁麦古滑坡地表最大形变速率可达-51.88 mm/a。结合区域降雨数据的分析结果反映滑坡体累计变形量呈“阶跃”式增长,强降雨是影响滑坡堆积体变形的重要因素之一。基于三维快速拉格朗日分析法(FLAC^(3D))的古滑坡稳定性计算结果表明,沙丁麦古滑坡的变形模式为牵引式,天然工况下滑坡整体处于基本稳定状态,坡体形变量较小;在极端暴雨工况下滑坡总体上处于不稳定状态,滑坡体变形表现为拉张、剪切破坏,滑动面贯通并发生整体失稳破坏,从而造成严重危害。

1951—2020年黄河上中游径流变化特征及归因分析

【目的】河川径流是地表重要的水资源,对其变化特征和原因进行解析,是流域水资源科学管理规划的前提。【方法】本文采用Mann-Kendall趋势检验、Pettitt突变检验、Budyko弹性系数法等方法分析了黄河上游和中游近70年(1951—2020年)径流变化的趋势和成因。【结果】(1)1951—2020年黄河上游年降水量呈不显著增加趋势(4.04 mm/(10 a),P> 0.05),中游呈不显著减少趋势(4.90 mm/(10 a),P> 0.05);上游、中游年潜在蒸散发均呈不显著增加趋势(1.77、2.23 mm/(10 a),P> 0.05);(2)黄河上游和中游1980—2020年土地利用/覆盖变化明显,主要表现在林草面积的增加,上游、中游年NDVI分别以0.025/(10 a)、0.042/(10 a)的速率显著增加(P <0.01);(3)1951—2020年,上游和中游年径流量分别以3.46、7.46 mm/(10 a)的速率显著减少(P <0.01),并分别在1986年、1990年发生突变;(4)上游和中游径流对降水变化最为敏感,其次是土地利用/覆盖变化、潜在蒸散发变化,且径流对各影响因子的敏感性逐年增强,即气候和土地利用/覆盖的变化将更容易引起径流的变化;(5)土地利用/覆盖变化是导致黄河上游和中游径流减少的主要原因,其次是降水和潜在蒸散,但各影响因子对径流变化的影响性质和程度在上游和中游不同区间存在一定的差异。其中,上游地区降水、潜在蒸散发、土地利用/覆盖变化对径流的影响性质和程度分别为-14.04%、1.30%、112.73%;中游地区分别为21.54%、3.63%、74.83%。【结论】1951—2020年黄河上游和中游径流变化是气候变化和土地利用/覆盖变化共同作用的结果,但主要影响因素为人类活动主导的土地利用/覆盖变化,且各因子对径流的影响在不同区间存在一定的差异。本研究结果可为黄河上游和中游不同区间的水资源管理和综合治理提供理论支持。

梯级水库中长期仿天然水文情势的生态流量多目标调度

针对现有研究较少从水文情势角度开展梯级水库中长期生态流量调度的现状,基于场景缩减(SBR)技术推求的仿天然水文情势生态流量过程,以梯级水库下泄流量与生态流量的动态时间规整(DTW)距离最小为生态目标,以梯级水库发电量最大为发电目标,构建梯级水库多目标生态流量调度模型,并采用“参数模拟−优化”思路求解,选择金沙江中游梨园、阿海、金安桥、龙开口、鲁地拉和观音岩6座梯级水库,对1953-2015年的旬径流资料开展分析研究,为梯级水库中长期生态流量调度提供参考。结果表明,推求的仿天然水文情势生态流量具有明显的季节性波动和上下游断面量级差异特征;相较梯级水库原调度方案,优化调度方案可通过径流调节,改善梯级水库中长期生态和发电效益,在不影响生态目标的状态下,可增加511亿kW·h的发电量,相应增幅为1.35%;在不影响发电目标的情况下,可减少134253的DTW距离,相应降幅为3.85%。

初探水电工程建设征地移民安置竣工验收主要问题的处理措施--以云南省金沙江中游大型水电工程为例

依托云南省已实施完成的金沙江中游6座大型水电站工程建设征地移民安置竣工验收工作实践情况,从验收依据、验收内容以及工作组织管理等方面分析制约水电工程建设征地移民安置竣工验收的主要问题,提出高位推动、调整规划、资金保障、工作大纲、技术支撑、资金清理审计与档案专项验收等工作的成功经验与对策措施。

晚清长江中上游民船运输状况——以《长江三峡及重庆游记》为中心的考察

1883年英国商人立德乐通过实勘实测的方法记录了其在长江中上游流域乘坐民船的航行情况,并留下数万字的旅行记录——《长江三峡及重庆游记》,生动再现了晚清我国长江中上游流域传统民船的运输状况。通过对行记的考察可以厘清我国民船的运输情形,自从清代前期长江流域全面贯通以来,逐渐积累了成熟的造船技术、完善的民船运营结构、丰富的行船经验等,都促进了长江民船运输专业化,高效率水运系统的形成。与近代轮船运输相比,传统民船在运输价格、航行范围、运营的灵活性上都具有优势,即使在晚清长江中上游开通轮船运输后,民船运输仍在持续发展。

基于文献计量分析的长江中上游鱼类资源研究综述

针对长江中上游鱼类资源领域研究,以主题“长江上游”“长江中游”“金沙江下游”“鱼类资源”“鱼类早期资源”为检索条件,筛选了2023年7月前中国知网及Web of Science核心合集数据库收录的503篇文献,利用CiteSpace进行文献计量分析并绘制科学知识图谱,在此基础上从文献数量分布、研究机构及代表作者分布、研究主题内容、研究热点及演变趋势方面对长江中上游鱼类资源领域研究进行了综述。结果表明:中国科学院和中国水产科学研究院等是该领域的领军机构;从发展趋势上看,该领域已形成了鱼类资源现状及变化趋势、鱼类资源的影响机制以及鱼类资源的保护对策3个重要的研究热点和方向。后面需进一步完善江段鱼类资源的长期动态监测方法、梯级开发背景下鱼类资源的变动情况以及鱼类资源的协同保护方法等方面的研究。

韩江中上游地区的崩岗分布特征

选取韩江中上游地区2016—2022年的Sentinel-1/2卫星星座遥感影像和其他辅助数据,基于机器学习方法进行区域尺度的崩岗识别和崩岗影响因子测度。结果表明:1)分类模型的总体精度达到84%,Kappa系数为0.8。其中,崩岗识别的用户精度和生产者精度都超过95%,且其FScore为0.97。2)截至2022年,韩江中上游地区的崩岗侵蚀面积共有435.5 km^(2),各县(市、区)崩岗侵蚀面积差异明显,年变化趋势不一。其中,五华县崩岗侵蚀面积最多(199.2 km^(2)),其年平均变化率为16.29 km^(2)/a。梅江区崩岗侵蚀面积最少(1.6 km^(2)),其年平均变化率为0.18 km^(2)/a。3)韩江中上游地区崩岗发生概率与高程、坡度、植被覆盖、地质类型、人口密度、大气压、降雨量、经向风速、纬向风速和风速等10个因素存在显著相关性(P<0.001)。在一定的变化范围内,高程、坡度、地质类型、大气压、经向风速、纬向风速和风速对研究区崩岗发生为正向影响,植被覆盖、人口密度和降雨量对崩岗发生为负向影响。

淮河中上游地区新石器时代中期文化影响研究

淮河中、上游地区处于我国地理单元上的过渡中心,也是史前文化交流碰撞的“漩涡地带”。新石器时代中期两区域以淮河及其支流为纽带开启了文化上的互动交流,并逐步增强。两者之间的文化交流互动直接促进了淮系文化的形成与发展,并对淮河上游所在中原地区文化传播与扩散及早期中国各地考古学文化由分散、孤立走向交流、融合形成相对的文化共同体产生了积极的影响。

生态环境保护与农业经济高质量发展的协调性--以黄河中上游四省(区)为例

在构建生态环境保护与农业经济高质量发展评价指标的基础上,利用熵权法与耦合协调测度模型,考察黄河流域中上游四省(区)生态环境保护与农业经济高质量发展的协调性。研究结果表明,2010—2020年青海的协调性最高,其次是陕西,甘肃、宁夏分别处在该流域的第三、第四位,显然两个因素之间的协调性在黄河流域四省(区)从上游到中游在空间上呈现典型的“V”形分布。鉴于该流域各省(区)在生态环境保护与农业经济高质量发展之间的耦合度、协调度以及相对发展程度上存在明显差异,需要各地政府继续加大生态环境保护工程建设,加强农业绿色发展投资,从农业科技、环境监管、生态补偿等多方面加强区域协调发展,以期为该流域生态环境建设、农业经济高质量发展提供制度保障。

云南省金沙江中下游流域致病性耶尔森菌调查研究

目的了解云南省金沙江中下游流域鼠疫耶尔森菌、假结核耶尔森菌及小肠结肠炎耶尔森菌3种致病性耶尔森菌的分布及流行现状。方法选择云南省金沙江中下游流域5个县,采集鼠盲肠及犬肛门拭子标本,通过冷增菌后提取增菌液DNA并对foxA、ail、inv、caf1等特异基因进行PCR检测,基因阳性可疑标本进行菌株分离纯化后进行菌落PCR鉴定,对实验结果进行统计分析。结果采集标本1631份,其中鼠盲肠段标本985份、犬肛门拭子标本646份。自鼠肠道中共分离到小肠结肠炎耶尔森菌24株,分离率为2.44%(24/985),自犬肛门拭子中共分离到14株,分离率为2.17%(14/646),小肠结肠炎耶尔森菌总分离率为2.33%(38/1631),且38株小肠结肠炎耶尔森菌毒力基因检测均为阴性;自昭通永善县犬肛门拭子中分离到唯一1株假结核耶尔森菌,分离率为0.15%(1/646);未分离到鼠疫耶尔森菌。结论云南省金沙江中下游流域鼠和家犬中携带非致病性小肠结肠炎耶尔森菌,云南省首次自鼠疫指示动物犬中分离到假结核耶尔森菌,未发现鼠疫耶尔森菌的相关线索。

黄河上中游地区水‒粮食‒能源协同发展战略研究

黄河上中游地区是我国水资源、粮食、能源矛盾最为突出的区域之一,系统识别水‒粮食‒能源安全形势并提出应对措施,是该地区实现高质量发展的重要保障。本文在科学认识水‒粮食‒能源纽带关系基本内涵的基础上,研判了地区水资源、粮食、能源发展的新形势,剖析了水‒粮食‒能源协同发展面临的机遇和挑战,针对黄河流域生态保护和高质量发展目标,提出了新发展理念下水‒粮食‒能源协同安全的“四化一创”保障战略框架。研究建议,重视水资源在纽带关系中的核心作用,实现水资源支撑作用最大化;将能源作为区域高质量发展的战略性支柱产业,实现能源对经济社会发展带动作用最大化;强化农业用水支撑,实现粮食安全保障作用最大化;加强水资源保护,实现粮食、能源对水资源与生态环境干扰的最小化;加强基础科技研究,发展水‒粮食‒能源安全保障技术。

黄河中上游黄河鮈的年龄鉴定与生长模型筛选

【目的】鉴定黄河鮈的年龄,分析其生长特性,丰富黄河中上游黄河鮈的生物学研究资料。【方法】在宁夏回族自治区、甘肃省境内共7个站点采捕黄河鮈,以耳石作为年龄鉴定材料,选择Von Bertalanffy生长方程(VBGF)、逻辑斯谛生长方程(Logistic GF)、Gompertz生长方程(Gompertz GF)和幂指数生长方程(Power exponential GF)4种模型分别模拟黄河鮈的体长生长,采用极大似然法估算模型参数,通过计算各模型的AIC值评估模型的拟合效果,确定黄河鮈的最适生长模型。【结果】共采集到黄河鮈样本550尾,分为5个年龄组,即1~5龄,其中2龄组数量最多,共351尾;体长为2.60~17.41 cm;体重为0.18~99.39 g。4种模型对黄河鮈的拟合结果为,Gompertz生长模型的AIC值最小(4.99),拟合效果最好;其次为Logistic GF(14.58)和VBGF生长模型(16.29);幂指数生长模型AIC值最大(82.42),拟合效果最差。黄河鮈生长模型的Gompertz GF为Lt=18.81×exp{-exp[-0.66×(ti-1.73)]}。【结论】Gompertz GF为黄河中上游黄河鮈的最适生长模型。