人工湿地改善长江水体透明度的示范研究

根据自然水体湿生植物、浮叶植物以及沉水植物的空间分布规律,利用水生高等植物构建由挺水植物、浮叶植物到沉水植物的野外示范研究区（面积9 048 m2）,模拟长江潮汐规律每天调长江水（浊度77.62 NTU,透明度17.6 cm）4 320 m3流经试验区,进行长江水体透明度改善试验。试验共进行100 h,进水量18 000 m3,试验区平均水力负荷0.477 5 m/d。结果表明：① 人工湿地对长江水体透明度的改善与维持具有重要作用,试验水体流经串连湿地系统后浊度降低为9.47 NTU（减小88%）,透明度提高到64.5 cm（提高2.66倍）;② 湿地植物对长江水体N、P等元素具有良好的净化作用;③ 由挺水、浮叶、沉水等水生高等植物组成的串连湿地系统对改善长江水体透明度和降低水体浊度具有良好的效果,是长江水体透明度和水质改善的重要措施之一。     

全站仪测定内陆水体水位的方法及精度分析

利用全站仪测定内陆水体水位的技术方法精度无明确技术规范可供参考。基于内陆水体水位控制测量的特殊性,从全站仪测量原理、方法、误差影响等方面展开分析和讨论。在实测资料基础上进行数据分析验证,阐述了采用全站仪进行水位控制测量的具体方法和技术要求,弥补了相关规范的不足。实际应用表明,隔点设站法进行水位测量是可行的,当两点距离超过300 m且小于1 200 m时,其精度较一站法高。     

水体面积和水位变化对旱情影响监测与分析

本文以安徽省部分湖泊、大中型水库为研究对象,应用高分辨卫星监测数据,对2019年水体面积、水位变化情况进行分析。结果表明:2019年旱情期间,安徽大部分湖泊水体面积均低于2014年水利普查面积,水库水体面积均低于正常蓄水位对应面积,水位整体呈下降趋势。     

长三角“水乡客厅”水体透明度数值模型构建

“水乡客厅”作为长三角区域一体化的重要示范性工程,如何提升其水体透明度,改善水体感官仍然是一个亟待解决的难题。在相关水质监测及悬浮物沉降试验的基础上,分析研究了“水乡客厅”水体透明度的主要影响因素,并构建了其与水体透明度的多元回归方程,基于该方程,构建了水体透明度数值模型。结果显示：相较于圩内河道,圩外河道及湖荡的水体透明度相对较低;研究区域内水体透明度的主要影响因素为悬浮物浓度,其皮尔逊相关系数为-0.48,呈明显负相关关系,次要因素为叶绿素浓度;分圩内河道、圩外河道、湖荡区域分别构建悬浮物沉降系数与悬浮物浓度、水体流速的拟合方程,决定系数R²均>0.8,拟合效果较好;基于上述分析结果所构建的水体透明度数值模型能够较好地描述“水乡客厅”水体透明度的分布规律,可为后续区域水生态修复及富营养化治理提供技术支撑。     

藕池（管）站水位流量单值化方案分析及应用探讨

藕池（管）水文站位于长江四口水系藕池河段,为荆江四口分流藕池口分支藕池河的控制站。水位～流量关系主要受洪水涨落、断面冲淤、洞庭湖回水顶托等影响,连时序绳套法定线较为复杂,流量测次多。通过对2016-2020年藕池（管）站水文资料单值化分析,选用新厂（二）水位站作为落差辅助站,采用试错法确定最优单值化方案。结果表明,水位～流量关系单值化分析结果较好,满足现行水文整编规范要求,优化精减了流量测验次数,提高了工作效率。     

妈祖城规划城区内湖水位控制与水体交换及陆域回填高程的探讨

随着社会经济日益发展,海堤建成后围区作为城市开发建设逐渐增多。莆田湄洲岛对岸妈祖城海堤建成后形成围区面积493.5hm2作为妈祖城城区开发用地。文章分析探讨了妈祖城规划城区内湖水位、水体交换和陆域回填高程的控制,为工程项目规划设计提供依据。     

北湾水库汛限水位及兴利水位确定分析

汛限水位和兴利水位的确定是新建水库中最重要的参数,在设计中不仅要经过详细的理论计算和比较,还要综合考虑淹没损失、下游河道防洪对象和防洪标准、兴利目标和用水次序等因素,才能合理地进行水库特征水位的选取,方可达到科学、经济的结果。     

褒河马道水文站水位流量关系分析

本文依据褒流域以及马道水文站测站实况,采用年特征值法对马道水文站进行了水位级的划分,选用2006年~2012年实测流量成果中各年最大洪峰过程中149次实测流量进行综合定线,结合历年水位流量关系曲线,进行误差分析。在满足规范规定的前提下,实现水位流量关系单值化的目的,为该站实行巡测提供技术条件。     

九台水文站水位、流量关系概述

水位、流量关系分析，是水文资料整编中的关键环节，水位、流量关系合理与否将直接影响水文资料成果的精度。本文主要通过对九台水文站建站至今35年来的实测资料进行水位、流量关系分析，阐述各种因素影响下的水位、流量关系特性。     

下司水文站水位流量关系及测流方法分析

对下司水文站1992年以后相对稳定河段的水位流量关系性质、特点进行了分析，为进一步了解该站的水文特性和掌握测流工作奠定了基础。     

Understanding Seasonal Water Clarity Dynamics of Lake Dahuchi from In Situ and Remote Sensing Data

Obtaining, analyzing and understanding the seasonal dynamics of water clarity is of importance for understanding and managing lakes and sustaining their ecosystem services. This study aimed to explore the seasonal dynamics of water clarity and to analyze how water level, wind velocity and total precipitation influence this dynamics in Lake Dahuchi, China. The Secchi disk depths recorded in the field and derived from Moderate Resolution Imaging Spectroradiometer (MODIS) images together demonstrated a seasonal pattern of water clarity, which was lower in winter and spring, increased in April or May to reach the highest values in summer, upon which it gradually declined from September onward. Piecewise linear regression analysis between water clarity and water level showed that water level could explain 70% of the variation of the logarithm of Secchi disk depth. The water clarity of Lake Dahuchi was primarily controlled by suspended sediment, while the seasonal variation of water level induced different sediment resuspension, thus we concluded that the water clarity seasonal dynamics of Lake Dahuchi was mainly regulated by seasonal variation of water level.     

Community structure,abundance variation and population trends of waterbirds in relation to water level fluctuation in Poyang Lake

Poyang Lake is China's largest freshwater lake, and it has been an internationally important wintering ground for migratory waterbirds. Based on waterbird censuses from 2001 to 2016, community structure and abundance trends of waterbirds were analyzed, as well as the potential correlations with the water level of Poyang Lake. The results showed that the annual average number of waterbirds in Poyang Lake was 426,707 ± 150,170, with 111 species from 17 families. Waterfowl was the most abundant family accounting for 74.4 ± 8.8% of all individuals, followed by shorebirds (14.8 ± 8.5%), wading birds (6.5 ± 1.8%) and open-water/waterbirds (4.4 ± 1.9%). Although waterbird abundance fluctuated dramatically, there were no significant trends in the abundance of most guilds or in total waterbird abundance; only geese significantly increased among the eight groups. Analysis of trends of 37 relatively abundant or regularly occurring species indicated that population trends appeared to be species-specific. As for the correlations between water level and waterbird abundance, only shorebirds showed significant correlations with average July water level, average water level, and high water level duration in wet season among four guilds, i.e. waterfowl, wading bird, shorebird and, open-water and waterbird. At the group level, abundances of swans, geese, and ducks were significantly correlated with monthly average water level during the wet season, and wader abundance was significantly correlated with average water levels and high water level duration during the wet season. Correlations between population abundance and monthly water level also exhibited species-specific patterns.     

基于MODIS数据的洞庭湖水面面积估算方法

利用美国Terra卫星上MODIS传感器提供的NDVI数据产品,采用两种方法分别在年和月时间尺度上对2000~2007年间洞庭湖的水面面积进行了估算。在年尺度上,采用ISODATA方法对NDVI时间序列进行非监督分类,区分水面及各种湿地类型,并分析了各类湿地的面积变化趋势。在月尺度上,采用16 d平均NDVI数据,通过NDVI阈值提取水面,在不同的季节选取不同的阈值,并将基于NDVI数据得到的水面面积与基于水位—面积曲线得到的水面面积进行了对比分析。在此基础上,探讨了两类不同尺度上分类方法的优点、缺点及适用范围。     

三峡工程建库后对洞庭湖水位、泥沙和水质的影响分析

长江与洞庭湖在地理和水文要素上联系紧密。三峡工程建成后，洞庭湖水住、含沙量和水质都将受到影响，主要表现在洞庭湖径流的年内分配比原来更加均匀，湖内泥沙淤积放缓，水质有所改善，枯水期污染物浓度有所降低等。为了更好地发挥三峡水库的作用，改善江湖关系，本文在分析基础上提出了一些建议。     

兴凯湖生态水位分析

基于兴凯湖1914~1957年水位过程线和水位-面积-库容曲线,通过计算兴凯湖多年平均和80%保证率水平年的来水量,并结合近期和远期需水量,进行水量平衡分析。结果表明,兴凯湖具有较大的调节功能,即使连续6年出现历史上水位从多年平均水位下降至历史最低水位,兴凯湖也能满足近期和远期水量需求。经分析、计算和推理,认为以1925年兴凯湖水位67.88 m为最低生态水位是合适的。     

太湖警戒水位研究

随着太湖流域防洪工程能力的不断提高,尤其是环湖大堤防洪能力的显著提高,3.50 m的太湖警戒水位已不能客观真实地反映环湖大堤实际防洪能力和太湖防洪形势,需要对太湖警戒水位进行复核调整。根据警戒水位定义,结合太湖特点,开展了环湖大堤防洪能力分析、堤防工程实际运用状况分析以及太湖水位频率分析,研究提出了太湖警戒水位调整的建议。     

Characterizations of individual suspended mineral particles in western Lake Erie: Implications for light scattering and water clarity

Light-scattering attributes of minerogenic particles from the water column of the western basin of Lake Erie (13 sites, plus one from the central basin and one from Sandusky Bay), collected after a wind event, were characterized by scanning electron microscopy interfaced with automated image and X-ray analyses (SAX). SAX results specified scattering attributes for individual particles, including size and chemical composition, and were used in forward Mie theory calculations of minerogenic scattering and backscattering coefficients (b_m and b_b,m). Clay mineral particles, in the size range of 1–20 μm, were the dominant form of minerogenic scattering, representing > 75% of b_m and b_b,m. Levels of b_m and b_b,m were high in the western basin, apparently in part due to wind-driven sediment resuspension, and wide spatial variability was observed. The credibility of the SAX-Mie estimates of b_m and b_b,m was supported by the extent of optical closure obtained with paired bulk measurements of particulate scattering and backscattering coefficients (b_p and b_bp), and independent estimates of organic particle contributions based on empirical bio-optical models. Minerogenic particles dominated b_p and particularly b_bp, and regulated spatial differences in the related common metrics of optical water quality, including turbidity and clarity. The b_bp:b_p ratio was found to be a good predictor of the spatial differences in the relative contributions of minerogenic particles versus phytoplankton to scattering.     

青海湖水位动态趋势预测

为预测青海湖水位下降趋势及其对湖泊生态的影响,本文对青海湖主要来水项——入湖径流采用一阶周期性自回归模型进行人工生成系列,并依据径流与降水和蒸发的频率对应关系,以及未来暖干气候条件下降水和蒸发的可能变化量,建立了相应的降水和蒸发序列。通过长系列水量平衡计算表明,青海湖水位仍会继续下降,2030年是未来50年序列中水位最低的时期,最低水位将达3191.35m,此后水位开始小幅度回升并逐渐趋稳。同时,在历史平均气候条件下对青海湖水位进行了预测,预计2035年后水位的持续下降速率开始变缓并趋于稳定,2100年左右稳定在3192.2m。     

洞庭湖湖区最低生态水位的确定

为确定洞庭湖湖区最低生态水位,针对洞庭湖湖区复杂、不同湖区差异较大的问题,基于城陵矶、鹿角、南嘴、小河嘴和杨柳潭5个水文站1953—2013年的水文资料,采用天然水位资料法、年保证率法、最低年平均水位法、生态水位法、湖泊形态分析法及最小空间需求法,分别对东洞庭湖、南洞庭湖和西洞庭湖的最低生态水位进行了计算,并与前人关于洞庭湖生态水位的研究成果进行了对比分析。结果表明:东洞庭湖、南洞庭湖和西洞庭湖的最低生态水位分别为22.62 m、27.19 m和28.11 m,相应的湖面面积分别为373.85 km~2、406.88 km~2和142.19 km~2,从保护洞庭湖自然保护区的角度看,确定的最低水位是合理的。     

基于MODIS数据的艾比湖湖面变化研究

艾比湖是中国四大沙尘暴策源地之一,MODIS数据以其时效性强,运行周期短,数据获取快,成本低的特点,适宜进行湖泊水域面积的监测.本文通过MODIS数据获取艾比湖湖面变化信息,同时从影响湖泊水量的主要因素入手分析了艾比湖面积变化的原因.