大宁河水体营养盐状况与水华爆发之间关系分析

通过对大宁河常规监测和水华爆发期间加密监测断面的氮、磷营养盐指标统计,运用综合评价、相关性分析等方法对大宁河氮、磷营养盐分布和叶绿素a与总磷、总氮的关系进行了分析.结果显示,水华爆发期间叶绿素a与总磷、总氮呈正相关关系,总磷是大宁河水华爆发的限制因子.氮磷水平呈现从上游到入长江口逐渐递增趋势,长江回灌作用对大宁河输入部分氮、磷营养盐.     

三峡库区大宁河2010年春季水华特征

以大宁河春季水华期间调查数据为基础,运用数理统计分析手段,通过描述大宁河春季水华期藻类及主要理化因子分布特征,揭示出影响藻类生长的主要因子。结果表明:大宁河春季水华期水华河段水体氮、磷含量较高,总氮浓度为1.2～4.11mg/L,平均值为1.748mg/L,总磷浓度为0.027～0.615mg/L,氮磷比均值为17.5。春季水华藻类适宜的光照强度为1400～3800lx,水温为13.0～14.0℃时叶绿素a含量有最大增长,平均水温为13.4℃,藻密度与总氮、总磷、水温、DO、pH、浊度、高锰酸盐指数呈显著正相关关系,与透明度呈负相关关系。回水河段流速小于0.05m/s,流速是藻类生长最主要的限制因子。大宁河回水河段春季水华藻类分布较广,主要有甲藻门、绿藻门、硅藻门、隐藻门、蓝藻门、裸藻门和黄藻门7门28属,其中甲藻门分布最广,其次是绿藻门。春季水华优势种主要有甲藻门的拟多甲藻,绿藻门的衣藻、小球藻,硅藻门的直链藻,蓝藻门的色球藻等。     

典型湖泊水华特征及相关影响因素分析

通过2011-2015年对太湖、巢湖和滇池水华高发季节的连续监测，以藻类密度和水华面积为判据评价了3个湖体的水华情况及变化趋势，探讨了水华发生的主要影响因素。结果表明：太湖水华程度以"轻度水华"为主，巢湖水华程度以"轻微水华"为主，滇池水华程度以"中度水华"为主；太湖、巢湖和滇池水华规模均以"零星性水华"为主；太湖和巢湖藻类密度与水温、pH、溶解氧、总氮、总磷和高锰酸盐指数均呈显著正相关，与透明度呈显著负相关，与氨氮无显著相关性；滇池藻类密度与水温、总磷和高锰酸盐指数均呈显著正相关，与透明度和氨氮呈显著负相关，与pH、溶解氧和总氮无显著相关性。     

水华蓝藻复苏的研究进展与水华预测

综合分析了当前国内外水华复苏的研究进展,确定了水华蓝藻复苏的定义,介绍了研究蓝藻复苏的方法,以及蓝藻复苏对水体中蓝藻种群生物量以及当年蓝藻水华形成的贡献,探索了驱动水华蓝藻复苏的环境因子。结合太湖的研究成果,阐述了研究水华蓝藻复苏在进行水华预测中的重要作用,并展望了未来研究的重点。     

贵州黔东南州三板溪水库春季拟多甲藻水华特征

2011年3月13日对贵州省黔东南州三板溪水库进行春季浮游植物调查的结果表明,三板溪水库Ⅱ号采样点(下革东)发生以佩纳形拟多甲藻为优势种的拟多甲藻水华,细胞密度高达1.15×10⁷cell/L;板溪水库总氮的最低值为2.09 mg/L,总磷的最低值为0.95 mg/L,三板溪水库的总氮、总磷含量较丰富,不存在总氮或总磷是限制性因子;通过SPSS16.0统计软件分别进行Pearson 积距相关系数分析表明,氮磷比是三板溪水库发生拟多甲藻水华的主要影响原因。     

太湖水华的遥感分析

随着太湖流域的经济迅速发展,太湖湖体的富营养化程度日趋严重,特别是在20世纪的后期,水华频繁爆发。国家环保总局常规的水质监测是基于21个点位对全湖进行评价,完成一次采样耗时近1月,其对大面积水华现象的监测具有很大的局限性。文章利用遥感技术快速、大尺度、动态监测的特点,基于多个时相的TM影像对太湖的水温、悬浮物、叶绿素等水质参数的浓度和分布进行了遥感反演,进而对太湖水华的成因、发展程度、影响因素等方面进行分析,从而对太湖水华发生的特点,太湖的水质情况有一个全面的了解。     

利用MALDI-TOF MS技术简便、快速检测水华蓝藻的方法研究

以水华蓝藻为研究对象,用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术对其进行测定分析并获得了蛋白质指纹图谱。对铜绿微囊藻标准株(NIES-843)样品通过3种前处理方法得到的质谱图进行对比,确定了质谱分析的样品前处理方法,建立了利用MALDI-TOF MS技术简便、快速检测水华蓝藻的方法。对在水华中出现的4种不同蓝藻进行MALDI-TOF MS分析,结果表明各种蓝藻具有其特征性波谱,可据此对水华蓝藻进行区分和鉴定。该方法快速、简便、精确、可程序化,具有广泛的应用前景。     

联合多源光学和雷达遥感的巢湖水华长时序时空变化分析

以巢湖水华爆发现象为研究对象,利用多源光学遥感和全极化SAR遥感作为数据源,对研究区域2008—2017年的水华进行识别提取,定量和定性分析水华面积及区域位置的时空变化。结果表明:在时间上,每年二、三季度巢湖水华面积普遍高于一、四季度,总体上呈现年平均水华面积逐渐减小趋势,前五年的水华面积比后五年高。在空间上,巢湖西北部水华发生频率最高,西部水华比东部水华发生频率高,沿岸比湖中心发生频率高。巢湖水华整体呈现改善趋势。     

基于BP神经网络的藻类水华预测模型研究

以宁波大学校内池塘2009年3—10月间30周的监测数据为基础,运用BP人工神经网络方法构建预测模型,探求颤藻生物量与总氮、总磷、透明度等6项环境因子之间的关系,选出最佳预测模型,并对模型进行敏感度分析。结果显示:①BP神经网络模型对颤藻生物量预测值与实测值之间拟合程度良好,相关系数达到了0.984,说明BP神经网络模型可以用于水体中藻类水华的短期预测。②通过对构建的BP神经网络模型进行敏感度分析,阐明了宁波大学校内池塘藻类水华的主要驱动因素,并指出控制水体的pH是宁波大学校内池塘藻类水华防治工作的重点。     

宁波市常见藻华的现场快速诊断

为了建立宁波市常见水华现场快速判断方法,根据宁波市常见水华的表观特征以及在叶绿素荧光仪上的响应,确定可能的水华优势种类,从而达到现场快速判断的目的。进一步结合实验室得出的水华藻影响因子和毒性等相关参数,得出水华的程度、可能的变化趋势和水源的安全性。结合水文、气象等其他影响因子,及时更新宁波市藻华数据库和检索表,可得出较为科学的判断结果。     

Longitudinal heterogeneity of sediment characteristics during southwest monsoon season in hyper-eutrophic Krishnagiri reservoir,India

Krishnagiri reservoir is a hyper-eutrophicated reservoir located in Krishnagiri district which is one of the drought-prone districts in Tamil Nadu, India. The reservoir water is being used for various purposes such as irrigation, drinking, fish rearing, livestock rearing, and recreation. Since there is no an evidence of investigation on bottom sediments in Krishnagiri reservoir, the present study was carried out during southwest monsoon season in 2008. This study examined the physical and chemical characteristics of the bottom sediments such as composition, redox potential, moisture content, organic carbon, organic matter, total phosphorus, and total iron at 15 locations in the reservoir. Phosphorus fractionation study was carried out to find out different fractions such as loosely adsorbed phosphorous, iron and aluminium-bound phosphorus, calcium-bound phosphorous, and organic phosphorous. Results indicated that there was spatial variation in the composition of sediments and low values of redox potential. The significant positive correlation exists between the organic carbon and organic phosphorus concentration. The lacustrine zone of the reservoir showed high accumulation of total phosphorus and total iron when compared to riverine and transition zones. This study concludes an allogenic origin of majority of inorganic phosphorus in the reservoir during the study period and this might have been derived from the catchment during the erosion process. The high concentration of surface sediment phosphorus clearly indicates a greater threat of eutrophication in Krishnagiri reservoir.     

稻田种植对地表径流污染状况调查研究

以辽宁省营口市水稻种植区为研究区域,通过对监测地块实地调研、资料收集、监测分析,在稻田整个作物生长周期化肥、农药的施加等情况下开展氮、磷污染物对地表径流污染状况的调查研究.结果表明:化肥、农药的施加均会使受纳水体中总磷、总氮质量浓度升高,施肥后总氮质量浓度上升最显著,绿色种植在扣除总氮背景值后达到37.7 mg/L,有...     

Spatial distributions and eco-partitioning of soil biogeochemical properties in the Everglades National Park

Large-scale ecosystem restoration efforts, such as those in the Florida Everglades, can be long-term and resource intensive. To gauge success, restoration efforts must have a means to evaluate positive or negative results of instituted activities. Edaphic properties across the Everglades landscape have been determined to be a valuable metric for such evaluation, and as such, a baseline condition from which to make future comparisons and track ecosystem response is necessary. The objectives of this work were to document this baseline condition in the southern most hydrologic unit of the Everglades, Everglades National Park (ENP), and to determine if significant eco-partitioning of soil attributes exists that would suggest the need to focus monitoring efforts in particular eco-types within the ENP landscape. A total of 342 sites were sampled via soil coring and parameters such as total phosphorus (TP), total nitrogen (TN), total carbon (TC), total calcium, total magnesium, and bulk density were measured at three depth increments in the soil profile (floc, 0-10 cm, and 10-20 cm). Geostatistical analysis and GIS applications were employed to interpolate site-specific biogeochemical properties of soils across the entire extent of the ENP. Spatial patterns and eco-type comparisons suggest TC and TN to be highest in Shark River Slough (SRS) and the mangrove interface (MI), following trends of greatest organic soil accumulation. However, TP patterns suggest greatest storages in MI, SRS, and western marl and wet prairies. Eco-partitioning of soil constituents suggest local drivers of geology and hydrology are significant in determining potential areas to focus monitoring for future change detection.     

Water Quality Prediction of Water Sources Based on Meteorological Factors using the CA-NARX Approach

With the increasingly serious problem of surface water environmental safety, it is of great significance to study the changing trend of reservoir water quality, and it is necessary to establish a water quality prediction and early warning system for the management and maintenance of water resources. Aiming at the problem of water quality prediction in reservoirs, a CA-NARX algorithm is designed, which combines the improved dynamic clustering algorithm with the idea of machine learning and the forward dynamic regression neural network. The improved dynamic clustering algorithm is used to classify the eutrophication degree of waterbodies according to the total phosphorus and total nitrogen content. Considering four meteorological factors, air temperature, water temperature, water surface evaporation, and rainfall, synthetically for each water quality condition, the total phosphorus and total nitrogen in the waterbody are forecasted by an improved forward NARX dynamic regression neural network. Based on this, the CA-NARX prediction algorithm can realize short period water quality prediction. Compared with the traditional support vector regression machine model, improved GA-BP neural network, and exponential smoothing method, the CA-NARX model has the least prediction error.

     

Atmospheric influences on water quality: a simulation of nutrient loading for the Pearl River Basin, USA

Knowledge of water quality conditions is essential in assessing the health of riverine ecosystems. The goal of this study is to determine the degree to which water quality variables are related to precipitation and air temperature conditions for a segment of the Pearl River Basin near Bogalusa, LA, USA. The AQUATOX ecological fate simulation model is used to estimate daily total nitrogen, total phosphorus, and dissolved oxygen concentrations over a 2-year period. Daily modeled output for each variable was calibrated against reliably measured data to assess the accuracy. Observed data were plotted against simulated data for controlled and perturbed models for validation, and stepwise multiple regression analysis was used to quantify the relationships between the water quality and meteorological variables. Results suggest that daily dissolved oxygen is significantly negatively correlated to concurrent daily mean air temperature with a total explained variance of 0.679 (p?<?0.01), and monthly dissolved oxygen is significantly negatively correlated to monthly mean air temperature with a total explained variance of 0.567 (p?<?0.01). Total mean monthly phosphorus concentration is significantly positively related to the previous month's precipitation with a total explained variance of 0.302 (p?<?0.01). These relationships suggest that atmospheric conditions have a strong influence on water quality in the Pearl Basin. Therefore, environmental planners should expect that future climatic changes are likely to alter water quality.     

杭州西湖水体生态环境参数的相互关系

采用 2 0 0 0年的西湖常规监测数据 ,分析了西湖水体中生态环境特征参数的季节变化和相互关系。分析表明 ,西湖水体各生态环境参数 ,除总氮外 ,均呈现出明显的季节性变化 ,总磷、溶性正磷酸盐、叶绿素 a和藻类季节变化一致 ,在夏季形成高峰 ,冬季最低 ;三无机氮高峰值出现在冬季 ,夏季含量为全年最低。 2 0 0 0年西湖水体总氮年均值为 2 .0 5 m g/L ,总磷年均值为 0 .12 6mg/L ,N/P大于 16,西湖属于磷控制型富营养湖泊。通过相关分析 ,从另一方面说明磷是西湖水体的限制因子 ;硝酸盐对西湖沉积物和湖水之间的磷酸盐平衡有一定的影响 ;硝酸盐对西湖水体中浮游植物生长繁殖可能有抑制作用     

汉江下游干支流浮游植物群落特征及其对水质的指示评价

浮游植物群落的动态变化可以全面、真实地反映水质的优劣,有利于了解水体污染状况的发展趋势.为及时掌握汉江下游水质变化,基于2019年3—12月汉江下游干流及主要支流浮游植物和水体理化指标监测数据,分析了浮游植物群落结构特征,并通过冗余分析研究了影响浮游植物群落结构的主要环境因子,同时运用浮游植物群落特征对汉江下游水质进行...     

Status of the Riparian Ecosystem in the Upper San Pedro River, Arizona: Application of an Assessment Model

A portion of Arizona’s San Pedro River is managed as a National Riparian Conservation Area but is potentially affected by ground-water withdrawals beyond the conservation area borders. We applied an assessment model to the Conservation Area as a basis for monitoring long-term changes in riparian ecosystem condition resulting from changes in river water availability, and collected multi-year data on a subset of the most sensitive bioindicators. The assessment model is based on nine vegetation bioindicators that are sensitive to changes in surface water or ground water. Site index scores allow for placement into one of three condition classes, each reflecting particular ranges for site hydrology and vegetation structure. We collected the bioindicator data at 26 sites distributed among 14 reaches that had similar stream flow hydrology (spatial flow intermittency) and geomorphology (channel sinuosity, flood-plain width). Overall, 39% of the riparian corridor fell within condition class 3 (the wettest condition), 55% in condition class 2, and 6% in the driest condition class. Condition class 3 reaches have high cover of herbaceous wetland plants (e.g., Juncus and Schoenoplectus spp.) along the perennial stream channel and dense, multi-aged Populus-Salix woodlands in the flood plain, sustained by shallow ground water in the stream alluvium. In condition class 2, intermittent stream flows result in low cover of streamside wetland herbs, but Populus-Salix remain abundant in the flood plain. Perennial wetland plants are absent from condition class 1, reflecting highly intermittent stream flows; the flood plain is vegetated by Tamarixa small tree that tolerates the deep and fluctuating ground water levels that typify this reach type. Abundance of herbaceous wetland plants and growth rate of Salix gooddingii varied between years with different stream flow rates, indicating utility of these measures for tracking short-term responses to hydrologic change. Repeat measurement of all bioindicators will indicate long-term trends in hydro-vegetational condition.     

厂界无组织排放监测气象条件判定及布点问题对策研究

通过对现有技术要求的分析,指出大气污染物无组织排放监测主要技术依据中气象条件判定和监控布点存在监测时段选择不合理、条件设置不具代表性和不具可操作性等问题和难点。对此提出了相应对策,指出可通过滑动计算相关数值的方式将气象和监控布点设置条件扩展至监测全过程,使用气象条件和点位判定系统来解决上述问题和难点。对技术依据中未规定的多点和区域无组织排放源的有效监控区域确定提出了解决思路,探讨了监测全过程监控点位有效性的评价方式。通过实施示例对提出的对策进行了说明。     

太湖流域果园种植面源氮磷输出强度及其定量评估方法

以太湖流域上游地区无锡阳山地区果园种植典型区域为研究对象,通过现场试验,调查了果园种植面源氮磷输出动态变化过程,计算并分析了氮磷输出强度,构建了果园种植面源氮磷输出强度定量评估模型。结果表明:取样监测期间,果园种植径流及淋溶氮磷指标变化幅度均超过200%;果园种植面源氮磷径流输出强度与其淋溶输出的变化一致,径流总氮的输出强度最高(13.201 kg/hm~2),淋溶硝酸盐输出强度最大(4.077 kg/hm~2);所建立的评估方程能较好地反映降雨量等环境因素对果园种植面源氮磷径流及淋溶输出强度的影响情况,模拟方程的复相关系数均在0.9左右。