Lake Jabel restoration project: Phosphorus status and possibilities and limitations of diversion of its nutrient-rich main inflow

External and internal phosphorus loading was studied in 1996 in the anthropogenically eutrophicated Lake Jabel, which is located in Mecklenburg (north‐eastern Germany). It has a dimictic 23‐m‐deep northern basin, a 19‐m‐deep middle basin and a 6‐m‐deep polymictic southern basin. The main tributary, Grabowhöfer Grenzgraben, which enters via a leaching field from a waste‐water treatment plant, has been identified as the major nutrient discharge (80% of total phosphorus loading) into the northern basin. The sediment is the second largest source of phosphorus for Lake Jabel, contributing 25.7%, 27.4% and 2.4% of the overall phosphorus load to the northern, middle and southern basins, respectively. Although the favoured diversion of the Grabowhöfer Grenzgraben would contribute to a reduction of 1.22 t P and 20.94 t NO₃^‐–‐N per year, it is mainly rejected for the following reasons. If the extreme monthly nitrate supply, between 4.84 and 189.6 mg N m^‐2 day^–1 ceased, the release of redox‐sensitive phosphorus in the northern basin would increase by a factor of 0.54, which is with 41.1% total phosphorus, twice as high as that in the middle basin. In addition, the nitrate supply can substantially lower the seasonal precipitation of stable iron sulphides, which would otherwise lower the concentration of redox‐sensitive phosphorus, but cannot change the phosphorus retention in the long term. Because of internal phosphorus sources, the diversion of the Grabowhöfer Grenzgraben would result in no substantial changes in the level of trophy.     

人工湖水体富营养化的活性炭处理技术及生态修复建议

通过对包头市两个典型人工湖的水体富营养化现状分析,研究木质和煤基活性炭对人工湖中叶绿素a、COD、浊度、蓝藻、总氮和总磷的去除效果。结果表明:木质活性炭对劳动园人工湖中叶绿素a、COD和浊度的去除率更高(96%);煤基活性炭对总氮和蓝藻的去除率更高(88%),出水达到地表水环境质量标准(GB3838-2002)二级标准。同时,提出了长期治理人工湖水体富营养化的生态修复方案,以期为长期有效治理人工湖水体富营养化提供帮助。     

Effect of hypolimnetic discharge on the faster deprivation of phosphorus from lake sediment (Lake Jabel, north-east Germany)

After the reduction in external phosphorus‐load (P‐load), in‐lake measures became practicable for eutrophic Lake Jabel. The benthic release of phosphorus (P) was efficiently suppressed by a significant nitrate supply via its main tributary. The in‐situ stimulation of P‐release as a result of the temporary decrease in this nitrate load, and the simultaneous P‐removal by deep‐water siphoning and external P‐elimination was primarily designed for the faster deprivation of P from lake sediment. This new strategy was aimed at exhausting the ‘P‐surplus’, that is, the mobile redox‐sensitive iron‐bound P‐portions of the uppermost sediment layers, where a re‐supply from deeper layers is needed within the stratification period of 2 consecutive years of operation of the P‐elimination system. By studying early benthic P‐diagenesis it remains to be demonstrated whether this procedure can contribute to a re‐availability of P‐binding sites to guarantee the long‐term effect of the measure.     

邵伯湖水生态状况及改善建议

过水型湖泊在承担防洪、保障人民生命财产安全的基本任务前提下,在用水、航运、旅游及维系区域生态平衡方面也发挥着巨大作用,通过对常规水质指标以及微生物指标的研究,探索过水型湖泊富营养化的微生物评价方法,针对湖泊水生态更替规律开展基础性研究,提升湖泊水生态管理水平。     

滇池沉积物内源磷释放初步研究

沉积物内源磷释放是湖泊富营养化重要的污染来源。本次研究在滇池20个采样点进行了原状柱状沉积物样品的采集。分析测试了分层沉积物样品的总磷、总氮、总有机质含量，揭示了滇池全湖沉积物中营养组分的含量特征和分布规律。为估算沉积物磷释放的通量水平和初步解释滇池磷释放的主要作用机制，现场提取出了沉积物间隙水，并分析了间隙水以及采样点湖水中溶解总磷、溶解磷酸盐和溶解有机磷的含量，根据实测运用费克扩散定律计算了沉积物-水界面之间磷的交换通量。同时对代表性样点进行了原样沉积物柱磷释放的实验室模拟。通量计算和模拟实验的结果表明，滇池沉积物具有较强的向水体的释磷能力，全湖沉积物平均磷释放通量为0．095mg／cm^2／a，沉积物磷释放成为全湖磷负荷的重要部分。实验数据相关性分析表明，滇池表层沉积磷活化释放的主要机制是表层沉积物有机质矿化降解，有机磷分解形成的浓度梯度驱动了溶解磷从沉积物向水体扩散。     

Biogeochemical characterization,phosphorus sources and intrinsic drivers to its speciation within the Nyanza Gulf of Lake Victoria

Lake Victoria, like many African great lakes, was formed through tectonic activity that formed East African Rift Valley. The lake's ecology has undergone dramatic reorganization dating back to the 1920s, before agricultural mechanization and high urban populations were observed, transforming from it from a desirable to less desirable state. The present study was conducted to better understand Nyanza Gulf's biogeochemical characteristics, phosphorus sources and the driving forces to their speciation. Five littoral‐limnetic‐littoral transects were sampled for water‐associated phosphorus (soluble reactive phosphorus, SRP; total phosphorus, TP_W); sediment‐associated phosphorus (non‐apatite inorganic phosphorus. NAIP); apatite phosphorus, AP; inorganic phosphorus, IP; organic phosphorus, OP; total phosphorus, TP_S); elemental compositions (calcium, Ca; iron, Fe; aluminium, Al; manganese, Mn); organic matter (OM); and organic carbon (OC) contents in the sediment. The SRP and TP_W concentrations ranged from 22.9 to 142.9 μg/L, and 57.1 to 277.1 μg/L, respectively. The littoral sampling sites exhibited relatively higher TP_W concentrations than the limnetic sites. Sheltered bays and sites located off sewerage discharge points had higher NAIP concentrations exceeding 400 mg/kg, compared with strong current areas. The AP and TP_S concentrations ranged from 136.7 to 1,511.3 mg/kg, and 512.5 to 2,254.4 mg/kg, respectively. The AP and TP_S concentrations were generally higher (>500 mg/kg) within the littoral zones compared to the limnetic zones; with the littoral sites located close to documented carbonatite rock substrates manifesting exceptionally high concentrations. Nyanza Gulf's eutrophic/hypertrophic status is derived highly from shoreline erosions of phosphorus‐enriched carbonatite rocks associated with rift valleys and from municipal sewerage discharges. Re‐afforestation, fringing wetland restorations and tertiary treatment of municipal waste waters are vital for its ecological restoration.     

HJ-1B和Landsat卫星蓝藻水华监测能力评估——以洱海为例

蓝藻水华是富营养化湖泊共同面临的问题。遥感技术为快速、大范围水华监测提供了可能,选取遥感数据应首先明确不同卫星的水华监测能力。以洱海为例,对比分析HJ-1B和Landsat卫星在内陆中小湖泊水华监测的时间和空间监测能力,评价两者在水华监测中的适用性及优势。结果表明:两者均能有效识别水华,提取水华分布细节信息,相比MODIS更适合用于中小湖泊水华监测;进一步分析表明,综合两者数据监测蓝藻水华,可以更加客观统计水华时间特征,描述水华空间分布发展规律,对于其它中小湖泊利用遥感手段辅助水华监测具有参考意义。     

Lakes of Malaysia: Water quality,eutrophication and management

The present study was undertaken to evaluate and verify the water quality status and trophic state of 15 major lakes and reservoirs in Malaysia. The lake water quality assessments were based on the National Water Quality Index (NWQI), while the trophic state assessments were based on Carlson's Trophic State Index (TSI). The findings of this water quality assessment, based on data collected between September and October 2012, indicated that a majority of the lakes were classified as Class II (Clean) waters suitable for recreational use. The results of the trophic state assessments, however, indicated that all of the lakes were eutrophic, meaning they were nutrient‐rich, they could experience algae blooms or macrophyte problems, and they were likely to exhibit poor water quality. Sustainable management measures and strategies are suggested to address the eutrophication problems of Malaysian lakes and reservoirs, with the national responses on lake and reservoir management also being discussed.     

Lake Erie phosphorus targets: An imperative for active adaptive management

Management actions taken to meet the phosphorus load targets in the 1978 Great Lakes Water Quality Agreement proved highly successful, initially. Eutrophication symptoms abated, and attention was redirected toward other important water quality problems. However, in the early 2000s Lake Erie, in particular, began to re-experience severe algal blooms and other problems associated with excessive nutrient inputs. The 2012 GLWQA prompted the development of updated phosphorus targets, and endorsed the concept of adaptive management. We propose that an active adaptive management program that maximizes learning opportunities will be imperative to sustain any future improvements realized in response to the new targets. Every year offers natural, albeit uncontrolled experiments to exploit the adaptive management concept of “learning by doing." A carefully thought out plan of complementary monitoring and modeling, supported by stakeholder engagement, will promote an improved understanding the processes that influence lake behavior and guide essential refinements to management goals and appropriate actions to attain them. In 2019 the International Joint Commission released a set of recommendations regarding the use of modeling approaches to support adaptive management in Lake Erie. We have incorporated those recommendations herein to further inspire the Great Lakes community to invest in an active adaptive management strategy that will serve us into the future.     

Burrowing mayfly (Ephemeroptera: Ephemeridae: Hexagenia spp.) bioturbation and bioirrigation: A source of internal phosphorus loading in Lake Erie

Traditional lake eutrophication models predict lower phosphorus concentrations with decreased external loads. However, in lakes where decreased external phosphorus loads are accompanied by increasing phosphorus concentrations, a seeming “trophic paradox” exists. Western Lake Erie is an example of such a paradox. Internal phosphorus loads may help explain this paradox. We examined bioturbation and bioirrigation created from burrowing mayfly, Hexagenia spp., as a possible source of internal phosphorus loading. Phosphorus concentrations of experimental microcosms containing lake sediments, filtered lake water, and nymphs (417/m²) collected from western Lake Erie were compared to control microcosms containing sediments and lake water over a 7-day period. Phosphorus concentrations in microcosms containing Hexagenia were significantly greater than microcosms without nymphs. Further, we estimate the soluble reactive phosphorus flux from the sediments due to Hexagenia is 1.03 mg/m²/day. Thus, Hexagenia are a source of internal phosphorus loading. High densities of Hexagenia nymphs in western Lake Erie may help explain the “trophic paradox.” Furthermore, Hexagenia may be a neglected source of internal phosphorus loading in any lake in which they are abundant. Future studies of phosphorus dynamics in lakes with Hexagenia must account for the ability of these organisms to increase lake internal phosphorus loading.     

Effects of Great Lakes Water Loading upon Glacial Isostatic Adjustment and Lake History

Over the last century geological studies of the ancestral Great Lakes have confirmed that the large surface load of the Laurentide ice sheet deformed the region causing tilting of ancient lake shorelines. Models of this glacial isostatic adjustment mechanism have promoted understanding of this process but have only included ice sheet loads as the source of earth deformation in the region. We describe a method, utilizing a model of glacial isostatic adjustment combined with GIS, that recreates the paleohydrology of the Great Lakes. Predictions include the extent of late glacial, postglacial, and Holocene lakes and their associated outlets and bathymetries. This predicted history of the Great Lakes is similar to that obtained from a century of detailed field studies but our method uses only the present digital elevation model, a prescribed ice sheet chronology, and an assumed earth viscoelastic rheology. Ancient lake bathymetry predictions provide an estimate of water loads associated with each lake. The effect of these lake loads upon vertical deformation of the Great Lakes region is shown to be small, less than 15 m, but not insignificant when compared to approximately 150 m of deformation forced by ice and ocean loads. Maximum lake-induced deformation is centered upon Lake Superior where water depths were greatest. Where topography is low relief, prediction of shoreline locations should include the lake loading effect as well as the ice and ocean loads.     

乌梁素海浅水湖泊沼泽化现状及成因分析

为揭示乌梁素海面临的湖泊沼泽化问题与其驱动因素,针对2013年8月乌梁素海浅水湖泊沼泽化现状及成因,进行了实地勘查和采样,利用基于植物生物量与沉积速率、植物种类和泥深的2种评价方法进行分析。结果表明:乌梁素海沼泽化程度存在空间差异,部分区域属于沼泽化后期,分别分布在总排干入湖口处和湖区的中东部,其中,沼泽化综合指数在近入湖口处各点最大,沼泽化综合指数处于3~4,向湖区中东部逐渐减小,但仍然大于湖区中南部的下游区,该区域的沼泽化综合指标数为2~3,仍属于沼泽化盛期,直至湖区下游的最南端,属湖泊沼泽化不显著区。造成乌梁素海浅水湖泊沼泽化的主要原因很可能是在湖水流速缓慢和富营养化的综合作用下,外源物质淤积和水生植物蔓延,淤积物质和植物残体逐年累积形成底泥泥炭,随着泥炭的增厚和湖水变浅,从而演化为沼泽。     

Historical pattern of phosphorus loading to Lake Erie watersheds

Phosphorus (P) applied to croplands in excess of crop requirements has resulted in large-scale accumulation of P in soils worldwide, leading to freshwater eutrophication from river runoff that may extend well into the future. However, several studies have reported declines in surplus P inputs to the land in recent decades. To quantify trends in P loading to Lake Erie (LE) watersheds, we estimated net anthropogenic phosphorus inputs (NAPI) to 18 LE watersheds for agricultural census years from 1935 to 2007. NAPI quantifies anthropogenic inputs of P from fertilizer use, atmospheric deposition and detergents, as well as the net exchange in P related to trade in food and feed. Over this 70-year period, NAPI increased to peak values in the 1970s and subsequently declined in 2007 to a level last experienced in 1935. This rise and fall was the result of two trends: a dramatic increase in fertilizer use, which peaked in the 1970s and then declined to about two-thirds of maximum values; and a steady increase in P exported as crops destined for animal feed and energy production. During 1974–2007, riverine phosphorus loads fluctuated, and were correlated with inter-annual variation in water discharge. However, riverine P export did not show consistent temporal trends, nor correlate with temporal trends in NAPI or fertilizer use. The fraction of P inputs exported by rivers appeared to increase sharply after the 1990s, but the cause is unknown. Thus estimates of phosphorus inputs to watersheds provide insight into changing source quantities but may be weak predictors of riverine export.     

膨胀蛭石对富营养化水体中氮、磷富集效果试验研究

 利用水上种植技术治理湖泊富营养化已被证明是一种行之有效的方法,而提高作物产量一直是阻碍该技术普及的一个难点。利用膨胀蛭石具有的强吸附性和阳离子交换能力,采用室内试验的方法,研究膨胀蛭石对富营养化水体中氮磷物质的富集效果。结果表明：当富营养化水体中的总磷和总氮浓度分别为0.5mg/L和5mg/L时,经过蛭石8h的富集后,吸附基本达到平衡,水体中总磷和总氮的去除率可达78%和30%,而蛭石压滤液中总磷和总氮的浓度分别约是水体中总磷和总氮浓度的4和3倍。     

人工鱼群算法在湖泊富营养化综合评价中的应用

提出了一种对多项指标都能普遍适用的湖泊水质富营养化评价的逻辑斯谛模型,将人工鱼群算法应用于逻辑斯谛曲线模型中的参数优化,并用优化后的逻辑斯谛曲线模型对湖泊富营养进行综合评价。对我国5个湖泊富营养化实测数据进行评价实例研究,并与其他多种评价方法进行比较,结果表明该模型具有实用性和可行性。     

Lake management in Italy: the implications of the Water Framework Directive

This paper constitutes the first consideration of the implications of the lake management in Italy arising from the requirements of the Water Framework Directive (WFD), in comparison to the provisions of existing national legislation. As a matter of fact, the Italian decrees anticipated the principles of the WFD and have substantially modified the legislation in the field of water in Italy. Important changes were introduced, both in the monitoring systems and in the classification methods for surface waters. The environmental quality status will be determined not only by monitoring the aqueous matrix, but also the sediment and the biota. The new WFD is the major piece of European Union (EU) legislation with environment at its core; it will guide the efforts for attaining a sustainable aquatic environment in the years to come. In the WFD one can see elements from all the different forces that guided the reform of EU water policy: environmental protection, deregulation and subsidiarity. Moreover, elements of the economic instruments approach (introduction of the cost recovery principle), quantitative concerns (setting of minimum flow objectives for rivers and abstraction limits for ground waters) and the quest for integration (river basin management with representation of all stakeholders) are all reflected in the WFD. The paper summarizes the present condition of the most important lakes in the Italian lake district and also highlights the case of Lake Varese, representing a unique case of lake management in Italy. Preliminary results show that there are very few examples dealing with the elements thought appropriate to lake water assessment as required by the WFD. The application of the objectives of the type specified is a largely unknown issue.     

太湖湖滨带生态系统退化原因以及恢复与重建设想

太湖湖滨带的生态系统由于受人类强烈活动的影响受到损坏 ,其改善水环境的功能被削弱 ,太湖湖滨带的生态修复显得非常必要和迫切。为此 ,在对湖滨带水环境恶化及生态退化原因分析的基础上 ,提出了太湖湖滨带生态修复的一些设想及对湖滨带尽快进行生态修复的详细规划 ,并建议尽早进行实际操作。     

Long-term effect of tourism on the recent upward trend of phosphorus in a shallow alpine lake, Japan

The trend of total phosphorus (TP) concentrations in May-October of the tourist season was analyzed to examine the effect of more than 30 years of tourism on a shallow oligo-mesotrophic lake, Lake Oze-Numa. Annual mean TP concentrations increased rapidly at the rate of 11.6%/yr, from 7.5mg/m³ to 14.4 mg/m³ in 1982-90, and a mesotrophic condition of 23.1 mg/m³ is predicted for the year 2000. TP concentrations at the end of the tourist season were higher than at the beginning due to autumn circulation of the bottom sediment, and correlated with the current year TP loadings from tourists. TP concentrations in May were the lowest for the season, and showed good correlation with previous year concentrations. The recent upward trend of phosphorus concentration was mainly brought about by long-term tourism because 10% of the TP loading by tourists was estimated to accumulate annually in the water column. Phosphorus reduction measures should be taken urgently in such a shallow lake which now shows an accelerated rate of eutrophication.     

小型人工湖蓝藻水华季节性发生规律及其防治研究

以西安鱼化湖为研究对象,通过原位观测总结了鱼化湖季节性蓝藻发生的现象和规律,表明蓝藻水华的发生季节与水质富营养化程度密切相关,人工湖蓝藻水华产生的原因主要可归纳为外源因素和内源因素。在蓝藻水华现象和原因分析的基础上针对鱼化湖具体特点提出了蓝藻的治理方法,所得结论与建议可为以后人工湖蓝藻预防与治理提供借鉴。     

环境微界面对湖泊内源磷释放的影响研究

为揭示湖泊内源污染的微界面环境行为及机制，从环境微界面角度出发，研究湖泊水-沉积物界面三相结构模式中磷的界面反应过程。利用微电极系统获取了微界面溶氧浓度剖面，结合Profile模型进行了分析计算。结果发现，玄武湖湖心区沉积柱含氧层厚度达5mm，而湖口区则不到3mm，湖心区微界面上氧气消耗主要以自由扩散为主，而湖口区受微界面上微生物活动影响较大。利用梯度扩散薄膜技术（DGT）获取了水-沉积物界面上分辨率高达1mm的可溶性活性磷DRP剖面浓度分布，结果发现在湖口区沉积物表层2cm处有强烈磷释放现象，而在湖心区则未发现，这可能与含氧层厚度有着密切的联系，这一重要现象在常规尺度下可能被掩盖。