Analysis on the Eutrophication and Algae Blooms of Hongfeng Lake Reservoir in Guizhou

[Objective] The research aimed to know the ecological environment pollution characteristics of Hongfeng Lake water area and the evolution rule,which provided the theory basis for improving the water quality condition.[Method] Based on the investigation and research of indoor and outdoor,the water quality,aquatic ecosystem,pollution characteristic of sediment and occurrence law of algae blooms in Hongfeng Lake were comprehensively analyzed by combining with the relevant literatures.[Result] Hongfeng Lake was in moderate-heavy eutrophication situation,and the water quality was V-bad V class.The sediment accumulated a lot of nutrient salt,which was the important pollution source of eutrophication in Hongfeng Lake Reservoir.The aquatic ecosystem degraded,and it was easy to form the algae blooms.[Conclusion] The pollution treatment of Hongfeng Lake was extremely urgent.

The oxygen isotopic composition of phosphate as an effective tracer for phosphate sources in Hongfeng Lake

In order to characterize the oxygen isotopic composition of internal phosphate and explore the possibility of using these data to identify phosphate sources, we measured oxygen isotopic compositions of phosphate(δ^(18)O_p) in sediment pore water in Hongfeng Lake, a typical deep-water lake in a mountainous area. These data, in combination with δ^(18)O_p in surface water samples and water column samples, were successfully used to identify phosphate sources. The δ^(18)O_p value of sediment pore water ranged from 15.2% to 15.8%, with an average value of 15.5%—the δ^(18)O_p value of internal phosphate. The δ^(18)O_p values decreased gradually through the water column from 19.4% in surface water to 16.4% in deeper water, implying that internal phosphate had more negative δ^(18)O_p values than external phosphate. This finding was substantiated by horizontal variations in δ^(18)O_p values, which decreased with increasing distance from inflowing rivers. All collected evidence suggests that external and internal phosphate have distinctly different isotopic signatures and that these signatures have not been considerably altered by biological mediation in Hongfeng Lake. Therefore, δ^(18)O_p can be used to distinguish phosphate sources. A two-endmember mixing model showed that internal phosphate had an average contribution of 40%, highlighting the influence of internal phosphorus loading on aqueous phosphate and eutrophication. This study illustrates the need to reduce the internal phosphorus load from sediment and provides guidance for nutrient management and in-lake restoration treatment in Hongfeng Lake. The data presented here are limited, but serve to highlight the great potential of δ^(18)O_p as an effective tracer for identifying phosphate sources. Systematic investigations of the oxygen isotopic compositions of external phosphate, internal phosphate, and phosphate through the water column, in combination with in-lake P biogeochemical cycle study, would be desirable in further research.

Agricultural Non-point Source Pollution in Drinking Water Conservation Area of the Hongfeng Lake in Guiyang City

On the basis of investigating rural population, land types, livestock and poultry breeding scale in drinking water conservation area of the Hongfeng Lake in Guiyang City, as well as the urban domestic pol utant discharge coefficient, livestock and poultry excretion coefficient, nitrogen fertilizer and phosphate fertilizer loss rate in the first national pollution source survey, this paper tried to explore current situation of agricultural non-point source pollution, and provide scientific support for the pollution control. The results showed that in the drinking water conservation area of the Hongfeng lake in 2013, contribution rate of pollution sources to the water pollution in the Hongfeng Lake followed the sequence "livestock and poultry breeding > rural life > farmland fertilizer". Among all agricultural non-point source pollutants, livestock and poultry breeding pollutants were major pollution sources, with a contribution rate to CODCr, TP and NH3-N in water above 50%; rural domestic pollutants were also important pollution sources, its contribution rate to CODCr and NH3-N was 43.49% and 46.69%, respectively; contribution rate of farmland fertilizer pollutants to TN and TP was 33.76% and 27.71%, respectively, higher than that of rural domestic pollutants(25.87% and 6.75%). Therefore, the control of non-point source pollution within the drinking water conservation area should be enhanced, so as to control the pollution from the source.

Relationship between Water Quality and Stream Grade,Landscape Background of Hongfeng Lake Watershed in Guizhou Province

Xiayun Township watershed in the upper reaches of Hongfeng Lake is selected to study the relationship between stream grade and water quality.Turbidity and ammonium nitrogen concentration are obviously related to the stream grade,generally speaking,are positively correlated,and the water quality is degrading from the upper reaches to the lower reaches.In the future,the influence of different land use types on the water quality should be fully analyzed on the basis of enhancing the water quality monitoring to provide supports for effectively controlling non-point source pollutions and treating the water environment of Hongfeng Lake.

ANNUAL LAMINATIONS IN THE SEDIMENTS OF HONGFENG LAKE, CHINA

Hongfeng Lake is an eutrophic freshwater atificial reservior.It began to restore water in 1960. Three sediment cores were taken from both about 25m of water in the center of Hongfeng bake in May 1991. The stratigraphy of the three cores was easily matched .by using prominent marking horizons and characteristic aqnences of laminations. In three layer Samples studied, diatom and other algae taxa appear in repeating apuences. The presence of laminations may reflect either the regular changes of physical-chemical conditions within the lake or the variation in the intensity of erosion and transport of material from the catchment, pat iculaly where instability in the lake-water system has occult as a result of human activities. The larninations were mainly cantal by seasonal variation of envionmental conditions,particularly climate.Unlike t of the previous examples, they have ben fo￣ at most recent Sediments, in a small freshwater lake in the eastern slOPe of the QinghaiXiZang Plateau, China in a subtropical climate, which is adenly controlled by ￣theastern and southwestern mon￣n. It is believed that it's the first reported instanceOf laminated lake sediments from China.

Zinc Isotope Characteristics in the Biogeochemical Cycle as Revealed by Analysis of Suspended Particulate Matter(SPM) in Aha Lake and Hongfeng Lake, Guizhou, China

Zn isotope is a useful tool for tracing biogeochemical processes as zinc plays important roles in the biogeochemistry of natural systems. However, the Zn isotope composition in the lake ecosystems has not been well characterized. In order to resolve this problem, we investigate the Zn isotope compositions of suspended particulate matter(SPM) and biological samples collected from the Aha Lake and Hongfeng Lake, and their tributaries in summer and winter, aiming to explore the potential of this novel isotope system as a proxy for biogeochemical processes in aqueous environments. Concentration of dissolved Zn ranges from 0.65 to 5.06 μg/L and 0.74 to 12.04 μg/L for Aha Lake and Hongfeng Lake, respectively, while Zn(SPM) ranges from 0.18 to 0.70 mg/g and 0.24 to 0.75 mg/g for Aha Lake and Hongfeng Lake, respectively. The Zn isotope composition in SPM from Aha Lake and its main tributaries ranges from -0.18‰ to 0.27‰ and -0.17‰ to 0.46‰, respectively, and it varies from -0.29‰ to 0.26‰ and -0.04‰ to 0.48‰, respectively in Hongfeng Lake and its main tributaries, displaying a wider range in tributaries than lakes. These results imply that Zn isotope compositions are mainly affected by tributaries inputting into Aha Lake, while adsorption process by algae is the major factor for the Zn isotope composition in Hongfeng Lake, and ZnS precipitation leads to the light Zn isotope composition of SPM in summer. These data and results provide the basic information of the Zn isotope for the lake ecosystem, and promote the application of Zn isotope in biogeochemistry.

Microscale Chemical Features of Sediment-Water Interface in Hongfeng Lake

In situ microscale distributions of 02, H2S, pH and redox potential in sediments of Hongfeng Lake, SW China, were investigated using the powerful microsensor technique. Our results show that O2 was depleted within the top 3.9 mm in surface sediments, and H2S was subsequently detected at -6.0 mm depth, and reached its maximum concentrations at -25 mm. The degradation of organic matter and reduction of sulfate might be the major pathways of producing H2S in sediments, pH rapidly reduced in surface layers mainly due to H＋ release in the oxidation of organic matter. Eh also decreased sharply in surface sediments, probabl indicating the coexistence of Fe and Mn oxides with O2 in aerobic region. Furthermore, the programme of PROFILE was applied to model the 02 gradient, and good fit was obtained between the simulative values and the factual values both in sediments and in the diffusive boundary layer （DBL）. The results indicate that the depth-integrated O2 consumption rates within sediments were 0.083 and 0.134 nmol·m-3·s-1 in site S1 and site S2, respectively. In addition, there were distinct DBL in two sediment profiles, with 1.2 mm thickness in S1 and 0.9 mm thickness in S2. The diffusive fluxes of O2 within the DBL were 67.13 nmol·m-2·s-1 in S1 and 88.54 nmol·m-2·s-1 in S2.

Investigation of low-molecular weight organic acids and their spatiotemporal variation characteristics in Hongfeng Lake,China

The identities and concentrations of low-molecular-weight organic acids （LMWOAs） were determined by ion chromatography throughout a 20-m water column in Hongfeng Lake, China. The spatiotemporal variations of LMWOAs and their contributions to dissolved organic matter （DOM） in a research period of 24 hr were also investigated. The results demonstrated that five LMWOAs （lactic, acetic, pyruvic, sorbic, oxalic acid） were detected, and their total concentration and proportion in DOC were 6.55 μmol/L and 7.47%. Their average levels were 2.50, 0.65, 2.35, 0.96 and 0.09 μmol/L, respectively. LMWOAs were higher during daytime （10：00-18：00 on Jun 13, 2008） than nighttime （21：00-6：00 the next morning）, in particular 4.99 μmol/L high in the epilimnion （ 1 m water depth）, reflecting the fact that direct import from terrigenous sources and photochemical production from humic materials were dominant during LMWOAs＇ origin and accumulation. The same factors caused LMWOAs to be 0.63 μmol/L in the epilimnion higher than in the hypolimnion. The rapid decrease of total organic acid （TOA） up until 18：00 mainly resulted from bio-uptake and mineralization in the hypolimnion （〉1 m water depth）. Pyruvic acid increased with time in the epilimnion and decreased in the hypolimnion, largely related to the two contrary processes of continuous degradation and synthesis of macromolecular organic matter during life materials＇ cycle mediated by organisms. Simultaneously, plankton behavior and thermal stratification played a pivotal role in LMWOAs＇ behavior in the water column, causing decreasing and increasing profiles. The distribution of LMWOAs represents an interesting resource for biogeochemical research of DOM in aquatic ecosystems.

Air–water CO2 flux in an algae bloom year for Lake Hongfeng,Southwest China:implications for the carbon cycle of global inland waters

The carbon cycle of global inland waters is quantitatively comparable to other components in the global carbon budget. Among inland waters, a significant part is man-made lakes formed by damming rivers. Manmade lakes are undergoing a rapid increase in number and size. Human impacts and frequent algae blooms lead to it necessary to make a better constraint on their carbon cycles. Here, we make a primary estimation on the air–water CO_2 transfer flux through an algae bloom year for a subtropical man-made lake—Hongfeng Lake, Southwest China. To do this a new type of glass bottles was designed for content and isotopic analysis of DIC and other environmental parameters. At the early stage of algae bloom,CO_2 was transferred from the atmosphere to the lake with a net flux of 1.770 g·C·m^(-2). Later, the partial pressure(pCO_2) of the aqueous CO_2 increased rapidly and the lake outgassed to the atmosphere with a net flux of 95.727 g·C·m^(-2). In the remaining days, the lake again took up CO_2 from the atmosphere with a net flux of 14.804 g·C·m^(-2). As a whole, Lake Hongfeng released 4527 t C to the atmosphere, accounting for one-third of the atmosphere/soil CO_2 sequestered by chemical weathering in the whole drainage. With an empirical mode decomposition method, we found air temperature plays a major role in controlling water temperature, aqueous pCO_2 and hence CO_2 flux. This work indicates a necessity to make detailed and comprehensive carbon budgets in man-made lakes.

7~Be: A Geochemical Tracer for Seasonal Erosion of Surface Soil in Watershed of Lake Hongfeng, Guizhou, China

e penetrative depth in undisturbed surface soil is within 4 mm.7￣Be activity shows exponential decrease with soil depth, which is expressed as a diffusion process.7￣Be penetrative depth in undisturbed surface soil is apparently deeper in the fall (0.22-0.37 g cm￣(-2) than in the spring (0.11-0.28 g cm￣(-2) at the same site; Whereas, ￣7Be apparent activity at the top of surface soil is higher in the spring (0.3-2.2 Bq g￣(-1_) than in the fall (0.2-0.5 Bq g￣(-1) at the same site. The ￣7Be inventory (189-544 Bq m￣(-2) changes with both locations and seasons. Although the ￣7Be flux to the earth's surface increases with amount of precipitation, its maximum inventory in the soil profiles decreases to 30%-40% after the rainy period. Calculated by the diffusion equation, the erosion and accumulation rates of soil particles are agreeable with the observation in situ., which shows that the rates in fall are 1.5 times those in spring. The eroded soil particles almost all have been removed on the tablelands rather than transported into the drainage system. This indicstes that the soil erosion process in the karst region is only partial transportation within a short distance.

DATING CHARACTERISTICS AND EROSION TRACES OF ^(137)Cs VERTICAL PROFILES IN HONGFENG LAKE SEDIMENTS

The fallout nuclide 137Cs（half-life 30.23 a）of nuclear tests is one of the important tracers for recent lake sedimentation and watershed erosion.According to the data of the 137Cs vertical profile in the sediment core HF8801,

VARIATION OF VERTICAL PROFILE FOR ^(210)PO_(ex) AT THE TOP OF SEDIMENT IN HONGFENG LAKE

Since 1963 when the 210Pb dating method was first used by Goldberg, the 210Pbex technique is widely employed for dating lake and estuarine sediments. However, due to the 222Rn loss from the surface of sediments, the calculated sediment accumulation rate

Enzymatic and Microbial Degradation of Organic Matter in Lake Hongfeng, Guizhou Province, China

In this work, enzymatic and microbial degradation of organic matter in Lake Hongfeng, Guizhou Province, is described in terms of variations in DNA, α-glucosidase and sulfate-reduction bacteria (SRB). Organic matter is degraded by microbes and extracellular enzymes excreted by the former, to a relatively low content below the 11-cm sediment depth. The distribution of DNA indicated that microbes are very active at the 9-cm sediment depth, where organic matter is degraded by microbes intensively. The contents of α-glucosidase are highest in suspend layer ({0.75} μmol·min+{-1}·g+{-1} dry sediments), showing that starch and hepatin in organic matter have been degraded intensively. α-glucosidase activity weakens with sediment depth. At the 11-cm depth where the degradation of organic matter started to slow down, α-glucosidase activity has been reduced to {0.17} μmol·min+{-1}·g+{-1} (dry sediment). Molecular biological research indicated that sulfate reduction bacteria (SRB) are distributed mainly at the upper 7-cm sediments in Lake Hongfeng. Combined with the results of research on the variations of organic matter and SO+{2-}-4, it is indicated that SO+{2-}-4 is unlikely to become an important electron acceptor and sulfate reduction is not limited by the supply of organic matter in Lake Hongfeng.

基于山水林田湖草协同/权衡的生态管控分区研究

【目的】厘清山、水、林、田、湖、草之间的协同和权衡关系,优化红枫湖流域的生态管控分区,制定科学的分区管理措施。【方法】以红枫湖流域为研究区,分析各子系统在全域和局部空间的协同/权衡关系,探讨基于山、水、林、田、湖、草协同理念的生态管控分区方案。【结果】流域内生产区与生态区的空间分异性明显,林地、草地的主要生态保护功能不同,湖面临高污染风险,除湖子系统调蓄水能力较好的区域外,其他区域农业种植依赖于降水。红枫湖流域可划分为9类生态管控区。【结论】基于协调、权衡关系的分区方法能够保证各类分区生态环境差异的最大化,各分区管理措施差异明显。

基于高通量测序的红枫湖入湖口湖岸缓冲带微生物学特征分析

本文选取贵阳市重要饮用水源地——红枫湖为研究对象,在不同生境下的4条主要支流入湖口缓冲带处布点采集土壤样品,采用HiSeq测序对土壤细菌16S rRNA V4区和真菌ITS1区进行测序,并结合土壤环境因子,对微生物群落组成特征与多样性进行分析,以期为恢复红枫湖湖岸缓冲带植被生态提供参考和依据。结果显示,4个缓冲带中共发现细菌种类有53个门、813属;真菌种类有6个门、406属,各缓冲带在门水平上的组成相似,共同的优势细菌门为变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、蓝菌门(Cyanbacteria)等,优势真菌门为子囊菌门(Ascomycota)、担子菌门(Basidiomycota)和壶菌门(Chytridiomycota)。在细菌属水平上,麦翁河缓冲带土壤中的硝化与反硝化细菌含量(7.13%)高于其余三个缓冲带。4个入湖口缓冲带中土壤细菌的多样性指数排序为:HL>MX>MW>YC;真菌的多样性指数:YC>MX>HL>MW。相关分析结果显示细菌多样性指数与全氮呈显著正相关(n=12,r=0.567,p<0.05),真菌群落多样性指数与全盐量呈显著正相关(n=12,r=0.622,p<0.05)。因此,不同的植物组成对湖岸缓冲带土壤微生物的组成和多样性产生影响,同时人类垦殖活动也起着不可忽视的作用。

水位调度对高原湖库水源地浮游藻类的影响模拟

高原湖库饮用水源地多面临严重的富营养化问题,探寻高效的生态调度控藻技术是解决此问题的关键,水位调度是其中最为经济和有效的调控方式之一。基于MIKE 3构建了湖库三维水动力-水质生态耦合模型,以红枫湖为例,开展了水位调度对高原湖库水源地浮游藻类的影响预测研究。结果表明:水位对湖区藻类生长聚集具有明显的调节作用,其中红枫湖区的流场在水位突降期间明显增加,在南湖与北湖连接段的流速普遍增加至0.3 m/s以上,而这种水动力引起的扰动对打破藻类结构、减少湖区的藻生物量具有明显的效果,红枫湖南湖的藻浓度大幅下降。另外,库区长时间稳定在低水位运行对于藻类防控具有十分不利的影响。

基于环境DNA宏条形码的红枫湖鱼类多样性研究

2020年11月,按地理区域将贵州省清镇市猫跳河梯级水电站拦河而成的典型喀斯特高原型深水人工水库红枫湖水域划分为南湖(S1、S2、S3)和北湖(S4、S5、S6)共6个采样点,利用eDNA(environmental DNA,eDNA)宏条形码技术探究了贵州喀斯特高原水域鱼类多样性。结果:共监测到鱼类28种,隶属于4个目、13个科、25个属,其中梭鲈属(Sander)、鲚属(Coilia)、鳜属(Siniperca)、乌塘鳢属(Bostrychus)和鲈属(Perca)为优势属;南北湖鱼类群落空间分布差异性不显著(P>0.05),但各样点鱼类群落组成差异明显,其中S2鱼类群落多样性指数最高(Chao1618.9;Shannon 3.16),S6鱼类群落多样性指数最低(Chao1190.87;Shannon 0.98)。在所有鱼类组成中,鲈形目共13种,占46.43%,这表明该水域可能受人工养殖及引种放流等影响而导致外来物种入侵。结果表明,环境DNA技术可用于喀斯特高原水域的鱼类多样性及空间分布研究,并丰富了红枫湖鱼类基础资料及调查手段。

红枫湖控制发电水位研究

红枫湖是长江流域乌江一级支流猫跳河流域梯级电站的龙头水库,属大(2)型水库,主要任务是为城市居民生活和工业供水、农业灌溉、发电,兼顾环保型旅游。红枫湖是贵阳市的重要饮用水水源地,随着红枫湖城市供水量逐渐增大,为优先满足市民用水需求,需要协调好城市供水和发电用水之间的关系。通过现状调查、兴利调算、水能指标复核等,综合考虑红枫湖的供水、防洪、发电之间的关系,拟定红枫湖的最低控制发电水位线,以保证贵阳市的饮用水安全。按发电控制水位调度,受红枫湖周边城市取水和工矿企业取水影响,红枫水电站多年平均年发电量将减少2166万kW·h;受红枫湖、百花湖周边城市取水和工矿企业取水影响,猫跳河梯级电站多年平均年发电量合计减少2.91亿kW·h,按红枫电厂上网电价0.2761元/kW·h计算,则梯级电站相应赔偿电量损失估算费用8035万元/a。

贵州红枫湖水体溶解有机质的剖面特征和季节变化

溶解有机氮（dissolved organic nitrogen，DON）与溶解有机碳（dissolved organic carbon，DOC）相结合在湖泊水体溶解有机质（dissolved organic matter，DOM）的研究中少有报道．本研究对贵州喀斯特地区高原性湖泊——红枫湖水体DOC和DON的含量进行了近2a的测定，研究了DOM的剖面特征和季节变化，并探讨了DOM垂向分布和季节变化的影响因素．结果表明，红枫湖DOC的浓度范围为1．60～3．08mg·L^-1，DON的浓度范围为0．10～0．37mg·L^-1．在湖水混合期表层和底层的DOC和DON的浓度基本一致，在湖水分层期DOC和DON浓度表现出从表层往底层减小的趋势．表层水体（0～2m或3m）DOC的浓度在春未夏初或夏季达到最大，DON的浓度在春末夏初稍高于其它月份结合叶绿素和降雨的数据分析认为，藻类活动和陆源输入直接导致了表层水体DOM的季节变化模式．DOM的C／N在一般情况下向下增大，但在夏季南湖的垂向水柱上，DOC和DON的浓度在12m以下增大，C／N从12m的18．1下降为14m的14．9，并向下持续减小，这很有可能是颗粒态有机质发生降解释放出C／N较低的DOM，成为水体内DOM的一个内源，

红枫湖沉积物中重金属污染特征与生态危害风险评价

调查了红枫湖沉积物中重金属的含量、分布特征与富集情况.分别以现代工业化前正常颗粒沉积物中重金属含量的最高背景值和红枫湖周边环境土壤的背景值为参比值,对红枫湖沉积物中重金属的富集系数和生态危害系数以及各采样点的生态危害指数进行了探讨,并结合瑞典学者Lars Hakanson潜在生态危害指数法对红枫湖沉积物中重金属的生态危害进行了评价.结果表明:该湖泊沉积物中重金属含量分布呈现一定的区域特征,北湖湖区重金属平均含量高于南湖湖区;以现代工业化前正常颗粒沉积物中重金属含量的最高背景值为参比值,重金属的富集顺序为Cd>Hg>As>Cu>Zn>Pb,污染水平顺序为Cd>Hg>As>Cu>Pb>Zn;以红枫湖周边环境土壤平均值为参比值,重金属的富集顺序为Cu>Cd>Zn>As>Pb>Hg,污染水平顺序为Cd>Hg>As>Cu>Pb>Zn.