Lake eutrophication management modeling using dynamic programming

Lake eutrophication problems have received considerable attention in Taiwan, especially because they relate to the quality of drinking water. In this study, steady-state river water quality and lake eutrophication models are solved using dynamic programming algorithms to find the nutrient removal rates for eutrophication control during dry season. The kinetic cycle of chlorophyll-a, phosphorus and nitrogen for a complete-mixed lake is considered in the optimization framework. The Newton-iterative technique is adopted to solve the nonlinear equations for the steady-state lake eutrophication model. The optimization framework is applied to Cheng-Ching Lake in southern Taiwan. Several nutrient loading scenarios for eutrophication control are studied. Optimization results for nutrient removal rates and corresponding wastewater treatment capacities of each reach of the Kao-Ping River define the least cost approach to lake eutrophication control. A natural purification method, structural free water surface wetland, is also suggested to save more investment and improve river water quality at the same time.     

The dualistic approach of FCA: a further insight into Ontario Lake sediments

The investigation of object-by-attribute matrices is very common in statistics and data analysis with the aim of uncovering every possible relationship among objects and/or attributes. Formal Concept Analysis (FCA) is a method, which stems directly from partial order and lattice theory, which provides an efficient tool to symmetrically uncover linkages among objects and attributes whenever a relation stands among the two sets. It provides efficacious graphical representation and computes association rules between attributes, thus helping in the detection of possible synergism or antagonism of attributes. In this paper, FCA potentialities are discussed and described by means of a case study already investigated by other partial order techniques: the case of Lake Ontario sediment samples. Data derive from a ‘test battery’ for a simultaneous analysis of degradation of Lake Ontario samples, which are basically of two typologies: hygienic and toxicity tests. A multi-valued approach is adopted to cope with the ordinal feature of data. Results highlight interesting interaction among hygienic compounds and a synergism between the two toxicity tests.     

洪泽湖富营养化和生态状况调查与评价

为了解洪泽湖水质状况，对2000年洪泽湖富营养化状态和生态特性的调查结果进行了分析，洪泽湖水中总磷、总氮和高锰酸盐指数年均值超《地表水环境质量标准》（GHZB1-1999）中Ⅱ类水标准，超标倍数分别为12倍、10倍和0.24倍；总磷、总氮、透明度年均值超湖库特定项目V类标准，洪泽湖处于中-富营养化状态。对洪泽湖生态特性分析表明，由于洪泽源独特的湖泊形态，“藻型浊水状态“和“泥沙型浊水状态“交替出现，遏制了湖水从高营养盐含量向全面富营养化状态演变，保证了底栖动物的良好生长环境，从而形成了洪泽湖独特的环境生态平衡状态。     

YSI 6600传感器在太湖蓝藻预警工作中的应用

通过对太湖饮用水源地2个取水口水体中的蓝藻密度(CBD)和叶绿素(Chl)分别进行 YSI 6600-v2水质多参数仪和实验室显微镜检分析,探讨了CBD和Chl在预警工作中的应用.结果表明,在CBD与Chl相关性显著时期内,藻类群落结构相对稳定;CBD和Chl相关性不显著时期内,藻类群落结构变化较大.ρ(CBD)/ρ(...     

饶河入鄱阳湖口处沉积物中重金属分布特征及形态研究

为了解饶河入鄱阳湖湖口重金属污染状况,在鄱阳湖饶河入湖段设置了3个采样点,用原子吸收分光光度计对沉积物进行了重金属Cu、Pb、Zn的测定,分析了这3种元素在各采样点的形态分布特征.结果表明:饶河人鄱阳湖口处沉积物中Cu、Pb、Zn的污染较为严重,呈现出复合污染的趋势.该区域沉积物中3种元素的分布受水流的影响较大,其形态...     

从溶解氧含量变化分析博斯腾湖水质现状

通过对博斯腾湖2002 - 2006年水质溶解氧含量变化的分析研究,得出博斯腾湖水位下降,水质溶解氧含量呈下降趋势,博斯腾湖的部分区域有富营养化的趋势的结论.并提出合理调配用水量、在湖周边保持适量的湿地、利用外力加速水质的循环等对策和建议.     

新疆艾比湖湿地自然保护区建设及效益分析

艾比湖是典型的干旱区湖泊,具有特殊湿地的干旱生态系统.晚更新世晚期开始,由于气候逐渐变干,艾比湖不断萎缩.20世纪50年代至80年代末,由于湖区人口的激增及其对水土资源的不合理开发利用,加速了湖泊干缩的进程,80年代后期至今,随着新疆北部的气候向暖湿转变,以及湖区人口和耕地增长趋缓,艾比湖湖面出现波动扩张态势.本文对艾比湖湿地自然保护区的建设及效益情况进行了阐述.     

逻辑斯谛模型在新疆喀纳斯湖旅游业发展中的启示

随着旅游业的发展,如何处理旅游业发展与生态环境的关系,寻求旅游与自然的和谐发展,成为旅游研究中的焦点.逻辑斯谛模型是一个属于增长类型的模型,经过逻辑斯谛方程在新疆喀纳斯湖旅游发展中的延伸应用,为进一步拓展生态旅游景区研究奠定了理论基础.     

太湖水-气界面温室气体N2O日通量变化特征

阐述了最重要的温室效应气体N2O的来源,湖泊中N2O产生机理,监测了太湖水-气界面四季N2O日通量,并分析了N2O日通量变化特征,发现太湖大部分时间是N2O的源,少部分时间是N2O的汇.春、夏、秋、冬四季的平均N2O日通量分别是0.018 mg/(m2·h)、0.065 mg/(m2·h)、0.003 mg/(m2·h)和-0.002 mg/(m2·h).夏季较高,而春、秋、冬季较低.     

西洞庭湖鱼类物种多样性及其时空变化

洞庭湖是长江中游现存仅有的两大通江湖泊之一,研究其鱼类资源对了解湖泊通江的生态作用有着重要意义。为此,在2002年9月~2004年6月每月定期定点在西洞庭湖区开展鱼类调查,结果如下：① 实地调查到鱼类111种,隶属9目20科,包括中华鲟、胭脂鱼等珍稀物种;②鱼类物种数年动态波动较大,最高月份达69种,最低为26种,月均50±13种;③物种多样性指数年动态与物种数年动态大体一致,最高达3.34,最低为1.89,月均2.84±0.38;④空间分布上,位于入湖口的调查点物种数和多样性指数高于内湖,且差异有显著性(p<0.05);⑤在数量上,湖泊定居型鱼类占50%以上,其中,鲫数量最多,占16%左右。可见：西洞庭湖作为通江湖泊在鱼类多样性的保护上起到避难所和交流场所的作用;目前,西洞庭湖鱼类在生态组成上,湖泊定居型鱼类比重有逐渐增加的趋势。