2007年京杭大运河扬州市区段和里下河段水质变化比较及对策的研究

通过对京杭大运河扬州市区段和里下河段pH、COD、DO、BOD、氨氮及石油类指标监测,分析2007年水质变化及主要污染物。得出京杭大运河扬州段主要为有机污染,里下河水质优于市区。大运河春秋季水质相对较差,夏、冬季相对好转。市区比里下河pH低0．5左右,COD含量高0．5～0．3mg·L^-1,DO含量高0．8mg·L^-1,春季BOD,含量高2．3mg·L^-1,氨氮含量高0．44mg·L^-1。因此,市区段春、秋季应重点针对削减BOD5、COD、氨氮进行水污染治理。里下河段春季针对降低COD进行治理,秋季针对降低COD、BOD5氨氮进行水污染治理。两区在夏季重点应针对提高水体中DO含量进行治理。提出的植物治理技术及管理对策措施,不仅为扬州到2010年建成生态市不断改善水环境质量,提供技术支撑和决策依据,也为如何提高具有跨流域、区域和内城河多重功能的水体水质提供启示。     

京杭运河(杭州段)河网水质模拟

京杭运河杭州段河网属于典型的平原河网地区,根据平原河网的水流以及污染特点,利用一维对流扩散方程建立了该地区河网水质模型,采用全隐中心差分格式离散方程,并用追赶法求解。对京杭运河杭州段河网进行水质模拟,并利用2007年上半年常规水质监测断面水质监测数据对模型计算结果进行验证。验证结果表明水质模拟结果较为理想,模型能较为准确的反映河网水质变化趋势,可以用于该地区河网水质改善研究。     

Vegetation Response to Early Holocene Warming as an Analog for Current and Future Changes

Abstract: Temperatures in southwestern North America are projected to increase 3.5–4 °C over the next 60–90 years. This will precipitate ecological shifts as the ranges of species change in response to new climates. During this shift, rapid‐colonizing species should increase, whereas slow‐colonizing species will at first decrease, but eventually become reestablished in their new range. This successional process has been estimated to require from 100 to over 300 years in small areas, under a stable climate, with a nearby seed source. How much longer will it require on a continental scale, under a changing climate, without a nearby seed source? I considered this question through an examination of the response of fossil plant assemblages from the Grand Canyon, Arizona, to the most recent rapid warming of similar magnitude that occurred at the start of the Holocene, 11,700 years ago. At that time, temperatures in southwestern North America increased about 4 °C over less than a century. Grand Canyon plant species responded at different rates to this warming climate. Early‐successional species rapidly increased, whereas late‐successional species decreased. This shift persisted throughout the next 2700 years. I found two earlier, less‐extreme species shifts following rapid warming events around 14,700 and 16,800 years ago. Late‐successional species predominated only after 4000 years or more of relatively stable temperature. These results suggest the potential magnitude, duration, and nature of future ecological changes and have implications for conservation plans, especially those incorporating equilibrium assumptions or reconstituting past conditions. When these concepts are extended to include the most rapid early‐successional colonizers, they imply that the recent increases in invasive exotics may be only the most noticeable part of a new resurgence of early‐successional vegetation. Additionally, my results challenge the reliability of models of future vegetation and carbon balance that project conditions on the basis of assumptions of equilibrium within only a century.     

京杭大运河中下游段天然水化学变化特征及驱动因素

为揭示京杭大运河天然水化学特征及人为活动的影响,于2019~2020年采集徐州至嘉兴段主要城市站点河水测试,同时收集苏锡常段1959~1962年和1975~1977年的水化学数据与沿线主要城市近年的社会经济数据,在此基础上进行了分析.结果表明,研究区水化学类型主要受流域碳酸盐岩风化作用,但K⁺+Na⁺当量浓度占总阳离子高达40.39%,高于一般地表水,说明运河天然水化学已受到人为因素的显著影响.空间上,运河主要离子质量浓度、总硬度和总碱度从徐州站向下游总体上有减小的趋势,但在无锡和苏州站各参数显著升高;分析苏锡常段60年来的水化学变化发现,其Na⁺和SO₄^2-分别升高了约16倍和12倍,总溶解固体（TDS）也升高了近3倍,同时苏锡常段河水目前（Ca²⁺+Mg²⁺）/HCO₃^-比值普遍大于1,显著高于1959~1962年,反映了人类活动影响的结果.结合运河流域社会经济发展情况的分析显示,人为活动排放的硫氧化物加速了流域碳酸盐岩的风化,这是导致这一变化的主要因素.进一步统计分析表明,城市生活污水和工业废水的排放等是造成大运河天然水化学盐渍化的主要驱动因素.本研究可为协调城市发展和保护大运河流域水生态环境提供科学基础.     

大运河丰水期水体中全氟化合物的分布

应用固相萃取分离富集与高效液相色谱/电喷雾负电离源串联质谱法分析了2014年6月采自京杭大运河水体41个样品中17 种全氟化合物,对其污染现状及分布进行了讨论,并对污染来源进行了分析.大运河水体中的全氟化合物总浓度（∑PFCs）范围为7.4~153.5ng/L.PFCs含量有一个大致从南到北递减的趋势.大运河江南部分∑PFCs在杭州嘉兴河段处出现高值点.长江以北部分在德州地区出现高值点,南方大部分河段以PFOA为主导化合物,而在北方河段PFOA的主导性降低.对大运河沿途地区城镇化、经济水平与各地区大运河水体平均∑PFCs浓度的关系进行了比较,结果表明具有较高的相关性.     

京杭运河淮安段水利防护林群落护堤防蚀效应

对京杭运河淮安段水利防护林群落的护堤防蚀效应进行了研究.结果表明,防护林植被可以明显改善地表土壤物理性能,明显增加土壤总孔隙度和毛管孔隙度,降低土壤容重.不同植物群落对地表土壤的护堤防蚀效应明显不同.早熟禾群落和女贞群落可以有效提高土壤有机质含量和土壤通气蓄水效应.有植被分布的地表土壤抗蚀性比裸地显著增强（P＜0.05）.相对而言,早熟禾群落土壤水稳性指数最大（0.892）,其余依次为女贞群落（0.835）、梨树群落（0.791）、桃树群落（0.530）、水杉群落（0.397）和裸地（0.341）.植物群落土壤的抗蚀性与植物根系生物量、根数和土壤有机质含量分别呈显著正相关（P＜0.01）.     

TROPHIC STATE EVALUATION FOR SELECTED LAKES IN GRAND TETON NATIONAL PARK1

ABSTRACT: Increased visitation at Grand Teton National Park (GTNP) has raised concerns about impacts on surface water in the park. The purposes of this study are to perform a benchmark trophic state survey for comparison to future evaluations and to identify possible areas of concern. Four watershed regions based on geographic and geologic features were delineated for study. Six Alpine lakes, six Moraine lakes, three Valley lakes, and two Colter Bay lakes are evaluated. Lakes were sampled for total phosphorus (TP), chlorophyll‐a, and transparency. The water quality, as defined by trophic state, in the park is generally good. Oligotrophic to mesotrophic conditions were found in the Alpine and Moraine lakes and mesotrophic to eutrophic conditions were found in the Colter Bay and Valley lakes. High inflow TP concentrations in the park's northeast side may be due to the presence of natural geologic phosphate from the Phosphoria Formation.     

梨形环棱螺保护酶分子标志物在大运河污染评价中的应用

运用室内模拟法、样点笼内放养法和直接采样法研究京杭大运河不同污染程度环境对梨形环棱螺内脏团中超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响.结果表明:梨形环棱螺组织抗氧化保护酶系统的SOD、POD、CAT活性是指示污染的敏感指标,其监测结果与水质化学评价结果基本一致.CAT活性在临界范围内随着污染程度加深,抑制作用加强.POD活性在污染环境中被激活, 但各时间段的增幅不尽相同.SOD活性变化不稳定,较适合作为短时间内的监测指标.比较而言,这3种测定保护酶分子标志物活性的试验方法以样点笼内放养法最优,直接采样法最不可取.     

京杭大运河(杭州段)三氮变化及影响因素浅析

根据已建立的ＮＨ_３－Ｎ、ＮＯ_２~－－Ｎ、ＮＯ_３~－－Ｎ基本水质数据库,对京杭大运河（杭州段）三氮的水质现状和趋势作了分析,结果表明,工业废水与生活污水是河水中ＮＨ_３－Ｎ升高的主要原因,ＮＯ_２~－－Ｎ和ＮＯ_３~－－Ｎ与硝化反应有关,不同水期对三氮都有影响。     

京杭大运河扬州段表层沉积物中多环芳烃的分布及风险评价

采用HPLC定量检出京杭大运河扬州段表层沉积物中16 种优控PAHs 的总量范围在505~4532.2ng/g (干重) 之间,平均值为2359.4ng/g,属中等污染水平,沉积物中的多环芳烃主要来源于煤炭、木材及石油的不完全燃烧;利用沉积物质量基准法(SQGs)对京杭大运河扬州段沉积物中多环芳烃的风险评价表明, 严重的多环芳烃生态风险在京杭大运河扬州段沉积物中不存在,负面生物毒性效应会偶尔发生, 风险主要来源于低环的多环芳烃。