东五里湖基底条件和湖岸(底)类型对生态重建的影响

湖泊地形地貌和湖岸类型对生态重建有很重要的影响.研究了东五里湖清淤后的地形地貌;在实地词查其水生生物生长的情况下,划分出5种湖岸(底)类型,并讨论了基底条件和湖岸(底)类型对生态重建的影响.     

ASPECTS OF THE UNDERWATER LIGHT FIELD OF EIGHT CENTRAL NEW YORK LAKES1

ABSTRACT: The underwater light field of eight central New York lakes, which represent a wide range of trophic state, was characterized through paired measurements of Sechi disc transparency (SD, m) and diffuse light attenuation (K_d, m^?1). A total of 90 paired measurements are included in the data base. Substantial variability in the K_d SD product with time within individual systems, and amongst systems, was observed, which indicates differences in the relative contributions of absorption and scattering to attenuation. More than 50 percent of the temporal variability in K_d was attributable to attendant variations in chlorophyll a (C, mg m^?3) in only two of the lakes. Estimates of the adsorption (a, m^?1) and scattering (b, m^?1) coefficients based on paired K_d and SD measurements compared well with more precise determinations available for one of the lakes. Determinations of a and b for the eight lakes, from SD and K_d measurements, indicated great system-specificity and temporal variability in these characteristics. The temporal variability in relative contributions of a and b to K_d is consistent with covariation of different attenuating components and the lack of correlation between C and K_d in most of the study lakes.     

OPTICAL HETEROGENEITY IN GREEN BAY1

Differences in light penetration and light attenuating components and processes are documented along 112 km of the major (NE/SW) axis of Green Bay (Lake Michigan) during a three-day cruise (May 25–27, 1982). Measurements included diffuse attenuation of downwelling irradiance (k_d), Secchi disk transparency (SD), phytoplankton pigments (chlorophyll a and phaeophytin), turbidity (T_n), and dissolved color (absorbance). The relative importance of absorption and scattering to attenuation was calculated from paired measurements of k_d and SD. Absorption and scattering coefficients were calculated; value estimates were supported by a strong linear relationship between the scattering coefficient (b) and T_n (b = 0.99 *T_n; r²= 097, n = 12). Light attenuation characteristics, including the extent of light penetration and the magnitudes and relative importance of absorption, scattering and individual attenuating components, were found to be heterogenous in space. This heterogeneity is due to the characteristics and positions of entry of fluvial discharges to the bay as they influence levels of dissolved color (Gelbstoff), phytoplankton standing crop, and inorganic particulates. Identification of key processes regulating light penetration and their potential for response to pollution control measures can aid in the development of a water quality management plan for Green Bay.     

Beyond accountability: alternative rationales for transparency in global trade politics

ABSTRACT

The conventional view of transparency is that it is a critical tool to combat corruption and ensure the democratic accountability of government. This article argues that the negotiation of mega-regional trade agreements (RTAs) and their content indicates the need distinguish different types of transparency. Trade activists that call for drafts of the text of a mega-RTA to be released while negotiations are ongoing are seeking deliberative transparency, which provides opportunities for meaningful public participation and consultation. The trade advisory systems that could provide opportunities for deliberation instead deliver technocratic transparency; the rationale is to increase the effectiveness of mega-RTAs rather than their democratic legitimacy. Frequent leaks of draft chapters of mega-RTAs provide opportunities for deliberation, but some actors involved in leaking are engaged in disruptive transparency where the aim is to complicate trade negotiations, making a final deal less likely. While these varieties of transparency emerge in the context of the negotiating process, disciplinary transparency – which often becomes a regulatory tool for multinational corporations to influence policy-making – is found in the text of mega-RTAs. Certain forms of transparency increase the likelihood that mega-RTAs will be compatible with strong environmental policy, while others may have a detrimental impact.     

Transparency in global sustainability governance: to what effect?

ABSTRACT

Transparency in environmental governance is no longer an uncontroversial answer to problems of accountability and effectiveness. How to design effective transparency systems and in what policy contexts they are effective remain contested issues. This special section, consisting of this introduction and four research articles, interrogates complex and potentially conflicting links between transparency, accountability, empowerment and effectiveness in environmental governance. Building on existing literature and the four contributions, we discuss persisting diversity in varieties of transparency, the evolving dynamics of commodity chain transparency, and the consequences of emerging novel forms of digitalized transparency. As we show, the contributions to this special section interrogate in novel ways the transformative potential of transparency, through shedding light on the performative effects of transparency in ever more complex environmental governance contexts. These contexts may include, inter alia, the growing ubiquity of traceability in transnational commodity chains, the need for ever more anticipatory (ex-ante) forms of environmental governance, and an ever-broadening quest for digitally monitored environments. In particular, the impacts of the real-time ‘radical’ transparency engendered by use of novel digital technologies remain under-analyzed in the sustainability domain. We conclude by raising several critical concerns that deserve further scientific research and policy debate.     

新型天然有机高分子阳离子改性絮凝剂的制备研究

为研发绿色絮凝剂,改善水资源短缺现状,以天然有机高分子玉米芯准纳米粉(QCCP,直径<0.147 mm)为母体,用三乙胺与环氧氯丙烷共聚产物为阳离子单体(M)进行改性.采用H2O2-FeSO4作引发剂,制得一种新型天然有机高分子阳离子改性絮凝剂DXSL-Ⅰ,确定了优化的反应条件.将2.0 g QCCP与含有0.7 g NaOH的8 mL水混合,40 ℃条件下碱化60 min.然后,加入8 mL醚化单体和体系总质量0.01%引发剂以及0.1% NaCl作为抑制剂,55 ℃条件下醚化3.5 h.实验表明,用该絮凝剂絮凝处理高岭土悬浊液时,不到5 min中层透光率就能达到95%以上.其絮凝性能达到传统絮凝剂聚丙烯酰胺的技术指标.此外,运用红外谱图化学结构分析和扫描电镜介观形貌分析辅助说明了改性反应的成功.     

Variations in Epilimnion Thickness in Small Boreal Shield Lakes: Relationships with Transparency, Weather and Acidification

We used multiple linear regression analysis to investigate relationships between late-summer epilimnion thickness, transparency, lake area, acidity and summer weather conditions in a large ($n = 116$) multi-year data set for 9 small Boreal Shield lakes. Dissolved organic carbon (DOC) was the best individual predictor of late summer epilimnion thickness ($r^{2} = 0.69$). Total chlorophyll~$a$, the number of days between ice-out and late-summer stratification, and lake area collectively explained an additional 14% of the variation in epilimnion thickness. The three attributes of summer weather that we examined, mean daily temperature, mean daily wind speed, and mean daily hours of bright sunshine, did not add to the predictive ability of our regression model. Lake acidity also did not add directly to the predictive ability of the model, likely because DOC concentrations already reflected the effects of pH. Our study supports an increasing body of evidence indicating that the dominant effects of climate change on lake thermal structure in small lakes will be through effects on processes that affect lake transparency.     

基于实测高光谱数据的太湖悬浮物浓度与透明度分区

通过实地测量太湖水体的反射光谱和表层水质,利用实测数据以及水-气界面辐射传输模型计算其遥感反射率,并根据太湖的实际水质状况将其划分为3个区域,分别分析太湖总体和分区的反射光谱曲线,建立太湖不同区域水体悬浮物浓度和透明度的反演模型。结果表明,就悬浮物浓度和透明度而言,太湖3个区域中以东太湖水质最佳,贡湖、梅梁湖和竺山湖次之,南部和西部最差;对太湖进行分区研究能够更好地反应太湖水质的差异性,拟合各区域的水质状况,分区模型精度较全湖区模型高,误差也普遍较小,能够提高研究结果的可信度和可行性。     

Estimations of the Transparency of the Forest Canopy: Analysis of the Ecological Content

The transparency of the forest canopy of lichen-green moss pine forests was estimated for different numbers of sectors of the celestial hemisphere. The ecological contents of these estimations are discussed. The dominance frequencies of species of the herbaceous-dwarf shrub and moss-lichen layers were analyzed. Based on the results of this analysis, it was concluded that the transparency estimated for the zenith sector alone better reflects the influence of leaf debris and the rainfall interception by the crowns. If the transparency was estimated taking into account all sectors of the celestial hemisphere, the effect of community disturbance increased and the redistribution of rainfall was masked.