2万年来我国东部海陆环境变化的不同步现象

冲绳海槽 DG96 0 3孔高分辨率的硅藻、有孔虫、孢粉和植物硅酸体化石的记录 ,提供了联系海洋与陆地气候变化的直接证据。结果显示 ,中国东部及邻海区最近 2 0 ka BP以来海洋环境的变化滞后陆地气候的变化约10 0 0 a。

Response of the Plankton to a Fresh Water Pulse in a Fresh Water Deprived, Permanently Open South African Estuary

This study assessed the influence of a freshwater pulse on selected physico-chemical and biological variables in a permanently open freshwater deprived southern African estuary. In the absence of the freshwater pulse a reverse gradient in salinity was evident with hypersaline (salinity > 40) conditions prevailing in the upper reaches of the estuary. Total chlorophyll-a (chl-a) concentration during this period ranged from 0.25 to 0.60 μg·l-1. The mean total zooplankton abundance and biomass in the absence of freshwater during the daytime was 666 ind·m-3 (SD ± 196) and 12.4 mg·dwt·m-3 (SD ± 3.3), respectively. During the night time the mean total zooplankton abundance was 3121 ind·m-3 (SD ± 1203) and the biomass 21.8 mg·dwt·m-3 (SD ± 196). The total zooplankton abundance during the dry season was numerically dominated by the copepod nauplii and the calanoid copepod, Pseudodiaptomus hessei, which contributed up to 76% of the total zooplankton counts. The freshwater pulse was associated with the establishment of a horizontal gradient in salinity along the length of the estuary and a significant increase in the total chl-a concentration (range from 0.74 to 11.75 μg·l-1) and zooplankton biomass (range from 23.7 to 76.6 mg·dwt·m-3) (p ally, there was a marked increase in the total zooplankton abundances and biomass within the estuary. A distinct shift in the zooplankton community composition was evident with the copepod, Acartia longipatella numerically dominating the zooplankton counts.

A geomorphological model of susceptibility to the effect of human interventions for environmental licensing determination(SHIELD)

Almost every country requires some form of environmental licensing prior to the inception of development projects that may affect the integrity of the environment and its social context.We developed a new conceptual and methodological model to instruct the assessment of the potential impacts posed by proposed projects.Susceptibility to Human Interventions for Environmental Licensing Determination(SHIELD)includes a novel geomorphological interpretation of the Environmental Impact Assessment(EIA).It considers the impact of human interventions on geomorphological processes and landscape functioning in the context of the entire ecosystem,going further than the classical concept of vulnerability.Estimated susceptibility of the site informs the screening stage,allowing local conditions to help define the criteria used in the process.Similarly,the level of detail of the environmental baseline is scoped by considering the degree of disturbance of natural processes posed by human intervention.Testing this geomorphological susceptibility model on different kinds of environments would allow shifting the environmental licensing practices from the prevailing anthropocentric and static conception of the environment towards an Ecosystem Approach.SHIELD addresses the need to improve the screening and scoping stages that form the basis of the rest of any EIA.SHIELD introduces several innovations to EIA including the incorporation of fuzzy logic,a preassembled database of contributions form experts,and a shifting of emphasis from the type of proposed intervention to the type of environment and its relative susceptibility.

Challenges at the early stages of the environmental licensing procedure and potential contributions from geomorphology

Defining impact significance is the main technical task that influences decision-making during the Environmental Licensing Procedure(ELP).The ELP begins with screening to determine potentially significant impacts of the proposed project.Scoping then follows to address any interventions deemed worthy of attention in the production of an Environmental Impact Assessment(EIA).This will include consideration of relevant landforms and geomorphological processes.However,preliminary assessments of environmental impacts often lack the scientific robustness to procure substantive and transactive effectiveness.This review presents an examination of the established practices of screening and scoping while highlighting the foremost challenges to improve the technical grounds of the ELP.The analysis of screening and scoping practices stresses the need for novel methods that ensure the sequential reasoning between their criteria while improving the preliminary evaluation of impact significance.Reducing the inherent subjectivity of discretionary judgment requires scientific methodologies that acknowledge the interaction between the natural system and human interventions,which has been addressed by geomorphological research.The knowledge consolidated in this review opens the gate to explore the compatibility between the United Nations strategy of Ecosystem Approach(EA)with the ELP through a novel geomorphological interpretation of the EIA.Therefore,this diagnosis demonstrate that screening and scoping practices would benefit from reliable methods that balance the precautionary principle with the efficient character required in the ELP.