1992—2021年抚仙湖海口水生态环境指标COD_(Mn)变化趋势及影响因素研究

为探明水生态环境指标——高锰酸盐指数突变特征、变化趋势及其影响因素,采用Mann-Kendall检验法对高锰酸盐指数变化趋势、突变特征进行研究,运用SPSS软件分析主要水文要素和经济社会指标与高锰酸盐指数的关系。结果表明,1992—2021年,抚仙湖海口断面高锰酸盐指数总体呈显著上升趋势,年均上升0.027 mg/L,近年浓度接近2.0 mg/L。高锰酸盐指数在研究时段内发生3次突变,1994年、1996年突变不显著,2021年突变极其显著。抚仙湖水位经历了上升、平稳、下降、上升、下降的变化过程,多年平均蒸发量约为多年平均降水量的1.4倍,蒸降比高时水位呈下降趋势。流域人口密度、蒸发量、水位可解释抚仙湖海口断面高锰酸盐指数变化的65.0%,人口密度、蒸发量与海口断面高锰酸盐指数呈正相关,水位与海口断面高锰酸盐指数呈负相关。流域人口密度、蒸发量、水位是海口断面高锰酸盐指数的主要影响因子,人口密度的影响程度最大。

Eco-Environment Status of the Bohai Bay and the Impact of Coastal Exploitation

With the rapid economic development in the surrounding coastal zone, more and more wastewater has been discharged into the Bohai Bay. And with the scale of coastal exploitation being expanded year by year, the eco-environment of the Bohai Bay has been confronted with great pressure. In this paper, the main problems in the eco-environment of the Bohai Bay were summarized firstly. Red tides occurred more frequently and more seriously; salinity rose in inshore area, the fishery resources degenerated; all the above indicate that the eco-environment of the Bohai Bay is under a severe situation Next, to make a concrete study of the existing status of the Bohai Bay, the eco-environment index system was set up. Then the principal components analytic method and grey relation method were adopted to carry on a comprehensive analysis on the status. The results show that serious pollution of inorganic nitrogen and active phosphate, and poor species diversity are the main presentations of the bad quality of the inshore aquatic eco-environment of the Bohai Bay, which is mainly induced by the massive discharge of pollutant from land and the overexploitation in the surrounding coastal zone. At last, the variations of hydrodynamic characteristics and the pollutant transport caused by coastal exploitations such as reclamation and seawater desalination are analyzed. The results show that reclamation in coastal water not only decreases the tidal prism and weakens the tidal current action, but also influences the pollution distribution in the coastal water. The seawater desalination project would cause tremendous influence to the aquatic eco-environment of the Bohai Bay as the pollutant＇s pulse impact. Much more attention would be paid to the reasonable use of the coastal zone resources and the control of pollution from land-based sources.

Taxonomic Distinctness of Macrofauna as an Ecological Indicator in Laizhou Bay and Adjacent Waters

In this paper, we assessed the ecological and biodiversity status in the Bohai Sea through a quantitative survey on mac-rofaunal community at 25 stations in Laizhou Bay and adjacent waters in the autumn of 2006.We tested the robustness and effectiveness of taxonomic distinctness as an ecological indictor by analyzing its correlation with species richness and natural environmental variables and by analyzing other ecological indicators (Shannon-Wiener H' and W statistics from Abundance Biomass Comparison curve).Results so obtained indicated that the benthic environment of the study waters in general is not under major impact of anthropogenic disturbance, but some stations in Laizhou Bay and along the coast of the Shandong Peninsula and even in the central Bohai Sea might be moderately disturbed and showed signs of ecological degradation.The taxonomic distinctness measures △+ and Λ+ were independent of sampling effort and natural environment factors and were compliant to other ecological indicators.Further application of the taxonomic distinctness indicator to assess marine biodiversity and ecosystem health on a larger regional scale with historical data seems promising.

A practical framework for scenario-based optimal decision-making on water-deficient river ecological restoration in mining areas

Mining activities may cause serious damages to the river ecological environment in mining areas. It has been realized that challenging is faced for optimal decision-making on the river ecological restoration resulting from system complexity, multi-objectives, long term restoration in which multiple stages may be needed to take, and difficulty in detailed process quan- tification. By analyzing and fully reflecting the differences between the central zone and surrounding zones of the restored river passing through the mining area, the comprehensive evaluation index systems of the central zone and surrounding zones are separately suggested firstly. Then a scenario-based optimization decision-making model for river ecological restoration in min- ing areas was established with taking advantages of spatial divisions and following procedure of first going through optimiza- tion by sub-region level, then optimizing by integration. Then, a framework for scenario-based optimal decision-making on water-deficient river ecological restoration in mining areas is proposed in which a multi-objective and multi-stage spatial division optimization method is considered to improve decision-making efficiency and enhance its practicability. It is indicated that this optimization framework is reasonable and practical, which is expected to offer reliable decision support in identifying the effective solutions on optimal management of the water-deficient river ecological restoration in mining areas. At the same time, it has implications in general land reclamation and ecological restoration in the mining areas.