THE EVOLUTIONARY DEVELOPMENT AND CURRENT STATE OF LAKE NERO ACCORDING TO SAPROPEL ANALYSIS

2020 ◽  
pp. 7-18
Author(s):  
V. Zakonnov ◽  
Sh. Pozdnyakov ◽  
S. Kondratiev ◽  
N. Ignatieva ◽  
A. Tsvetkov ◽  
...  
Keyword(s):  
Shallow Lake ◽  
Granulometric Composition ◽  
Suspended Particles ◽  
Evolutionary Development ◽  
Lake Ecosystem ◽  
Layer By Layer ◽  
Hydrochemical Parameters ◽  
Current State ◽  
Hydrodynamic Processes ◽  
Wind Driven Currents

The paper presents the characteristics of sapropel based on the results of analysis of samples collected at 21 stations in Lake Nero. Its current state is assessed based on hydrophysical and hydrochemical parameters. A layer-by-layer (0–10, 30–40 and 60–70 cm) granulometric composition of stratigraphic cores made it possible to compare the evolutionary development of the lake corresponding to the periods 100, 300–400 and 600–800 years ago. It is found that natural hydrodynamic processes (wind-driven waves and wind-driven currents) cause erosion and mixing of the surface (0–10 cm) polluted sapropel layer with clean underlying horizons and carry pollutants absorbed on suspended particles outside the lake. The approach used made it possible to identify the ways of a shallow lake ecosystem formation and outline promising directions

STUDY OF THE ORGANIZATION ADAPTIVITY RATE CORRELATION IN RELATION TO ITS INTERNAL INTEGRITY

2020 ◽  
Vol 3 (4) ◽  
pp. 292-304
Author(s):  
Inna O. Hordieieva ◽  
Valentina M. Molokanova
Keyword(s):  
Project Management ◽  
Stable State ◽  
Evolutionary Development ◽  
Current State ◽  
Modern Project ◽  
Development Processes ◽  
Methodological Principles ◽  
Internal Integration ◽  
Strategic Project ◽  
Rate Correlation

The focus of modern project management is increasingly shifting from the management of individual projects to the management of strategic project-oriented development of organizations. Now there is a need to pay more attention to project management as a universal tool for the development of systems at any level. The aim of the article is to study the processes of organization adaptation to constant changes through a synergetic portfolio of projects based on a strategic plan for the development and evolution of the organization. The spiral movement of systems development for studying development processes is considered: the process of transition of an organization from one stable state to another, the process of radical changes that accompanies innovation, as well as the processes of growth and development of crisis phenomena. The methodological principles of the organization evolutionary development management through the implementation of portfolio using its methods and tools are considered. It is proposed to manage the organization evolutionary development by building actions in the form of a synergistic portfolio of appropriate projects content, in order to increase the value of the entire portfolio of projects over the value of individual projects. The synergetic portfolio of projects is seen as a tool for a harmonious transition to the desired evolutionary state, by preserving the internal integrity of the organization and ensuring its sustainability. A mathematical model for estimating the desired properties and relations of the organizational synergetic portfolio of projects is proposed, which allows to determine and minimize the magnitude of the evolutionary goals inconsistency and to stabilize the current state of organization. It is determined that the two main tasks of any organization - external adaptation and internal integration - constantly push the organization to evolutionary development. The article proposes the author's approach to managing the organization evolutionary development through a portfolio of projects identifies indicators of adaptation of the organization to changes in the environment, defines the conditions for maintaining the integrity of the organization in the process of organizational changes.

scholarly journals Antecedent lake conditions shape resistance and resilience of a shallow lake ecosystem following extreme wind storms

2021 ◽  
Author(s):  
Michael W. Thayne ◽  
Benjamin M. Kraemer ◽  
Jorrit P. Mesman ◽  
Bastiaan W. Ibelings ◽  
Rita Adrian
Keyword(s):  
Shallow Lake ◽  
Lake Ecosystem ◽  
Extreme Wind ◽  
Wind Storms

scholarly journals Application of the Conditional Nonlinear Optimal Perturbations Method in the Shallow Lake Ecological Degradation and Restoration

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Bo Wang ◽  
Qianqian Qi
Keyword(s):  
Shallow Lake ◽  
Sediment Resuspension ◽  
Finite Amplitude ◽  
Water Transparency ◽  
Lake Ecosystem ◽  
Lake Ecosystems ◽  
Ecological Degradation ◽  
Parameter Condition ◽  
Restoration Model ◽  
Simple Combination

In the shallow lake ecosystems, the recovery of the aquatic macrophytes and the increase in the water transparency have been the main contents of the ecological restoration. Using the shallow lake ecological degradation and restoration model, CNOP method is adopted to discuss the instability and sensitivity of the ecosystem to the finite-amplitude perturbations related to the initial condition and the parameter condition. Results show that the linearly stable clear (turbid) water states can be nonlinearly unstable with the finite-amplitude perturbations, which represent the nature factors and the human activities such as the excessive harvest of the macrophytes and the sediment resuspension caused by artificially dynamic actions on the ecosystems. The results also support the viewpoint of Scheffer et al., whose emphasis is that the facilitation interactions between the submerged macrophytes and the water transparency are the main trigger for an occasional shift from a turbid to a clear state. Also, by the comparison with CNOP-I, CNOP-P, CNOP, and (CNOP-I, CNOP-P), results demonstrate that CNOP, which is not a simple combination of CNOP-I and CNOP-P, could induce the shallow lake ecosystem larger departure from the same ground state rather than CNOP-I, CNOP-P, and (CNOP-I, CNOP-P).

scholarly journals High net CO<sub>2</sub> and CH<sub>4</sub> release at a eutrophic shallow lake on a formerly drained fen

2016 ◽  
Vol 13 (10) ◽  
pp. 3051-3070 ◽  
Author(s):  
Daniela Franz ◽  
Franziska Koebsch ◽  
Eric Larmanou ◽  
Jürgen Augustin ◽  
Torsten Sachs
Keyword(s):  
Global Warming ◽  
Shallow Lake ◽  
Typha Latifolia ◽  
Open Water ◽  
Emergent Vegetation ◽  
Lake Ecosystem ◽  
Co2 Uptake ◽  
Mild Winter ◽  
Ch4 Emissions ◽  
Northeastern Germany

Abstract. Drained peatlands often act as carbon dioxide (CO2) hotspots. Raising the groundwater table is expected to reduce their CO2 contribution to the atmosphere and revitalise their function as carbon (C) sink in the long term. Without strict water management rewetting often results in partial flooding and the formation of spatially heterogeneous, nutrient-rich shallow lakes. Uncertainties remain as to when the intended effect of rewetting is achieved, as this specific ecosystem type has hardly been investigated in terms of greenhouse gas (GHG) exchange. In most cases of rewetting, methane (CH4) emissions increase under anoxic conditions due to a higher water table and in terms of global warming potential (GWP) outperform the shift towards CO2 uptake, at least in the short term.Based on eddy covariance measurements we studied the ecosystem–atmosphere exchange of CH4 and CO2 at a shallow lake situated on a former fen grassland in northeastern Germany. The lake evolved shortly after flooding, 9 years previous to our investigation period. The ecosystem consists of two main surface types: open water (inhabited by submerged and floating vegetation) and emergent vegetation (particularly including the eulittoral zone of the lake, dominated by Typha latifolia). To determine the individual contribution of the two main surface types to the net CO2 and CH4 exchange of the whole lake ecosystem, we combined footprint analysis with CH4 modelling and net ecosystem exchange partitioning.The CH4 and CO2 dynamics were strikingly different between open water and emergent vegetation. Net CH4 emissions from the open water area were around 4-fold higher than from emergent vegetation stands, accounting for 53 and 13 g CH4 m−2 a−1 respectively. In addition, both surface types were net CO2 sources with 158 and 750 g CO2 m−2 a−1 respectively. Unusual meteorological conditions in terms of a warm and dry summer and a mild winter might have facilitated high respiration rates. In sum, even after 9 years of rewetting the lake ecosystem exhibited a considerable C loss and global warming impact, the latter mainly driven by high CH4 emissions. We assume the eutrophic conditions in combination with permanent high inundation as major reasons for the unfavourable GHG balance.

Advantages of multi-region kriging over bi-region techniques for computed tomography-scan segmentation

Soil Research ◽  
2019 ◽  
Vol 57 (6) ◽  
pp. 521 ◽  
Author(s):  
M. Azhar ◽  
X. Chang ◽  
J. Debes ◽  
P. Delmas ◽  
C. Duwig ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Soil Structure ◽  
Ct Scanning ◽  
Optimal Number ◽  
Environmental Conservation ◽  
Layer By Layer ◽  
Region Segmentation ◽  
Current State ◽  
Intact Soil Cores ◽  
Layer Segmentation

Quantifying the structure of soil is essential for developing effective soil management for farming and environmental conservation efforts. One approach to quantify soil structure is to scan intact soil cores by X-ray computed tomography (CT), which allows using computer vision algorithms to identify internal components within the soil. One commonly used approach is the colour-based segmentation of CT-scan soil images into two regions – matter and void – for the purpose of determining the soil porosity. A key problem with this approach is that soil CT images tend to be rather complicated, and thus this type of bi-region segmentation is a non-trivial problem, with algorithms following this type of bi-region approach typically performing unreliability across a variety of image sets. In this work, a technique is proposed that identifies an optimal number of regions present in the soil, rather than just two. It is claimed that this more sophisticated representation of soil structure leads to a more accurate representation than traditional bi-region segmentation; however, it is reducible to a bi-region segmentation yielding the required estimation of porosity with more accuracy and robustness than traditional methods. It is also proposed that segmentation is performed using a multi-region kriging algorithm, which establishes relationships between distance and regions that allows the segmentation to overcome many of the artefacts and noise issues associated with CT scanning. Our experiments focused on layer-by-layer segmentation and results demonstrated that the proposed approach produced segmentations consistent across a variety of scanned cores and were visually more correct than current state-of-the-art bi-region techniques.

scholarly journals Modelling the Impacts of Bathymetric Changes on Water Level in China’s Largest Freshwater Lake

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1469 ◽  
Author(s):  
Lingyan Qi ◽  
Jiacong Huang ◽  
Junfeng Gao ◽  
Zhen Cui
Keyword(s):  
Water Level ◽  
Water Resource Management ◽  
Freshwater Lake ◽  
Lake Ecosystem ◽  
Spatial Gradient ◽  
Dramatic Decline ◽  
Hydrodynamic Processes ◽  
Lake Poyang ◽  
The Stability ◽  
Bathymetric Changes

A recent dramatic decline in water level during the dry season in China’s largest freshwater lake (Lake Poyang) significantly influenced water availability and biogeochemical processes. To learn the potential causes of water level decline, this study investigated the hydrodynamic response to bathymetric changes during three typical hydrological years by scenario simulation using Environmental Fluid Dynamics Code (EFDC). The simulation results indicated that bathymetric changes resulted in a water level decrease during a low water level period. Inter-annual variation in the decrease rate implied that water level in typical dry and wet years were influenced more significantly than that in moderate hydrological years. A spatial gradient in the distribution of water level changes was also observed, which was mainly concentrated in the main channel. Water velocities also slowed down, weakly corresponding to the decrease in water level during the low water level period. Overall, bathymetric changes caused by sand mining contributed to water level and velocity variations, influencing the stability and sustainability of the lake ecosystem. This study can potentially enhance our understanding of the hydrodynamic processes in Lake Poyang and support water resource management.

Application of the CNOP Method in the Shallow Lake Ecosystem

2014 ◽  
Vol 1010-1012 ◽  
pp. 658-661 ◽  
Author(s):  
Qian Qian Qi ◽  
Bo Wang
Keyword(s):  
Ecological Restoration ◽  
Shallow Lake ◽  
Submerged Macrophytes ◽  
Finite Amplitude ◽  
Water Transparency ◽  
Lake Ecosystem ◽  
Initial Condition ◽  
Turbid Water ◽  
Variable Model

It is serious on the degradation of the shallow lake ecosystem at present, while the recovery of the macrophytes vegetations and the increase in water transparency have been the main contents of the ecological restoration. Using a two-variable model, we discuss the instability and sensitivity of the ecosystem to the finite-amplitude perturbations related to the initial condition with CNOP-I method. Results show that the linearly stable clear (turbid) water states can be nonlinearly unstable with the finite-amplitude perturbations. The results also demonstrate that the facilitation interactions between the submerged macrophytes and the water transparency are the main trigger for a shift from the turbid to the clear state.

Biodiversity changes in a shallow lake ecosystem: a multi‐proxy palaeolimnological analysis

1999 ◽  
Vol 26 (1) ◽  
pp. 97-114 ◽  
Author(s):  
C. Sayer ◽  
N. Roberts ◽  
J. Sadler ◽  
C. David ◽  
P. M. Wade
Keyword(s):  
Shallow Lake ◽  
Lake Ecosystem ◽  
Biodiversity Changes
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