Investigation of Water pH in Calcasieu Lake Area Using Regional Scale Hydrodynamic Models

Author(s):  
Ning Zhang ◽  
Weihao Wang

In Southwest Louisiana, the Calcasieu Lake and surrounding water systems are the major fresh water sources to the nearby coastal wetlands and agricultural areas. There are two national wide life refuges located in both east and west sides of Calcasieu Lake. Both refuges are covered by coastal wetlands. The health of the wetland vegetation is essential to the wetland losses in the area. One of the major problems related to the health of marshes is the nutrient deficiency. In addition, the surface water system is a possible source for agriculture use that requires sufficient nutrient components in water. Understanding the transport and distribution of various nutrients in the coastal water system is very important to the above-mentioned issues. In this study, a regional scale hydrodynamic model was utilized to simulate the hydrodynamics, salinity transport and sediment transport in this major water system in Southwest Louisiana. The pH distribution in water is a good indication of many nutrient components, such as phosphorous, and is essential to understand the nutrient distributions in the target area. A pH calculation procedure was implemented in the model to determine pH values based on the salinity and other water properties. The model results can be used to indicate the dynamic change of nutrient distributions and the areas of nutrient deficiency.

Author(s):  
Ireneusz Cymes ◽  
Iwona Cymes ◽  
Ewa Dragańska ◽  
Sławomir Szymczyk

The influence of weather conditions on mid-field ponds situated in a reclaimed area in Sępopolska PlainThe investigations were conducted in northeastern Poland near Lidzbark Warmiński (54° 08" N, 20° 36" E). Five mid-field ponds situated on grasslands were chosen: four of them were dredged and deepened, and one of them remained as a natural reservoir. The aim of this paper was to assess the influence of weather conditions on the quantity and quality of water in mid-field ponds situated in agricultural areas. It was found that the quantity of water in mid-field ponds was related much more to the air temperature, which was responsible for either water evaporation or snow melting, rather than to the amount of precipitation. The reduction in the volume of water stored in the ponds during very dry years had a negative influence on its quality. During the observation period, the dredged ponds were characterized by permanent water tables, whereas the natural reservoir dried out in very dry years. Atmospheric conditions influenced the concentrations of ammonium nitrogen and calcium and chlorine ions in the studied water bodies. The volume of water retained in mid-field ponds influenced the concentrations of phosphorus and sulphates. Increased precipitation sums caused lower water pH; however in warmer periods, at increased pH and COD


2019 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Ana Paula Dias Turetta ◽  
Bruno Pedrosa ◽  
Luca Eufemia ◽  
Michelle Bonatti ◽  
Stefan Sieber

Open data are important for adding legitimacy and transparency to public sciences. These data have also a potential to be used as a first approach for scientific investigation, such as spatial evaluation of ecosystem services. This paper presents a methodological approach to evaluate the trade-offs between agriculture and supporting ecosystem services based on spatial analysis and open data. The study area is an important agricultural production region in Bahia State, Brazil. The framework was able to establish the spatial interactions between agriculture and ecosystem service provision, while the regional scale was useful in supporting guidelines regarding sustainable land use for agricultural areas.


2021 ◽  
Author(s):  
◽  
Georgina Hart

<p>The Earth's climate system is entering a period of dynamic change after millennia of relatively stable climate. Coastal communities will need to adapt to dynamically shifting coastal environments as the climate system changes and sea levels rise. This study adds to a growing literature that investigates coastal vulnerability, adaptation, and resilience to climate change. It investigates regional scale social and institutional barriers to adaptation to sea level rise; examines the exposure, sensitivity and adaptation options at two coastal settlements in the Auckland region – Mission Bay/Kohimarama and Kawakawa Bay; and it analyses coastal adaptation response options from a resilience perspective. Mission Bay/Kohimarama and Kawakawa Bay, Auckland will experience increasing coastal hazard risk as the numbers of people and property potentially affected by storm events increases as sea level rises. Findings from the present study suggest that existing settlements in the Auckland region may already be 'locked in' to a coastal adaptation approach focused on maintaining the current coastline through coastal stabilisation, an approach that will decrease community resilience and increase vulnerability in the long term, even if this is found to be a successful response in the short term. Retreat offers an alternative approach that is strongly aligned with reducing community vulnerability and increasing resilience; however, strong opposition from communities to any retreat approach is expected. Developing trusted climate science information, education around coastal hazard risk, and participatory community led decision-making are identified as central enablers for a retreat approach to be included as a viable coastal adaptation option for communities in the Auckland region.</p>


2019 ◽  
Vol 88 (2) ◽  
pp. 23-32
Author(s):  
Franco Carpegna ◽  
Giovanni Soldato ◽  
Roberto Toffoli

During the Spring of 2011, we studied the bird community in an area of Val Borbera, in the province of Alessandria (NW Italy). In the study area, situated at an altitude between 655 and 1700 m a.s.l., we conducted 110 points count ten minutes each in four microhabitats (agricultural areas, shrubs, forests, and prairies). In total, we surveyed 72 species, of which 51 were passerine and 21 non passerine. The most abundant species were Sylvia atricapilla, Phylloscopus collybita, Apus apus, and Turdus merula. In the agricultural areas, we detected a total of 50 species (Sylvia atricapilla, Parus major, Turdus merula were the most abundant). In the shrubs, we detected 30 species (Sylvia atricapilla, Parus major, Fringilla coelebs, Phylloscopus collybita, Turdus merula, Erithacus rubecula were the most abundant). In the forest areas, we found 45 species (Sylvia atricapilla, Parus major, Fringilla coelebs, Phylloscopus collybita, Turdus merula, Erithacus rubecula were the most abundant), and in the prairies, we detected 48 species (Alauda arvensis, Anthus campestris, Sylvia atricapilla, Turdus merula, Anthus trivialis, Sylvia communis were the most abundant). Compared to the other macro habitats, the agricultural areas have a significantly high abundance and richness in species, which highlights the importance of the agricultural mosaics in the Piedmont and mountain areas. The data which has been collected so far confirms the important role of this area, given the presence of some species which are rare at a regional scale.


Author(s):  
Xiao Han ◽  
Ning Zhang

Storm-surge flood is a major thread to the inhabitants and the health of the marshes in Southwest Louisiana. The floods caused direct damages to the area, but also indirectly caused excessive sedimentations in the water system, especially in Calcasieu Ship Channel which is a vital industrial water way connecting the City of Lake Charles to the Gulf. It is well known that coastal wetlands and marshes have significant impacts on the prevention and reduction of coastal floods. The wetland vegetation creates larger frictions to the flooding water and acts as the first line of defense against any storm surge floods. In this study, we center Calcasieu Ship Channel, and hydrodynamic and sediment transport simulations were conducted for Calcasieu Ship Channel and surrounding areas. The target area ranges from the city of Lake Charles as the north end and the Gulf of Mexico as the south end, and includes three connected water systems, Calcaiseu Lake, Prien Lake and Lake Charles. The entire Calcasieu Ship Channel running from north to south is included in the domain along with the Gulf Intracoastal Waterway (GIWW) in east and west directions. In authors’ previous study, only the area of south portion of the ship channel, Calcasieu Lake and its surrounding wetlands was simulated and studied. This study is a major upgrade to the model, which provides more complete understanding of the flow and sediment transport in the entire area, as well as the interactions among all water systems surrounding the ship channel. There are wetlands (two National Wild Life Refuges, one in the west and one in the east) surrounding Calcaiseu Lake, while there are various of vegetated and non-vegetated areas surrounding Prien Lake and Lake Charles. The standard 2-D depth averaged shallow water solver was utilized for the simulation of the flow phase and a standard Eulerian scalar transport equation was solved for the sediment and salinity phases. In the sediment phase, the sediment deposition and re-suspension effects are included, while in the salinity phase, the precipitation and evaporation are included. A realistic vegetation model was implemented to represent various types of vegetation coverage in the target area, and appropriate friction values were assigned to different non-vegetated areas. Measured and observed vegetation data were utilized. A coastal storm surge flood was simulated, and effects of vegetation on flood reduction and sediment distribution were investigated. The total flooded area, the flood speed, and the distribution of the flooding water and sediments were compared between vegetated and non-vegetated areas to show the differences between different types of surfaces.


2020 ◽  
Vol 12 (24) ◽  
pp. 4114
Author(s):  
Shaobo Sun ◽  
Yonggen Zhang ◽  
Zhaoliang Song ◽  
Baozhang Chen ◽  
Yangjian Zhang ◽  
...  

Coastal wetlands provide essential ecosystem services and are closely related to human welfare. However, they can experience substantial degradation, especially in regions in which there is intense human activity. To control these increasingly severe problems and to develop corresponding management policies in coastal wetlands, it is critical to accurately map coastal wetlands. Although remote sensing is the most efficient way to monitor coastal wetlands at a regional scale, it traditionally involves a large amount of work, high cost, and low spatial resolution when mapping coastal wetlands at a large scale. In this study, we developed a workflow for rapidly mapping coastal wetlands at a 10 m spatial resolution, based on the recently emergent Google Earth Engine platform, using a machine learning algorithm, open-access Synthetic Aperture Radar (SAR) and optical images from the Sentinel satellites, and two terrain indices. We then generated a coastal wetland map of the Bohai Rim (BRCW10) based on the workflow. It has a producer accuracy of 82.7%, according to validation using 150 wetland samples. The BRCW10 data reflected finer information when compared to wetland maps derived from two sets of global high-spatial-resolution land cover data, due to the fusion of multiple data sources. The study highlights the benefits of simultaneously merging SAR and optical remote sensing images when mapping coastal wetlands.


1986 ◽  
Vol 1 (20) ◽  
pp. 183
Author(s):  
P.C. Chyen ◽  
C.S. Yang ◽  
I.L. Wang ◽  
H.H. Hwung

The numerical simulations on thermal diffusion always concentrated upon the raised temperature and temperature distributions after the heated water discharged from outlet into surrounding water, and the surrounding water temperature was assumed to be a constant. Actually, the water temperature on surface layer in shallow water area varies several centigrade degrees depended upon the weather conditions during a whole day. In order to obtain the absolute water temperature prepared for the ecological changes assessment and even provided for the operation basis of the cooling water system that air-sea heat exchange has to be considered in the numerical simulation of thermal discharges. For the practical application of this numerical simulation, the first nuclear power plant in Taiwan was taken as an example and simulated in this paper. And the results were presented in figures.


2013 ◽  
Vol 864-867 ◽  
pp. 2739-2743
Author(s):  
Song Wu ◽  
Qi Gang Jiang ◽  
Nan Lin

Based on the GIS technology, ETM date of 2000 and CBERS date of 2007 have been used as main data source in this paper.The dynamic degree and transfer matrixof wetland in the study area have been analyzed in order to clear the dynamic change of the wetland in liaohe river water system area in recent years.The results show that the wetland area in liaohe river region during 2000-2007 is obviously the volatility of the whole the increasing trend,the river area and offshore area and coastal wetlands area have been decreased,the areas with decreased river area is mainly distributed in the north of liaohe river region and central region.The areas with increased artificial wetland is mainly distributed in the north centre of liaohe river region. The increase of artificial Wetland and swamp meadow wetland area mainly comes from the transformation of non wetland area,the wetland types and changes of areas also have some correlation among the temperature and precipitation.


2011 ◽  
Vol 21 (12) ◽  
pp. 3577-3587 ◽  
Author(s):  
KLAUS FRAEDRICH ◽  
FRANK SIELMANN

A biased coinflip Ansatz provides a stochastic regional scale surface climate model of minimum complexity, which represents physical and stochastic properties of the rainfall–runoff chain. The solution yields the Schreiber–Budyko relation as an equation of state describing land surface vegetation, river runoff and lake areas in terms of physical flux ratios, which are associated with three thresholds. Validation of consistency and predictability within a Global Climate Model (GCM) environment demonstrates the stochastic rainfall–runoff chain to be a viable surrogate model for regional climate state averages and variabilites. A terminal (closed) lake area ratio is introduced as a new climate state parameter, which quantifies lake overflow as a threshold in separating water from energy limited climate regimes. A climate change analysis based on the IPCC A1B scenario is included for completeness.


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