7 research outputs found
Impacts of the eastern route of the South-to-North Water Diversion Project emergency operation on flooding and drainage in water-receiving areas: an empirical case in China
The water levels of lakes along the eastern route of the
South-to-North Water Diversion Project (ER-SNWDP) are expected to rise
significantly and subsequently affect the processes of flood control and
drainage in corresponding lake basins. However, few studies have focused on
the impacts of inter-basin water diversion on the flood control and drainage
of water-receiving areas at the lake basin scale. Using MIKE software, this
paper builds a coupled hydrodynamic model to address the existing literature
gap regarding the impacts of inter-basin water diversion on the processes of
flood control and drainage in a water-receiving lake basin, and it considers
the many types of hydraulic structures in the model. First, a flood
simulation model was constructed to simulate the complex movement of water
transferred by the ER-SNWDP, by waterlogging in the lakeside area around
Nansi Lake (NL), and water in NL and its tributaries. The ER-SNWDP was also
considered in the model. Second, the model was calibrated and verified with
measurement data, and the results showed that the model was efficient and
presented a Nash–Sutcliffe efficiency coefficient (NSE) between 0.65 and
0.99. Third, the processes of flooding and draining in the lakeside area of
NL were simulated under different water diversion and precipitation values.
Finally, the impacts of the emergency operations of the ER-SNWDP on flood
control and waterlogging drainage in the lakeside area of NL were analysed
based on the results from the proposed model, and some implications are
presented for the integrated management of inter-basin water diversion and
affected lakes.</p
CHROMIUM, COPPER, AND ARSENIC CONCENTRATION AND SPECIATION IN SOIL ADJACENT TO CHROMATED COPPER ARSENATE (CCA) TREATED LUMBER ALONG A TOPOHYDROSEQUENCE
Arsenic (As), Chromium (Cr), and Copper (Cu) are ubiquitous in soils as a result of anthropogenic and geogenic processes. The fate of As, Cr, and Cu in the environment is largely governed by their speciation, which is influenced by soil physiochemical properties. This study investigated the influence of soil physiochemical properties and landscape position on As, Cr, and Cu concentration and speciation in soils adjacent to Chromated Copper Arsenate (CCA) treated lumber fence posts. Concentration gradients showed elevated total As and Cu adjacent to the three fence posts, which decreased with increasing distance from the posts. In addition, As and Cu had higher concentrations in the surface soil samples than the subsoil samples possibly due to enhanced weathering of the CCA treated posts at the surface. Concentrations of As, Cr, and Cu were similar among the Maury and Donerail silt loam, however, they were closer to the background concentration in the Newark silt loam, a partially hydric soil, indicating mobility of the metals. Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy indicates As(V) is the predominate species which is principally coordinated with Fe and Al whereas, Cu(II) is coordinated with soil organic matter. Overall, the use of CCA treated lumber as a metal source can help determine how soil properties influence mobility and speciation of As, Cr, and Cu across the soil landscape
Climate Change and Environmental Sustainability-Volume 4
Anthropogenic activities are significant drivers of climate change and environmental degradation. Such activities are particularly influential in the context of the land system that is an important medium connecting earth surface, atmospheric dynamics, ecological systems, and human activities. Assessment of land use land cover changes and associated environmental, economic, and social consequences is essential to provide references for enhancing climate resilience and improving environmental sustainability. On the one hand, this book touches on various environmental topics, including soil erosion, crop yield, bioclimatic variation, carbon emission, natural vegetation dynamics, ecosystem and biodiversity degradation, and habitat quality caused by both climate change and earth surface modifications. On the other hand, it explores a series of socioeconomic facts, such as education equity, population migration, economic growth, sustainable development, and urban structure transformation, along with urbanization. The results of this book are of significance in terms of revealing the impact of land use land cover changes and generating policy recommendations for land management. More broadly, this book is important for understanding the interrelationships among life on land, good health and wellbeing, quality education, climate actions, economic growth, sustainable cities and communities, and responsible consumption and production according to the United Nations Sustainable Development Goals. We expect the book to benefit decision makers, practitioners, and researchers in different fields, such as climate governance, crop science and agricultural engineering, forest ecosystem, land management, urban planning and design, urban governance, and institutional operation.Prof. Bao-Jie He acknowledges the Project NO. 2021CDJQY-004 supported by the Fundamental Research Funds for the Central Universities and the Project NO. 2022ZA01 supported by the State Key Laboratory of Subtropical Building Science, South China University of Technology, China. We appreciate the assistance of Mr. Lifeng Xiong, Mr. Wei Wang, Ms. Xueke Chen, and Ms. Anxian Chen at School of Architecture and Urban Planning, Chongqing University, China
Metals in seawater and sediments of the Azores platform
Doutoramento em QuÃmicaA presente tese tem por objetivo principal contribuir para o conhecimento da
geoquÃmica sedimentar da zona oceânica da crista da Terceira e montanhas
submarinas a sul (região entre 29-39ºN e 27-32ºW), integrando também a
caraterização dos metais e nutrientes na coluna de água e propondo
concentrações para servirem de referência nesta região do Atlântico Central.
Para o efeito foram realizadas amostragens na coluna de água em sete locais
e de sedimento em cinco locais, durante a campanha oceanográfica designada
por EMEPC/AÇORES/G3/2007 a bordo do navio SV Kommandor Jack, no
âmbito do projeto da Estrutura de Missão para a Extensão da Plataforma
Continental (EMEPC).
Os perfis de CTD da coluna de água na região estudada revelam a presença
de massas de água distintas: a Western North Atlantic Central Water
(WNACW), a Eastern North Atlantic Central Water tropical (ENACWt), a
Eastern North Atlantic Central Water polar (ENACWp), a Mediterranean
Overflow Water (MOW), a Deep Mediterranean Water (DMW) e a North
Eastern Atlantic Deep Water (NEADW). Observou-se nos perfis de
temperatura e salinidade, referentes aos primeiros 200 m da coluna de água,
um gradiente meridional negativo entre as estações localizadas na crista da
Terceira e as estações localizadas mais a sul.
Observou-se nas águas superficiais valores de oxigénio dissolvido de 93% e
de pH de 8,1, assim como que as concentrações dos nutrientes NOx, PO4 e
SiO2 variam de acordo com a atividade biológica, tendo-se registado
concentrações medianas mais baixas, respetivamente de 6,5, 0,23 e
1,3 mol L-1, que aumentam com a profundidade devido à ausência de
produção primária (respetivamente 31, 1,4 e 22 mol L-1). As concentrações de
NH4 e de SO4 não variam significativamente nas massas de água, sendo os
valores medianos mÃnimos e máximos de 0,69 a 0,79 mol L-1 para o NH4 e de
30 a 32 mol L-1 para o SO4. São propostas concentrações de referência para
as massas de água, para os elementos cobre, cádmio, chumbo e arsénio.
Os perfis de sedimento analisados permitem distinguir os sedimentos na crista
da Terceira (core A) dos restantes (cores B a E).
A grande variabilidade textural encontrada no core A, que contrasta com os
outros cores analisados, deve-se a importantes contribuições terrÃgenas,
originadas pela erosão sub-aérea e pela atividade vulcânica das ilhas
próximas.
iv
resumo (continuação) A análise mineralógica, efetuada à fração areia e à fração fina (< 63 μm),
confirma que os sedimentos do core A derivam de rochas vulcânicas formadas
maioritariamente por piroxenas, olivinas, anfÃbolas, biotite, alterites e ainda
calcite, plagióclase e magnetite, tendo-se identificado ao microscópio a
glauconite e o vidro vulcânico.
De acordo com a composição quÃmica destes minerais o core A apresenta
valores mais elevados de Al, Fe, K, P, Mg, Si, Na, Zn, V, Cr e Mn relativamente
aos cores B a E. Os cores B a E apresentam grandes quantidades de calcite
(>80%) formada maioritariamente por foraminÃferos e nanoplâncton calcário
(cocolitóforos). A fração areia confirma a composição maioritariamente
carbonatada com grande abundância de material biogénico formado por oozes
de foraminÃferos (planctónicos e bentónicos) com raras espÃculas de
espongiários e restos de conchas. Os cores B a E apresentam valores muito
mais elevados que o core A para os elementos Ca e Sr. Os resultados para o
Al, Fe, K, P, Si, Na, As, Cu, Ni, Zn, V, Cr, Li, Pb, Cd e Co presentes nos locais
B, C, D e E sugerem que estes cores são comparáveis aos sedimentos de
fundo carbonatados.
Propõe-se concentrações de referência para a região do Atlântico
compreendida entre 29-39ºN e 27-32ºW considerando a primeira camada
colhida em cada core. Para o core A as concentrações são normalizadas a 5%
de Al e CaCO3, enquanto que para os cores B a E são normalizadas a 2% de
Al e CaCO3. Assim as concentrações de referência para o core A são: As – 18
mg kg-1, Cr – 91 mg kg-1, Cu – 127 mg kg-1, Ni – 84 mg kg-1, Pb – 41 mg kg-1,
Hg – 41 ng g-1 e Zn – 482 mg kg-1. Para os cores B a E as concentrações de
referência são: As – 3 mg kg-1, Cr – 10 mg kg-1, Cu – 36 mg kg-1 Ni – 12
mg kg -1, Hg – 3 ng g-1 e Zn – 20 mg kg-1.
Para os restantes metais as concentrações de referência para o core A são: Al
– 9%, Si – 25%, Fe – 6%, Ca – 13%, K – 2%, Mg – 2%, Na – 3%, P – 0,4%, Sr
– 900 mg kg-1, Li – 10 mg kg-1, Mn – 1200 mg kg-1, Ba – 700 mg kg-1 e V – 140
mg kg-1. Para os cores B a E as concentrações de referência são: Al – 0,9%, Si
– 2%, Fe – 0,2%, Ca – 95%, K – 0,3%, Mg – 0,4%, Na – 0,3%, P – 0,04%, Sr –
2600 mg kg-1, Li – 5 mg kg-1, Mn – 240 mg kg-1, Ba – 345 mg kg-1, Co – 2
mg kg-1 e V – 6 mg kg-1.
Os resultados da presente tese constituem um contributo para a caraterização
geoquÃmica da região e podem servir de referência à monitorização futura do
mar dos Açores e montes submarinos a sul.This thesis aims to contribute to the sedimentary geochemistry knowledge in
the oceanic zone of Azores platform including Terceira ridge and the
underwater mountains to the south (region between 29-39° N and 27-32° W),
integrating also the characterization of metals and nutrients in the water column
and submiting a proposal on guideline values for this region of the central
Atlantic.
For this purpose, a total of seven samples of water column and five samples of
sediment were collected during the oceanographic campaign
EMEPC/AÇORES/G3/2007 aboard the ship SV Kommandor Jack working
within Task Force for the Extension of the Continental Shelf (EMEPC).
The CTD profiles of the water column in the region studied reveal the presence
of distinct water masses: the Western North Atlantic Central Water (WNACW),
the Eastern North Atlantic Central Water tropical (ENACWt), the Eastern North
Atlantic Central Water polar (ENACWp), the Mediterranean Overflow Water
(MOW), the Deep Mediterranean Water (DMW) and the North Eastern Atlantic
Deep Water (NEADW). It was observed that the temperature and salinity
profiles, for the first 200 m of the water column, feature a southern negative
gradient between stations located on the Terceira ridge and stations located
further south.
Values of dissolved oxygen of 93% and pH 8.1 were observed in the surface
waters, as also that nutrient concentrations of NOx, PO4 and SiO2 vary
according to the biological activity, as lower median concentrations of 6.5, 0.23
and 1.3 mol L-1 respectively, which increase with depth due to the absence of
primary production (31, 1.4 and 22 mol L-1, respectively). The concentrations
of NH4 and SO4 do not vary significantly in the water masses, being the median
minimum and maximum values 0.69 to 0.79 mol L-1 for NH4 and 30 to 32
mol L-1 for SO4. Background concentration values are proposed for the water
masses for elements copper, cadmium, plumb and arsenic.
Sediment profiles analyzed allow the distinction of the sediments found near
the Terceira ridge (core A) from the remaining (cores B to E).
The great textural variability found in core A, which contrast with the other
cores analyzed, is due to important terrigenous contributions, originated in subaerial
erosion and in the volcanic activity of the nearby islands.
vi
abstract (cont.) Mineralogical analysis of the sand fraction and of the fine fraction (< 63 m)
confirms that core A sediments derives from volcanic rocks formed mainly by
pyroxenes, olivine, amphiboles, biotite, alterites and calcite, plagioclase and
magnetite, with glauconite and volcanic glass being identified in the
microscope.
According to the chemical composition of the minerals core A has higher values
of Al, Fe, K, P, Mg, Si, Na, Zn, V, Cr, and Mn relatively to cores B to E.
Cores B to E feature large amounts of calcite (80%) formed mostly by
foraminifera and nanoplancton limestone (coccolithophores). Sand fraction
confirms the composition mainly carbonated with great abundance of biogenic
material formed by oozes of foraminifera (plantonic and benthonic) with rare
spicules of spongiary and remains of shells. Cores B to E feature much higher
values than core A for Ca and Sr. Results for Al, Fe, K, P, Si, Na, As, Cu, Ni,
Zn, V, Cr, Li, Pb, Cd and Co present in sites B, C, D and E suggest that these
cores are comparable to carbonated bottom sediments.
Background concentration values are proposed for the Atlantic region between
29-39° N and 27-32° W considering the first layer collected in each core. For
core A the concentrations are normalized to 5 % Al and CaCO3, while for cores
B to E they are normalized to 2 % Al and CaCO3. The proposed background
concentration values for core A are: As - 18 mg kg-1, Cr - 91 mg kg-1, Cu - 127
mg kg-1, Ni - 84 mg kg-1, Pb - 41 mg kg-1, Hg - 41 ng g-1 and Zn - 482 mg kg-1.
For cores B to E the proposed background concentration values are: As – 3
mg kg-1, Cr – 10 mg kg-1, Cu – 36 mg kg-1, Ni – 12 mg kg -1, Hg – 3 ng g-1 and
Zn – 20 mg kg-1.
For the remaining metals the background concentration values for core A are:
Al – 9%, Si – 25%, Fe – 6%, Ca – 13%, K – 2%, Mg – 2%, Na – 3%, P – 0,4%,
Sr – 900 mg kg-1, Li – 10 mg kg-1, Mn – 1200 mg kg-1, Ba – 700 mg kg-1 and V –
140 mg kg-1.. For cores B to E background concentration values are: Al – 0,9%,
Si – 2%, Fe – 0,2%, Ca – 95%, K – 0,3%, Mg – 0,4%, Na – 0,3%, P – 0,04%,
Sr – 2600 mg kg-1, Li – 5 mg kg-1, Mn – 240 mg kg-1, Ba – 345 mg kg-1, Co – 2
mg kg-1 and V – 6 mg kg-1.
The results of this thesis constitute a contribution for the geochemical
characterization of the region and may serve as a reference for future
monitoring of Azores sea and seamounts to the south