Suggested solutions for the problems of salinity increase and cumulated pollution in lake Qarun, Egypt: Present and future (A review)

The soil salinity increase in the Mediterranean basin is one of the consequences of the climate change. The aim of this study was to evaluate the adaptability of giant reed (Arundo donax L.) to salinity, in conditions of higher temperatures, in order to hypothesise the future use of giant reed under these conditions. The trial was carried out in pots under a permanent metal structure, open on the sides and with a clear PE on the top. Four levels of soil salinity in the range 3.3-15.5 dS m–1 were imposed. The stem number of the most stressed treatment was about 45% lower than the control and also the stem height was lower than in all other treatments. The green and yellow leaf number decreased as the soil salinity increased, and their sum was significantly lower in the two most stressed treatments. Osmotic potential of the leaf sap was not affected by salinity. Leaf water potential and stomatal conduc- conductance in the saline treatments were lower than in the control. tance Assimilation rate showed similar pattern of stomatal conductance. Intrinsic WUE remained almost stable until July and increased during August under the most stressful conditions. PSII photochemistry was not affected by soil salinity. Biomass yield was not different from the control until to soil ECe 12.0 dS m–1: only the most stressed treatment (15.5 dS m–1) caused yield losses (50%). Tolerance threshold to salinity was 11.2 dS m–1 and the relative yield losses were 11.6% per dS m–1.

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The structure of the Persian Gulf outflow subjected to density variations

Ocean Science Discussions ◽

10.5194/osd-5-135-2008 ◽

2008 ◽

Vol 5 (2) ◽

pp. 135-161 ◽

Cited By ~ 1

Author(s):

A. A. Bidokhti ◽

M. Ezam

Keyword(s):

Mass Transport ◽

Persian Gulf ◽

Anthropogenic Factors ◽

Oman Sea ◽

The Earth ◽

Salinity Increase ◽

Persian Gulf Water ◽

Oceanographic Data ◽

The Persian Gulf ◽

Simple Dynamical Model

Abstract. Oceanographic data and a dynamic model are used to consider the structure of Persian Gulf outflow. This outflow influences the physical properties of Oman seawater which appear in the CTD profiles of the Oman Sea. The observations show that thickness of the outflow, which is banked against the Oman coasts due to the earth rotation, is about 200 m with tongues extending east and north that may be due to the internal waves. A simple dynamical model of the outflow based on potential vorticity conservation is used to find the horizontal extension of the outflow from the coast. Typical mass transport estimate by the outflow is about 0.4 Sv, which is larger than those reported by others. This may be due to the fact the model is inviscid but the outflow is influenced by the bottom friction. Variability of the outflow structure may reflect the changing ecosystem of the Persian Gulf. Any change of the outflow source, the Persian Gulf Water (PGW), say salinity increase due to excessive evaporation (climate factor) or desalination (anthropogenic factors) of the PGW may change the outflow structure and the product waters in the Oman Sea. Hence, one can test different scenarios of changing the outflow source, the Persian Gulf Water (PGW), say by salinity increase due to excessive evaporation or desalination (ecosystem factors) of the PGW to estimate changes in the outflow structure and the product waters in the Oman Sea. The results of the model show that these can increase the outflow width and mass transport substantially.

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Reversal of freshening trend of Antarctic Bottom Water in the Australian-Antarctic Basin during 2010s

Scientific Reports ◽

10.1038/s41598-020-71290-6 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

S. Aoki ◽

K. Yamazaki ◽

D. Hirano ◽

K. Katsumata ◽

K. Shimada ◽

...

Keyword(s):

Continental Slope ◽

Bottom Water ◽

Ross Sea ◽

Bottom Layer ◽

Ice Shelves ◽

West Antarctic ◽

Sea Bottom ◽

Salinity Increase ◽

Bottom Waters ◽

Late Twentieth

Abstract The Antarctic continental margin supplies the densest bottom water to the global abyss. From the late twentieth century, an acceleration in the long-term freshening of Antarctic Bottom Waters (AABW) has been detected in the Australian-Antarctic Basin. Our latest hydrographic observations reveal that, in the late 2010s, the freshening trend has reversed broadly over the continental slope. Near-bottom salinities in 2018–2019 were higher than during 2011–2015. Along 170° E, the salinity increase between 2011 and 2018 was greater than that observed in the west. The layer thickness of the densest AABW increased during the 2010s, suggesting that the Ross Sea Bottom Water intensification was a major source of the salinity increase. Freshwater content on the continental slope decreased at a rate of 58 ± 37 Gt/a in the near-bottom layer. The decadal change is very likely due to changes in Ross Sea shelf water attributable to a decrease in meltwater from West Antarctic ice shelves for the corresponding period.

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