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Effects of Water Stratification and Mixing on Plankton Community Structure in a Floating Solar Power Plant
Issue:
Volume 12, Issue 1, February 2023
Pages:
1-9
Received:
29 November 2022
Accepted:
26 December 2022
Published:
10 January 2023
Abstract: Plankton community structure play pivotal roles in aquatic ecosystems, influencing their structure, function and services. However, little is known about the effects of water stratification and mixing on the dynamics of aquatic ecosystems. The influence of water stratification and mixing on plankton community structure was studied in the Floating Da Mi Solar Power Plant was done between March 2020 and September 2022, encompassing both dry and rainy seasons. Data from 4 sites were used as a representative example for the study area to conduct a qualitative study. To implement this assessment, the analyses were based on MRC methods and classifications, these improved by the scientific group. The results showed that 86 species of phytoplankton and 23 species of zooplankton were found in the study area. The density of phytoplankton at each site ranged from 279 to 32,282 individuals/sample, while the density of zooplankton at each site fluctuated from 5 to 33 individuals/sample. The calculated values for the diversity index (H’) of phytoplankton and zooplankton fluctuated from medium to quite high levels from 1.55 to 3.69; 1.562.95 respectively. The results also showed that several environmental variables, including temperature, dissolved oxygen, and chlorophyll-a were correlated with species richness, density and diversity index of phytoplankton and zooplankton. The obtained results will be useful for the monitoring of changes of aquatic ecosystem at the study area, in particular the sensitivity of aquatic flora and fauna to changes in environmental variables.
Abstract: Plankton community structure play pivotal roles in aquatic ecosystems, influencing their structure, function and services. However, little is known about the effects of water stratification and mixing on the dynamics of aquatic ecosystems. The influence of water stratification and mixing on plankton community structure was studied in the Floating D...
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Assessing the Potential of Shallow Groundwater for Agriculture Adapting to Drought and Saltwater Intrusion, Ben Tre Province, Mekong River Delta, Vietnam
Nguyen Van Lap,
Ta Thi Kim Oanh,
Lieu Kim Phuong,
Nguyen Thi Mong Lan,
Vo Thi Hong Quyen
Issue:
Volume 12, Issue 1, February 2023
Pages:
10-16
Received:
7 December 2022
Accepted:
26 December 2022
Published:
10 January 2023
Abstract: Ben Tre province is located in the lower delta-plain of the Mekong River Delta, southern Vietnam surrounded by the Tien River system and 65 km long coastline on East Sea. Tropical monsoon climate characterized by high annual rainfall of 1,250 - 1,500 mm and high average annual temperature which are favorable for agricultural cultivation. In the dry season, due to the long coastline and large river mouths, saltwater intrusion appears seriously, greatly affecting cultivation and people's lives in rural areas, especially drought and saltwater intrusion are more serious in the recent years due to the effect of climate change. Research on the use of shallow groundwater for living use and crop irrigation, contributing to agricultural development in drought and salinity conditions. On the base of available research data, 8 geological boreholes and 6 hydrogeological boreholes were carried out in this study. The research results have determined characteristics of sediment from the cores and distributions of shallow groundwater consisting of layers and lenses that interbedded with silty layers. Fresh water is found at the depths of 10 - 14 m belonging to Holocene aquifer and the 40 - 60 m deep in upper Pleistocene aquifer, and brackish- salt water is at 24-35 m deep. Analytical results show low level of chloride, sulphate, Fe total, and As total, concentrations, excepting Fe total is high - very high in many places. Two models of Fe treatment from shallow groundwater were established showing good efficiency in Cho Lach and Chau Thanh districts.
Abstract: Ben Tre province is located in the lower delta-plain of the Mekong River Delta, southern Vietnam surrounded by the Tien River system and 65 km long coastline on East Sea. Tropical monsoon climate characterized by high annual rainfall of 1,250 - 1,500 mm and high average annual temperature which are favorable for agricultural cultivation. In the dry...
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Sedimentary Characteristics of Shallow Aquifers and Suitability to Irrigation in the Drought Season: The Case of the Fruit Tree Area in Ben Tre Province, Mekong River Delta
Nguyen Van Lap,
Ta Thi Kim Oanh,
Duong Ba Man,
Lieu Kim Phuong,
Nguyen Thi Mong Lan,
Vo Thi Hong Quyen
Issue:
Volume 12, Issue 1, February 2023
Pages:
17-25
Received:
23 December 2022
Accepted:
27 December 2022
Published:
10 January 2023
Abstract: In Ben Tre province, shallow groundwater found at a depth of 8 to 60 m is exploited for domestic use and for irrigation of crops in rural areas. The water wells have different depths and are usually moderately to high contaminated with iron alum, moreover the saline- brackish water is at different depths and locations. In recent years, due to the effects of climate change and drought, the problem of drinking water and irrigation for planting is an urgent need. The study determined the distribution characteristics of aquifers, the environment for forming sediments and analyzed some chemical indicators of water for crop irrigation. This study shows that shallow groundwater is clarified and consisting of the Holocene (qh) and upper Pleistocene (qp3) aquifers from 8 to 60 m in depth. The Holocene aquifer consists of fresh water commonly found at of 8.5-17.5 m in depth, and saline- brackish water appearing by layers and lenticular are commonly found at about 25- 35 m in depth. Fresh water is usually found in the fluvial flat, channel and estuary facies, and saline - brackish water is in the tidal flat, delta front and pro-delta facies belong to the subaqueous delta plain. It suggests that sedimentary facies in boreholes and geological cross-sections play an important role in determining distribution characteristics and water quality, clarifying the distribution of fresh and saline water in Holocene sediments in the study area. This result can be referenced for research in the Mekong River Delta and other regions. Shallow aquifers have not great thickness, uneven water quality, cannot provide concentrated water. However, the water source has an important meaning in providing water for agricultural irrigation in the drought season, especially in the fruit tree area in Ben Tre Province.
Abstract: In Ben Tre province, shallow groundwater found at a depth of 8 to 60 m is exploited for domestic use and for irrigation of crops in rural areas. The water wells have different depths and are usually moderately to high contaminated with iron alum, moreover the saline- brackish water is at different depths and locations. In recent years, due to the e...
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A Prominent Iron Silicides Strewn Field and Its Relation to the Bronze Age/Iron Age Chiemgau Meteorite Impact Event (Germany)
Kord Ernstson,
Frank Bauer,
Michael Hiltl
Issue:
Volume 12, Issue 1, February 2023
Pages:
26-40
Received:
22 January 2023
Accepted:
8 February 2023
Published:
24 February 2023
Abstract: About 20 years ago, amateur archeologists and local history researchers discovered the iron silicide (FESI) strewn field measuring about 60 km x 30 km in the districts of the Chiemgau and the Inn-Salzach region in southeast Germany. They evidenced the connection between the FESi distribution and the pervasive rim wall craters and suggested a meteorite impact event, now widely recognized under the name of the Chiemgau impact. Widespread in the strewn field and in individual finds far beyond it they recovered and documented thousands of FESI particles of millimeter to centimeter size with a total mass of more than 2 kg, whereby a large lump of 8 kg stands out as a single find. The find layer is largely uniformly located at a depth of 30 - 40 cm in a glacial loose sediment soil. Microprobe, SEM-EDS, TEM and EBSD analyses determined as main minerals gupeiite and xifengite, subordinately hapkeite, naquite and linzhite. Besides the main elements Fe and Si of the matrix, more than 30 other chemical elements have been addressed so far, including uranium and various REE. Incorporated into the FESI matrix are the carbide minerals moissanite and titanium carbide as superpure crystals, and khamrabaevite, zirconium carbide, and uranium carbide, furthermore CAIs. SEM images indicate shock metamorphism. The present article describes the discovery history of this worldwide unique FESI occurrence with the exact find situations, as well as the very varied morphologies of the find particles with the macroscopically recognizable components and SEM EDS examples.
Abstract: About 20 years ago, amateur archeologists and local history researchers discovered the iron silicide (FESI) strewn field measuring about 60 km x 30 km in the districts of the Chiemgau and the Inn-Salzach region in southeast Germany. They evidenced the connection between the FESi distribution and the pervasive rim wall craters and suggested a meteor...
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