scholarly journals Macrophytes in the littoral of Lake Arakhley in different states of water regime

2019 ◽  
Vol 38 (3) ◽  
pp. 225-239
Author(s):  
Alexey P. Kuklin ◽  
Balzhit B. Bazarova
Keyword(s):  
Water Content ◽  
Water Level ◽  
Mixed Type ◽  
Water Regime ◽  
Aquatic Vegetation ◽  
High Water ◽  
Sand Beach ◽  
Climate Fluctuations ◽  
High Water Period

AbstractThe study of aquatic vegetation in the littoral of the dimictic water bodies of taiga is of particular interest in case of long-term observations carried out under conditions of climate fluctuations. During the low-water period, drying of the littoral with a decrease in the water level leads to the changes in phytomass of macrophytes, as well as in the composition of species and their distribution by depth. The area of littoral covered with ice in winter is also large in the low-water period; it affects the growth of perennial plants. When the water level decreases, the sand beach replaces the sand and pebble beach; it leads to the disappearance of epilithon and the predominance of rooting plants. The features of vegetation were determined for each period of water content. The low-water period is characterised mostly by grass-type vegetation; the high-water period is characterised by vegetation of mixed type.

scholarly journals The Change of the Water Regime of the Volga River in the Area of the Protected Island Bakhilovsky

2020 ◽  
Author(s):  
Keyword(s):  
Water Content ◽  
Water Regime ◽  
High Water ◽  
Ecological State ◽  
Spring Flood ◽  
Volga River ◽  
High Water Period ◽  
Average Water ◽  
Annual Water

The ecological state of the protected Islands Seredysh and Shalyga (now Bakhilovsky island) depends on the water content and flow of the Volga River. We have analyzed the long-term changes in the water flow of the Volga River for the period 1958-2017 in the alignment Zhiguli dam, located 12 km upstream from the island. According to the average annual water consumption, there are three periods that differ from each other in water content: low-water period (1958–1976), high-water period (1977–1997) and the period of average water content (1998–2017), with extremely low-water (1967, 1973, 1975, 1976, 1977, 1996) and extremely high-water (1966, 1979, 1981, 1990, 1991, 1994) years. In highwater years, during the passage of the spring flood, the island is almost completely flooded, and in low-water years, during the summer low water, the area of the island increases and changes its configuration.

Empirical settlement predictions in overconsolidated Champlain Sea clays

2001 ◽  
Vol 38 (4) ◽  
pp. 720-731 ◽  
Author(s):  
Luc Morissette ◽  
Michel W St-Louis ◽  
Gordon C McRostie
Keyword(s):  
Water Content ◽  
Correction Factor ◽  
Empirical Model ◽  
High Water ◽  
High Water Content ◽  
Overconsolidation Ratio ◽  
Compressibility Index ◽  
Marine Clays

Using settlement observations published for several embankments on marine clays of the Champlain Sea, an empirical model is proposed to estimate long-term settlements. The effect of the overconsolidation ratio is taken into consideration within the model. Footing- and raft-type foundation cases are considered to give guidelines when using the model for these foundation types. A specific embankment resting on a foundation of high water content clay with a high compressibility index demonstrates that a correction factor should be applied under these conditions.Key words: settlement, embankment, Champlain Sea clay, consolidation, empirical model.

scholarly journals Toward the understanding of saline water intrusion and nutrient flushing in Lake Nokoué

2021 ◽  
Author(s):  
Metogbe Djihouessi ◽  
Rita Houngue ◽  
Firmin Adandedji ◽  
Luc Sintondji
Keyword(s):  
Water Quality ◽  
Atlantic Ocean ◽  
Water Level ◽  
Water Flow ◽  
River Flow ◽  
Saline Water ◽  
High Water ◽  
The North ◽  
High Water Period ◽  
Mike 21

To understand the salinity dynamic at the outlet of Lake Nokoué and to simulate the nutrient flushing from this lake into the Atlantic Ocean, a 2D hydrodynamic model was designed with Mike 21. The choice of the Mike 21 was motivated by the long practice that decision-makers in Benin have with this software. The Hydrodynamics (HD) module simulated water level variations and flows in response, while the ECO-Lab module has been used for water quality modelling. The data used covered the hydrological period of 2013. The results from the HD simulation indicated that for a flow of 725 m3/s at Bonou on the Ouémé River, a tributary of Lake Nokoué. 70% of the land in the delta of Ouémé, between the Ouémé River and the So River (also a tributary of Lake Nokoué), are flooded against 90% for a river flow of 1100 m3/s. The water level in the delta showed a water increase of 0.6 m, in seven days, for a water flow of 725 m3/s at Bonou and a water increase of 1.3 m, in seven days, for a water flow of 1100 m3/s at Bonou. Water quality simulations indicated that the seawater intrusion from the Atlantic Ocean into Lake Nokoué occurred from the bottom to the surface towards the surface of the lake. During flooding, despite the large inflow of fresh water, more than 60% of the water at the bottom of the lake had concentrations greater than 8. Simulation of the dispersion of nutrient point source pollution indicated that there was an accumulation of pollution at the bottom of the lake during low water periods. This accumulation increases in amplitude as one moves away from the Atlantic Ocean towards the north of the lake. In this period tidal flushing evacuated about 20% of the pollution ejected. In the high water period, about 70% of the pollution ejected in the lake was automatically flushed out in the lake the Atlantic Ocean.

scholarly journals Present-day Special Features of the Don River Basin Rivers Spring Tide

2013 ◽  
pp. 60-76
Author(s):  
Keyword(s):  
River Basin ◽  
Water Regime ◽  
Spring Tide ◽  
High Water ◽  
Annual Runoff ◽  
Water Runoff ◽  
Regime Changes ◽  
Flow Duration ◽  
High Water Period ◽  
Don River

The article is devoted to present-day specific features of the Don River basin rivers spring tide. On the basis of the recent data on the rivers’ water regime changes of maximal water flow, duration of high water period, high water runoff fractions in the annual runoff and hydrograph forms have been shown. It has been demonstrated that the spring tide character change is closely linked with the other phases of rivers’ water regime change.

scholarly journals Satellite Imageries and Field Data of Macrophytes Reveal a Regime Shift of a Tropical Lake (Lake Ziway, Ethiopia)

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 396
Author(s):  
Yohannes Tefera Damtew ◽  
Boud Verbeiren ◽  
Aymere Awoke ◽  
Ludwig Triest
Keyword(s):  
Surface Water ◽  
Water Level ◽  
Regime Shift ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Aquatic Vegetation ◽  
Meteorological Data ◽  
Water Area ◽  
Ethiopian Rift

Lake Ziway is one of the largest freshwater lakes located in the central Ethiopian rift valley. The lake shoreline is dominated by macrophytes which play an important role in immobilizing run-off pollution, stabilize sediments and support biodiversity. Monitoring the spatio-temporal changes of great lakes requires standardized methods. The aim of this study was to assess the current and long-term trends of macrophyte distribution, surface water area and the water level of Lake Ziway using remote sensing images from 1986 to 2016 with additional hydro-meteorological data. A supervised image classification with classification enhancement using Normalized Difference Aquatic Vegetation Index (NDAVI) and Normalized Difference Vegetation Index (NDVI) was applied. The classification based on NDAVI revealed eight target classes which were identified with an overall producer’s accuracy of 79.6%. Contemporary open water and macrophyte fringes occupied most of the study area with a total area of 407.4 km2 and 60.1 km2, respectively. The findings also revealed a regime shift in the mean water level of the lake and a decline in macrophyte distribution. The long-term water surface area of Lake Ziway also decreased between 1986 and 2016. The changes in water level could be explained by climate variability in the region and strong anthropogenic disturbance. A decline in water level was also associated with lowered surface water area, lakeward retreated macrophyte fringes and enhanced landward encroachment of mudflats, and resulted in a succession of macrophytes with semi-terrestrial vegetations.

scholarly journals Analisis Formalin Secara Kualitatif pada Bakso dan Mie Basah di Kecamatan Sukarame, Wayhalim, dan Sukabumi

KOVALEN ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 218-223
Author(s):  
Riri Fauziyya ◽  
Anjar Hermadi Saputro
Keyword(s):  
Qualitative Analysis ◽  
Water Content ◽  
Food Products ◽  
High Water ◽  
High Water Content ◽  
Food Preservatives ◽  
Maximum Profit ◽  
Positive Results

Meatballs and wet noodles are foods that are favored by the community. The high water content causes these two types of food to be vulnerable and easily damaged in storage. The addition of chemicals such as preservatives in the manufacture of food products is carried out by producers so that the products are more durable, economical, and produce maximum profit. One chemical that is often misused for food preservatives is formaldehyde. Formalin is a dangerous chemical that is carcinogenic, mutagenic, corrosive, and irritating. This study aims to determine whether there is formalin content in meatballs and wet noodles that are sold in the districts of Sukarame, Wayhalim, and Sukabumi. This research was conducted in a qualitative analysis using Schiff's reagent on 30 samples of meatballs and 30 samples of wet noodles which were sold in Sukarame, Wayhalim, and Sukabumi. The results showed that 10 samples of meatballs and 2 wet noodles showed positive results containing formaldehyde.  This shows that around 33.3% of the meatball sample and 6.66% of the wet noodles sample analyzed were identified to contain formaldehyde so that they are not safe for consumption in the long term and people must be careful in selecting meatballs and wet noodles for consumption. Keywords: Qualitative analysis, formalin, meatballs, wet noodles

scholarly journals CHARACTERISTICS PHYSICAL PROPERTIES OF SOIL FOR CONSERVATION POND PLANNING IN KECAMATAN LIANG ANGGANG PEATLANDS

2017 ◽  
Vol 3 (3) ◽  
pp. 13-17
Author(s):  
Rusliansyah Rusliansyah ◽  
Rusdiansyah Rusdiansyah ◽  
Muhammad Afief Ma’ruf ◽  
Meilinda Ayunita Santoso
Keyword(s):  
Physical Properties ◽  
Water Level ◽  
Ecosystem Restoration ◽  
High Water ◽  
Land Conservation ◽  
Land Area ◽  
Fire Point ◽  
Main Factor ◽  
Properties Of Soil

Peatland fires in 2015 that hit 23 of 33 provinces in Indonesia is one of the worst fires in history. South Kalimantan is one of the 23 provinces with the burned land area of 19.179,9 hectares. Peatland burning in Banjarbaru and of Banjar Regency which totaled 1.536 fire point burning with a land area of approximately 1.500 hectares. The main factor of this land fires is of decreased water level in the peat land. Therefore, to overcome that fires will not happen again by creating a conservation pond to hold water, especially during the rainy season in order to keep moist peat.   The planning an peat land conservation in this area of 900 hectares. Peat ecosystem restoration can be done through the realignment of hydrological function where peat dome as a long-term water storage. The purpose of the research is to knowing the state of the physical properties soil for conservation pond made and knowing the condition of the ground water level in the field.  From the results of an investigation soil physical properties obtained peat has not undergone recast and the number of pores in the soil are very large so that the soil becomes porous with a high water level conditions.

scholarly journals Long-Term Productivity of Canvasbacks (Aythya Valisineria) in a Snowpack-Driven Desert Marsh

The Auk ◽  
2003 ◽  
Vol 120 (1) ◽  
pp. 107-119
Author(s):  
Kammie L. Kruse ◽  
James R. Lovvorn ◽  
John Y. Takekawa ◽  
Jeffrey Mackay
Keyword(s):  
Water Level ◽  
Nest Success ◽  
High Water ◽  
Breeding Population ◽  
Breeding Performance ◽  
Wetland Birds ◽  
Factors Affecting ◽  
Mammalian Predators ◽  
Aythya Valisineria

Abstract Ruby Lake, Nevada, is a large palustrine wetland that hosts the southern-most major breeding population of Canvasbacks (Aythya valisineria). That arid marsh, fed by springs derived from mountain snowpack, differs in climate and hydrology from glaciated potholes of the northern prairies where most Canvasbacks breed. Fourteen years of nesting data on Canvasbacks over a 31 year period (1970–2000) were analyzed to determine factors affecting breeding performance at Ruby Lake and whether they differed from those in the prairies. Long-term Mayfield nest success at Ruby Lake (50% of all nests) was in the range of that in the northern prairies (21–65%). Of all Canvasback nests, 73% were parasitized (mostly by Redheads [Aythya americana]) as compared to 83–97% in a large Manitoba marsh and 57–65% in Manitoba potholes. However, as in the northern prairies, nest parasitism generally had little or no effect on either nest success or percentage of host eggs that hatched. In Manitoba potholes, nest success was unrelated to habitat variables measured; but successful nests at Ruby Lake were over shallower water, farther from shore, in wider bands of emergent vegetation, and surrounded by lower stem densities than unsuccessful nests. Water level is the key factor in breeding performance of Canvasbacks at both Ruby Lake and the northern prairies; however, the source of water differs (mountain snowpack at Ruby Lake, direct precipitation in the prairies) and effects of water-level variations are reversed. In small prairie potholes (mostly <0.4 ha) with many mammalian predators, productivity of Canvasbacks (which build floating nests) is increased by high water that floods the emergent fringe. At Ruby Lake, a very large marsh (2,830 ha) with mostly avian predators, Canvasback productivity is decreased by high water that floods interior emergent stands too deeply. Water level at Ruby Lake was highly correlated (multiple R2 = 0.91) with mountain snowpack up to three years earlier, emphasizing the strong effect of climatic variations on wetland birds in that arid region.

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