scholarly journals Recognition of Environmentally Vulnerable Depositional Facies in the Chacahua Lagoon, Oaxaca, Mexico

2005 ◽  
Vol 32 (2) ◽  
pp. 17 ◽  
Author(s):  
FELIPE RÍOS ◽  
GELIA SANDOVAL ◽  
ALFREDO FRÍAS

Over the years, human activity and environmental problems have impacted the Chacahua Lagoon in the State of Oaxaca, Mexico. In an attempt to gain more insight into the current environmental conditions of this lagoon, twenty-eight bottom sediment samples were collected in August 2003. Using depth, physical properties (grain-size and texture) and biological characteristics (organic matter and CaCO3 contents) of sediments as environmental indicators, three depositional facies were identified implementing cluster analysis, each facies seems to be under the influence of different processes. In terms of environmental concern, it was determined that the central part of the lagoon presents a high potential of pollutant sorption, thus this sector should be closely monitored.

2004 ◽  
Vol 31 (2) ◽  
pp. 17
Author(s):  
Felipe RÍOS ◽  
Gelia SANDOVAL ◽  
Alfredo FRÍAS

Over the years, human activity and environmental problems have impacted the Chacahua Lagoon in the State of Oaxaca, Mexico. In an attempt to gain more insight into the current environmental conditions of this lagoon, twenty-eight bottom sediment samples were collected in August 2003. Using depth, physical properties (grain-size and texture) and biological characteristics (organic matter and CaCO3 contents) of sediments as environmental indicators, three depositional facies were identified implementing cluster analysis, each facies seems to be under the influence of different processes. In terms of environmental concern, it was determined that the central part of the lagoon presents a high potential of pollutant sorption, thus this sector should be closely monitored.


2017 ◽  
Vol 50 (1) ◽  
pp. 295
Author(s):  
S. Doani ◽  
K. Albanakis ◽  
O. Koukousioura ◽  
K.K. Koliadimou

The aim of the present study is to investigate the sedimentological characteristics of Lake Koronia down to a depth of 3.5m below lake bottom. Sampling operations took advandage of a season that the lake bottom was exposed to subaerial conditions. The sedimentological analysis proved that sediments consist of mud to sandy mud, with 2 phases of very fine sand fractions. The proportion of dry organic matter contained into sediment, appears to be generally small while the rates of moisture and volatiles are relatively high. Furthermore, this study examines the distribution of ostracod populations in the sediments of the lake in relation to depth, grain size and other environmental conditions of this water body. Four ostracod species were identified: Candona neglecta, Darwinula stevensoni, Heterocypris spp. and Limnocythere inopinata. The study of freshwater ostracods provides information for the palaeoecological/palaeoenvironmental conditions during the sedimentation.


Hydrology ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 18
Author(s):  
Mebrahtom G. Kebedew ◽  
Seifu A. Tilahun ◽  
Fasikaw A. Zimale ◽  
Tammo S. Steenhuis

Sediment concentration of rivers in developing countries has been increasing greatly over the last 50 years due to the conversion of forest to continuously cultivated land with the increasing population. Few studies have addressed its effect on sedimentation and water quality of the lakes by analyzing bottom sediment characteristics. In this study, the objective was to investigate the spatial distribution (and their interrelationships) of the bottom sediment characteristics in the largest lake in Ethiopia, Lake Tana where water hyacinths have been spreading rapidly during the last decade. Sediment samples were collected from the lake bottom at 60 locations and analyzed for texture, organic matter, total nitrogen, and available phosphorus. Bottom sediment samples had a median of 75% clay, 13% silt, and 9% sand. Clay was greatest in the northwestern part and smallest in the areas near the major rivers entering or exiting the lake. Clay percentage and lake depth were strongly correlated. The mean organic matter content of bottom sediment was 16 g kg−1, total nitrogen 0.8 g kg−1, and Olsen available phosphorus 19 mg kg−1. Phosphorus concentrations peaked where water hyacinths were found in the northeastern part of the lake. This study will serve as a baseline for future water quality and sedimentation changes in Lake Tana. In particular, it might aid in explaining the spread of the water hyacinths.


2020 ◽  
Vol 9 (4) ◽  
pp. 423-430
Author(s):  
Gadisza Asmara Yudha ◽  
Chrisna Adhi Suryono ◽  
Adi Santoso

Pantai Kartini merupakan salah satu kawasan wisata di Kabupaten Jepara. Berbagai aktifitas masyarakat serta infrastruktur perairan menjadi kebutuhan yang sangat krusial dengan letak Pantai Kartini. Adanya aktivitas dan bangunan dapat menyebabkan perubahan sebaran ukuran butir dan kandungan bahan organik. Penelitian ini memiliki tujuan untuk mengetahui jenis dan klasifikasi sedimen serta jumlah kandungan bahan organik yang terdapat dalam sedimen di Pantai Kartini, Jepara. Pengambilan data pada penelitian ini yaitu pengambilan data primer yang berupa sampel sedimen dengan menggunakan sediment core. Dilanjutkan dengan analisis sampel sedimen dan analisis kandungan bahan organik. Hasil penelitian menunjukkan bahwa di perairan Pantai Kartini, Jepara memiliki jenis sedimen pasir (sand) dimana nilai ukuran butir tersebut berkisar dari 81-96%, yang mana pada Stasiun 1 rata-rata sebesar 91,6-96%, Stasiun 2 rata-rata sebesar 93,5-96,9%, dan Stasiun 3 rata-rata sebesar 81,4-92,9%. Sedangkan, Kandungan Bahan Organik yang terdapat di perairan tersebut memiliki konsentrasi berkisar dari 5-14% yang termasuk dalam kriteria rendah-sedang, dimana pada Stasiun 1 rata-rata sebesar 10,9-13,3%, Stasiun 2 rata-rata sebesar 5,92-10,18%, dan Stasiun 3 rata-rata sebesar 7,7-14%. Kartini Beach is one of the tourist areas in Jepara Regency. Various community activities and water infrastructure have become crucial needs in Kartini Beach. The existence of activities and buildings can cause changes in the distribution of grain size and content of organic matter. This study aims to determine the type and classification of sediments and the amount of organic matter content contained in sediments in Kartini Beach, Jepara. Data collection in this study is primary data collection in the form of sediment samples using sediment cores. Followed by analysis of sediment samples and analysis of organic matter content. The results showed that in Kartini Coast waters, Jepara had a sand sediment type where the grain size values ranged from 81-96%, which at Station 1 averaged 91,6-96%, Station 2 on average amounted to 93,5-96,9%, and Station 3 averaged 81,4-92,9%. Meanwhile, the content of organic matter contained in these waters has concentrations ranging from 5-14% which are included in the criteria of low-moderate, where at Station 1 an average of 10,9-13,3%, Station 2 an average of 5,92-10,18%, and Station 3 averaging 7,7-14%. 


Author(s):  
Olga Konechnaya ◽  
Christina Schwanen ◽  
Jan Schwarzbauer

Abstract The tremendous increase of plastic production, its intensive usage in packaging, as transport material and the insufficient management of plastic garbage lead to a rise of microplastic particles as anthropogenic contaminant in our environment. To develop appropriate management and remediation strategies for this global pollution problem, reliable and consistent analytical procedures for measuring plastics in the complex matrices need to be designed. The applicability of an easy, robust and fast multi-step approach was tested on three sediment samples from riverine, beach and backwater areas of varying origin, grain size and organic matter content is reported here. The optimized method included grain size fractionation, density separation and μ-FTIR analyses. Identification was based on two complementary methods of μ -FTIR measurements, the Image mode for small microplastics (<1 mm) and the ATR method for bigger (1–5 mm) particles. The analyses revealed the identification of several polymers in various grain sizes at different pollution levels. Major findings are the dominance of PET particles and the highest frequency of microplastic particles in the midsize fraction of 100–500 μm. Generally, the method was able to reliably detect microplastic particles in several grain size fractions and down to very low contamination levels of approximately. ten particles per 50 g of sediments with different organic matter content and various grain size characteristics. Moreover, the presented multi-step approach represents a fast, easy and less cost-effective method as alternative to more expensive and time-consuming methods.


2020 ◽  
Vol 7 (3) ◽  
pp. 168-175
Author(s):  
Rifka Rimbi Anggraini ◽  
Yenny Risjani ◽  
Uun Yanuhar

Lekok water is one of the open waters. This will greatly affect the sedimentation process in Lekok water. The purpose of this study is to examine the distribution of bottom sediments in Lekok Water, Pasuruan Regency. The study was conducted in October-November 2019 using ekman grab at 9 site points. Sediment samples were obtained then analyzed in the laboratory to determine the grain size, as well as statistical calculations to analyze the distribution of the sediment. Based on the results of the study note that sediments distributed in Lekok Water are generally dominated by three types of sediments namely: sandy loam, loam and silt loam. Sorting values are in a well-sorted to the moderately well-sorted condition where the sediment conditions are well sorted. The skewness value is skewed positively where the value indicates a positive skewed sedimentary condition. The value of kurtosis is in the leptokurtic condition where the sediment from station 1 to station 9 is homogeneous.


2017 ◽  
Vol 46 (2) ◽  
Author(s):  
Anna Czaplicka ◽  
Ewa Szarek-Gwiazda ◽  
Zbigniew Ślusarczyk

AbstractThe study determines the differences in Pb accumulation in sediments of dam reservoirs with respect to locations of the old river beds and their depth (deep Czorsztyn Reservoir and shallow Goczałkowice Reservoir in southern Poland). Parameters (grain size, organic matter content and reservoir depth) that may influence the spatial distribution of Pb concentrations in the sediments were analyzed. Based on the hierarchical cluster analysis, sediment samples from the reservoirs were ranked with respect to particle size distribution. We found differences in the spatial distribution of grain size and organic matter in the studied reservoirs, caused mostly by the topography of these reservoirs. The spatial distribution of Pb concentrations in the sediments of the Czorsztyn Reservoir (range 4.8-35.8 μg g


Author(s):  
Truong Van Tuan ◽  
Irina Vladimirovna Volkova

Research was held in the estuary of the river Bach Dang (Dongbay community, Rakhtay district, Hai Phong, Vietnam) in June, 2012 - May, 2013. Concentration of lead was studied in water, suspended solids and bottom sediment. Clam beach (natural breeding environment of Meretrix lyrata ) was inspected regularly, every month. Water samples were taken 6 times from the bottom layer 10 cm down the bottom, once per 3 hours in each of 12 investigated zones. Bottom sediment samples were taken at the depth 2 cm. The findings show that lead accumulates mainly in suspended solids (23.3 mg/kg) and in bottom sediment (14.31 mg/kg), in water it is in small quantities (0.003 mg/kg). Analysis of bottom sediment samples taken in different places showed that they have even leadcontent, lead is distributed uniformly, localization of contaminations is not found. The results obtained can be assumed as the basis for investigating lead accumulation and its excretion by clam Meretrix lyrata organisms in the natural habitat.


1984 ◽  
Vol 19 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Alena Mudroch

Abstract Surface sediment samples obtained at the offshore and nearshore area of Lake Erie were separated into eight different size fractions ranging from <2 µm to 250 µm. The concentration of major elements (Si, Al, Ca, Mg, K, Na, Fe, Mn and P), metals (Zn, Cu, Cr, Ni, V, Co and Pb) and organic matter was determined together with the mineralogical composition and morphology of the particles in each size fraction. The distribution of the metals in the offshore sediment was bimodal with the majority of the metals divided between the 63 to 250 um size fraction which also contained the highest concentration of organic matter (about 20%) and the <4 µm fraction containing up to 60% of clay minerals. However, the metals in the nearshore sediment were associated mainly with the clay minerals.


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