scholarly journals Tracking the water fingerprints of Cocos Island: a stable isotope analysis of precipitation, surface water, and groundwater

2016 ◽  
Vol 64 (1) ◽  
pp. 105 ◽  
Author(s):  
José L. Corrales ◽  
Ricardo Sánchez-Murillo ◽  
Germain Esquivel-Hernández ◽  
Esteban Herrera ◽  
Jan Boll
Keyword(s):  
Costa Rica ◽  
Surface Water ◽  
Stable Isotope ◽  
Isotopic Composition ◽  
Central America ◽  
Dry Season ◽  
Wet Season ◽  
Surface Water And Groundwater ◽  
Cocos Island ◽  
Isotopic Characterization

<p>The use of stable isotopes of water, both <span>δ</span><sup>2</sup>H and <span>δ</span><sup>18</sup>O has provided novel insights in hydrological studies, ecological applications, understanding climate variability, and reconstructing paleoclimate. However, information on the stable isotope composition of water in tropical marine island environments is normally scarce within the Central America Isthmus. Here, we present the first isotopic characterization of precipitation, surface water, and groundwater at Cocos Island, Costa Rica within the eastern tropical Pacific Ocean region. Our results show that the Cocos Island MWL can be described as: <span>δ</span><sup>2</sup>H=8.39·<span>δ</span><sup>18</sup>O+13.3; r<sup>2</sup>=0.98 (n=29). Dry season rainfall events ranged from -4.9 ‰ <span>δ</span><sup>18</sup>O up to -2.4 ‰ <span>δ</span><sup>18</sup>O with a mean <em>d-</em>excess of 13.2 ‰. By the beginning of May, the Intertropical Convergence Zone reaches Costa Rica resulting in a notable depletion in isotope ratios (up to -10.4 ‰ <span>δ</span><sup>18</sup>O and -76.2 ‰ <span>δ</span><sup>2</sup>H). During the wet season, <span>δ</span><sup>18</sup>O composition averaged -6.1 ‰ <span>δ</span><sup>18</sup>O and -38.5 ‰ <span>δ</span><sup>2</sup>H with a mean <em>d-</em>excess of 9.9 ‰. HYSPLIT air mass back trajectories indicate a strong influence on the origin of precipitation of two main moisture transport mechanisms, the northeasterly (January-May) and southwesterly (May-November) trade winds. Small seasonal variations were observed in the isotopic composition of surface water throughout the year with mean values ranging from -3.9 ‰ <span>δ</span><sup>18</sup>O (dry season, n=19) up to -4.8 ‰ <span>δ</span><sup>18</sup>O (wet season, n=13). Groundwater samples exhibited a similar trend with more depleted composition during the wet season (-5.2 ‰ <span>δ</span><sup>18</sup>O and -29.8 ‰ <span>δ</span><sup>2</sup>H). Overall, the marine isotopic composition measured in meteoric water at Cocos Island serves to better delineate the isotopic contribution of Pacific moisture towards the Central America Isthmus. It also provides a valuable isotopic reference to discriminate from orographic distillation and Caribbean enriched rainfall inputs in continental studies.</p><div> </div>

scholarly journals Examining the Value of Global Seasonal Reference Evapotranspiration Forecasts to Support FEWS NET’s Food Insecurity Outlooks

2017 ◽  
Vol 56 (11) ◽  
pp. 2941-2949 ◽  
Author(s):  
Shraddhanand Shukla ◽  
Daniel McEvoy ◽  
Mike Hobbins ◽  
Greg Husak ◽  
Justin Huntington ◽  
...  
Keyword(s):  
Food Insecurity ◽  
Central Asia ◽  
East Africa ◽  
Central America ◽  
Southern Africa ◽  
Early Warning ◽  
Reference Evapotranspiration ◽  
Dry Season ◽  
Wet Season ◽  
Skill Evaluation

AbstractThe Famine Early Warning Systems Network (FEWS NET) team provides food insecurity outlooks for several developing countries in Africa, central Asia, and Central America. This study describes development of a new global reference evapotranspiration (ET0) seasonal reforecast and skill evaluation with a particular emphasis on the potential use of this dataset by FEWS NET to support food insecurity early warning. The ET0 reforecasts span the 1982–2009 period and are calculated following the American Society for Civil Engineers formulation of the Penman–Monteith method driven by seasonal climate forecasts of monthly mean temperature, humidity, wind speed, and solar radiation from the National Centers for Environmental Prediction CFSv2 model and the National Aeronautics and Space Administration GEOS-5 model. The skill evaluation, using deterministic and probabilistic scores, focuses on the December–February (DJF), March–May (MAM), June–August (JJA), and September–November seasons. The results indicate that ET0 forecasts are a promising tool for early warning of drought and food insecurity. Globally, the regions where forecasts are most skillful (correlation > 0.35 at leads of 2 months) include the western United States, northern parts of South America, parts of the Sahel region, and southern Africa. The FEWS NET regions where forecasts are most skillful (correlation > 0.35 at lead 3) include northern sub-Saharan Africa (DJF; dry season), Central America (DJF; dry season), parts of East Africa (JJA; wet season), southern Africa (JJA; dry season), and central Asia (MAM; wet season). A case study over parts of East Africa for the JJA season shows that ET0 forecasts in combination with the precipitation forecasts would have provided early warning of recent severe drought events (e.g., in 2002, 2004, 2009) that contributed to substantial food insecurity in the region.

Study on the Contamination of NH3-N and Total Phosphorus in the Seasonal River

2013 ◽  
Vol 864-867 ◽  
pp. 79-82
Author(s):  
Xue Ying Song ◽  
Xiao Jun Hu ◽  
Ru Jing Liang ◽  
Yu Shuang Liang ◽  
Wen Juan Sun
Keyword(s):  
Surface Water ◽  
Total Phosphorus ◽  
Industrial Wastewater ◽  
Quality Standards ◽  
Domestic Sewage ◽  
Dry Season ◽  
Main Stream ◽  
Wet Season ◽  
Permissible Levels ◽  
Taizi River

Water samples were collected from the upstream to the downstream of a seasonal river, the Taizi River, and its main tributaries in dry season, normal season, and wet season. The variations of NH3-N, and total phosphorus (TP) within a hydrological year were analyzed, aimed to study the pollution characteristics and sources of the water bodies. It was found that the tributaries of the Taizi River were heavily contaminated by NH3-N, with 83.8%, 100% and 100% of the sampling sites exceeding the fifth level in the dry season, wet season and normal season, respectively. The concentration of TP in the dry season fluctuated wildly, which was much higher than those in the wet and normal season. Compared with the permissible levels set by the environmental quality standards for surface water standard (GB3838-2002) of China, 57.1% of the sampling sites in the main stream and tributaries of the Taizi River belong to the fifth level or exceed the fifth level in the dry season, and only 7.1% of the sampling sites were belonging to the fifth level or exceed the fifth level in the wet and normal season. Overall, the waterbody of Taizi River was more seriously polluted by urban domestic sewage and point source of industrial wastewater.

scholarly journals Hydrogeological, hydrochemical, and natural isotopes evaluation of groundwater and surface water interactions in the alluvial plain, tropical region of southeastern Brazil

2021 ◽  
Author(s):  
Waldilene Correa ◽  
Sueli Pereira ◽  
Joaquim Ernesto Bernardes ◽  
Paulo Ricardo Pereira
Keyword(s):  
Surface Water ◽  
Groundwater Flow ◽  
Rainy Season ◽  
Dry Season ◽  
Alluvial Plain ◽  
Morphological Features ◽  
Southeastern Brazil ◽  
Wet Season ◽  
Natural Isotopes ◽  
Abandoned Meanders

Groundwater-Surface water interactions in alluvial plains facing morphological features are the subject of the study. Considered transitions zones, alluvial plains have different morphological features interfering with groundwater flow and hydrochemistry. The alluvial plain of Mogi Guaçu river (southeastern Brazil) presented topography-controlled groundwater flow, nevertheless, natural levees, wet fields, oxbow lakes, and abandoned meanders can control local flow and interfere in discharges points of the main river. Two sampling water campaigns were done in the dry and wet season for physicochemical and natural isotopes analysis, collecting in total 44 groundwaters samples from monitoring wells and eight water samples from the river, creek, and lake. The groundwaters in wet fields and terraces, and surface waters from creek and lake presented low mineralization (EC from 8 to 37 μS.cm), pH acidic (4.98 to 5.8), and essentially Ca and Na-HCO composition. River waters samples presented pH between 5.92 e 7.69 (acidic in the rainy season and basic in the dry season), and EC from 24.2 and 181.1 μS/cm (lower values in the wet season), Na-HCO and Na-HCO-SO (dry season) and Ca-HCO and Na-HCO (rainy season) compositions. In dry season groundwaters composition showed evolution from sodium mixed (SO – HCO) to bicarbonate waters and higher mineralization; in wet season waters varied from Ca to Na-HCO composition and low mineralization, denoting dilution due to rainwater infiltration. Closer to the river margins, in abandoned meanders and oxbows, the groundwaters have increased values of EC and major ions indicating GW-SW mixtures, and effluent-influent changes (descendent and ascendent flux) in wet and dry seasons, respectively. Natural isotopes in groundwaters imply meteoric origin, without evaporation during recharge and high d-excess can be influenced by continental air masses and Amazonia Basin low-level jet. Shallow water table, permeable silty-sand material of vadose zone, flat terrain, and pristine conditions can contribute to direct infiltration of rainwaters, recharging the shallow aquifer.

Seasonal Variations of the Regular Indices of the Surface Water in the Taizi River

2014 ◽  
Vol 513-517 ◽  
pp. 4486-4489
Author(s):  
Xiao Jun Hu ◽  
Li Qi Sun ◽  
Xue Ying Song ◽  
Wen Juan Sun ◽  
Ru Jing Liang
Keyword(s):  
Surface Water ◽  
Seasonal Variations ◽  
Dry Season ◽  
Liaoning Province ◽  
Wet Season ◽  
Ph Values ◽  
Northeast Of China ◽  
Taizi River

The regular indices of the surface water of the Taizi River, Liaoning Province, northeast of China, were investigated. Samples were collected from upstream to downstream locations of the mainstream, and also from the tributaries of the Taizi River in dry season, wet season, and normal season, respectively. The DO values of the surface water ranged from 3.35 mg/L to 18.73 mg/L, 0.09 mg/L to 13.44mg/L, and 3.49 mg/L to 16.9 mg/L, respectively, in the dry season, wet season, and normal season, respectively. The seasonal variations of the pH values of the surface water were in the order of dry season >wet season >normal season.

Phenological studies of shrub and treelet species in tropical cloud forests of Costa Rica

1988 ◽  
Vol 4 (4) ◽  
pp. 323-346 ◽  
Author(s):  
Suzanne Koptur ◽  
William A. Haber ◽  
Gordon W. Frankie ◽  
Herbert G. Baker
Keyword(s):  
Costa Rica ◽  
Cloud Forest ◽  
Seasonal Pattern ◽  
Dry Season ◽  
First Year ◽  
Pollination Syndromes ◽  
Wet Season ◽  
Flowering Season ◽  
Fly Pollination ◽  
Lowland Wet Forest

ABSTRACT(1) During 1978–1981, marked individuals of 107 species of treelets and shrubs in three forest types between 1300–1650 m elevation at Monteverde, Costa Rica, were monitored at monthly intervals for behaviour of leafing, flowering, and fruiting.(2) Although there was not a pronounced seasonal pattern of leafing activity, more species produced new leaves in the dry season. Species that flush large quantities of new leaves do so more commonly in the drier months. Leaf loss was gradual and unobtrusive in species observed.(3) Flowering activity was greatest in the late dry season and early wet season. Most species exhibited extended flowering; only 15% of the species were massively flowering. Massive flowerers showed less seasonality than extended flowerers.(4) Of the species studied, the majority had relatively unspecialized flowers which were visited by a variety of insects; small bee-pollination was the next most common, followed by hummingbird, beetle, settling moth, sphingid, butterfly, large bee and fly pollination (the pollination system of 18 species was unknown). Hummingbird pollinated species showed little seasonality of flowering when compared with species exhibiting small moth, and beetle pollination syndromes, as well as those with unspecialized flowers.(5) The vast majority of species studied have fleshy fruits (sarcochores). Fruiting activity was less markedly seasonal than flowering. Species with fruit are more numerous in the second half of the year (the wet season and early dry season). The second year of the study saw substantially fewer species in fruit than the first year; this is attributed to the greater than usual rainfall and inclement weather during the peak flowering season.(6) Cloud forest shrub and treelet phenology is compared with patterns of other forests that have been studied. In general, the greater the rainfall, the less seasonality of flowering and fruiting is seen. Although Monteverde is very wet, rainfall is intermediate between that of lowland dry and lowland wet forest in Costa Rica. Seasonality of flowering and fruiting at Monteverde is more pronounced than at La Selva (wet) and less obvious than in Guanacaste (dry).

scholarly journals Effect of Port Activities on the Physicochemical and Microbiological Quality of Surface Water in Warri and Onne Port Terminals, Nigeria

2021 ◽  
pp. 46-57
Author(s):  
D. N. Ogbonna ◽  
S. A. Ngah ◽  
E. M. Anthony
Keyword(s):  
Surface Water ◽  
Microbiological Quality ◽  
Oxygen Demand ◽  
Dry Season ◽  
Industrial Wastes ◽  
Wet Season ◽  
Salmonella Spp ◽  
Environmental Implications ◽  
Port Area

Activities around the port terminals such as cargo handling, and others has environmental implications both inside and outside the port area which may in turn pose severe risks to the environment and water resources resulting to adverse effect on the physicochemical and microbiological quality of the water body. Hence this study was aimed at determination of the effect of port activities on the physicochemical and microbiological quality of surface water at Warri and Onne Port terminals. Surface water samples were collected during wet and dried season between January to June from Onne and Warri port terminals, using sterile containers and transported in an ice packed container to Department of Microbiology laboratory of the Rivers State University for microbiological and physicochemical analyse using standard methods. Statistical analyses were carried out using ANOVA and All pairs tukey-kramer. Results of the Physicochemical Characteristics of the surface water of the  dry season ranged as follows; pH (5.6±0.15 to 6.08±0.22),Temperature (27.6±4.278 to 30±1ºC),  Electric  conductivity (14168±1.90to  2138±27.871 µs/cm), Total dissolved solid  (2622±1.70 to  974.2±9.09 mg/l ),Total suspended solid (7.6±0.54 to 111±21.284 mg/l), Dissolved oxygen (2.08±0.19 to 2.68±0.31 mg/l ), Biological oxygen demand (0.78±0.19 to 1.2±0.45 mg/l ), Chemical oxygen demand (1.56±0.38 to 2.4±0.90 mg/l),Turbidity (0.2±0 to 1.36±0.336 NTU),Bromine (0.3±0.01  to 0.6±0 mg/l), Chlorine (<0.001±0 to 0.3±0 mg/l),Nitrate (0.32±0.15  to 5.98±0.74 mg/l ), Sulphate (3.32±0.75 to  694±1.9 mg/l) Phosphate (0.634±0.42 to 2.316±0.44 mg/l ), similar trends were recorded during the wet season.   There were significant differences ( P<0.05) between the wet and dry seasons. The mean values of the microbiological results ranged from 1.6±0.77 x 106 to 5.6±2.17 x 106 cfu/ml (Total heterotrophic bacterial count), 0.8 ±2.51 x 104 to 5.6±2.77 x 104 cfu/ml (Total heterotrophic Fungal count), 0.2 ±1.14 x 104 to 3.6 ±1.52 cfu/ml (Hydrocarbon utilizing Bacteria counts) 0.3 ±1.52 x 104 to 1.2 ±2.05cfu/ml (Hydrocarbon utilizing Fungal counts), 0.2±0.71x 104 to 0.6±0.89 x 104cfu/ml (Salmonella spp.). 0.4±0.55 x 104 cfu/ml (Shigella spp), 0.3 ±2.19 x 104 to 1.6±5.13 x 104 cfu/ml (Vibrio spp.) 1.6 ±14.7 x 104 to 2.1±6.39 x 104 cfu/ml Staphylococci spp), 3.9±0.81 x 104 to 4.6 ±1.79 x 104cfu/ml (total coliform), 1.8±0.44 x 104   to 2.7 ±1.03 x 104cfu/ml (feacal coliform). Higher counts were recorded during the wet season compared to dry season. In this study, nine bacteria isolates belonging to the genera and species:-  E.coli, Vibrio, Pseudomonas, Klebsiella, Bacillus sp., Shigella, Staphylococcus, Salmonella, and Proteus, Six fungal isolates, namely, Penicillium sp Candida sp, Mucor sp, Aspergillus, Rhizopus spp, and Yeast were obtained. The results obtained in this study Port terminal houses several companies with beehive of activities which generate various industrial wastes which causes adverse environmental effects which consequently are major atmospheric and water pollution around port terminals. Therefore, proper waste management system should be maintained to avoid emergence of virulent pathogens.

scholarly journals TUTORIAL PENGGUNAAN SOFTWARE SMS 11.1 MODUL RMA2 UNTUK MENGANALISA POLA PERGERAKAN ARUS DI PELABUHAN BELAWAN

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Rizky Franchitika
Keyword(s):  
Surface Water ◽  
Flow Velocity ◽  
Flow Pattern ◽  
Neap Tide ◽  
Spring Tide ◽  
Dry Season ◽  
Wind Pressure ◽  
Wet Season ◽  
Water Modeling ◽  
Surface Water Modeling

ABSTRAKPelabuhan Belawan merupakan pelabuhan terbesar di Sumatera dan ketiga terbesar di Indonesia setelah Tanjung Priok dan Tanjung Perak. Pelabuhan Belawan berada didaratan semenanjung diantara Sungai Belawan dan Sungai Deli. Modelisasi pada pola arus di Pelabuhan Belawan akan menemui masalah yang sangat kompleks, karena geometri daerah pantai yang tidak beraturan adalah bagian sungai yang berhubungan langsung dengan laut. Pengaruh pasang surut terhadap sirkulasi kecepatan pola arus dan debit sungai yang masuk ke Pelabuhan Belawan sangat besar.  Salah satu model matematik untuk pemecahan masalah diatas adalah melakukan kajian dengan menggunakan software SMS (Surface-Water Modeling System) versi 11.1 pada modul RMA2, untuk mengetahui elevasi muka air pada titik di hulu dan hilir pelabuhan pada saat spring tide dan neap tide di musim basah (November) dan musim kering (Juli). Berdasarkan hasil yang didapatkan, kecepatan arus saat pasang tertinggi di musim basah adalah 0,04367 m/s - 0,4608 m/s, kecepatan arus saat pasang terendah di musim tersebut adalah berkisar antara 0,00028 m/s – 0,00287 m/s. Sedangkan kecepatan arus saat pasang tertinggi pada musim kering adalah 0,0229 m/s - 0,2744 m/s dan kecepatan arus saat pasang terendah adalah 0,0003 m/s – 0,0019 m/s. Kecepatan arus pada musim basah cenderung lebih besar daripada musim kering, disebabkan karena pengaruh pasang surut dan debit yang besar, meskipun pada simulasi angin dianggap konstan, tidak menutup kemungkinan bahwa pengaruh tekanan angin pada pelabuhan mempengaruhi kecepatan aliran.Kata Kunci : Eddy Viscosities, Pelabuhan Belawan, Pola Aliran, SMS v11.1 ABSTRACTBelawan Port is the largest port in Sumatra and the third largest in Indonesia's after the Tanjung Priok and Tanjung Perak. Belawan Port is located in mainland peninsula between Belawan and Deli river.The modeling of flow pattern in Belawan Port will encounter a very complex problem, because of the irregular geometry of coastal area which is directly connected to the sea. Tidal influence on flow circulation and the river discharge into Belawan Port is very significant. One of the mathematical models to solve the above problem is aimed to study the use of SMS software (Surface-Water Modeling System) version 11.1 on RMA2 module, to determine the water level at port including upstream and downstream during spring tide and neap tide on the wet season (November) and the dry season (July). Based on the obtained results, the flow velocity of the highest tide on the wet season is 0.04367 m/s - 0.4608 m/s, the flow velocity of the lowest tide on the dry season is between 0.00028 m/s  and 0.00287 m s. While the flow velocity of the highest tides on the dry season is 0.0229 m/s - 0.2744 m/s and low tide flow velocity is 0.0003 m/s - 0.0019 m/s. Flow velocity on the wet season tends to be larger than the dry season due to the influence of tide and large discharge. Although the wind is considered constant on this simulation, it is possible that the wind pressure against the port affects the flow velocity. Keywords: Belawan Port, Eddy Viscosities, Flow Pattern, SMS v11.1

scholarly journals Application of Assessment Models for Health Risk and Pollution From Surface Water From Okumpi River in Nwangele, Imo State, Nigeria

2021 ◽  
Author(s):  
Ihenetu chukwuemeka Stanley ◽  
Njoku Obinna ◽  
Ibe Chizoruo
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Hazard Quotient ◽  
Contamination Factor ◽  
Carcinogenic Risk ◽  
Dry Season ◽  
Wet Season ◽  
Dry Seasons ◽  
The Mean ◽  
Wet And Dry Seasons

Abstract The study targets at examining the pollution assessment and environmental health effects of surface water from Okumpi River. Ten surface water samples were collected randomly both in wet and dry seasons within the river that was assessed. The models used for assessment include contamination factor (Cf), pollution load index (PLI), water quality index, dermal and absorption exposure dose, hazard quotient (HQ), hazard index (HI) and carcinogenic risk (CR). The mean and standard deviation pH value in the present study during the wet and dry seasons varied from 6.21±0.22 - 5.75±0.41. The mean and standard deviation EC in the current study ranges between 219.15±12.20 - 193.30±14.81 μS/cm for wet and dry seasons which are found to be in line with the WHO standard used. The mean and standard deviation of DO for this study during the wet and dry seasons were found to be 10.03±0.58 - 6.47±0.41 (mg/L). TDS for wet and dry seasons ranges from 374.79±5.33 - 121.65±6.33 mg/L. The colour of the water samples at both seasons were lower than the permissible limit 9.60±0.89 - 11.20±3.11 PCU against 15 PCU used as the standard. The nitrate [9.05±1.08 - 8.09±1.57], sulphate [3.91±0.51 - 3.73±0.46] and phosphate [82.78±3.86 - 81.76±3.32] in this present study for wet and dry season were all found to be below the standard of WHO for safe drinking water. Among all the heavy metals studied, Iron [1.28±0.01 - 0.37±0.01 (mg/L)] and Nickel [0.98±0.04 - 1.03±0.04 (mg/L)] were found more in the study in wet and dry seasons while cadmium was not detected in both seasons. Nickel showed high contamination factor of 48.24 – 42.40 in wet and dry season while cupper showed the least contamination factor of 0.012 – 0.008 in wet and dry season. The study has revealed that the surface water is not suitable for drinking purposes as seen by the high water quality index which the calculated value gave 1205.56-1236.26 for wet season and dry season which is > 300. The Hazard quotient via ingestion and Hazard quotient via dermal has a reduction in the order of lead > nickel > iron > manganese > copper > zinc and lead > zinc > nickel > copper > iron > manganese > cadmium, in cooperation in children and adults in wet season, correspondingly. The Hazard quotient via ingestion and Hazard quotient via dermal has a decrease in the following order of nickel > lead > manganese > copper > iron > zinc and lead >zinc > nickel > copper > manganese > iron > for both children and adults in dry season, respectively. Lead possess carcinogenic risk for the inhabitants of this area due to the value of the carcinogenic risk n wet season of 4.05E-4 in adult and 1.55E-3 in children, in dry season of 2.57E-4 in adult and 9.88E-4 in children, against the standard set by the USEPA of 10-6 – 10-4. The water pollution monitoring agency of this area should regularly check the water quality assessment of this river and should suggest treatment through filtration, boiling and the use of additives in order to reduce the risk of water related problems.

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