scholarly journals Determinación de caudales ecológicos en el río Cutuchi, Ecuador

2020 ◽  
Vol 5 (2) ◽  
pp. 33
Author(s):  
Mercy Llbay Yupa ◽  
Paola Albarrasín ◽  
Víctor M García
Keyword(s):  
Reference Method ◽  
Aquatic Life ◽  
Flow Rates ◽  
Minimum Flow ◽  
Tukey Test ◽  
Seasonal Flow ◽  
Ecological Flow ◽  
Del Rio ◽  
Hydrological Station ◽  
Ecological Flows

  La legislación del Ecuador obliga a mantener un caudal ecológico para preservar los ecosistemas y la biodiversidad. Sin embargo, son pocos los ríos en el país en los que se ha establecido el flujo mínimo. El objetivo de esta investigación fue determinar el caudal ecológico en el río Cutuchi, estación hidrológica Cutuchi A.J. Yanayacu (H792), mediante los métodos: Caudal de permanencia, Suizo, Tennant, Rafael Heras y Referencial. Adicionalmente, se comparó con el caudal ecológico al 10% del caudal medio mensual multianual establecido en la transitoria sexta de la ley ecuatoriana. También se analizó las tendencias del caudal y la precipitación en la cuenca alta del río Patate. Los resultados evidencian un caudal promedio anual de 9,64 m3/s para el río Cutuchi, con dos regímenes hidrológicos (avenidas y estiaje) que respondes a la distribución de las precipitaciones. La comparación de medias según la prueba de Tukey al 5%, determinó a los métodos Referenciales seguidos de Tennant, como adecuados para la sobrevivencia de la vida acuática en el río. De igual manera, los caudales estimados fueron superiores al caudal mínimo observado para el periodo 1990-2014. El análisis de tendencia mediante la prueba estadística de Mann-Kendall evidenció que el caudal anual y estacional presentaron cambios o tendencias significativas (p<0,01). Sin embargo, la precipitación no mostró cambios de aumento o disminución durante los 20 años (p<0,05=.   Palabras claves: Río Cutuchi, Caudales ecológicos, método Referencial, Tennant.   Abstract =Ecuador's legislation requires maintaining an ecological flow to preserve ecosystems and biodiversity. However, few rivers in the country where the minimum flow has been established. The objective of this research was to determine the ecological flow in the Cutuchi River, Cutuchi A.J. Yanayacu hydrological station (H792), using the methods: Permanence Flow, Swiss, Tennant, Rafael Heras and Referential. In addition, it was compared with the ecological flow to 10% of the average monthly multi-year flow established in the transitional sixth of Ecuadorian law. Flow and precipitation trends in the upper Patate River basin were also analyzed. The results show an average annual flow of 9.64 m3/s for the Cutuchi River, with two hydrological regimes (avenues and styling) that respond to the distribution of precipitation. The comparison of means according to the Tukey test at 5%, determined the Referential methods followed by Tennant, as suitable for the survival of aquatic life in the river. Similarly, the estimated flow rates were higher than the minimum flow observed for the period 1990-2014. Trend analysis using Mann-Kendall's statistical test showed that annual and seasonal flow showed significant changes or trends (p<0.01). However, precipitation showed no changes in increase or decrease during the 20 years (p<0.05=.   Keywords: Cutuchi River, Ecological flows, Reference method, Tennant.  

scholarly journals Instream ecological flow and reservoir ecological operation in the upper reaches of Irtysh River

2018 ◽  
Vol 246 ◽  
pp. 01103
Author(s):  
Jian Li ◽  
Ziqiang Xia ◽  
Wei Yin ◽  
Haiyan Jia
Keyword(s):  
Lower Limit ◽  
River Systems ◽  
Aquatic Life ◽  
Ecological Flow ◽  
Suitable Target ◽  
Reservoir Construction ◽  
Irtysh River ◽  
Dry Seasons ◽  
Ecological Flows ◽  
The Irtysh River

Instream ecological flow (IEF) and flow-related variations were important for healthy river systems. However, water conservancy projects such as reservoirs altered the processes of IEF and thereby posed considerable threat to the health of river systems and aquatic lives. To that end, in this study the effects of reservoir construction on IEF in the upper reaches of the Irtysh River were analyzed using an improved hydrological method. The computed results were in turn used to determine the maximum (MaxIEF), minimum (MinIEF) and optimal (OptIEF) instream ecological flows of the river. Based on the study, reservoir impoundments limited IEF in wet seasons but enhanced it in dry seasons. It also narrowed suitable flow range for reproduction and growth of aquatic life. Reservoirs could be used to regulate Irtysh River discharge. For healthy instream processes in wet years, OptIEF could be set as the lower limit and MaxIEF as the upper limit. For much the same reasons, MinIEF could be set as the lower limit in dry years and OptIEF as a suitable target in normal years.

scholarly journals Ecological Flow to Protect Aquatic Resources on the Cebadas River, Chambo River Basin

2021 ◽  
Author(s):  
M. Ilbay-Yupa ◽  
M. García-Mora ◽  
N. Llugsha
Keyword(s):  
Flow Rate ◽  
Aquatic Ecosystems ◽  
Habitat Conditions ◽  
Hydrological Variability ◽  
Ecological Flow ◽  
Del Rio ◽  
The Relationship ◽  
Long Term Trend ◽  
Ecological Flows

The assessment of ecological flow is a great challenge, which has important implications in the protection of aquatic ecosystems and socio-economic development of an area. The Tennant-Montana method provides the ability to determine ecological flows considering the relationship between aquatic habitat conditions and the average annual flow of a channel. This research presents an estimat∫e of the ecological flow at 10, 30 and 60% of the average flow and trends of the Cebadas River located in the central Andes of Ecuador through a hydrological approach during the period 1966 to 2015. The results allowed to determine an average annual flow rate of 20,768 m3/s and identify a period of avenues (May-September) and a period of dry (October-April). Long-term trend analysis using linear regression and Spearman Rho's test determined that the flow rate has remain Zvirtually unchanged for 50 years and for decade periods. The selected ecological flow was 30% of the seasonal average with values of 6.22 m3/s and 8.32 m3/s for the dry and avenue period respectively. The hydrological variability of the Cebadas River was considered because it is a restrictive factor for the development of the different aquatic species. Flow rates at 30% flow could ensure adequate development and conservation of the aquatic habitats of the Barley River while ensuring a sufficient supply of water for food security. Keywords: Cebadas River, ecological flow, trends, tennant. Resumen La evaluación del caudal ecológico es un gran desafío, que tiene importantes implicaciones en la protección de ecosistemas acuáticos y desarrollo socioeconómico de una zona. El método de Tennant-Montana provee la capacidad de determinar caudales ecológicos considerando la relación entre las condiciones del hábitat acuático y el flujo anual medio de un cauce. Esta investigación presenta una estimación del caudal ecológico al 10, 30 y 60% del caudal medio y tendencias del río Cebadas ubicado en los Andes centrales del Ecuador mediante un enfoque hidrológico durante el periodo de 1966 al 2015. Los resultados permitieron determinar un caudal promedio anual de 20.768 m3/s e identificar un periodo de avenidas (mayo- septiembre) y otro de estiaje (octubre-abril). El análisis de tendencias a largo plazo mediante la regresión lineal y el test de Spearman Rho determinaron que el caudal se ha mantenido prácticamente sin cambios durante 50 años y para los períodos decadales. El caudal ecológico seleccionado fue al 30% de la media estacional con valores de 6.22 m3/s y 8.32 m3/s para el periodo de estiaje y avenida respectivamente. Se consideró la variabilidad hidrológica del río Cebadas porque constituye un factor restrictivo para el desarrollo de las diferentes especies acuáticas. Los caudales al 30% de flujo podrían asegurar un desarrollo y conservación adecuada de los hábitats acuáticos del río Cebada y al mismo tiempo garantiza un suministro suficiente de agua para la seguridad alimentaria. Palabras claves: río Cebadas, régimen fluvial, tendencias, tennant.

The minimum flow rate of electrosprays in the cone-jet mode

2019 ◽  
Vol 876 ◽  
pp. 553-572 ◽  
Author(s):  
Manuel Gamero-Castaño ◽  
M. Magnani
Keyword(s):  
Dielectric Constant ◽  
Reynolds Number ◽  
Flow Rate ◽  
Numerical Solutions ◽  
Viscous Stress ◽  
Flow Rates ◽  
Minimum Flow ◽  
Electric Stress ◽  
Work Done ◽  
Minimum Flow Rate

Stable electrospraying in the cone-jet mode is restricted to flow rates above a minimum, and understanding the physics of this constraint is important to improve this atomization technique. We study this problem by measuring the minimum flow rate of electrosprays of tributyl phosphate and propylene carbonate at varying electrical conductivity $K$ (all other physical properties such as the density $\unicode[STIX]{x1D70C}$, surface tension $\unicode[STIX]{x1D6FE}$ and viscosity $\unicode[STIX]{x1D707}$ are kept constant and equal to those of the pure liquids), and through the analysis of numerical solutions. The experiments show that the dimensionless minimum flow rate is a function of both the dielectric constant $\unicode[STIX]{x1D700}$ of the liquid and its Reynolds number, $Re=(\unicode[STIX]{x1D70C}\unicode[STIX]{x1D700}_{o}\unicode[STIX]{x1D6FE}^{2}/\unicode[STIX]{x1D707}^{3}K)^{1/3}$. This result is unexpected in the light of existing theories which, for the conditions investigated, predict a minimum flow rate that depends only on $\unicode[STIX]{x1D700}$ and/or is marginally affected by $Re$. The experimental dependency on the Reynolds number requires the viscous stress to be a factor in the determination of the minimum flow rate. However, the numerical solutions suggest that a balance of opposing forces including the fixing viscous stress, which at decreasing flow rates may lower the acceleration of the flow to the point of making it unstable, is unlikely to be the cause. An alternative mechanism is the significant viscous dissipation taking place in the transition from cone to jet, and which at low flow rates cannot be supplied by the work done by the tangential electric stress in the same area. Instead, mechanical energy injected into the system farther downstream must be transferred upstream where dissipation predominantly takes place. This mechanism is supported by the balance between the energy dissipated and the work done by the electric stress in the transition from cone to jet, which yields a relationship between the minimum flow rate, the Reynolds number and the dielectric constant that compares well with experiments.

Experimental Study of Low Concentration Sand Transport in Multiphase Air–Water Horizontal Pipelines

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Kamyar Najmi ◽  
Alan L. Hill ◽  
Brenton S. McLaury ◽  
Siamack A. Shirazi ◽  
Selen Cremaschi
Keyword(s):  
Experimental Study ◽  
Gas Flow ◽  
Intermittent Flow ◽  
Sand Transport ◽  
Physical Parameters ◽  
Internal Diameter ◽  
Flow Rates ◽  
Minimum Flow ◽  
Wide Range ◽  
Sand Size

The ultimate goal of this work is to determine the minimum flow rates necessary for effective transport of sand in a pipeline carrying multiphase flow. In order to achieve this goal, an experimental study is performed in a horizontal pipeline using water and air as carrier fluids. In this study, successful transport of sand is defined as the minimum flow rates of water and air at which all sand grains continue to move along in the pipe. The obtained data cover a wide range of liquid and gas flow rates including stratified and intermittent flow regimes. The effect of physical parameters such as sand size, sand shape, and sand concentration is experimentally investigated in 0.05 and 0.1 m internal diameter pipes. The comparisons of the obtained data with previous studies show good agreement. It is concluded that the minimum flow rates required to continuously move the sand increases with increasing sand size in the range examined and particle shape does not significantly affect sand transport. Additionally, the data show the minimum required flow rates increase by increasing sand concentration for the low concentrations considered, and this effect should be taken into account in the modeling of multiphase sand transport.

scholarly journals DETERMINATION OF ACETATE IN FOODS BY ION CHROMATOGRAPHY-FLOW INJECTION

1995 ◽  
Vol 3 (3) ◽  
pp. 9-22
Author(s):  
E. Esteve-Juan ◽  
R. Puchades ◽  
A. Maquieira
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Ion Chromatography ◽  
Chromatographic Analysis ◽  
Reference Method ◽  
Spectrophotometric Detection ◽  
Flow Rates ◽  
Injection Volume ◽  
Relative Standard

A method for acetate determination using IC separation and FI post-column spectrophotometric detection based on the La(OH)3-I2 reaction has been developed. The chromatographic conditions (eluants, flow-rates, sensitivity, and so on) and FI variables (length of coils, injection volume, pH, ... ) were optimized. Linearity was observed over the concentration range 0 to 1 gl-1 with HAc as standard (r = 0.9916) and a detection limit of 0.1 g AcH/l. The IC-FI method afforded a low relative standard deviation (3.6%) and was free from interferences. The IC-FI procedure was applied to the determination of acetate in mustard sauce and the results obtained agree with those provided by the reference method. Additionally, the developed method permits the simultaneous chromatographic analysis of other anions such as chloride, nitrate, phosphate, sulphate, and so on.

scholarly journals Analysis of seasonal flow and minimum water discharge of Veliki Rzav for the purposes of regional water supply system "Rzav"

2007 ◽  
Vol 87 (2) ◽  
pp. 41-50 ◽  
Author(s):  
Marko Urosev
Keyword(s):  
Water Supply ◽  
Water Discharge ◽  
Supply System ◽  
Water Supply System ◽  
Seasonal Flow ◽  
First Time ◽  
Method Analysis ◽  
Hydrological Station ◽  
Regional Water ◽  
Frequency Curves

Minimum water discharge and seasonal flow calculations of Veliki Rzav at Arilje have been conducted for the purposes of regional water supply system "Rzav". For the first time for this hydrological station minimum water discharges have been calculated by frequency curves, parameters of which have been determined by method of moments. Also for the first time in Serbia seasonal flow was calculated using "composing method". Analysis presented in this paper can be used for exploitation and planning of upcoming water management activities in the regional water supply system "Rzav.

scholarly journals Variaciones de los niveles de mercurio y zinc en agua y sedimentos de la subcuenca del río Carrizal, Manabí

2019 ◽  
Vol 4 (1) ◽  
pp. 25
Author(s):  
Ana María Aveiga Ortiz ◽  
Patricio Noles ◽  
Patricio Noles ◽  
Julio Loureiro ◽  
Fabian Peñarrieta ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Environmental Pollution ◽  
Human Health ◽  
Aquatic Life ◽  
Natural Sources ◽  
Water And Sediment ◽  
Sampling Points ◽  
International Regulations ◽  
Index Terms ◽  
Del Rio

Excessive concentrations of mercury and zinc in natural sources are a risk to human health and to the development of adequate aquatic life. In the present study, the concentrations of Hg and Zn in samples of water and sediment from the Carrizal River (Cantón Bolívar, Manabí) were determined in two periods (August and October). In addition, 5 sampling points were characterized at La Esperanza reservoir, 7 at Carrizal river micro-basin, and 9 at the river sub-basin, covering an area of 51 km. The concentrations of Hg and Zn in the sediments were significantly higher than the concentrations obtained in the water. The contents of Hg in water and sediments of Carrizal River exceeded the safety limits established by national and international regulations; while the Zn concentrations obtained are considered to be a risk for aquatic life. Index Terms—bioaccumulation, adsorption, environmental pollution, heavy metals

Cardiac Output during Total Hip Replacement in Dogs

2000 ◽  
Vol 13 (02) ◽  
pp. 49-58
Author(s):  
U. Matis ◽  
P. Böttcher ◽  
W. Erhardt ◽  
S. Gantke
Keyword(s):  
Cardiac Output ◽  
Total Hip Replacement ◽  
Doppler Echocardiography ◽  
Hip Replacement ◽  
Reference Method ◽  
Femoral Prosthesis ◽  
Noninvasive Method ◽  
Flow Rates ◽  
Total Hip ◽  
Pulsed Wave Doppler

SummaryTrans-oesophageal pulsed-wave Doppler echocardiography was evaluated as a noninvasive method of determining cardiac output during total hip replacement in 10 dogs. Cardiac output was estimated by determining the crosssectional area of the aorta via caudal transverse echocardiography and the outflow velocity of the ascending aorta via cranial transverse Doppler echocardiography. Thermodilution was used as the reference method. In addition, cardiopulmonary changes, at the time of femoral prosthesis insertion, were determined. Comparison of 160 measurements yielded a correlation coefficient of 0.48. Linear regression analysis revealed the equation, cardiac outputDoppler echocardiography = 0.45 cardiac outputthermodilution + 3.3. In comparison to thermodilution, trans-oesophageal pulsedwave Doppler echocardiography overestimated cardiac output at flow rates less than 61/min and underestimated the cardiac output at flow rates greater than 61/min. There was a significant decrease in the partial pressure of carbon dioxide at end-expiration (PETCO2), the systolic arterial blood pressure (mmHg) and the invasive stroke volume (ml/beat/m2) and a significant increase in the pulmonary vascular resistance (dynes/sec/cm5) immediately after insertion of the femoral prosthesis.The purpose of this study was to evaluate the trans-oesophageal pulsed-wave Doppler echocardiography as a noninvasive method of determining cardiac output in dogs during total hip replacement. Thermodilution was used as the reference method. The correlation coefficient was r = 0.48. In conclusion, this study confirms that the trans-oesophageal Doppler echocardiography is not suitable for measuring the absolute CO-value. This ultrasound technique only allows an approximate estimation of the CO-trend.

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