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.

Assessment of the impact of water parameters on the flow rate of ceramic pot filters in a long-term experiment

2015 ◽  
Vol 15 (6) ◽  
pp. 1425-1432 ◽  
Author(s):  
C. Salvinelli ◽  
A. C. Elmore
Keyword(s):  
Flow Rate ◽  
Water Production ◽  
Premature Failure ◽  
Initial Flow ◽  
Flow Rates ◽  
Treated Water ◽  
Long Term Study ◽  
The Impact ◽  
The Relationship

Poor water quality is a major contributing factor to disease in developing countries. Silver-coated ceramic pot filters (CPFs) are a relatively common form of household water treatment system (HWTS) representing an effective and sustainable technology for poor communities. Water production seems to be the major limiting factor of the CPF's lifetime and sustainability since low flow rates do not produce an adequate daily volume of treated water. This paper describes a long-term study of CPF flow rates under controlled conditions using three different water sources. The relationship between water characteristics and flow rate was assessed with the intent of identifying the principal parameters that impact CPF water production. The study concluded that turbidity seems to be the principal indicator in determining CPF lifetime in terms of quantity of treated water. There is no evidence that biological activity also contributes to premature failure of CPFs and the data did not indicate that chemical precipitation is responsible for the filter clogging. Manufacturers commonly conduct initial flow rate tests using clear water as a measure of quality assurance. However, the relationship between initial flow rate and average flow rate during the lifetime of the CPF should be further studied.

scholarly journals Relationship of Abrupt Vegetation Change to Climate Change and Ecological Engineering with Multi-Timescale Analysis in the Karst Region, Southwest China

2019 ◽  
Vol 11 (13) ◽  
pp. 1564 ◽  
Author(s):  
Xiaojuan Xu ◽  
Huiyu Liu ◽  
Zhenshan Lin ◽  
Fusheng Jiao ◽  
Haibo Gong
Keyword(s):  
Climate Change ◽  
Southwest China ◽  
Abrupt Change ◽  
Karst Region ◽  
The West ◽  
Term Trend ◽  
Relationship Of ◽  
The Relationship ◽  
Long Term Trend

Vegetation is known to be sensitive to both climate change and anthropogenic disturbance in the karst region. However, the relationship between an abrupt change in vegetation and its driving factors is unclear at multiple timescales. Based on the non-parametric Mann-Kendall test and the ensemble empirical mode decomposition (EEMD) method, the abrupt changes in vegetation and its possible relationships with the driving factors in the karst region of southwest China during 1982–2015 are revealed at multiple timescales. The results showed that: (1) the Normalized Difference Vegetation Index (NDVI) showed an overall increasing trend and had an abrupt change in 2001. After the abrupt change, the greening trend of the NDVI in the east and the browning trend in the west, both changed from insignificant to significant. (2) After the abrupt change, at the 2.5-year time scale, the correlation between the NDVI and temperature changed from insignificantly negative to significantly negative in the west. Over the long-term trend, it changed from significantly negative to significantly positive in the east, but changed from significantly positive to significantly negative in the west. The abrupt change primarily occurred on the long-term trend. (3) After the abrupt change, 1143.32 km2 farmland was converted to forests in the east, and the forest area had significantly increased. (4) At the 2.5-year time scale, the abrupt change in the relationships between the NDVI and climate factors was primarily driven by climate change in the west, especially rising temperatures. Over the long-term trend, it was caused by ecological protection projects in the east, but by rising temperatures in the west. The integration of the abrupt change analysis and multiple timescale analysis help assess the relationship of vegetation changes with climate changes and human activities accurately and comprehensively, and deepen our understanding of the driving mechanism of vegetation changes, which will further provide scientific references for the protection of fragile ecosystems in the karst region.

scholarly journals THE CARTOGRAPHIC TECHNIQUE FOR THE STUDY OF CHEMICAL COMPOSITION OF THE URBAN AIR ENVIRONMENT

2020 ◽  
Vol 25 (3) ◽  
pp. 192-200
Author(s):  
Olga N. Nikolaeva ◽  
◽  
Gennadiy P. Martynov ◽  
Anastasia V. Mogil'nikova ◽  
◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Complete Information ◽  
Urban Air ◽  
Atmospheric Air ◽  
Urban Green Spaces ◽  
Urban Gardening ◽  
Multi Temporal ◽  
The Relationship ◽  
Long Term Trend

The article deels witn the problem of reducing of oxygen concentration in the urban air environmental. A hypothesis was put forward on the relationship between a decrease in oxygen levels and a reduction of urban green spaces. It was decided to use the cartographic technique to gather more complete information about reducing of urban gardening over a long period of time. The results of a statistical analysis of oxygen concentration in the atmospheric air of Sochi for 50 years are presented. The fact of a steady long-term trend of a decrease in the concentration of oxygen in the atmospheric air of Sochi in comparison with the values in Moscow and on average in Russia is confirmed. The sequence of collection and processing of freeware multi-temporal cartographic data for 50 years is presented. The stages of GIS-analysis of gathered materials are described. Preliminary conclusions are made about the validity of the hypothesis. The lack of modern accurate cartographic data of Sochi is noted. Prospects for further research are outlined.

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 Fingerprint of climate change in precipitation aggressiveness across the central Mediterranean (Italian) area

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nazzareno Diodato ◽  
Fredrik Charpentier Ljungqvist ◽  
Gianni Bellocchi
Keyword(s):  
Economic Losses ◽  
Rainfall Erosivity ◽  
Central Mediterranean ◽  
The Past ◽  
Recent Warming ◽  
Hydrological Extremes ◽  
Main Driver ◽  
The Relationship ◽  
Long Term Trend

AbstractRainfall erosivity and its derivative, erosivity density (ED, i.e., the erosivity per unit of rain), is a main driver of considerable environmental damages and economic losses worldwide. This study is the first to investigate the interannual variability, and return periods, of both rainfall erosivity and ED over the Mediterranean for the period 1680–2019. By capturing the relationship between seasonal rainfall, its variability, and recorded hydrological extremes in documentary data consistent with a sample (1981–2015) of detailed Revised Universal Soil Loss Erosion-based data, we show a noticeable decreasing trend of rainfall erosivity since about 1838. However, the 30-year return period of ED values indicates a positive long-term trend, in tandem with the resurgence of very wet days (> 95th percentile) and the erosive activity of rains during the past two decades. A possible fingerprint of recent warming is the occurrence of prolonged wet spells in apparently more erratic and unexpected ways.

NAEP Trends: Main NAEP vs. Long-Term Trend

2010 ◽  
Author(s):  
Albert E. Beaton ◽  
James R. Chromy
Keyword(s):  
Term Trend ◽  
Long Term Trend

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

Risk Attitude and Corporate Investment under Output Market Uncertainty: Evidence from The Mekong River Delta, Vietnam

2016 ◽  
pp. 59-70
Author(s):  
Ninh Le Khuong ◽  
Nghiem Le Tan ◽  
Tho Huynh Huu
Keyword(s):  
Negative Relationship ◽  
Risk Attitude ◽  
Business Strategies ◽  
Risk Averse ◽  
Market Uncertainty ◽  
Firm Investment ◽  
Output Market ◽  
The Impact ◽  
The Relationship

This paper aims to detect the impact of firm managers’ risk attitude on the relationship between the degree of output market uncertainty and firm investment. The findings show that there is a negative relationship between these two aspects for risk-averse managers while there is a positive relationship for risk-loving ones, since they have different utility functions. Based on the findings, this paper proposes recommendations for firm managers to take into account when making investment decisions and long-term business strategies as well.

Financial Folly and Spain’s Black Legend

2017 ◽  
Author(s):  
Mauricio Drelichman ◽  
Hans-Joachim Voth
Keyword(s):  
Seventeenth Century ◽  
Economic History ◽  
Military Power ◽  
Great Flexibility ◽  
Loan Contracts ◽  
Historical Tradition ◽  
Black Legend ◽  
Contractual Obligations ◽  
The Relationship

This epilogue argues that Castile was solvent throughout Philip II's reign. A complex web of contractual obligations designed to ensure repayment governed the relationship between the king and his bankers. The same contracts allowed great flexibility for both the Crown and bankers when liquidity was tight. The risk of potential defaults was not a surprise; their likelihood was priced into the loan contracts. As a consequence, virtually every banking family turned a profit over the long term, while the king benefited from their services to run the largest empire that had yet existed. The epilogue then looks at the economic history version of Spain's Black Legend. The economic history version of the Black Legend emerged from a combination of two narratives: a rich historical tradition analyzing the decline of Spain as an economic and military power from the seventeenth century onward, combined with new institutional analysis highlighting the unconstrained power of the monarch.

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