scholarly journals Reservoir evaporation in a Mediterranean climate: comparing direct methods in Alqueva Reservoir, Portugal

2020 ◽  
Vol 24 (12) ◽  
pp. 5973-5984
Author(s):  
Carlos Miranda Rodrigues ◽  
Madalena Moreira ◽  
Rita Cabral Guimarães ◽  
Miguel Potes
Keyword(s):  
Eddy Covariance ◽  
Mediterranean Climate ◽  
Direct Methods ◽  
Irrigated Agriculture ◽  
Pan Evaporation ◽  
June July August ◽  
Alqueva Reservoir ◽  
Pan Coefficient ◽  
June July ◽  
Water Scarce

Abstract. Alqueva Reservoir is one of the largest artificial lakes in Europe and is a strategic water storage for public supply, irrigation, and energy generation. The reservoir is integrated within the Multipurpose Alqueva Project (MAP), which includes almost 70 reservoirs in a water-scarce region of Portugal. The MAP contributes to sustainability in southern Portugal and has an important impact on the entire country. Evaporation is the key component of water loss from the reservoirs included in the MAP. Evaporation from Alqueva Reservoir has been estimated by indirect methods or pan evaporation measurements; however, specific experimental parameters such as the pan coefficient were never evaluated. Eddy covariance measurements were performed at Alqueva Reservoir from June to September in 2014 as this time of the year provides the most representative evaporation volume losses in a Mediterranean climate. This period is also the most important period for irrigated agriculture and is, therefore, the most problematic period of the year in terms of managing the reservoir. The direct pan evaporation approach was first tested, and the results were compared to the eddy covariance evaporation measurements. The total eddy covariance (EC) evaporation measured from June to September 2014 was 450.1 mm. The mean daily EC evaporation in June, July, August, and September was 3.7, 4.0, 4.5, and 2.5 mm d−1, respectively. A pan coefficient, Kpan, multivariable function was established on a daily scale using the identified governing factors: air temperature, relative humidity, wind speed, and incoming solar radiation. The correlation between the modelled evaporation and the measured EC evaporation had an R2 value of 0.7. The estimated Kpan values were 0.59, 0.57, 0.57, and 0.64 in June, July, August, and September, respectively. Consequently, the daily mean reservoir evaporation (ERes) was 3.9, 4.2, 4.5, and 2.7 mm d−1 for this 4-month period and the total modelled ERes was 455.8 mm. The developed Kpan function was validated for the same period in 2017 and yielded an R2 value of 0.68. This study proposes an applicable method for calculating evaporation based on pan measurements in Alqueva Reservoir, and it can be used to support regional water management. Moreover, the methodology presented here could be applied to other reservoirs, and the developed equation could act as a first evaluation for the management of other Mediterranean reservoirs.

scholarly journals Reservoir evaporation in a Mediterranean climate: Comparing direct methods in Alqueva Reservoir, Portugal

2020 ◽  
Author(s):  
Carlos Miranda Rodrigues ◽  
Madalena Moreira ◽  
Rita Cabral Guimarães
Keyword(s):  
Eddy Covariance ◽  
Mediterranean Climate ◽  
Direct Methods ◽  
Irrigated Agriculture ◽  
Pan Evaporation ◽  
Water Losses ◽  
Southern Portugal ◽  
Alqueva Reservoir ◽  
June July ◽  
Water Scarce

Abstract. Alqueva Reservoir is one of the largest artificial lakes in Europe and is a strategic water storage for public supply, irrigation, and energy generation. The reservoir is integrated within the Multipurpose Alqueva Project (MAP), which includes almost 70 reservoirs in a water-scarce region of Portugal. The MAP contributes to sustainability in southern Portugal and has an important impact for the entire country. Evaporation is the key component of water losses from the reservoirs included in the MAP. To date, evaporation from Alqueva Reservoir has been estimated by indirect methods or pan evaporation measurements. Eddy covariance measurements were performed at Alqueva Reservoir from July to September in 2014 as this time of the year provides the most representative evaporation volume losses in a Mediterranean climate. This period is also the most important for irrigated agriculture, and is therefore the most problematic part of the year in terms of managing the reservoir. The direct pan evaporation approach was first tested and compared to eddy covariance evaporation measurements. A relationship was then established based on a pan coefficient (Kpan) multivariable function by using the identified governing factors: air temperature, relative humidity, wind speed, and incoming solar radiation. The mean Kpan for the period from June to September 2014 was 0.59, and the modelled mean daily reservoir evaporation in June, July, August, and September was 3.9 mm d−1, 4.2 mm d−1, 4.5 mm d−1, and 2.7 mm d−1, respectively. The total estimated reservoir evaporation for this 4-month period was 455.8 mm. The correlation between the estimated evaporation and the measured EC evaporation had an R2 value of 0.7. The developed Kpan function was validated for the same period in 2017, and yielded an R2 value of 0.68. This study provides an applicable method for calculating evaporation based on pan measurements in Alqueva Reservoir, which can support regional water management. Moreover, the methodology presented here could be applied to other reservoirs, and the developed equation for Alqueva Reservoir could act as a first evaluation for the management of other Mediterranean reservoirs.

scholarly journals Spatio-Temporal Trends of Monthly and Annual Precipitation in Aguascalientes, Mexico

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 437
Author(s):  
Osías Ruiz-Alvarez ◽  
Vijay P. Singh ◽  
Juan Enciso-Medina ◽  
Ronald Ernesto Ontiveros-Capurata ◽  
Arturo Corrales-Suastegui
Keyword(s):  
Time Series ◽  
Annual Precipitation ◽  
Irrigated Agriculture ◽  
Monthly Precipitation ◽  
Precipitation Trend ◽  
Precipitation Time Series ◽  
June July August ◽  
Precipitation Decrease ◽  
Weather Stations ◽  
June July

The objective of this research was to analyze the temporal patterns of monthly and annual precipitation at 36 weather stations of Aguascalientes, Mexico. The precipitation trend was determined by the Mann–Kendall method and the rate of change with the Theil–Sen estimator. In total, 468 time series were analyzed, 432 out of them were monthly, and 36 were annual. Out of the total monthly precipitation time series, 42 series showed a statistically significant trend (p ≤ 0.05), from which 8/34 showed a statistically significant negative/positive trend. The statistically significant negative trends of monthly precipitation occurred in January, April, October, and December. These trends denoted more significant irrigation water use, higher water extractions from the aquifers in autumn–winter, more significant drought occurrence, low forest productivity, higher wildfire risk, and greater frost risk. The statistically significant positive trends occurred in May, June, July, August, and September; to a certain extent, these would contribute to the hydrology, agriculture, and ecosystem but also could provoke problems due to water excess. In some months, the annual precipitation variability and El Niño-Southern Oscillation (ENSO) were statistically correlated, so it could be established that in Aguascalientes, this phenomenon is one of the causes of the yearly precipitation variation. Out of the total annual precipitation time series, only nine series were statistically significant positive; eight out of them originated by the augments of monthly precipitation. Thirteen weather stations showed statistically significant trends in the total precipitation of the growing season (May, June, July, August, and September); these stations are located in regions of irrigated agriculture. The precipitation decrease in dry months can be mitigated using shorter cycle varieties with lower water consumption, irrigation methods with high efficiency, and repairing irrigation infrastructure. The precipitation increase in humid months can be used to store water and use it during the dry season, and its adverse effects can be palliated with the use of varieties resistant to root diseases and lodging. The results of this work will be beneficial in the management of agriculture, hydrology, and water resources of Aguascalientes and in neighboring arid regions affected by climate change.

scholarly journals Differential Influences of Teleconnections from the Indian and Pacific Oceans on Rainfall Variability in Southeast Asia

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 886
Author(s):  
Abdul Azim Amirudin ◽  
Ester Salimun ◽  
Fredolin Tangang ◽  
Liew Juneng ◽  
Muhamad Zuhairi
Keyword(s):  
Indian Ocean ◽  
Southeast Asia ◽  
El Niño ◽  
El Nino ◽  
Rainfall Variability ◽  
June July August ◽  
Rainfall Patterns ◽  
Negative Impacts ◽  
The Individual ◽  
June July

This study investigates the individual and combined impacts of El Niño and the positive Indian Ocean Dipole (IOD) on the Southeast Asia (SEA) rainfall variability. Using composite and partial correlation techniques, it is shown that both inter-annual events have individually distinct impacts on the SEA rainfall anomaly distribution. The results showed that the impacts of the co-occurrence of El Niño and IOD events are significant compared to the individual effects of pure El Niño or pure IOD. During June-July-August and September-October-November, the individual impacts of the pure El Niño and IOD events are similar but less significant. Both events caused negative impacts over the southern part of SEA during June-July-August (JJA) and propagated northeastward/eastward during September-October-November (SON). Thus, there are significant negative impacts over the southern part of SEA during the co-occurrence of both events. The differential impacts on the anomalous rainfall patterns are due to the changes in the sea surface temperature (SST) surrounding the region. Additionally, the differences are also related to the anomalous regional atmospheric circulations that interact with the regional SST. The anomalous Walker circulation that connects the Indian Ocean and tropical Pacific Ocean also plays a significant role in determining the regional anomalous rainfall patterns.

scholarly journals Significant seasonal variations in the rate of women diagnosed with gestational diabetes: A observational single centre study of 28,128 women

2021 ◽  
Author(s):  
Matthew Cauldwell ◽  
Yolande VanDerI'isle ◽  
Ingrid Watt-Coote ◽  
Philip Steer
Keyword(s):  
Gestational Diabetes ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Test Design ◽  
Single Centre ◽  
June July August ◽  
Single Centre Study ◽  
The Mean ◽  
June July

Objective To test the hypothesis that there is seasonal variation in the rates of gestational diabetes (GDM) diagnosed using a 2 hour oral glucose tolerance test. Design Monthly assessment of the percentage of women screened from 1st April 2016 to the 31st December 2020 who were diagnosed as having gestational diabetes Setting London Teaching Hospital Population 28,128 women receiving antenatal care between April 1st 2016 and 31 December 2020. Methods Retrospective study of prospectively collected data. Main Outcome Measures Proportion of women screened diagnosed as having gestational diabetes. Results The mean (SD) percentage of women diagnosed with GDM was 14.78 (2.24) in summer (June, July, August) compared with 11.23 (1.62) in winter (p < 0.001), 12.13 (1.94) in spring (p = 0.002), and 11.88 (2.67) in autumn (p = 0.003). There was a highly significant positive correlation of the percentage testing positive for GDM with the mean maximum monthly temperature (R2 = 0.248, p < 0.001). There was a statistically significant 33.8% increase in the proportion of GDM diagnoses from June 2020 onwards, possibly related to a reduction in exercise secondary to the Covid-19 pandemic. Conclusions There is a 23.3% higher rate of GDM diagnoses in the warmer summer months. There has been a 33.8% rise in GDM diagnoses associated with the Covid-19 pandemic.

scholarly journals Opportunities for saving and reallocating agricultural water to alleviate water scarcity

Water Policy ◽  
2017 ◽  
Vol 19 (5) ◽  
pp. 886-907 ◽  
Author(s):  
Brian D. Richter ◽  
James D. Brown ◽  
Rachel DiBenedetto ◽  
Adrianna Gorsky ◽  
Emily Keenan ◽  
...  
Keyword(s):  
Water Use ◽  
Water Scarcity ◽  
Water Saving ◽  
Internet Survey ◽  
Irrigated Agriculture ◽  
Irrigation Systems ◽  
Water Savings ◽  
Consumptive Water Use ◽  
Water Scarce ◽  
Consumptive Water

As water scarcity worsens globally, there is growing interest in finding ways to reduce water consumption, and for reallocating water savings to other uses including environmental restoration. Because irrigated agriculture is responsible for more than 90% of all consumptive water use in water-scarce regions, much attention is being focused on opportunities to save water on irrigated farms. At the same time, many recent journal articles have expressed concern that claims of water-saving potential in irrigation systems lack technical credibility, or are at least exaggerated, due to failures to properly account for key elements of water budgets such as return flows. Critics have also asserted that opportunities for reallocating irrigation savings to other uses are limited because any freed-up water is taken up by other farmers. A comprehensive literature and internet survey was undertaken to identify well-documented studies of water-saving strategies in irrigated agriculture, as well as a review of case studies in which water savings have been successfully transferred to other uses. Our findings suggest that there is in fact considerable potential to reduce consumptive water use in irrigation systems when proper consideration is given to water budget accounting, and those savings can be beneficially reallocated to other purposes.

May—June—July—August

Fireflies ◽  
2017 ◽  
pp. 59-92
Author(s):  
David P. Owen
Keyword(s):  
June July August ◽  
June July

INVESTIGATION AND EVALUATION OF NOISE LEVEL IN THE NORTHERN PART OF KLAIPEDA CITY/TRIUKŠMO LYGIO ŠIAURINĖJE KLAIPĖDOS MIESTO DALYJE TYRIMAI IR ĮVERTINIMAS/ИССЛЕДОВАНИЕ И АНАЛИЗ ШУМОВОГО УРОВНЯ В СЕВЕРНОЙ ЧАСТИ ГОРОДА КЛАЙПЕДЫ

2008 ◽  
Vol 16 (2) ◽  
pp. 89-96 ◽  
Author(s):  
Vaidotas Vaišis ◽  
Tomas Januševičius
Keyword(s):  
Noise Level ◽  
Heavy Traffic ◽  
Motor Vehicles ◽  
Noise Levels ◽  
June July August ◽  
The World ◽  
Noise Measurements ◽  
June July ◽  
July August September

The problem of noise is topical not only in Lithuania but the world over as well. The northern part of Klaipeda city is distinct for its industry and heavy traffic in the streets. Noise research was carried out in 17 selected measurement locations in the northern part of Klaipeda city. Noise measurements were taken in May, June, July, August, September, October and November. The measurements were made three times during the day: in the day time from 6 a.m. till 6 p.m., in the evening from 6 p.m. till 10 p.m. and at night from 10 p.m. till 6 a.m. The locations of the measurements are marked on the map. In order to distinguish the source of bigger noise between industry and transport, the northern part was divided into two belts. Industry is prevalent in the first belt, whereas the main troublemakers in the second belt are motor vehicles. The measured noise level is compared with permissible standards in measurement locations, where noise level is usually exceeded, and the analysis of noise levels is presented. In order to show the spread of noise in Klaipeda at all three times of the day more vividly, maps of isolines were compiled. Santrauka Triukšmas - ne tik Lietuvoje, bet ir visame pasaulyje aktuali problema. Klaipedos miesto šiaurine dalis yra išskirtine savo pramone ir intensyviu eismu gatvese. Triukšmo tyrimai atlikti šiaurineje Klaipedos miesto dalyje, 17‐oje pasirinktu matavimo vietu. Triukšmas matuotas gegužes, birželio, liepos, rugpjūčio, rugsejo, spalio ir lapkričio menesiais. Matavimai atlikti trimis paros laikais: diena nuo 6–18 valandos, vakare nuo 18–22 valandos ir nakti nuo 22–6 valandos. Matavimo vietos pateiktos žemelapyje. Siekiant nustatyti, kas kelia didesni triukšma ‐ pramone ar transportas, šiaurine miesto dalis suskirstyta i dvi zonas. Pirmojoje zonoje vyrauja pramone, o antrojoje zonoje pagrindinis triukšmo šaltinis automobiliai. Išmatuotas triukšmo lygis palygintas su leistinosiomis normomis. Pateikta matavimo vietu, kuriose dažniausiai viršijamas triukšmo lygis, triukšmo lygiu analize. Siekiant aiškiau parodyti, kaip triukšmas pasiskirsto Klaipedos mieste visais trimis paros laikais, sudaryti izoliniju žemelapiai. Резюме Шум является актуальной проблемой не только в Литве, но и во всем мире. Северная часть города Клайпеды является промышленным районом с интенсивным транспортным движением. Для исследования шума в этой части города было выбрано 17 мест замера. Шум измерялся с мая по ноябрь. Измерения проводились 3 раза в разное время суток: днем в 6–18 ч, вечером в 18–22 ч и ночью в 22–6 ч. Места замеров показаны на карте. С целью установить, что является бóльшим источником шума – промышленные предприятия или транспортные средства, северная часть города была поделена на две зоны. В первой зоне преобладали промышленные предприятия, а во второй – транспорт. Измеренный уровень шума сравнивался с разрешенным нормами. Для мест замеров, в которых чаще всего уровень шума превышал норму, предлагался анализ уровня шума. Для лучшего представления о распределении шума в городе Клайпеде в разное время суток были созданы карты изолиний.

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