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

2020 ◽  
Author(s):  
Femke Jansen
2020 ◽  
Vol 24 (12) ◽  
pp. 5973-5984
Author(s):  
Carlos Miranda Rodrigues ◽  
Madalena Moreira ◽  
Rita Cabral Guimarães ◽  
Miguel Potes

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.


2020 ◽  
Author(s):  
Carlos Miranda Rodrigues ◽  
Madalena Moreira ◽  
Rita Cabral Guimarães

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.


Author(s):  
James F. Hainfeld

Lipids are an important class of molecules, being found in membranes, HDL, LDL, and other natural structures, serving essential roles in structure and with varied functions such as compartmentalization and transport. Synthetic liposomes are also widely used as delivery and release vehicles for drugs, cosmetics, and other chemicals; soap is made from lipids. Lipids may form bilayer or multilammellar vesicles, micelles, sheets, tubes, and other structures. Lipid molecules may be linked to proteins, carbohydrates, or other moieties. EM study of this essential ingredient of life has lagged, due to lack of direct methods to visualize lipids without extensive alteration. OsO4 reacts with double bonds in membrane phospholipids, forming crossbridges. This has been the method of choice to both fix and stain membranes, thus far. An earlier work described the use of tungstate clusters (W11) attached to lipid moieties to form lipid structures and lipid probes.


Author(s):  
G. W. Hacker ◽  
I. Zehbe ◽  
J. Hainfeld ◽  
A.-H. Graf ◽  
C. Hauser-Kronberger ◽  
...  

In situ hybridization (ISH) with biotin-labeled probes is increasingly used in histology, histopathology and molecular biology, to detect genetic nucleic acid sequences of interest, such as viruses, genetic alterations and peptide-/protein-encoding messenger RNA (mRNA). In situ polymerase chain reaction (PCR) (PCR in situ hybridization = PISH) and the new in situ self-sustained sequence replication-based amplification (3SR) method even allow the detection of single copies of DNA or RNA in cytological and histological material. However, there is a number of considerable problems with the in situ PCR methods available today: False positives due to mis-priming of DNA breakdown products contained in several types of cells causing non-specific incorporation of label in direct methods, and re-diffusion artefacts of amplicons into previously negative cells have been observed. To avoid these problems, super-sensitive ISH procedures can be used, and it is well known that the sensitivity and outcome of these methods partially depend on the detection system used.


Author(s):  
I.G.C. Kerr ◽  
J.M. Williams ◽  
W.D. Ross ◽  
J.M. Pollard

The European rabbit (Oryctolagus cuniculus) introduced into New Zealand in the 183Os, has consistently flourished in Central Otago, the upper Waitaki, and inland Marlborough, all areas of mediterranean climate. It has proved difficult to manage in these habitats. The 'rabbit problem' is largely confined to 105,000 ha of low producing land mostly in semi arid areas of Central Otago. No field scale modifications of the natural habitat have been successful in limiting rabbit numbers. The costs of control exceed the revenue from the land and continued public funding for control operations appears necessary. A system for classifying land according to the degree of rabbit proneness is described. Soil survey and land classification information for Central Otago is related to the distribution and density of rabbits. This intormation can be used as a basis for defining rabbit carrying capacity and consequent land use constraints and management needs. It is concluded that the natural rabbit carrying capacity of land can be defined by reference to soil survey information and cultural modification to the natural vegetation. Classification of land according to rabbit proneness is proposed as a means of identifying the need for, and allocation of, public funding tor rabbit management. Keywords: Rabbit habitat, rabbit proneness, use of rabbit prone land.


Author(s):  
Fan Hai-fu ◽  
Hao Quan ◽  
M. M. Woolfson

AbstractConventional direct methods, which work so well for small structures, are less successful for macromolecules. Where it has been demonstrated that a solution might be found using direct methods it is then found that the usual figures of merit are unable to distinguish the few good sets of phases from the large number of sets generated. The reasons for the difficulties with very large structures are considered from a first-principles approach taking into account both the factors of having a large number of atoms and low resolution data. A proposal is made for trying to recognize good phase sets by taking a large structure as a sum of a number of smaller structures for each of which a conventional figure of merit can be applied.


1994 ◽  
Vol 30 (1) ◽  
pp. 23-32 ◽  
Author(s):  
John R. Argue

The water resources crisis facing countries of the Mediterranean Basin is reflected, in diminished form, in the semi-arid, “Mediterranean-climate” zone of Australia. Some creative solutions involving the collection, treatment, storage, retrieval and use of storm runoff to replace the component of mainssupplied water presently used for “second quality” purposes, are emerging in Adelaide, capital city of South Australia. The paper describes one initiative being taken to achieve source control of stormwater – quantity and quality – in mixed-density residential streets. The resulting streetscape is suitable for use in both “greenfields” and re-development projects. The paper explores the hydrological/hydraulic performance of the system and shows that it satisfies all theoretical- requirements for safety in the full range of flooding up to and including the “once in 100-years” event. The new streetscape holds the following advantages over conventional streetscapes : reduced peak outflows, greatly improved effluent water quality, aids “greening” of the landscape, potential for aquifer recharge where appropriate, aquiferretrieved groundwater can replace mains water used for irrigation, “nuisance” flows are fully contained (no surface appearance), major flows only occupy the swale, street residences are less flood prone and the streetscape fits more harmoniously into undulating terrain.


1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.


Sign in / Sign up

Export Citation Format

Share Document