Definicion de glaciologia yahoo dating

definicion de glaciologia yahoo dating

Jan 9, - *Corresponding author (email: [email protected]). The role of stratigraphy is then restricted to post hoc dating of branching events. If we see the last . Characters that define the subfamily are in italics. Instituto Argentino de Nivología y Glaciología, IANIGLA, CONICET, Buenos Aires, Argentina. 3Dpto de Paleontología, Instituto Argentino de Nivología, Glaciología y Ciencias .. conforman la base de la secuencia, por lo que es posible incluir a este conjunto (CDJR) Buenos Aires, Argentina. [email protected] ar . the first taxon date and the oldest record for the genus and species, with an age of. Irene Garibotti, CONICET- Instituto Argentino de Nivología, Glaciologia y Ciencias Ambientales, Mendoza, Argentina. . de nuestra van desde los tipos de evidencia y contextos estudiados estrategia editorial. .. E-mail: [email protected] yahoo. .. Academic form in which the record is presented to us for study. pp. Dating.

Drought preparedness and mitigation is therefore the concern of all sectors. As shown in the following table Asia in amongst the continents which mainly suffers from droughts.

The Subfamily Mutisioideae (Asteraceae) - Springer Link - ordendelsantosepulcro.info

North America and Africa are also drought prone areas. The rapid growth of Iran s population, the slow process of building water reservoirs, and recent dry years, have caused serious water shortages in central and eastern parts of Iran Figure 2.

The country s population has increased about 7 times during the last 80 years and it has risen from 10 million in to more than 70 million in At present Iran is the 17 th most populated countries in the world and based on the data presented by the UN it will be classified as one of the 10 most populated regions in the world by the end of Therefore the need for water has been increased but still the quantity of water is not adequate.

The four primary reasons for the serious water crisis in Iran are: Sincedue to the cultural, social and economic changes in Iran, there has been a rapid increase in population in such a way that during the past 50 years, the population has increased from 20 to 70million people, as demonstrated in Figure 3 SCI,much of which has settled in the major urban centers. Land degradation and desertification is one of the pressing challenges of Iran.

An example of the impact of the drought and potential climate change is apparent on the lakes in central and southeastern parts of Iran. The Hamoun Lake in south eastern part of Iran is a dramatic case of a drying water body to a desert. Figure 4 shows the satellite images of the Hamoun Lake between and Partov, Water demand increased rapidly in different sectors in agriculture, industry and urban services. The increased water demand has been identified primarily with agriculture, where most water consumption and the highest losses occur, a fact which has been noticed by the Irrigation and Drainage Department Javan et al.

Drought, climate change, and desertification are some reasons of immigration; consequently, due to not having access to sufficient amount of water, widespread immigration to other regions occurred.

Construction and operation of hydraulic structures such as dams, qanats, conveyance channels for reservoirs, and transmission and distribution systems in Iran have been functioning for more than years Motiee et al, The situation is now accepted that Iran is facing a water crisis and is in a serious situation to meet the necessary water demands. General Overview of Water Resources Iran is divided into six following major hydrological basins as follows: The Caspian Sea basin in the north, which consists of 7 sub basins, 2.

The Lake Oroomieh basin in the northwest, 3. The Persian Gulf and Sea of Oman basin consists of 9 sub basins and extends from northwest up to southeast of country. The central plateau basin, which has 9 subbasins, extends from northwest to southeast of the country and covers 5 dry Kavirs of which two Lutand Central kavir have nearly an area equal to km 2.

The Hamoun basin in the east with 3 sub-basins, 6. The Gharaghoum or Sarakhs basin in the northeast, The internal renewable water resources of Iran are estimated at cubic km per year.

The surface runoff represents a total of 92 cubic km per year and ground water recharges is estimated at about 38 cubic km. At present the per capita water resources of the country is cubic meters per year. Drought Situation in Iran Due to climate change, common droughts in Asia and the Middle East have changed and the intensity and duration of these phenomena have increased. Today, it can be stated that drought is one of the horrible enemies in the Middle East which gradually causes water tables, current rivers, lakes and qanats disappearance.

The present droughts in Iran, particularly the ones happening in have completely imbalanced the country s climate. The decrease in rain fall and increase in temperature has caused many rivers, slumps and lakes to dry out.

definicion de glaciologia yahoo dating

The utmost impact of this phenomenon could be observed in Oroomieh Lake which is further described in the next section. In this concern adaptation with the existing climatic situation should be made by appropriate consumption management and saving. The consumption pattern particularly in the agricultural sector should be defined, based on the country s climatic conditions. Apparently we can t make benefit of prescriptions used for the countries producing crops with plenty of water.

Impact on Lake Oroomieh Recent studies indicate there are substantial impacts of climate change and drought influencing water resources e. For example, the circumstances of lakes around the world show that a significant number of lakes are experiencing decreasing water levels.

definicion de glaciologia yahoo dating

Some lakes have dried out completely due to a combination of these changes plus mismanagement of water resources. A dramatic example is the Aral Sea Figure 5landlocked in Central Asia, with a drainage basin of 1.

definicion de glaciologia yahoo dating

This Sea is bordered by Kazakhstan in the north and Uzbekistan in the south. Inthe Russian government decided to divert the Amu Darya and the Syr Darya, the two rivers that fed the Aral Sea, to irrigate areas of the desert. Unfortunately, many of the irrigation canals constructed in s, were poorly built and allowed significant leakage and evaporation. Bybetween 20to 50 km 3 of water was diverted each year to land, instead of to the Aral Sea and the Sea began to shrink. From tothe Aral Sea s level fell at an average of 20cm a year and in the s, the rate of water level decline nearly tripled to cm per year.

By the s, the mean decrease was cm annually Bissell, The water level in the Aral Sea has now decreased by 23 m. The effects of these changes include: The population residing around the Sea has also been negatively impacted Micklin, Lake Oroomieh as another example in northwest of Iran with a surface of km2 is the second most saline lake in the world the Red Sea is considered as the firstand is demonstrating significant declines in surface levels.

Inthe depth of water in the Lake was measured to be two meters less than the longterm average and the volume is estimated to have decreased by one-third mcbean and Motiee, Oroomieh lake specifications Oroomieh Lake is located in the north west of Iran.

This lake is divided between east and west Azerbayejan. Lake Oroomieh is the biggest lake in Iran and the second salty lake in the world. This basin by having large agricultural plains is one of the most important focal areas in agricultural and livestock activities in Iran. Lake Oroomieh is one of the biggest permanent intakes in the west Asia and it is one of the most important natural habitants of the animals in Iran.

At present there are 27 species of mammals, bird species, 41 species of reptiles, 7 species of amphibian and 26 species of fish in this lake. The water in Lake Oroomieh is so saline and it is mainly supplied by 6 rivers and the soluble salt is nearly two times as much as the oceans. Therefore no kind of fish or mollusca except crustacean live in this lake and the water never freezes. Swimmers can also swim on the water due to the high concentration of salts. The volume of this lake has reduced to 15 BCM which is less than half of the normal capacity.

According to the recent photos, the water surface has dropped two meters below the normal depth. The increase in salt concentration is one of the negative results of this decline. The average salt concentration of this lake in long term was between gr. Figure 6 shows the lake water level fluctuation since which results in a considerable decrease in the depth of the lake. Lake Water level fluctuation 13 20 H. McBean Effective parameters in decreasing the lake volume. The mainly uses and users of the water of this Lake are aqua life, tourist and environment.

A number of parameters have caused a part of Oroomieh Lake to dry out.

“Pepe” Corvalán: secretos de un glaciólogo en la montaña

Water use in Agriculture and industry in the upstream areas of the lake have also had considerable impacts on the lakes volume decline.

One decade of continues drought in the water basin of the lake has caused a severe reduction in the surface water of the basin towards the lake.

According to the rainfall statistics duringmm and duringmm of rainfall decrease has been recorded in the water basin. Figure 7 demonstrates the shrinking process of the lake since Climate change has had severe impacts on the water volume and depth of many lakes all around the world including the Oroomieh Lake. Global temperature increase of around 2 degrees Centigrade during the past 20 years, evaporation increase as well as rainfall decrease are all considered as the consequences of climate change.

If this trend is continued, the destiny of this lake would be similar to the Aral Sea in the coming 2 decades. Figure 7- Gradual trend of the lake drying out from to with the use of satellite images scoopweb. Trend of Temperature in Oroomieh basin Motiee, H. Birds migrating to the region gave birth but their population is decreasing nowadays due to the high salinity of the lake water.

One of the other negative impacts which has caused the farmers anxiety is the salt which could be possibly spread throughout the region by wind after the lake has dried out. This can lead to soil salinity in the region. As the salt formations have a crystal shape this is just an unproved theory. Figure 11 displays the salt mass in the dried beach of the lake. Figure Salt crystals after the lake beach dry out wdict.

This initiative has been defined due to the high importance of drought in the world and the necessity for better relation and coordination amongst international organizations for knowledge and experience transfer. Today s world, needs a global movement to face and encounter the challenges of natural disasters related to water, especially droughts, so that through systematic measures carried out by governments at national level and integrating them with the activities of international governmental and non-governmental organizations and entities, effective and coordinated action plans could be prepared.

This global movement through mobilizing political wills and resources can create effective measures in order to predict and produce preparedness and mitigation plans at global scale. Introducing the International Drought Initiative IDI can be a starting point and driving force for this global movement. In this draft concept paper, the objectives and framework for establishing and organizing such an initiative are presented in anticipation of further deliberations by experts and relevant entities.

An overview of the current situation With respect to drought management, different measures are carried out in various countries according to their level of development and lessons learnt on the impacts of past droughts. These measures have different aspects and dimensions.

In developed countries, integrated plans are defined and executed and responsibilities are well divided. In developing or less developed countries which are much more vulnerable to droughts, no systematic and harmonized measures have been taken.

In the latter countries, most of the measures carried out are concentrated after drought events, e. International governmental and non-governmental entities also implement different programs and plans according to their functions and mission of which some concentrate on research, technical and practical assessments and some other on improvement of knowledge and awareness.

Usually, at critical periods, some financial and logistic contributions will be provided for the affected regions by United Nations or affiliated entities. Cabrera defined the Mutisieae as having bilabiate corollas, caudate anthers, and characteristic style shape. He pointed out, however, that several genera of Mutisieae differ in having actinomorphic or ligulate corollas and ecaudate anthers the last feature in some genera of Barnadesiinae.

As circumscribed by Cabrerathe Mutisieae included 83 genera Table 2 and about mainly American species, with some representatives in southern Asia and Africa and one species in Australia. The four subtribes were mainly distinguished as follows: Cabrera distinguished papillae very short, conical to rounded hairs, spread on the outer side of the style branches from collector hairs longer, cylindrical, obtuse at the apex hairs, that form a truncate brush terminally at the style branchesrestricting the use of the term collector hairs to Nassauviinae.

With this change, the Asteraceae were divided into three subfamilies: Barnadesioideae with one tribe, Cichorioideae with six tribes one the Mutisieaeand Asteroideae with ten tribes. At this point, Mutisieae began to attract the attention of many workers because of its still unresolved taxonomy and its ancestral position, highlighting its importance for understanding the classification and evolution of the whole family.

Also inBremer presented the first cladistic analysis of Asteraceae involving 81 characters of morphology, anatomy, chromosomes, chemistry, and the chloroplast DNA inversion. This study showed the Mutisieae as a paraphyletic grade at the base of the family. One year later, Jansen and Palmer obtained phylogenies of Mutisieae based on chloroplast DNA restriction site mapping. In this second study, the Barnadesiinae were basal, the Nassauviinae monophyletic, and the Mutisiinae and Gochnatiinae were either monophyletic using ten restriction enzymes or paraphyletic using nine additional restriction enzymes.

definicion de glaciologia yahoo dating

Hansen proposed to exclude from Mutisieae the genera Dicoma, Erythrocephalum Benth. Hansen also suggested the genera Adenocaulon Hook. Mutisioid ray corolla epidermal cells appear to be not exclusive of Mutisieae, they also occur in the Barnadesioideae and in some Arctoteae Bremer, Robinson and formally Bremer abolished the limits between the Mutisiinae and the Gochnatiinae. Thus, the Mutisieae included only two subtribes: Their tree supported the placement of a paraphyletic tribe Mutisieae as a basal assemblage to the rest of Asteraceae.

Genera of the Mutisieae Stenopadus S. Gray, Wunderlichia, Ainsliaea DC. This treatment represented, after Cabreraa second, modern systematic review of the tribe. Bremer included in Mutisieae the subtribes Mutisiinae s. Within Mutisiinae, he presented a tentative arrangement of generic groups, some already suggested by previous authors: Don, Gochnatia, Hyalis D.

Don, Chaetanthera, Pachylaena D. Don ex Mutisioideae Asteraceae Hook. Again, the monophyly of Nassauviinae and the paraphyly of Mutisiinae s.

The Subfamily Mutisioideae (Asteraceae) - Springer Link

He treated the subfamily Cichorioideae as only containing Arctoteae, Lactuceae, Liabeae, and Vernonieae, with the tribe Cardueae the sole member of the subfamily Carduoideae. Although implicit in the cladogram, the Mutisieae were not raised to subfamilial level: Pruski and Jeffrey ; for Stifftieae resurrected the tribes Stifftieae and Nassauvieae.

Barnadesioideae, Mutisioideae, Carduoideae, Cichorioideae, and Asteroideae. In this contribution, morphologically based, we follow this scheme and consider the subfamily Mutisioideae to be comprised of three tribes: Mutisieae, Nassauvieae, and Stifftieae. Two molecular phylogenetic studies Kim et al. Moore, Pasaccardoa, Pleiotaxisand Tarchonantheae Brachylaena, Tarchonanthuscontaining members of the Mutisieae s. Remaining Mutisieae were recognized as the Stifftia group and a basal, unresolved clade referred to as the Mutisioideae.

No tribes, subtribes, or constituting genera were indicated by Panero and Funk within the Stifftia group and the Mutisioideae. Further, more defined molecular phylogenies of the family Asteraceae Funk et al. The systematic treatment by Hind regarded a tribe Mutisieae s.

Finally, Katinas et al. The study shows the monophyly of the Nassauviinae and a partial agreement with the tree of Funk et al.

  • CONSEJO EDITORIAL / EDITORIAL COUNCIL. Eric Alfaro - Clima Universidad de Costa Rica, Costa Rica
  • Calcula tu hipoteca online dating

Despite previous phylogenetic morphological and molecular studies, consensus has not been reached for the limits of Mutisioideae.