scholarly journals Os sobreirais da bacia ceno-antropozóica do Tejo (Província Lusitano-Andaluza Litoral), Portugal.

2007 ◽  
Vol 32 ◽  
pp. 201-210 ◽  
Author(s):  
Carlos Neto ◽  
José Carlos Costa ◽  
Jorge Capelo ◽  
Natália Gaspar ◽  
Tiago Monteiro-Henriques

RESUMO. Os sobreirais da bacia ceno-antropozóica do Tejo (Província Lusitano-Andaluza Litoral),Portugal. A análise das características das formações litológicas de enchimento da Bacia do Tejo,com idades que vão do Miocénico ao Plistocénico, permitiu compreender melhor o mosaico desobreirais potenciais, pertencentes respectivamente ao Oleo sylvestris-Quercetum suberis e aoAsparago aphylli-Quercetum suberis. A composição granulométrica, a coesão das partículas e o efeitoda acção antrópica sobre as formações litológicas são os factores fundamentais que intervêm nadistribuição dos dois sobreirais potenciais e nas respectivas etapas subseriais. A acção antrópica sobreas formações areníticas promove a libertação e a acumulação de areias. Este processo permite aentrada de espécies psamofílicas e desta forma a vegetação potencial primitiva (Asparago aphylli-Quercetum suberis) é substituída pela série psamofílica do sobreiro (Oleo sylvestris-Quercetumsuberis).Palavras-chave. Tejo, formações litológicas, sobreirais, séries de vegetação, Portugal.SUMMARY. The Quercus suber woodlands of the ceno-anthropozoic Tagus river basin. Portugal.The analysis of the lithological formations on the Tagus river basin, with ages between Miocene andPleistocene, allows the understanding of the mosaic of two potential vegetation communities,respectively, Oleo sylvestris-Quercetum suberis and Asparago aphylli-Quercetum suberis. The grainsizeanalysis, the cohesion of particles and the effect of the anthropic actions on the lithologicalformations are the major factors that justify the mosaic of the two potential cork tree woodlands andthe respective dynamic stages. Human activities over sandy formations and conglomerates, promoteliberation and accumulation of sand particles. This process induces psammophilous species to colonize,surrogating primitive potential vegetation (Asparago aphylli-Quercetum suberis) with the cork treepsammophilous series (Oleo sylvestris-Quercetum suberis).Key words. Tagus river, lithological formations, Quercus suber woodlands, vegetation series, Portugal.

Author(s):  
G. Bayrak

Features of changes of land cover and exogenous processes in a river basin of Poltva in connection with decreasing of the economic activities during the Post-Soviet period are considered. For researches the remote materials occurring at different times are used. Changes in agricultural and the forest use of the earth have caused in the majority stabilization exogenous processes. Changes aquicultural, urban and industrial human activities have caused activization of these processes in a river basin. Key words: changes of land cover, exogenous processes.


2017 ◽  
pp. 66-68
Author(s):  
V.I. Boyko ◽  
◽  
S.A. Tkachenko ◽  

The objective: depression of frequency of perinatal pathology at women with decompensation form of placental dysfunction by improvement of the main diagnostic and treatment-and-prophylactic actions. Patients and methods. 154 pregnant women in gestation term from 22 to 40 weeks were surveyed. Depending on features of course of pregnancy and families of all surveyed it was divided into 4 groups. The group of the retrospective analysis was made by 45 pregnant women with decompensation placental dysfuction, the group of prospective research included 109 pregnant women of whom the main group was made by 38 women with decompensation form of placental dysfunction, the group of comparison included 47 pregnant women with the compensated form of placental dysfunction. The control group was made by 24 pregnant women with the uncomplicated course of pregnancy and labors. The complex of the conducted researches included clinical, ehografical, dopplerometrical, laboratory, morphological and statistical methods. Results. Use of advanced algorithm of diagnostic and treatment-and-prophylactic actions allows to increase efficiency of diagnostics of decompensation form of placental dysfunction for 33.3%, and rational tactics of a delivery leads to depression of perinatal pathology for 22.7%. Conclusion. Decompensation placental dysfuction is one of the main reasons for perinatal mortality and a case rate at the present stage. Use of the algorithm of diagnostic and treatment-and-prophylactic actions improved by us allows major factors of risk of this complication and the indication for change of tactics and delivery times. Key words: decompensation placental dysfunction, diagnostics, delivery tactics.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaowan Liu ◽  
Dingzhi Peng ◽  
Zongxue Xu

Quantifying the impacts of climate changes and human activities on runoff has received extensive attention, especially for the regions with significant elevation difference. The contributions of climate changes and human activities to runoff were analyzed using rainfall-runoff relationship, double mass curve, slope variation, and water balance method during 1961–2010 at the Jinsha River basin, China. Results indicate that runoff at upstream and runoff at midstream are both dominated by climate changes, and the contributions of climate changes to runoff are 63%~72% and 53%~68%, respectively. At downstream, climate changes account for only 13%~18%, and runoff is mainly controlled by human activities, contributing 82%~87%. The availability and stability of results were compared and analyzed in the four methods. Results in slope variation, double mass curve, and water balance method except rainfall-runoff relationship method are of good agreement. And the rainfall-runoff relationship, double mass curve, and slope variation method are all of great stability. The four methods and availability evaluation of them could provide a reference to quantification in the contributions of climate changes and human activities to runoff at similar basins in the future.


Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1085 ◽  
Author(s):  
Shanshan Guo ◽  
Zhengru Zhu ◽  
Leting Lyu

Climate change and human activities are the major factors affecting runoff and sediment load. We analyzed the inter-annual variation trend of the average rainfall, air temperature, runoff and sediment load in the Xihe River Basin from 1969–2015. Pettitt’s test and the Soil and Water Assessment Tool (SWAT) model were used to detect sudden change in hydro-meteorological variables and simulate the basin hydrological cycle, respectively. According to the simulation results, we explored spatial distribution of soil erosion in the watershed by utilizing ArcGIS10.0, analyzed the average erosion modulus by different type of land use, and quantified the contributions of climate change and human activities to runoff and sediment load in changes. The results showed that: (1) From 1969–2015, both rainfall and air temperature increased, and air temperature increased significantly (p < 0.01) at 0.326 °C/10 a (annual). Runoff and sediment load decreased, and sediment load decreased significantly (p < 0.01) at 1.63 × 105 t/10 a. In 1988, air temperature experienced a sudden increase and sediment load decreased. (2) For runoff, R2 and Nash and Sutcliffe efficiency coefficient (Ens) were 0.92 and 0.91 during the calibration period and 0.90 and 0.87 during the validation period, for sediment load, R2 and Ens were 0.60 and 0.55 during the calibration period and 0.70 and 0.69 during the validation period, meeting the model’s applicability requirements. (3) Soil erosion was worse in the upper basin than other regions, and highest in cultivated land. Climate change exacerbates runoff and sediment load with overall contribution to the total change of −26.54% and −8.8%, respectively. Human activities decreased runoff and sediment load with overall contribution to the total change of 126.54% and 108.8% respectively. Runoff and sediment load change in the Xihe River Basin are largely caused by human activities.


1994 ◽  
Vol 5 (3) ◽  
pp. 247-259 ◽  
Author(s):  
Annamaria Testi ◽  
Carla Lucattini

2002 ◽  
Vol 27 ◽  
pp. 189-228 ◽  
Author(s):  
Andrés V. Pérez Latorre ◽  
Patricia Navas ◽  
David Navas ◽  
Yolanda Gil ◽  
Baltasar Cabezudo

RESUMEN. Datos sobre la flora y vegetación de la cuenca del río Guadiamar (Sevilla-Huelva, España). Sc ha realizado un estudio florístico, fitocenológico y fitogeográfico de la cuenca hidrográfica del río Guadiamar (Sevilla-Huelva, Andalucía, España). Bioclimáticamente domina en la cuenca el piso termomecliterráneo (con un reducto mesomediterráneo al NW) y el ombrotipo subhúmedo (seco al S). Se propone una sectorización fitogeográfica para la cuenca a un nivel inferior al de sector y resaltando el papel de conector de la cuenca del Guadiamar entre la provincia Luso-Extremadurense (Sierra Morena) y la Tingitano-Onubo-Algarviense (arenales y marismas). Como resultado sobre la flora, se presenta un conjunto de especies de interés por estar protegidas, por su escasez en la cuenca, en Andalucía Occidental, o por indicar determinados ecosistemas frágiles o singulares. Respecto a la vegetación, el territorio presenta una gran diversidad de asociaciones y comunidades (96), algunas de ellas son novedades sintaxonómicas: Imperato cylindricae-Scirpetum holoschoeni, Cisto salvifolii-Ulicetum australis lavanduletosum sampaianae, Malcomio trilobae-Hytnenocarpetum hamosi loeflingietosunz baeticae, Ornithopi isthmocarpi-Anthoxantetum ovati y vulpietosum alopecuroris, Ranunculo peltati-Callitrichetum brutiae y Ranunculo hederacei-Callitrichetum stagnalis. Además se lectotipifican Polypogono monspeliensis-Ranunculetum scelerati y Scolymo maculati-Sylibetum mariani. Se han catalogado 13 series de vegetación, 5 de tipo climatófilo, dominadas por fagáceas (Quercus suber y Quercus rotundtfolia) con faci aciones de Pious pinea, Olea europaea var. sylvestris o Quercus broteroi, y 8 de tipo edafohidrófi lo (caracterizadas respectivamente por Populus alba, Fraxinus angustifolia, Ulmus minor, Alnus glutinosa, Salix pedicellata, Nerium oleander, Tamariz gallica y Securinega tinctorea). Así mismo, aparecen complejos edafogénicos (mosaicos) de vegetación halófila en Entremuros (Parque Natural de Doñana) y de vegetación dulceacuícola por toda la cuenca. La vegetación permanente edafoxerófila corresponde a Genistetum polyanthi. Se presentan un esquema sintaxonómico, tablas fitosociológicas de novedades y un mapa de las series de vegetación.Palabras clave. Flora, vegetación, Fitogeografía, río Guadiamar, Sevilla, Huelva, Andalucía, España.SUMMARY. Flora and vegetation in the basin of the Guadiamar river (Seville-Huelva, Spain). We have carried out a floristical, phytocoenological and phytogeographical study about the Guadiamar river basin (Seville-Huelva, Andalusia, Spain). Thermo-mediterranean bioclimatic belt (appearing a little meso-mediterranean belt area towards NW) and sub humid ombro-type (dry towards S) characterises the basin. It is proposed a phytogeographical scheme under sector level for the Guadiamar basin. Stands out the corridor role of the Guadiamar river between the phytogeographical provinces Luso-Extremadurense (Sierra Morena) and Tingitano-Onubo- Algarviense (sandy lands and marshes). A group of species are highlighted as a result of being protected, rare in the basin or in Western Andalusia or because of living in fragile or singular ecosystems. Regarding the vegetation, a high diversity of plant communities has been found (96), some of them are new syntaxa or combinations: Impercaocylindricae-Scirpetumholoschoeni, Cisto salvifolii-Ulicetum australis lavanduletosum sampaianae, Malcomio trilobae- flymenocarpetum hamosi loeflingietosum baeticae, Ornithopi istlunocarpi-Anthoxantetum ovati and vulpietosutn alopecuroris, Ranunculo peltati-Callitrichetum brutiae, Ranunculo hederacei- Callitrichetum stagnalis. Two syntaxa are lectotypified here: Polypogono tnonspeliensis- Ranunculetum scelerati and Scolymo niaculati-Sylibetum mariani. 13 vegetation series have been recorded: 5 climactic, characterised by Quercus sober and Quercus rotundifolia showing variants with Pious pinea, Olea sylvestris or Quercus broteroi. 8 series are linked to riverside biotopes and respectively characterised by Populus alba, Fraxinus angustifolia, Ulmus minor, Alnus glutinosa, Salix pee/ice//ala, Nerium oleander, Tamarix gal lica and Securinega tinctorea. Halophytic vegetation (mosaics) is located in Entremuros near the Doilana marshes and also wetlands with hydrophilic vegetation are spread all over the basin. Soil-xeric permanent vegetation is represented by Genistetum polyanthi. A syntaxonomical scheme, phytosociological tables and one map of the vegetation series are also included.Key words. Flora, vegetation, Phytogeography, Guadiamar river basin, Seville, Huelva, Andalusia, Spain.


2011 ◽  
Vol 4 (1) ◽  
pp. 161
Author(s):  
Max Furrier ◽  
Saulo Roberto de Oliveira Vital

Evidências de dolinas são bastante comuns na cidade de João Pessoa-PB, mas ainda pouco estudadas. As dolinas são consideradas depressões fechadas, circulares, associadas a rebaixamento topográfico coadjuvado por fenômenos cársticos de sub-superfície, caracterizando um carste inumado. Assim como as encostas e os vales entalhados, as dolinas também são alvo da intensa ocupação nas cidades por parte da camada social menos favorecida, tendo em vista, serem áreas bastante deprimidas e susceptíveis a enchentes. A partir de então, esta pesquisa tem como objetivo, identificar os principais fatores de predisposição do terreno para criação de relevo do tipo carste, exclusivamente as dolinas e os riscos associados. Para isso, foram levantados dados sobre o embasamento geológico a partir do mapa geológico do Estado da Paraíba, e informações sobre a morfologia do terreno, coletadas a partir do radar SRTM (Shuttle Radar Topography Mission), além das observações de campo. Como produto, obteve-se os Modelos Digitais do Terreno, por meio dos quais se tornou possível realçar as evidências de subsidência do relevo local, corroborado pelas informações sobre a geologia local, marcada por uma intensa interação dinâmica entre as Formações Barreiras e Gramame (Sub-bacia Sedimentar Alhandra). Concluiu-se que os planos de falha existentes nos calcários da Formação Gramame contribuem de forma conspícua para percolação da água nessa formação perfazendo uma reação química capaz de dissolver o calcário, rebaixando a Formação Barreiras que se encontra sobreposta, dando origem a depressões circulares.Palavras-Chave: Dolinas, Formação Gramame, Formação Barreiras, João Pessoa. The Formation of Dolines in Urban Areas: The Case of Cruz das Armas in João Pessoa-PB ABSTRACTEvidence of dolines are much common in João Pessoa, the capital of the state of Paraíba, but they are still poorly studied. The dolines are considered to be closed and circled depressions, associated to a topographic smoothing assisted by subsurface karstic phenomenons, characterizing an inhumed karst. As well as the slopes and the carved valleys, the dolines are also intensively occupied in the city by people who are less favoured, what represents a serious problem considering that these are depressed areas and susceptible to flooding. The research aims to verify the major factors of the terrain susceptibility to the karst features formation, exclusively the dolines, and the associated risks. In view of this objective, the geological basement data were gathered from the geological map of the State of Paraíba and the terrain morphological information were collected from the SRTM radar (Shuttle Radar Topography Mission), besides the observations of the fieldwork developed. As result, the Digital Terrain Models were achieved enabling to present the evidences of the local subsidence features, corroborated by the information about the local geography marked by a intense dynamic interaction between Barreiras and Gramame Formation (Alhandra Sedimentary Sub-Basin). The analysis showed that the failed plans presented in the limestones of the Gramame Formation contribute evidently to the percolation of water on this formation totalizing a chemical reaction able to dissolve the limestone, lowering the superposed Barreiras Formation, what give rise to circular depressions.   Key-Words: Dolines, Gramame Formation, Barreiras Formation, João Pessoa.


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