scholarly journals Ocupación de la llanura aluvial e inundaciones en el Pirineo Central

2017 ◽  
Vol 43 (1) ◽  
pp. 309 ◽  
Author(s):  
R. Serrano-Notivoli ◽  
D. Mora ◽  
A. Ollero ◽  
M. Sánchez-Fabre ◽  
P. Sanz ◽  
...  

Floods modify the natural dynamics of river environments and greatly affect urban areas, especially in mountain regions where flooding is frequent because of the precipitation characteristics and orographic configuration. In this study the vulnerability of the central sector of the Pyrenees to flood events was investigated using frequency analysis of daily flow and precipitation data for the period from 1940 to 2012 for the headwaters of the Aragón and Ésera rivers. The land use evolution over the past 60 years was also analyzed. The return periods showed that floods have not been exceptional, and the high flow frequency has been large and closely related to precipitation events. This, combined with a large increase in human occupation, particularly since the 1990s, of fluvial areas associated with the land use evolution since 1956, has increased exposure to flood risks.

Land ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 343
Author(s):  
Wiwandari Handayani ◽  
Uchendu Eugene Chigbu ◽  
Iwan Rudiarto ◽  
Intan Hapsari Surya Putri

This study explores urbanization and flood events in the northern coast of Central Java with river basin as its unit of analysis. Two types of analysis were applied (i.e., spatial data and non-spatial data analysis) at four river basin areas in Central Java—Indonesia. The spatial analysis is focused on the assessment of LULC change in 2009–2018 based on Landsat Imagery. The non-spatial data (i.e., rural-urban classification and flood events) were overlaid with results of spatial data analyses. Our findings show that urbanization, as indicated by the growth rate of built-up areas, is very significant. Notable exposure to flood has taken place in the urban and potentially urban areas. The emerging discussion indicates that river basins possess dual spatial identity in the urban system (policy- and land-use-related). Proper land use planning and control is an essential instrument to safeguard urban areas (such as the case study area) and the entire island of Java in Indonesia. More attention should be put upon the river basin areas in designing eco-based approach to tackle the urban flood crises. In this case, the role of governance in flood management is crucial.


2018 ◽  
Vol 10 (3) ◽  
pp. 66-77
Author(s):  
Rosana Amaral Carrasco ◽  
Lucas Prado Osco ◽  
Rejane Ennes Cicerelli ◽  
Paulo Antônio Silva ◽  
Ana Paula Marques Ramos

Anthropogenic actions cause changes in the natural dynamics of the landscape, such as variations in climate and land use. Land Surface Temperature (LST) is one of the main physical parameters Recebido em: 27/08/2018Revisado em: 04/09/2018Aprovado em: 06/09/2018 67Colloquium Exactarum, v. 10, n.3,Jul-Set. 2018, p.66–77. DOI: 10.5747/ce.2018.v10.n3.e246of terrestrial surface processes. The importance of LST is increasingly recognized and there is a strong interest in developing methodologies for measuring LST using orbital platforms, such as the Landsat series. This work aims to verify if there was a change in the LST in the region of Pontal doParanapanema from the LST recorded by the Landsat series over the last 30 years. We adopted orbital images from Landsat5 TM and Landsat8 OLI satelliteto extract the LST value, and thenwe evaluated the LST variation at the studied area. A correlation was found between the LST variation and the type of land use and land cover. The urban areas, pasture, agriculture, vegetation and watercourses showed discrepancies in temperature when compared to each other. At Pontal, there were variations of 5 ° C of the average LST, between maximum and minimum temperatures. We concluded that temperature variations are associated with the dynamics of land use.


Author(s):  
Feiqing Jiang ◽  
Zengchuan Dong ◽  
Yun Luo ◽  
Moyang Liu ◽  
Tao Zhou ◽  
...  

Abstract Flood events are typically triggered by extreme precipitation in rain-dominant basins. In this study, to better understand the genetic mechanisms and characteristics of floods, copula functions are used to analyze the response of flood events to extreme precipitation. The coincidence probabilities of the typical extreme flood and precipitation events are calculated; different return periods of their arbitrary combinations are calculated, whereas the dangerous domains for flood control under different return periods are identified; furthermore, flood risk analysis under different extreme precipitation scenarios is performed via their conditional exceedance probabilities. The Xitiaoxi catchment (XC) and Dongtiaoxi catchment (DC) in the Zhexi Region of the Taihu Basin are selected as the study area. The results show that in four scenarios with precipitation frequencies of 80%, 90%, 93.33%, and 95%, the probabilities of the dangerous flood are 9.72%, 10.57%, 10.86%, and 11.01% in the XC, respectively, and 5.91%, 6.31%, 6.44%, and 6.51% in the DC, respectively. This study provides a practical basis and guidance for the computation of rainstorm designs, management of flood control safety, and water resource scheduling in the Taihu Basin.


2016 ◽  
Author(s):  
Bruno Wilhelm ◽  
Hendrik Vogel ◽  
Flavio S. Anselmetti

Abstract. Mediterranean Alpine populations are particularly exposed to natural hazards like floods and earthquakes because of both the close Mediterranean humidity source and the seismically active Alpine region. Knowledge of long-term variability in flood and earthquake occurrences is of high value since it can be useful to improve risk assessment and mitigation. In this context, we explore the potential of a lake-sediment sequence from Lago Inferiore de Laures in Valle d'Aosta (Northern Italy) as a long-term record of past floods and earthquakes. The high-resolution sedimentological study revealed 77 event layers over the last ca. 270 years; 8 are interpreted as most probably induced by earthquakes and 68 by flood events. Comparison to historical seismic data suggests that the recorded earthquakes are strong (epicentral MSK intensity of VI–IX) and/or close to the lake (distance of 25–120 km). Compared to other lake-sediment sequences, Lago Inferiore de Laures sediments appear to be regionally the most sensitive to earthquake shaking, offering a great potential to reconstruct the past regional seismicity further back in time. Comparison to historical and palaeoflood records suggests that the flood signal reconstructed from Lago Inferiore de Laures sediments well represents the regional and (multi-)decennial variability of summer–autumn floods, in connection to Mediterranean mesoscale precipitation events. Overall, our results reveal the high potential of Lago Inferiore de Laures sediments to extend the regional earthquake and flood catalogues far back in time.


2021 ◽  
Author(s):  
Berkay Dönmez ◽  
Kutay Dönmez ◽  
Deniz Diren-Üstün ◽  
Yurdanur Ünal

<p>Studies concerning the effects of urbanization on heavy precipitation events mostly focused on the summertime convective precipitation events. In these studies, the Urban Heat Island (UHI) effect was prominent over the urbanized region before the event, changing the spatial and temporal distribution of the precipitation. We aim to reveal the impact of urbanization over Ankara on the springtime frontal precipitation event of 5 May 2014, when the ground heating and UHI effects are not as strong as those in the summertime. We performed two different simulations based on the land-use scenarios with urban (URBAN) and without urban areas (NOURBAN) over Ankara, integrating the CORINE Land Use dataset into the Weather Research and Forecasting Model (WRF v3.8) and replacing the urban areas with the dominant land use category over the region. Four sub-regions with the identical area coverages corresponding to the upwind, central, and downwind parts of the city center are defined to have a lucid spatial and temporal representation of the event. The two simulation results agreed reasonably with the observations. In the simulation (URBAN) with the urban land use included, the spatial average of the daily rainfall amounts over the predefined sub-regions slightly decreased, especially the sub-regions to the upwind and downwind of the highly urbanized area. However, the difference in precipitation amount in the vicinity of the urbanized area between the two different simulations is not of significance in comparison to what was observed in other summertime precipitation studies. On the other hand, the UHI effect might be crucial in determining the impact of urban land use on the distribution and magnitude of the heavy springtime rainfall. To support this idea, we performed a similar analysis for a summertime convective precipitation event over Ankara and compared the results.</p>


1989 ◽  
Vol 21 (2) ◽  
pp. 145-159 ◽  
Author(s):  
G Giuliano

Theories of relationships between land use and transportation, and the empirical research conducted to test these relationships are reviewed. Recent empirical research seldom supports theoretical expectations. These results are explained by the changes in urban structure that have occurred over the past three decades. The paper concludes with some suggestions for revising the theories to represent conditions in contemporary urban areas better.


2021 ◽  
Author(s):  
Fatemeh Yavari ◽  
Seyyed Ali Akbar Salehi Neyshabouri ◽  
Jafar Yazdi ◽  
amir molajou

Abstract The study of non-stationary effects of hydrological time series and land-use changes in urban areas is essential to predict future floods and their probable damage. In the current study, a novel method was proposed for analyzing their simultaneous impact. For this purpose, rainfall frequency and land-use changes analyses were conducted for two different long-term periods, and the results were compared. Then, hydrologic modeling of the catchment was carried out using the HEC-HMS model, and obtained hydrographs were fed to the HEC-RAS2D model for estimating flood inundation areas. Using the economic information of assets and their damage functions, flood damages related to these two periods were evaluated through the HEC-FIA model. The results indicated that in the low return periods (e.g., 2-year flood), the damage in the second period was increased with respect to the first one but increased for the return periods of 5 to 100 years. Furthermore, surface runoff showed a 4.65% increase due to land-use change and a 12% increase due to rainfall non-stationarity. Moreover, flood damage showed a 136% increase on average, and among the two studied factors, the non-stationarity of rainfalls is considerably more effective on flood intensification.


2020 ◽  
Vol 64 (4) ◽  
pp. 40407-1-40407-13 ◽  
Author(s):  
Ran Pang ◽  
He Huang ◽  
Tri Dev Acharya

Abstract Yongding River is one of the five major river systems in Beijing. It is located to the west of Beijing. It has influenced culture along its basin. The river supports both rural and urban areas. Furthermore, it influences economic development, water conservation, and the natural environment. However, during the past few decades, due to the combined effect of increasing population and economic activities, a series of changes have led to problems such as the reduction in water volume and the exposure of the riverbed. In this study, remote sensing images were used to derive land cover maps and compare spatiotemporal changes during the past 40 years. As a result, the following data were found: forest changed least; cropland area increased to a large extent; bareland area was reduced by a maximum of 63%; surface water area in the study area was lower from 1989 to 1999 because of the excessive use of water in human activities, but it increased by 92% from 2010 to 2018 as awareness about protecting the environment arose; there was a small increase in the built-up area, but this was more planned. These results reveal that water conservancy construction, agroforestry activities, and increasing urbanization have a great impact on the surrounding environment of the Yongding River (Beijing section). This study discusses in detail how the current situation can be attributed to of human activities, policies, economic development, and ecological conservation Furthermore, it suggests improvement by strengthening the governance of the riverbed and the riverside. These results and discussion can be a reference and provide decision support for the management of southwest Beijing or similar river basins in peri-urban areas.


1963 ◽  
Vol 3 (3) ◽  
pp. 424-442
Author(s):  
Jamila Akhtar

This review of the Literacy and Education Bklletin1 of the 1961 Census is fourth in the series of review articles published in this journal2. The Bulletin under review forms a part of the interim report on the characteristics of the population of Pakistan. It gives information on the number of illiterate and literate persons by age and sex for rural and urban areas on division and district basis; illiterate and literate.population in selected cities and towns; and the educational levels attained by the literate population by age and sex for divisions and districts. Relevant statistical notes and statements precede the tables in the Bulletin. The objective of this review is to describe the meaningfulness and significance of literacy statistics. To this end, a distinction is made between formal and functional levels of literacy. Comparisons of the 1951 and 1961 census figures are undertaken to indicate the progress of literacy and education during the past decade with reference to the effect of intercensal rate of population growth on such progress. Certain questions regarding the reliability of data are raised, which emphasize the need for caution in the interpretation of literacy statistics.


2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Ahmad Nazri Muhamad Ludin ◽  
Norsiah Abd. Aziz ◽  
Nooraini Hj Yusoff ◽  
Wan Juliyana Wan Abd Razak

Land use planning plays a crucial role in creating a balance between the needs of society, physical development and the ecosystem. However, most often poor planning and displacement of land uses particularly in urban areas contribute to social ills such as drug abuse and criminal activities. This research explains the spatial relationship of drug abuse and other criminal activities on urban land use planning and their implications on the society at large. Spatial statistics was used to show patterns, trends and spatial relationships of crimes and land use planning. Data on crime incidents were obtained from the Royal Malaysia Police Department whilst cases of drug abuse were collected from the National Anti-Drug Agency (AADK). Analysis of the data together with digital land use maps produced by Arnpang Jaya Municipal Council, showed the distribution of crime incidents and drug abuse in the area. Findings of the study also indicated that, there was a strong relationship between petty crimes, drng abuse and land use patterns. These criminal activities tend to concentrate in residential and commercial areas of the study area.


Sign in / Sign up

Export Citation Format

Share Document