scholarly journals Geo-climatic hazards in the eastern subtropical Andes: Distribution, Climate Drivers and Trends

2020 ◽  
Author(s):  
Iván Vergara ◽  
Stella M. Moreiras ◽  
Diego Araneo ◽  
René Garreaud
Keyword(s):  
Meteorological Data ◽  
Winter Precipitation ◽  
Positive Trend ◽  
Future Projection ◽  
Study Region ◽  
Climatic Hazards ◽  
Eastern Zone ◽  
Western Zone ◽  
Spatio Temporal

Abstract. Detection and understanding of historical changes in the frequency of geo-climatic hazards (G-CHs) is crucial for the quantification of current hazard and their future projection. Here we focus in the eastern subtropical Andes (32–33° S), using meteorological data and a century-long inventory on 553 G-CHs triggered by rainfall or snowfall. First we analysed their spatio-temporal distributions and the role of climate variability on the year-to-year changes in the number of days with G-CHs. Precipitation is positively correlated with the number of G-CHs across the region and year-round; mean temperature is negatively correlated with snowfall-driven hazards in the western (higher) half of the study region during winter, and with rainfall-driven hazards in the eastern zone during summer. The trends of the G-CHs frequency since the mid-20th century were calculated taking cautions for their non-systematic monitoring. The G-CHs series for the different triggers, zones and seasons were generally stationary. Nonetheless, there is a small positive trend in rainfall-driven G-CHs in the eastern zone during summer congruent with a rainfall increase there. We also found a decrease in snowfall-driven G-CHs in the western zone since the late 1990's onwards, most likely due to a reduction in winter precipitation rather than an increase in temperature.

scholarly journals Geo-climatic hazards in the eastern subtropical Andes: distribution, climate drivers and trends

2020 ◽  
Vol 20 (5) ◽  
pp. 1353-1367 ◽  
Author(s):  
Iván Vergara ◽  
Stella M. Moreiras ◽  
Diego Araneo ◽  
René Garreaud
Keyword(s):  
20Th Century ◽  
Meteorological Data ◽  
Winter Precipitation ◽  
Positive Trend ◽  
Study Region ◽  
Climatic Hazards ◽  
Eastern Zone ◽  
Western Zone ◽  
Spatio Temporal

Abstract. Detecting and understanding historical changes in the frequency of geo-climatic hazards (G-CHs) is crucial for the quantification of current hazards and project them into the future. Here we focus in the eastern subtropical Andes (32–33∘ S), using meteorological data and a century-long inventory of 553 G-CHs triggered by rainfall or snowfall. We first analyse their spatio-temporal distributions and the role of climate variability in the year-to-year changes in the number of days per season with G-CHs. Precipitation is positively correlated with the number of G-CHs across the region and year-round; mean temperature is negatively correlated with snowfall-driven hazards in the western (higher) half of the study region during winter and with rainfall-driven hazards in the eastern zone during summer. The trends of the G-CH frequency since the mid-20th century were calculated, paying attention to their non-systematic monitoring. The G-CH series for the different triggers, zones and seasons were generally stationary. Nonetheless, there is a small positive trend in rainfall-driven G-CHs in the eastern zone during summer, congruent with a rainfall increase there. We also found a decrease in snowfall-driven G-CHs in the western zone from the late 1990s onwards, most likely due to a reduction in winter precipitation rather than to an increase in temperature.

Dendroclimatic response of mountain hemlock (Tsuga mertensiana) in Pacific North America

2001 ◽  
Vol 31 (2) ◽  
pp. 322-332 ◽  
Author(s):  
Ze'ev Gedalof ◽  
Dan J Smith
Keyword(s):  
Large Scale ◽  
Winter Precipitation ◽  
Influential Factor ◽  
Limiting Factor ◽  
Study Region ◽  
Queen Charlotte Islands ◽  
Summer Temperatures ◽  
Cross Correlations ◽  
Tsuga Mertensiana

In this paper we review the ecology and physiology of mountain hemlock (Tsuga mertensiana (Bong.) Carrière) in the context of a dendroclimatological analysis. To better understand the relationship between mountain hemlock growth and climate variability throughout its range we have analyzed chronologies from 10 coastal sites, located along a transect extending from northern California to southern Alaska. The chronologies exhibit significant large-scale cross-correlations, with two distinct growth regions implied: chronologies from the northern Cascades in California, to the Queen Charlotte Islands, British Columbia, are correlated with each other but are distinct from Alaskan chronologies. While intervals of coherent reduced growth along the entire transect occur episodically throughout the record, intervals of coherent enhanced growth are less common. Response function analyses indicate that summer temperature is the most influential factor limiting growth throughout the study region, while winter precipitation is an additional limiting factor south of Alaska. Warm summer temperatures are associated with enhanced growth in the current year but with reduced growth in the following year. This response is believed to be a reflection of the energy required to mature cones initiated in the preceding year. The association with winter precipitation may reflect the role of deep, persistent snowpacks in regulating the duration of the growing season.

scholarly journals Critical air pollution events analysis in Itabira – Minas Gerais, Brazil

2021 ◽  
Vol 10 (1) ◽  
pp. e51610110587
Author(s):  
Higor dos Santos Alves ◽  
Ana Carolina Vasques Freitas
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Minas Gerais ◽  
Anthropogenic Factors ◽  
Positive Trend ◽  
The City ◽  
Pollution Events

The rates of atmospheric pollution are increasing in world over the years, which makes this topic more and more concerning. Weather conditions, associated with anthropogenic factors, play a fundamental role in modifying the air quality. In this context, this article aims to analyze the influence of meteorological factors during critical episodes of air pollution in the city of Itabira – Minas Gerais. Hourly air quality and meteorological data, provided by the Municipal Environment Secretariat (SMMA) of the Itabira City Hall, were used in this analysis. A selection of the critical events was made and, after that, the composites and daily anomalies for each event were calculated. The results obtained showed that in the critical days of pollution negative anomalies of precipitation, atmospheric pressure, relative humidity and wind speed were observed. For temperature, solar radiation and wind direction the anomalies are positive during critical days. In terms of emitting sources, there has been an increase in the vehicle fleet since 2014, presenting a positive trend of 1.151 vehicles per year. In addition, a number of 111 fire outbreaks were observed on the most critical day of all events. It is important to highlight the role of air quality control and monitoring, together with the analysis of meteorological conditions, as, currently, the maximum values established by legislation do not include changes in weather conditions, that can worsen air quality and harm the health of the population.

scholarly journals Spatio-temporal precipitation error propagation in runoff modelling: a case study in central Sweden

2006 ◽  
Vol 6 (4) ◽  
pp. 597-609 ◽  
Author(s):  
J. Olsson
Keyword(s):  
Winter Precipitation ◽  
Early Spring ◽  
Time Variability ◽  
Spring Flood ◽  
Study Region ◽  
Flood Peak ◽  
Spring Runoff ◽  
Precipitation Estimates ◽  
Spatio Temporal ◽  
Hbv Model

Abstract. The propagation of spatio-temporal errors in precipitation estimates to runoff errors in the output from the conceptual hydrological HBV model was investigated. The study region was the Gimån catchment in central Sweden, and the period year 2002. Five precipitation sources were considered: NWP model (H22), weather radar (RAD), precipitation gauges (PTH), and two versions of a mesoscale analysis system (M11, M22). To define the baseline estimates of precipitation and runoff, used to define seasonal precipitation and runoff biases, the mesoscale climate analysis M11 was used. The main precipitation biases were a systematic overestimation of precipitation by H22, in particular during winter and early spring, and a pronounced local overestimation by RAD during autumn, in the western part of the catchment. These overestimations in some cases exceeded 50% in terms of seasonal subcatchment relative accumulated volume bias, but generally the bias was within ±20%. The precipitation data from the different sources were used to drive the HBV model, set up and calibrated for two stations in Gimån, both for continuous simulation during 2002 and for forecasting of the spring flood peak. In summer, autumn and winter all sources agreed well. In spring H22 overestimated the accumulated runoff volume by ~50% and peak discharge by almost 100%, owing to both overestimated snow depth and precipitation during the spring flood. PTH overestimated spring runoff volumes by ~15% owing to overestimated winter precipitation. The results demonstrate how biases in precipitation estimates may exhibit a substantial space-time variability, and may further become either magnified or reduced when applied for hydrological purposes, depending on both temporal and spatial variations in the catchment. Thus, the uncertainty in precipitation estimates should preferably be specified as a function of both time and space.

Changing Role of Agriculture in Income and Employment, and Trends of Agricultural Worker Productivity in Indian States

2020 ◽  
pp. 183-189
Keyword(s):  
Green Revolution ◽  
Positive Trend ◽  
Worker Productivity ◽  
Indian States ◽  
Agricultural Worker ◽  
The Sixties ◽  
High Level ◽  
The Cost ◽  
Changing Role

The productivity of land has been often discussed and deliberated by the academia and policymakers to understand agriculture, however, very few studies have focused on the agriculture worker productivity to analyze this sector. This study concentrates on the productivity of agricultural workers from across the states taking two-time points into consideration. The agriculture worker productivity needs to be dealt with seriously and on a time series basis so that the marginal productivity of worker can be ascertained but also the dependency of worker on agriculture gets revealed. There is still disguised unemployment in all the states and high level of labour migration, yet most of the states showed the dependency has gone down. Although a state like Madhya Pradesh is doing very well in terms of income earned but that is at the cost of increased worker power in agriculture as a result of which, the productivity of worker has gone down. States like Mizoram, Meghalaya, Nagaland and Tripura, though small in size showed remarkable growth in productivity and all these states showed a positive trend in terms of worker shifting away from agriculture. The traditional states which gained the most from Green Revolution of the sixties are performing decently well, but they need to have the next major policy push so that they move to the next orbit of growth.

scholarly journals Human Capital Disparities and Earnings Inequality in The Portuguese Private Labour Market

2021 ◽  
Author(s):  
Derick R. C. Almeida ◽  
João A. S. Andrade ◽  
Adelaide Duarte ◽  
Marta Simões
Keyword(s):  
Human Capital ◽  
Labour Market ◽  
Tertiary Education ◽  
Earnings Inequality ◽  
Kuznets Curve ◽  
Positive Trend ◽  
Returns To Schooling ◽  
Education Inequality ◽  
Using Data

AbstractThis paper examines human capital inequality and how it relates to earnings inequality in Portugal using data from Quadros de Pessoal for the period 1986–2017. The objective is threefold: (i) show how the distribution of human capital has evolved over time; (ii) investigate the association between human capital inequality and earnings inequality; and (iii) analyse the role of returns to schooling, together with human capital inequality, in the explanation of earnings inequality. Our findings suggest that human capital inequality, computed based on the distribution of average years of schooling of employees working in the Portuguese private labour market, records a positive trend until 2007 and decreases from this year onwards, suggesting the existence of a Kuznets curve of education relating educational attainment levels and education inequality. Based on the decomposition of a Generalized Entropy index (Theil N) for earnings inequality, we observe that inequality in the distribution of human capital plays an important role in the explanation of earnings inequality, although this role has become less important over the last decade. Using Mincerian earnings regressions to estimate the returns to schooling together with the Blinder-Oaxaca decomposition of real hourly earnings we confirm that there are two important forces associated with the observed decrease in earnings inequality: a reduction in education inequality and compressed returns to schooling, mainly in tertiary education.

scholarly journals Big Data Analytics in urology: the story so far and the road ahead

2021 ◽  
Vol 13 ◽  
pp. 175628722199813
Author(s):  
B. M. Zeeshan Hameed ◽  
Aiswarya V. L. S. Dhavileswarapu ◽  
Nithesh Naik ◽  
Hadis Karimi ◽  
Padmaraj Hegde ◽  
...  
Keyword(s):  
Big Data ◽  
Data Analytics ◽  
Early Stage ◽  
Big Data Analytics ◽  
Positive Trend ◽  
The Road ◽  
Healthcare Data ◽  
Urological Disorders ◽  
Different Sources

Artificial intelligence (AI) has a proven record of application in the field of medicine and is used in various urological conditions such as oncology, urolithiasis, paediatric urology, urogynaecology, infertility and reconstruction. Data is the driving force of AI and the past decades have undoubtedly witnessed an upsurge in healthcare data. Urology is a specialty that has always been at the forefront of innovation and research and has rapidly embraced technologies to improve patient outcomes and experience. Advancements made in Big Data Analytics raised the expectations about the future of urology. This review aims to investigate the role of big data and its blend with AI for trends and use in urology. We explore the different sources of big data in urology and explicate their current and future applications. A positive trend has been exhibited by the advent and implementation of AI in urology with data available from several databases. The extensive use of big data for the diagnosis and treatment of urological disorders is still in its early stage and under validation. In future however, big data will no doubt play a major role in the management of urological conditions.

Coastline Vulnerability Assessment through Landsat and Cubesats in a Coastal Mega City

2020 ◽  
Vol 12 (5) ◽  
pp. 749 ◽  
Author(s):  
Majid Nazeer ◽  
Muhammad Waqas ◽  
Muhammad Imran Shahzad ◽  
Ibrahim Zia ◽  
Weicheng Wu
Keyword(s):  
Spatial Resolution ◽  
Land Reclamation ◽  
Anthropogenic Activities ◽  
Monsoon Season ◽  
Coastal Protection ◽  
Landsat Images ◽  
Intergovernmental Panel ◽  
Eastern Zone ◽  
Stable Conditions ◽  
Western Zone

According to the Intergovernmental Panel on Climate Change (IPCC), global mean sea levels may rise from 0.43 m to 0.84 m by the end of the 21st century. This poses a significant threat to coastal cities around the world. The shoreline of Karachi (a coastal mega city located in Southern Pakistan) is vulnerable mainly due to anthropogenic activities near the coast. Therefore, the present study investigates rates and susceptibility to shoreline change using a 76-year multi-temporal dataset (1942 to 2018) through the Digital Shoreline Analysis System (DSAS). Historical shoreline positions were extracted from the topographic sheets (1:250,000) of 1942 and 1966, the medium spatial resolution (30 m) multi-sensor Landsat images of 1976, 1990, 2002, 2011, and a high spatial resolution (3 m) Planet Scope image from 2018, along the 100 km coast of Karachi. The shoreline was divided into two zones, namely eastern (25 km) and western (29 km) zones, to track changes in development, movement, and dynamics of the shoreline position. The analysis revealed that 95% of transects drawn for the eastern zone underwent accretion (i.e., land reclamation) with a mean rate of 14 m/year indicating that the eastern zone faced rapid shoreline progression, with the highest rates due to the development of coastal areas for urban settlement. Similarly, 74% of transects drawn for the western zone experienced erosion (i.e., land loss) with a mean rate of −1.15 m/year indicating the weathering and erosion of rocky and sandy beaches by marine erosion. Among the 25 km length of the eastern zone, 94% (23.5 km) of the shoreline was found to be highly vulnerable, while the western zone showed much more stable conditions due to anthropogenic inactivity. Seasonal hydrodynamic analysis revealed approximately a 3% increase in the average wave height during the summer monsoon season and a 1% increase for the winter monsoon season during the post-land reclamation era. Coastal protection and management along the Sindh coastal zone should be adopted to defend against natural wave erosion and the government must take measures to stop illegal sea encroachments.

scholarly journals The Role of Spatio-Temporal Information to Govern the COVID-19 Pandemic: A European Perspective

2021 ◽  
Vol 10 (3) ◽  
pp. 166
Author(s):  
Hartmut Müller ◽  
Marije Louwsma
Keyword(s):  
European Union ◽  
Spatial Distribution ◽  
Spatial Information ◽  
National Level ◽  
Temporal Information ◽  
The European Union ◽  
Member States ◽  
Heavy Burden ◽  
Spatio Temporal

The Covid-19 pandemic put a heavy burden on member states in the European Union. To govern the pandemic, having access to reliable geo-information is key for monitoring the spatial distribution of the outbreak over time. This study aims to analyze the role of spatio-temporal information in governing the pandemic in the European Union and its member states. The European Nomenclature of Territorial Units for Statistics (NUTS) system and selected national dashboards from member states were assessed to analyze which spatio-temporal information was used, how the information was visualized and whether this changed over the course of the pandemic. Initially, member states focused on their own jurisdiction by creating national dashboards to monitor the pandemic. Information between member states was not aligned. Producing reliable data and timeliness reporting was problematic, just like selecting indictors to monitor the spatial distribution and intensity of the outbreak. Over the course of the pandemic, with more knowledge about the virus and its characteristics, interventions of member states to govern the outbreak were better aligned at the European level. However, further integration and alignment of public health data, statistical data and spatio-temporal data could provide even better information for governments and actors involved in managing the outbreak, both at national and supra-national level. The Infrastructure for Spatial Information in Europe (INSPIRE) initiative and the NUTS system provide a framework to guide future integration and extension of existing systems.

scholarly journals From Loschmidt daemons to time-reversed waves

2016 ◽  
Vol 374 (2069) ◽  
pp. 20150156 ◽  
Author(s):  
Mathias Fink
Keyword(s):  
Wave Propagation ◽  
Time Reversal ◽  
Degrees Of Freedom ◽  
Point Of View ◽  
Propagation Time ◽  
Reversal Invariance ◽  
Spatial Boundary ◽  
Dual Approaches ◽  
Spatio Temporal

Time-reversal invariance can be exploited in wave physics to control wave propagation in complex media. Because time and space play a similar role in wave propagation, time-reversed waves can be obtained by manipulating spatial boundaries or by manipulating time boundaries. The two dual approaches will be discussed in this paper. The first approach uses ‘time-reversal mirrors’ with a wave manipulation along a spatial boundary sampled by a finite number of antennas. Related to this method, the role of the spatio-temporal degrees of freedom of the wavefield will be emphasized. In a second approach, waves are manipulated from a time boundary and we show that ‘instantaneous time mirrors’, mimicking the Loschmidt point of view, simultaneously acting in the entire space at once can also radiate time-reversed waves.

Sign in / Sign up

Export Citation Format

Share Document