scholarly journals A Climatic Perspective on the Impacts of Global Warming on Water Cycle of Cold Mountainous Catchments in the Tibetan Plateau: A Case Study in Yarlung Zangbo River Basin

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2338
Author(s):  
Zhicheng Xu ◽  
Lei Cheng ◽  
Peng Luo ◽  
Pan Liu ◽  
Lu Zhang ◽  
...  
Keyword(s):  
Global Warming ◽  
Flow Regimes ◽  
Low Flow ◽  
The Tibetan Plateau ◽  
Groundwater Storage ◽  
Annual Time Scale ◽  
Yarlung Zangbo River ◽  
Basin Scale ◽  
Annual Time

Global warming has a profound influence on global and regional water cycles, especially in the cold mountainous area. However, detecting and quantifying such changes are still difficult because noise and variability in observed streamflow are relatively larger than the long-term trends. In this study, the impacts of global warming on the catchment water cycles in the Yarlung Zangbo River Basin (YZRB), one of most important catchments in south of the Tibetan Plateau, are quantified using a climatic approach based on the relationship between basin-scale groundwater storage and low flow at the annual time scale. By using a quantile regression method and flow recession analysis, changes in low flow regimes and basin-scale groundwater storage at the Nuxia hydrological station are quantified at the annual time scale during 1961–2000. Results show annual low flows (10th and 25th annual flows) of the YZRB have decreased significantly, while long-term annual precipitation, total streamflow, and high flows are statistically unchanged. Annual lowest seven-day flow shows a significantly downward trend (2.2 m3/s/a, p < 0.05) and its timing has advanced about 12 days (2.8 day/10a, p < 0.1) during the study period. Estimated annual basin-scale groundwater storage also shows a significant decreasing trend at a rate of 0.079 mm/a (p < 0.05) over the study period. Further analysis suggests that evaporation increase, decreased snow-fraction, and increased annual precipitation intensity induced by the rising temperature possibly are the drivers causing a significant decline in catchment low flow regimes and groundwater storage in the study area. This highlights that an increase in temperature has likely already caused significant changes in regional flow regimes in the high and cold mountainous regions, which has alarming consequences in regional ecological protection and sustainable water resources management.

A large-scale hydroclimatological perspective on western European river flow regimes

2012 ◽  
Vol 44 (5) ◽  
pp. 809-833 ◽  
Author(s):  
Donna Wilson ◽  
David M. Hannah ◽  
Glenn R. McGregor
Keyword(s):  
Large Scale ◽  
Western Europe ◽  
River Flow ◽  
Flow Regimes ◽  
Climatic Conditions ◽  
Low Flow ◽  
Annual Rainfall ◽  
Time Variability ◽  
Runoff Generation

A novel flow regime classification scheme was applied to 141 river basins across western Europe, providing more robust analysis of space–time variability in regimes and their driving hydroclimatological processes. Regime shape (timing) and magnitude (size) were classified to regionalise long-term average flow regimes and to quantify year-to-year variation in regimes for each basin. Six long-term regime shape regions identified differences in seasonality related to latitude and altitude. Five long-term magnitude regions were linked to location plus average annual rainfall. Spatial distribution of long-term regimes reflected dominant climate and runoff generation processes. Regions were used to structure analysis of (relative) inter-annual regime dynamics. Six shape and five magnitude inter-annual regimes were identified; and regime stability (switching) assessed at pan-European, regional and basin scales. In some years, certain regime types were more prevalent, but never totally dominant. Regime shape was more stable at higher altitude due to buffering by frozen water storage-release (cf. more variable rainfall-runoff at lower altitudes). The lower inter-annual magnitude regimes persisted across larger domains (cf. higher magnitude) due to the more widespread climatic conditions generating low flow. Notably, there was limited spatio-temporal correspondence between regime shape and magnitude, suggesting variations in one attribute cannot be used to infer the other.

scholarly journals A site-level comparison of lysimeter and eddy-covariance flux measurements of evapotranspiration

2016 ◽  
Author(s):  
Martin Hirschi ◽  
Dominik Michel ◽  
Irene Lehner ◽  
Sonia I. Seneviratne
Keyword(s):  
Eddy Covariance ◽  
Time Scale ◽  
Rainfall Events ◽  
Source Areas ◽  
Annual Time Scale ◽  
Time Period ◽  
Flux Measurements ◽  
A Site ◽  
Annual Time

Abstract. Accurate measurements of evapotranspiration are required for many meteorological, climatological, ecological, and hydrological research applications and developments. Here we examine and compare two well-established methods to determine evapotranspiration at the site level: lysimeter-based measurements (EL) and eddy-covariance (EC) flux measurements (EEC). The analyses are based on parallel measurements carried out with these two methods at the research catchment Rietholzbach in northeastern Switzerland, and cover the time period June 2009 to December 2015. The measurements are compared on various time scales, and with respect to a 40-year lysimeter-based evapotranspiration time series. Overall, the lysimeter and EC measurements agree well, especially on the annual time scale. On that time scale, the long-term lysimeter measurements also correspond well with catchment water-balance estimates of evapotranspiration. This highlights the representativeness of the site-level lysimeter and EC measurements for the entire catchment despite their comparatively small source areas and the heterogeneous land use and topography within the catchment. Furthermore, we identify that lack of reliable EC measurements during and following rainfall events (due to limitations of the measurement technique under these conditions) significantly contributes to an underestimation of EEC and to the overall energy balance gap at the site.

951: “Experience in the Treatment of Low Flow Priapism”; A Novel, Easy and Effective Technique: A Long-Term, Binational, Multi-Institutional Study in 18 Patients Over 8 Years

2007 ◽  
Vol 177 (4S) ◽  
pp. 314-315
Author(s):  
Jose A. Medina Machuca ◽  
Jose A. Medina Coello ◽  
Hugo Manzanilla ◽  
Francisco A. Gutierrez
Keyword(s):  
Low Flow ◽  
Effective Technique

Long-Term Increase in Hibernating Bats in Swedish Mines — Effect of Global Warming?

2019 ◽  
Vol 20 (2) ◽  
pp. 421 ◽  
Author(s):  
Jens Rydell ◽  
Johan Eklöf ◽  
Hans Fransson ◽  
Sabine Lind
Keyword(s):  
Global Warming

scholarly journals Anthropogenic drought dominates groundwater depletion in Iran

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samaneh Ashraf ◽  
Ali Nazemi ◽  
Amir AghaKouchak
Keyword(s):  
Economic Security ◽  
Groundwater Depletion ◽  
Groundwater Storage ◽  
Rates Of Change ◽  
Level Data ◽  
Basin Scale ◽  
Storage Basin ◽  
Groundwater Reserves ◽  
The Impact ◽  
Hydrological Droughts

AbstractUsing publicly-available average monthly groundwater level data in 478 sub-basins and 30 basins in Iran, we quantify country-wide groundwater depletion in Iran. Natural and anthropogenic elements affecting the dynamics of groundwater storage are taken into account and quantified during the period of 2002–2015. We estimate that the total groundwater depletion in Iran to be ~ 74 km3 during this period with highly localized and variable rates of change at basin and sub-basin scales. The impact of depletion in Iran’s groundwater reserves is already manifested by extreme overdrafts in ~ 77% of Iran’s land area, a growing soil salinity across the entire country, and increasing frequency and extent of land subsidence in Iran’s planes. While meteorological/hydrological droughts act as triggers and intensify the rate of depletion in country-wide groundwater storage, basin-scale groundwater depletions in Iran are mainly caused by extensive human water withdrawals. We warn that continuation of unsustainable groundwater management in Iran can lead to potentially irreversible impacts on land and environment, threatening country’s water, food, socio-economic security.

scholarly journals Influence of the Environment on the Reliability of Security Magnetic Contacts

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 401
Author(s):  
Martin Boros ◽  
Andrej Velas ◽  
Viktor Soltes ◽  
Jacek Dworzecki
Keyword(s):  
Global Warming ◽  
Extreme Conditions ◽  
Alarm System ◽  
Test Device ◽  
Reaction Distance ◽  
Ambient Temperatures ◽  
Thermal Chamber

Magnetic contacts are one of the basic components of an alarm system, providing access to buildings, especially windows and doors. From long-term reliability tests, it can be concluded that magnetic contacts show sufficient reliability. Due to global warming, we can measure high as well as low ambient temperatures in the vicinity of magnetic contacts, which can directly affect their reliability. As part of partial tests, research into the reliability of magnetic contacts, we created a test device with which their reaction distance was examined under extreme conditions simulated in a thermal chamber. The results of the practical tests have yielded surprising results.

scholarly journals Atmospheric Thermal and Dynamic Vertical Structures of Summer Hourly Precipitation in Jiulong of the Tibetan Plateau

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 505
Author(s):  
Yonglan Tang ◽  
Guirong Xu ◽  
Rong Wan ◽  
Xiaofang Wang ◽  
Junchao Wang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Tibetan Plateau ◽  
Precipitation Amount ◽  
Summer Precipitation ◽  
The Tibetan Plateau ◽  
Hourly Precipitation ◽  
Air Convection ◽  
Precipitation Variation ◽  
Long Term Observation

It is an important to study atmospheric thermal and dynamic vertical structures over the Tibetan Plateau (TP) and their impact on precipitation by using long-term observation at representative stations. This study exhibits the observational facts of summer precipitation variation on subdiurnal scale and its atmospheric thermal and dynamic vertical structures over the TP with hourly precipitation and intensive soundings in Jiulong during 2013–2020. It is found that precipitation amount and frequency are low in the daytime and high in the nighttime, and hourly precipitation greater than 1 mm mostly occurs at nighttime. Weak precipitation during the daytime may be caused by air advection, and strong precipitation at nighttime may be closely related with air convection. Both humidity and wind speed profiles show obvious fluctuation when precipitation occurs, and the greater the precipitation intensity, the larger the fluctuation. Moreover, the fluctuation of wind speed is small in the morning, large at noon and largest at night, presenting a similar diurnal cycle to that of convective activity over the TP, which is conductive to nighttime precipitation. Additionally, the inverse layer is accompanied by the inverse humidity layer, and wind speed presents multi-peaks distribution in its vertical structure. Both of these are closely related with the underlying surface and topography of Jiulong. More studies on physical mechanism and numerical simulation are necessary for better understanding the atmospheric phenomenon over the TP.

Stochastic Models for Actuarial Use: The Equilibrium Modelling of Local Markets

2009 ◽  
Vol 39 (1) ◽  
pp. 339-370 ◽  
Author(s):  
Robert J. Thomson ◽  
Dmitri V. Gott
Keyword(s):  
Local Market ◽  
Market Participants ◽  
Market Portfolio ◽  
One Year ◽  
The One ◽  
Mean Variance ◽  
Annual Time ◽  
Time Subject

AbstractIn this paper, a long-term equilibrium model of a local market is developed. Subject to minor qualifications, the model is arbitrage-free. The variables modelled are the prices of risk-free zero-coupon bonds – both index-linked and conventional – and of equities, as well as the inflation rate. The model is developed in discrete (nominally annual) time, but allowance is made for processes in continuous time subject to continuous rebalancing. It is based on a model of the market portfolio comprising all the above-mentioned asset categories. The risk-free asset is taken to be the one-year index-linked bond. It is assumed that, conditionally upon information at the beginning of a year, market participants have homogeneous expectations with regard to the forthcoming year and make their decisions in mean-variance space. For the purposes of illustration, a descriptive version of the model is developed with reference to UK data. The parameters produced by that process may be used to inform the determination of those required for the use of the model as a predictive model. Illustrative results of simulations of the model are given.

The Southern Ocean benthic fauna and climate change: a historical perspective

1992 ◽  
Vol 338 (1285) ◽  
pp. 299-309 ◽  
Keyword(s):  
Global Warming ◽  
Southern Ocean ◽  
Environmental Change ◽  
Benthic Communities ◽  
Benthic Fauna ◽  
Marine Fauna ◽  
Short Term Change ◽  
Term Change ◽  
Continental Ice Sheets

Environmental change is the norm and it is likely that, particularly on the geological timescale, the temperature regime experienced by marine organisms has never been stable. These temperature changes vary in timescale from daily, through seasonal variations, to long-term environmental change over tens of millions of years. Whereas physiological work can give information on how individual organisms may react phenotypically to short-term change, the way benthic communities react to long-term change can only be studied from the fossil record. The present benthic marine fauna of the Southern Ocean is rich and diverse, consisting of a mixture of taxa with differing evolutionary histories and biogeographical affinities, suggesting that at no time in the Cenozoic did continental ice sheets extend sufficiently to eradicate all shallow-water faunas around Antarctica at the same time. Nevertheless, certain features do suggest the operation of vicariant processes, and climatic cycles affecting distributional ranges and ice-sheet extension may both have enhanced speciation processes. The overall cooling of southern high-latitude seas since the mid-Eocene has been neither smooth nor steady. Intermittent periods of global warming and the influence of Milankovitch cyclicity is likely to have led to regular pulses of migration in and out of Antarctica. The resultant diversity pump may explain in part the high species richness of some marine taxa in the Southern Ocean. It is difficult to suggest how the existing fauna will react to present global warming. Although it is certain the fauna will change, as all faunas have done throughout evolutionary time, we cannot predict with confidence how it will do so.

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