3,944 research outputs found
Automated estimation and analyses of meteorological drought characteristics from monthly rainfall data
The paper describes a new software package for automated estimation, display and analyses of various drought indices – continuous functions of precipitation that allow quantitative assessment of meteorological drought events to be made. The software at present allows up to five different drought indices to be estimated. They include the Decile Index (DI), the Effective Drought Index (EDI), the Standardized Precipitation Index (SPI) and deviations from the long-term mean and median value. Each index can be estimated from point and spatially averaged rainfall data and a number of options are provided for months' selection and the type of the analysis, including a running mean, single value or multiple annual values. The software also allows spell/run analysis to be performed and maps of a specific index to be constructed. The software forms part of the comprehensive computer package, developed earlier and designed to perform the multitude of water resources analyses and hydro-meteorological data processing. The 7-step procedure of setting up and running a typical drought assessment application is described in detail. The examples of applications are given primarily in the specific context of South Asia where the software has been used
Global Environmental Flow Information for the Sustainable Development Goals
Environmental flows (EF) are an important component of Goal 6 (the ‘water goal’) of the Sustainable Development Goals (SDGs). Yet, many countries still do not have well-defined criteria on how to define EF. In this study, we bring together the International Water Management Institute’s (IWMI’s) expertise and previous research in this area to develop a new methodology to quantify EF at a global scale. EF are developed for grids (0.1 degree spatial resolution) for different levels of health (defined as environmental management classes [EMCs]) of river sections. Additionally, EF have been separated into surface water and groundwater components, which also helps in developing sustainable groundwater abstraction (SGWA) limits. An online tool has been developed to calculate EF and SGWA in any area of interest
Measurement of the e+e- -> pi+pi- cross section with the CMD-2 detector in the 370-520 MeV c.m. energy range
The cross section of the process e+e- -> pi+pi- has been measured at the
CMD-2 detector in the 370-520 MeV center-of-mass (c.m.) energy range. A
systematic uncertainty of the measurement is 0.7 %. Using all CMD-2 data on the
pion form factor, the pion electromagnetic radius was calculated. The cross
section of muon pair production was also determined.Comment: 11 pages, 4 figure
Measurement of the Pion Form Factor in the Energy Range 1.04-1.38 GeV with the CMD-2 Detector
The cross section for the process is measured in the
c.m. energy range 1.04-1.38 GeV from 995 000 selected collinear events
including 860000 events, 82000 events, and 33000
events. The systematic and statistical errors of measuring the
pion form factor are equal to 1.2-4.2 and 5-13%, respectively.Comment: 5 pages, 2 figure
Indexing the Environmental Vulnerability of Mountain Streams in Azerbaijan
A simple environmental vulnerability assessment scheme is developed and illustrated using several streams in Azerbaijan as examples. Vulnerability of a river ecosystem is defined in terms of a combined impact of pressure factors such as water withdrawals, pollution, climate change impact on flow variability, and land use. These factors are used to measure the sensitivity of various elements/components of the system to impacts. The choice of these indicators may vary from area to area and depends on the nature of man-made and natural conditions. Each factor is characterized and quantified using a specific indicator and score. The total vulnerability score is estimated as a sum of the scores of all indicators. Most of the streams studied in Azerbaijan were found to be very vulnerable or extremely vulnerable, according to the developed scheme. The overall approach is straightforward and transparent. Conclusions are made about the vulnerability and/or resiliency of streams, to be taken into consideration when planning for water-sources development for the future
ЛЕДОВЫЙ РЕЖИМ ОЗЁР ЗАБАЙКАЛЬЯ В УСЛОВИЯХ СОВРЕМЕННОГО ПОТЕПЛЕНИЯ
The problem of the climate change impact on the ice regime of lakes has become topical in view of the revealed (observed) shortening of the freeze-up duration and a decrease in the ice thickness for many years. The relationship between timing and duration of the ice events and climate characteristics had been found. The influence of climate change on the ice regime in the Transbaikalia was previously estimated by the example of the Ivano-Arakhley lakes. In this work we determined the trends of changes of the following parameters: air temperature, the duration of freeze-up and the maximal ice thickness as well as the reliability of these trends on lakes Arakhley, Shakshinsky, Bolshoy Leprindo, Gusinoye, Baunt, Sosnovoye. The least-squares method was used to determine the long-term trends; consistency of the changes in the studied characteristics was evaluated by means of the correlation analysis. The significance of the trends and correlation coefficients was evaluated using Student's t-statistics.Оценено влияние изменений климата на ледовый режим озёр Забайкалья с 1975 по2012 г. Современная тенденция повышения температуры воздуха влияет на даты начала и окончания ледостава, формирование максимальной толщины льда и его прирост. Продолжительность ледостава и максимальная толщина льда за многолетний период уменьшились
Environmental Flow Assessment: Recent Examples from Sri Lanka
Abstract Assessment and provision of Environmental Flows (EF) is important for the protection of aquatic ecosystems. EF are a set of discharges of a particular magnitude, frequency and timing that are necessary to ensure a certain range of benefits from a river. Such flows need to be scientifically determined and economically justified. Limited exposure to the concept of EF exists in developing countries. This paper gives two recent relevant example studies, which were conducted by IWMI, with foci on EF Assessment (EFA) and valuation of EF benefits in the Walawe and Menik Ganga river basins located in a semi-arid zone of southern Sri Lanka. The Walawe example illustrates the simple method for estimation of EF. The EF are approximated at two sites along the main stream of the Walawe River, which are located below the two main reservoirs. A desktop method is used, which is based on simulated, unregulated daily flow time series and their flow duration curves. The study also illustrates how the required hydrological information can be generated for the locations where EF assessment is intendedquickly and in conditions of limited observed data. The second Menik Ganga example is used as a case study to evaluate the costs and benefits of environmental water allocations. The EF components evaluated include the water needs for religious festivals, and the requirements of the Yala National Park, the Pilinnawa coastal wetland and grasslands, and the Yala Fisheries Management Area (YFMA) off the coast. Almost all estimates are based on use values of EF such as marketed goods and recreation. The paper intends to stimulate discussion and further research in the fields of EF assessment and economic valuation
Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions
Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV
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