scholarly journals Spatial-temporal Variability of Seasonal Precipitation in Iran

2016 ◽  
Vol 10 (1) ◽  
pp. 84-102 ◽  
Author(s):  
Majid Javari

Spatial-seasonal variability and temporal trends has essential importance to climatic prediction and analysis. The aim of this research is the seasonal variations and temporal trends in the Iran were predicted by using rainfall series. The exploratory-confirmatory method, and seasonal time series procedure (STSP), temporal trend (TT), seasonal least squares (SLS) and spatial (GIS) methods (STSP¬-SLS-GIS) were employed to bring to light rainfall spatial-seasonal variability and temporal trends (SSVTT). To explore the spatial-seasonal variability and temporal trends during the period over 1975 to 2014 at 140 stations. To investigate the spatial-seasonal variability and temporal trends amount of each series was studied using ArcGIS 10.3 on different time scale. New climatic findings for the region: the investigates and predictions revealed that: (a) range of monthly and seasonal changes of rainfall tends to be highest (increasing trend) during winter (Winter Seasonal Index or WUSI=137.83 mm); (b) lowest (decreasing trend) during summer (Summer Seasonal Index or SUSI=20.8l mm) and (c) the coefficient of rainfall seasonal pattern variations in winter to 5.94 mm, in spring to 11.13 mm, in summer to 4.44 mm and in autumn to 8.05 mm with seasonality being the most effective of all. Mean annual rainfall changed from 51.45 mm (at Bafgh) to 1834.9 mm (at Bandar Anzali). Maximum decrease in annual rainfall was obtained at Miandeh Jiroft (-143.83%) and minimum at Abali (-0.013%) station. The most apparent year of variation was 2007 in annual rainfall.

2008 ◽  
Vol 26 (7) ◽  
pp. 1751-1757 ◽  
Author(s):  
S. V. Thampi ◽  
S. Ravindran ◽  
T. K. Pant ◽  
C. V. Devasia ◽  
R. Sridharan

Abstract. In an earlier study, Thampi et al. (2006) have shown that the strength and asymmetry of Equatorial Ionization Anomaly (EIA), obtained well ahead of the onset time of Equatorial Spread F (ESF) have a definite role on the subsequent ESF activity, and a new "forecast parameter" has been identified for the prediction of ESF. This paper presents the observations of EIA strength and asymmetry from the Indian longitudes during the period from August 2005–March 2007. These observations are made using the line of sight Total Electron Content (TEC) measured by a ground-based beacon receiver located at Trivandrum (8.5° N, 77° E, 0.5° N dip lat) in India. It is seen that the seasonal variability of EIA strength and asymmetry are manifested in the latitudinal gradients obtained using the relative TEC measurements. As a consequence, the "forecast parameter" also displays a definite seasonal pattern. The seasonal variability of the EIA strength and asymmetry, and the "forecast parameter" are discussed in the present paper and a critical value for has been identified for each month/season. The likely "skill factor" of the new parameter is assessed using the data for a total of 122 days, and it is seen that when the estimated value of the "forecast parameter" exceeds the critical value, the ESF is seen to occur on more than 95% of cases.


2021 ◽  
Vol 78 (5) ◽  
pp. 364-370
Author(s):  
Rubing Pan ◽  
Qizhi Wang ◽  
Weizhuo Yi ◽  
Qiannan Wei ◽  
Jian Cheng ◽  
...  

ObjectiveWe aimed to examine the temporal trends of the association between extreme temperature and schizophrenia (SCZ) hospitalisations in Hefei, China.MethodsWe collected time-series data on SCZ hospitalisations for 10 years (2005–2014), with a total of 36 607 cases registered. We used quasi-Poisson regression and distributed lag non-linear model (DLNM) to assess the association between extreme temperature (cold and heat) and SCZ hospitalisations. A time-varying DLNM was then used to explore the temporal trends of the association between extreme temperature and SCZ hospitalisations in different periods. Subgroup analyses were conducted by age (0–39 and 40+ years) and gender, respectively.ResultsWe found that extreme cold and heat significantly increased the risk of SCZ hospitalisations (cold: 1st percentile of temperature 1.19 (95% CI 1.04 to 1.37) and 2.5th percentile of temperature 1.16 (95% CI 1.03 to 1.31); heat: 97.5th percentile of temperature 1.37 (95% CI 1.13 to 1.66) and 99th percentile of temperature 1.38 (95% CI 1.13 to 1.69)). We found a slightly decreasing trend in heat-related SCZ hospitalisations and a sharp increasing trend in cold effects from 2005 to 2014. However, the risk of heat-related hospitalisation has been rising since 2008. Stratified analyses showed that age and gender had different modification effects on temporal trends.ConclusionsThe findings highlight that as temperatures rise the body’s adaptability to high temperatures may be accompanied by more threats from extreme cold. The burden of cold-related SCZ hospitalisations may increase in the future.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Saqib Chaudhry ◽  
Ibrahim Laleka ◽  
Zelalem Bahiru ◽  
Mohammad Rauf A Chaudhry ◽  
Hussan S Gill ◽  
...  

Background: Avoidance of readmission is linked to improved quality of care, reduction in cost, and is a desirable patient-centered outcome. Nationally representative readmission metrics for patients with acute ischemic stroke treated with intravenous thrombolytic treatment (IV-tPA) are unavailable to date. Such estimates are necessary for benchmarking performance. Objectives: To identify US nationwide estimates and a temporal trend for 30-day hospital readmissions. Methods: We identified the cohort by year-wise analysis of the Nationwide Readmissions Database between January 1, 2010, and September 30, 2015. The database represents 50% of all US hospitalizations from 22 geographically dispersed states. Participants were adult (=>18 years) patients with a primary discharge diagnosis of acute ischemic (ICD-9-CM 433.x1 and 434.x1) who were treated with thrombolytic therapy (ICD-9-CM 9910). Readmission was defined as any admission within 30 days of index hospitalization discharge. Results: Based on study criteria, 57,676 eligible patients were included (mean [SE] age, 68.7 ± 14.4 years; 48.7% were women). Thirty-day readmission rate for acute ischemic stroke patients treated with IV-tPA was 11.17 % (95%CI, 10.92 %-11.43%). On average, there was a 4.4% annual decline in readmission between 2010 and 2014, which was statistically significant for the period of investigation (odds ratio, 0.95; 95%CI, 0.94-0.97). Age ≥ 65 years (OR 1.16 P <.0001), medical history of congestive heart failure (OR 1.11 P = 0.0056), chronic lung disease (OR 1.11 P = 0.0034) and renal failure (OR 1.35 P = <.0001) were independent predictors of readmission within 30 days. Conclusion: Nationally representative readmission metrics can be used to benchmark hospitals’ performance, and a temporal trend of 4.4 % may be used to evaluate the effectiveness of readmission reduction strategies.


2013 ◽  
Vol 12 (1) ◽  
Author(s):  
Victor Hugo De Morais Danelichen ◽  
Nadja Gomes Machado ◽  
Marcelo Sacardi Biudes ◽  
Maísa Caldas Souza

Rainfall is the key element in regional water balance, and have direct influence over economic activity. In this study, we evaluate the estimates of precipitation by TRMM satellite (Tropical Rainfall Measuring Mission) on the Midwest region of Brazil. The rainfall measured by TRMM satellite was compared with rainfall series obtained by the Office of Instituto de Controle de Espaço Aéreo (ICEA) of Comando da Força Aérea. The TRMM satellite overestimated annual rainfall between 0.6 and 37.4%, with greater overestimation in the dry season. However, the rainfall estimate by TRMM satellite had a high correlation (0.88) with the rainfall series and had high Willmott coefficient. The Northern of Brazilian Midwest had the highest annual accumulated rainfall and the Southwest and Northeast of Midwest had the lowest annual accumulated rainfall. There was a inverse seasonal pattern of accumulated rainfall, with higher values in the Northern of Midwest during the rainy season in the Southwest and Northeast during the dry season.


2010 ◽  
Vol 54 (7) ◽  
pp. 2953-2959 ◽  
Author(s):  
Emilio Pérez-Trallero ◽  
Jose E. Martín-Herrero ◽  
Ana Mazón ◽  
Celia García-Delafuente ◽  
Purificación Robles ◽  
...  

ABSTRACT A nationwide multicenter susceptibility surveillance study (Susceptibility to the Antimicrobials Used in the Community in España [SAUCE] project), SAUCE-4, including 2,559 Streptococcus pneumoniae, 2,287 Streptococcus pyogenes, and 2,736 Haemophilus influenzae isolates was carried out from May 2006 to June 2007 in 34 Spanish hospitals. Then, the results from SAUCE-4 were compared to those from all three previous SAUCE studies carried out in 1996-1997, 1998-1999, and 2001-2002 to assess the temporal trends in resistance and the phenotypes of resistance over the 11-year period. In SAUCE-4, on the basis of the CLSI breakpoints, penicillin (parenteral, nonmeningitis breakpoint) and cefotaxime were the antimicrobials that were the most active against S. pneumoniae (99.8% and 99.6%, respectively). Only 0.9% of isolates had a penicillin MIC of ≥2 μg/ml. In S. pyogenes, nonsusceptibility to erythromycin was observed in 19.4% of isolates. Among the H. influenzae isolates, a β-lactamase-positive prevalence of 15.7% was found. A statistically significant temporal decreasing trend over the 11-year period was observed for nonsusceptibility (from 60.0% to 22.9%) and resistance (from 36.5% to 0.9%) to penicillin and for the proportion of erythromycin-resistant isolates of S. pneumoniae of the macrolide-lincosamide-streptogramin B (MLSB) phenotype (from 98.4% to 81.3%). A similar trend was observed for the prevalence of ampicillin resistance (from 37.6% to 16.1%), β-lactamase production (from 25.7% to 15.7%), and β-lactamase-negative ampicillin resistance (BLNAR) in H. influenzae (from 13.5% to 0.7%). Among erythromycin-resistant isolates of S. pyogenes, a significant increasing trend in the prevalence of MLSB was observed (from 7.0% to 35.5%). SAUCE-4 confirms a generalized decline in the resistance of the main respiratory pathogens to the antimicrobials as well as a shift in their resistance phenotypes.


Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Jorge A Motta ◽  
Carlos Gordon ◽  
Beatriz Gomez ◽  
Eva Castillo ◽  
Hugo Herrera-Ballesteros

Seasonal patterns of cardiovascular (CV) mortality have been reported in many regions of the world, but mostly in temperate zones. These cycles and seasonal patterns of mortality have been identified by looking at mortality rate series over extended periods of time and by filtering its stochastic components. The reasons for these variations have been attributed to multiple causes. Empirical observations by health care worker have suggested that in Panama there are seasonal changes of CV disease mortality but this phenomenon had not been studied. The speculation is that this may be related to variation in the incidence of respiratory diseases, weather changes or to population activity patterns associated with holidays. Our hypothesis for this study is that in Panama mortality related to CV disease has a seasonal pattern. We compiled from the National Registry of Mortality all deaths that occurred in the country from cardiovascular diseases (n=36,145) and diabetes (n=7,076) for the years 2001–2009. A monthly time series of mortality was calculated and its components were decomposed utilizing moving averages. Elements, like cycle, seasonal occurrence and stochastic components, were separated. We also developed a seasonal index of mortality for these diseases. For the same years, we performed a similar analysis for all deaths attributed to cancer and external causes. Analysis of these mortality series revealed seasonal cycles for total cardiovascular mortality and diabetes mortality. Death from cancer and external causes also showed seasonal cycles. CV mortality and diabetes mortality peaked at the beginning of the third trimester of the year and were lowest during the first trimester. For the month of July, the CV mortality seasonal index showed a score of 108, and an average number of CV deaths of 364. The lowest seasonal index score for CV mortality was 87 in February, with an average number of CV deaths of 296. The cycles observed for cancer and deaths from external causes did not match the cycles observed for CV diseases and diabetes. We conclude that there is a seasonal pattern of CV mortality in Panama. The drivers of these cyclical changes of CV mortality have not yet been identified, but we are evaluating the relationship of acute respiratory illnesses, population activity patterns and weather changes to these seasonal mortality variations.


2019 ◽  
Vol 12 (1) ◽  
pp. 73 ◽  
Author(s):  
Juan Torres-Batlló ◽  
Belén Martí-Cardona ◽  
Ramiro Pillco-Zolá

Lake Poopó is located in the Andean Mountain Range Plateau or Altiplano. A general decline in the lake water level has been observed in the last two decades, coinciding roughly with an intensification of agriculture exploitation, such as quinoa crops. Several factors have been linked with the shrinkage of the lake, including climate change, increased irrigation, mining extraction and population growth. Being an endorheic catchment, evapotranspiration (ET) losses are expected to be the main water output mechanism and previous studies demonstrated ET increases using Earth observation (EO) data. In this study, we seek to build upon these earlier findings by analyzing an ET time series dataset of higher spatial and temporal resolution, in conjunction with land cover and precipitation data. More specifically, we performed a spatio-temporal analysis, focusing on wet and dry periods, that showed that ET changes occur primarily in the wet period, while the dry period is approximately stationary. An analysis of vegetation trends performed using 500 MODIS vegetation index products (NDVI) also showed an overall increasing trend during the wet period. Analysis of NDVI and ET across land cover types showed that only croplands had experienced an increase in NDVI and ET losses, while natural covers showed either constant or decreasing NDVI trends together with increases in ET. The larger increase in vegetation and ET losses over agricultural regions, strongly suggests that cropping practices exacerbated water losses in these areas. This quantification provides essential information for the sustainable planning of water resources and land uses in the catchment. Finally, we examined the spatio-temporal trends of the precipitation using the newly available Climate Hazards Group Infrared Precipitation with Stations (CHIRPS-v2) product, which we validated with onsite rainfall measurements. When integrated over the entire catchment, precipitation and ET showed an average increasing trend of 5.2 mm yr−1 and 4.3 mm yr−1, respectively. This result suggests that, despite the increased ET losses, the catchment-wide water storage should have been offset by the higher precipitation. However, this result is only applicable to the catchment-wide water balance, and the location of water may have been altered (e.g., by river abstractions or by the creation of impoundments) to the detriment of the Lake Poopó downstream.


2020 ◽  
Vol 12 (4) ◽  
pp. 709 ◽  
Author(s):  
Abhishek Banerjee ◽  
Ruishan Chen ◽  
Michael E. Meadows ◽  
R.B. Singh ◽  
Suraj Mal ◽  
...  

This paper analyses the spatio-temporal trends and variability in annual, seasonal, and monthly rainfall with corresponding rainy days in Bhilangana river basin, Uttarakhand Himalaya, based on stations and two gridded products. Station-based monthly rainfall and rainy days data were obtained from the India Meteorological Department (IMD) for the period from 1983 to 2008 and applied, along with two daily rainfall gridded products to establish temporal changes and spatial associations in the study area. Due to the lack of more recent ground station rainfall measurements for the basin, gridded data were then used to establish monthly rainfall spatio-temporal trends for the period 2009 to 2018. The study shows all surface observatories in the catchment experienced an annual decreasing trend in rainfall over the 1983 to 2008 period, averaging 15.75 mm per decade. Analysis of at the monthly and seasonal trend showed reduced rainfall for August and during monsoon season as a whole (10.13 and 11.38 mm per decade, respectively); maximum changes were observed in both monsoon and winter months. Gridded rainfall data were obtained from the Climate Hazard Infrared Group Precipitation Station (CHIRPS) and Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR). By combining the big data analytical potential of Google Earth Engine (GEE), we compare spatial patterns and temporal trends in observational and modelled precipitation and demonstrate that remote sensing products can reliably be used in inaccessible areas where observational data are scarce and/or temporally incomplete. CHIRPS reanalysis data indicate that there are in fact three significantly distinct annual rainfall periods in the basin, viz. phase 1: 1983 to 1997 (relatively high annual rainfall); phase 2: 1998 to 2008 (drought); phase 3: 2009 to 2018 (return to relatively high annual rainfall again). By comparison, PERSIANN-CDR data show reduced annual and winter precipitation, but no significant changes during the monsoon and pre-monsoon seasons from 1983 to 2008. The major conclusions of this study are that rainfall modelled using CHIRPS corresponds well with the observational record in confirming the decreased annual and seasonal rainfall, averaging 10.9 and 7.9 mm per decade respectively between 1983 and 2008, although there is a trend (albeit not statistically significant) to higher rainfall after the marked dry period between 1998 and 2008. Long-term variability in rainfall in the Bhilangana river basin has had critical impacts on the environment arising from water scarcity in this mountainous region.


2018 ◽  
Vol 2018 ◽  
pp. 1-26
Author(s):  
Wei Wei ◽  
Baitian Wang ◽  
Kebin Zhang ◽  
Zhongjie Shi ◽  
Genbatu Ge ◽  
...  

In order to examine temperature changes and extremes in the Beijing-Tianjin Sand Source Region (BTSSR), ten extreme temperature indices were selected, categorized, and calculated spanning the period 1960–2014, and the spatiotemporal variability and trends of temperature and extremes on multitimescales in the BTSSR were investigated using the Mann-Kendall (M-K) test, Sen’s slope estimator, and linear regression. Results show that mean temperatures have increased and extreme temperature events have become more frequent. Annual temperature has recorded a significant increasing trend over the BTSSR, in which 51 stations exhibited significant increasing trends (p<0.05); winter temperature recorded the most significant increasing trend in the northwest subregion. All extreme temperature indices showed warming trends at most stations; a higher warming slope in extreme temperature mainly occurred along the northeast border and northwest border and in the central-southern mountain area. As extreme low temperature events decrease, vegetation damage due to freezing temperatures will reduce and low cold-tolerant plants may expand their distribution range northward to revegetate barren areas in the BTSSR. However, in water-limited areas of the BTSSR, increasing temperatures in the growing season may exacerbate stress associated with plants relying on precipitation due to higher temperatures combining with decreasing precipitation.


2019 ◽  
Author(s):  
Yasunori Tohjima ◽  
Hitoshi Mukai ◽  
Toshinobu Machida ◽  
Yu Hoshina ◽  
Shin-Ichiro Nakaoka

Abstract. Time series of atmospheric O2/N2 ratio and CO2 mole fraction of flask samples obtained from NIES’s flask sampling network are presented. The network includes two ground sites, Hateruma Island (HAT, 24.05 °N, 123.81 °E) and Cape Ochiishi (COI, 43.17 °N, 145.50 °E), and cargo ships regularly sailing in the western Pacific. Based on temporal changes in fossil fuel-derived CO2 emissions, global atmospheric CO2 burden, and atmospheric potential oxygen (APO), which were calculated from the observed O2/N2 ratio and CO2 mole fraction according to APO = O2 + 1.1 × CO2, we estimated the global carbon sinks of the ocean and land biosphere for a period of more than 15 years. In this carbon budget calculation, we adopted a correction for the time-varying ocean O2 outgassing effect with an average of 0.43 PgC yr−1 for 2000–2016. The outgassing effect, attributed to global ocean warming, was evaluated under the assumption that the net ocean gas flux is proportional to the change in the ocean heat content for the 0–2000 m layer. The resulting oceanic and land biotic carbon sinks were 2.5 ± 0.6 PgC yr−1 and 1.6 ± 0.8 PgC yr−1, respectively, for a 17-year period (2000–2016) and 2.3 ± 0.6 PgC yr−1 and 2.0 ± 0.8 PgC yr−1, respectively, for a 14-year period (2003–2016). Despite the independent approaches, these sink values of this study agreed with those estimated by the Global Carbon Project (GCP) within a difference of about ±0.3 PgC yr−1. We examined the carbon sinks for an interval of five years to assess the temporal trends. The pentad (5-year) ocean sinks showed an increasing trend at a rate of 0.09 ± 0.02 PgC yr−2 during 2001–2014, while the pentad land sinks showed an increasing trend at a rate of 0.23 ± 0.03 PgC yr−2 for 2001–2009 and a decreasing trend at a rate of − 0.23 ± 0.05 PgC yr−2 during 2009–2014. Although there is good agreement in the trends of the pentad sinks between this study and that of GCP, the increasing rate of the pentad ocean sinks of this study was about two times larger than that of GCP.


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