scholarly journals Anomalies of precipitation and drought in objectively derived climate regions of Iran

2021 ◽  
Vol 70 (2) ◽  
pp. 163-174
Author(s):  
Sohrab Ghaedi
Keyword(s):  
Standardized Precipitation Index ◽  
Hierarchical Cluster ◽  
The Caspian Sea ◽  
South West ◽  
Central Regions ◽  
South West Coast ◽  
The Standardized Precipitation Index ◽  
Line Slope ◽  
Average Annual Precipitation ◽  
East West

By regionalizing precipitation in 113 synoptic stations in Iran, the characteristics of precipitations and the occurrence of droughts in each region were investigated over a period of 30 years, 1988–2017. Elevation, latitude and distance from moisture source have caused strong East–West and South–North gradients of precipitation across the territory of Iran so that the average annual precipitation increases from 55 mm in the eastern and central regions to 1,730 mm in the south-west coast of the Caspian Sea. Hierarchical cluster analysis identified six precipitation regions in Iran, including the arid, semi-arid, moderate, semi-humid, humid, and high humid regions. An investigation of the standardized precipitation index (SPI) showed that the trend in about 19 per cent of stations was significantly decreasing. It was non-significantly decreasing in 65 per cent, significantly increasing in less than 1 per cent, and non-significantly increasing in 15 per cent of the stations. While the occurrence of drought has increased in most parts of Iran, it has decreased in some stations only in the northern strip of the country. The line slope in more than 84 per cent of the stations represent negative values in SPI, which confirms an increase in the occurrence of droughts in Iran.

On the number of Patella species in south-west England

1980 ◽  
Vol 60 (3) ◽  
pp. 565-574 ◽  
Author(s):  
Patrick M. Gaffney
Keyword(s):  
Morphological Variation ◽  
West Coast ◽  
Gel Electrophoresis ◽  
The South ◽  
The West ◽  
Enzyme Systems ◽  
South West ◽  
South West Coast ◽  
East West ◽  
South West England

Limpet populations of the genus Patella from the south-west coast of England were examined by means of gel electrophoresis in order to settle debate on the specific status of the three Patella forms. Populations varied morphologically along an east-west gradient, from three distinct forms in the west to continuous intergradation in the east, in accord with earlier studies. Patella collected were divided into three groups on the basis of a complex of external features described by earlier workers, corresponding to the morphologically defined taxa P. vulgata Linn., 1758, P. aspera Röding, 1798, and P. depressa Pennant, 1777. These groups were electrophoretically distinct in five of seven enzyme systems examined, with no hybrids or intermediates. Incomplete speciation and hybridization can be ruled out as possible causes of the observed morphological variation.

scholarly journals Analyzing Wetness and Dryness Severity in Bangladesh: Using Standardized Precipitation Index (SPI) in GIS Environment

2015 ◽  
Vol 7 (2) ◽  
pp. 127-131
Author(s):  
NMR Nasher ◽  
MN Uddin
Keyword(s):  
Standardized Precipitation Index ◽  
Precipitation Index ◽  
Eastern Region ◽  
Time Period ◽  
Daily Precipitation Data ◽  
Distance Weighting ◽  
Central Regions ◽  
Gis Environment ◽  
The Standardized Precipitation Index ◽  
Inverse Distance

Daily precipitation data of 33 stations were analyzed to know the Standardized Precipitation Index (SPI). Both spatial and temporal SPI were analyzed. Inverse Distance Weighting (IDW) technique was used to map the spatial SPI with a decadal change. From 1983 to 2013, four maps showed the decadal changes of SPI over Bangladesh. 1993 was a dry year in the regarding time period. Station based trends were analyzed for Dhaka, Srimongol, Khulna, Cox’s bazaar and Rangpur as preventative for five regions in Bangladesh. Dryness is increasing over Northern and Central regions whereas wetness is increasing over Southwestern, Northern and eastern region in Bangladesh.DOI: http://dx.doi.org/10.3329/jesnr.v7i2.22220 Environ. Sci. & Natural Resources, 7(2): 127-131 2014

DROUGHT OCCURRENCE UNDER LITHUANIAN CLIMATIC CONDITIONS

2015 ◽  
Author(s):  
Laima TAPARAUSKIENĖ ◽  
Veronika LUKŠEVIČIŪTĖ
Keyword(s):  
Meteorological Data ◽  
Standardized Precipitation Index ◽  
Vegetation Period ◽  
Climatic Conditions ◽  
Precipitation Record ◽  
Calculation Step ◽  
Drought Conditions ◽  
The Standardized Precipitation Index ◽  
June July

This study provides the analysis of drought conditions of vegetation period in 1982-2014 year in two Lithuanian regions: Kaunas and Telšiai. To identify drought conditions the Standardized Precipitation Index (SPI) was applied. SPI was calculated using the long-term precipitation record of 1982–2014 with in-situ meteorological data. Calculation step of SPI was taken 1 month considering only vegetation period (May, June, July, August, September). The purpose of investigation was to evaluate the humidity/aridity of vegetation period and find out the probability of droughts occurrence under Lithuanian climatic conditions. It was found out that according SPI results droughts occurred in 14.5 % of all months in Kaunas region and in 15.8 % in Telšiai region. Wet periods in Kaunas region occurred in 15.8 %, and in Telšiai region occurrence of wet periods was – 18.8 % from all evaluated months. According SPI evaluation near normal were 69.7 % of total months during period of investigation in Kaunas and respectively – 65.5 % in Telšiai. The probability for extremely dry period under Lithuania climatic conditions are pretty low – 3.0 % in middle Lithuania and 2.4 % in western part of Lithuania.

scholarly journals Hydrological response to different time scales of climatological drought: an evaluation of the Standardized Precipitation Index in a mountainous Mediterranean basin

2005 ◽  
Vol 9 (5) ◽  
pp. 523-533 ◽  
Author(s):  
S. M. Vicente-Serrano ◽  
J. I. López-Moreno
Keyword(s):  
Time Scales ◽  
Hydrological Cycle ◽  
Standardized Precipitation Index ◽  
Precipitation Index ◽  
Drought Indices ◽  
Long Time ◽  
The Standardized Precipitation Index ◽  
Hydrological Droughts ◽  
Different Time Scales

Abstract. At present, the Standardized Precipitation Index (SPI) is the most widely used drought index to provide good estimations about the intensity, magnitude and spatial extent of droughts. The main advantage of the SPI in comparison with other indices is the fact that the SPI enables both determination of drought conditions at different time scales and monitoring of different drought types. It is widely accepted that SPI time scales affect different sub-systems in the hydrological cycle due to the fact that the response of the different water usable sources to precipitation shortages can be very different. The long time scales of SPI are related to hydrological droughts (river flows and reservoir storages). Nevertheless, few analyses empirically verify these statements or the usefulness of the SPI time scales to monitor drought. In this paper, the SPI at different time scales is compared with surface hydrological variables in a big closed basin located in the central Spanish Pyrenees. We provide evidence about the way in which the longer (>12 months) SPI time scales may not be useful for drought quantification in this area. In general, the surface flows respond to short SPI time scales whereas the reservoir storages respond to longer time scales (7–10 months). Nevertheless, important seasonal differences can be identified in the SPI-usable water sources relationships. This suggests that it is necessary to test the drought indices and time scales in relation to their usefulness for monitoring different drought types under different environmental conditions and water demand situations.

Meteorological aspects of mud bank formation along south west coast of India

2013 ◽  
Vol 65 ◽  
pp. 45-51 ◽  
Author(s):  
Asha S. Philip ◽  
C.A. Babu ◽  
P.V. Hareeshkumar
Keyword(s):  
West Coast ◽  
West Coast Of India ◽  
South West ◽  
South West Coast ◽  
Mud Bank

scholarly journals Developing Objective Operational Definitions for Monitoring Drought

2009 ◽  
Vol 48 (6) ◽  
pp. 1217-1229 ◽  
Author(s):  
Steven M. Quiring
Keyword(s):  
Water Conservation ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Severity Index ◽  
Decision Makers ◽  
Drought Severity ◽  
Specific Method ◽  
The Standardized Precipitation Index ◽  
Spatially Variant ◽  
Objective Methodology

Abstract Drought is a complex phenomenon that is difficult to accurately describe because its definition is both spatially variant and context dependent. Decision makers in local, state, and federal agencies commonly use operational drought definitions that are based on specific drought index thresholds to trigger water conservation measures and determine levels of drought assistance. Unfortunately, many state drought plans utilize operational drought definitions that are derived subjectively and therefore may not be appropriate for triggering drought responses. This paper presents an objective methodology for establishing operational drought definitions. The advantages of this methodology are demonstrated by calculating meteorological drought thresholds for the Palmer drought severity index, the standardized precipitation index, and percent of normal precipitation using both station and climate division data from Texas. Results indicate that using subjectively derived operational drought definitions may lead to over- or underestimating true drought severity. Therefore, it is more appropriate to use an objective location-specific method for defining operational drought thresholds.

Inter-annual and seasonal dynamics of amino acid, mineral and vitamin composition of silver belly Leiognathus splendens

2014 ◽  
Vol 95 (4) ◽  
pp. 817-828 ◽  
Author(s):  
Kajal Chakraborty ◽  
Deepu Joseph
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Content ◽  
West Coast ◽  
Sensor Data ◽  
The South ◽  
Post Monsoon ◽  
South West ◽  
South West Coast ◽  
Protein Amino Acids

Silver bellies, Leiognathus splendens were studied for their spatial (south-west and south-east coasts of India), annual (2008–2011) and seasonal (pre-monsoon, monsoon and post-monsoon) variations of protein, amino acids, vitamins and minerals. The monthly mean Sea Viewing Wide Field-of-view Sensor data for the period from January 2008 to December 2011 were taken into account to indicate the distribution of the photosynthetic pigment chlorophyll-a to test the hypothesis that surface productivity might be related to nutritional biochemistry of this species. The four year average total protein content and chlorophyll-a showed good correlation during monsoon on the south-west coast and monsoon/post-monsoon on the south-east coast, suggesting that the protein content is prejudiced by the chlorophyll-a concentration. Amino acid scores observed monsoon maxima along the south-west and south-east coasts. Significant seasonal variations in vitamin content were observed at the study locations with high content of vitamins D3, E, K1 and C on the south-west coast. Na content was maximal during pre-monsoon on the south-west coast, while post-monsoon maxima of Ca and K content were observed. The Fe, Mn and Zn were abundant in the samples collected from the south-west coast. The concentration of Se exhibited maximum values post-monsoon along the south-west and south-east coasts. The present study demonstrated L. splendens as a valuable source of the protein, amino acids, minerals and vitamins, showing that this low-value species is a good source of well balanced proteins with high biological value to be qualified as a preferred healthy food for human consumption.

Comparison of Lipid Profile in Three Species of Myctophids from the South West Coast of Kerala, India

2014 ◽  
Vol 37 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Libin Baby ◽  
Thazhakot Vasunambisan Sankar ◽  
Rangasamy Anandan
Keyword(s):  
Lipid Profile ◽  
West Coast ◽  
The South ◽  
South West ◽  
South West Coast
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