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Rainfall probability analysis for Kerala (Record no. 195313)

MARC details
000 -LEADER
fixed length control field	05671nam a22002057a 4500
082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER
Classification number	630.31
Item number	POO/RA PG
100 ## - MAIN ENTRY--PERSONAL NAME
Personal name	Pooja, A
245 ## - TITLE STATEMENT
Title	Rainfall probability analysis for Kerala
260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT)
Place of publication, distribution, etc	Vellanikkara
Name of publisher, distributor, etc	Department of Agricultural Statistics, College of Horticulture
Date of publication, distribution, etc	2020
300 ## - PHYSICAL DESCRIPTION
Extent	110p.
502 ## - DISSERTATION NOTE
Dissertation note	MSc
520 3# - SUMMARY, ETC.
Abstract	The study entitled “Rainfall Probability Analysis for Kerala”, was conducted to<br/>estimate the probabilities and amounts of normal, excess and deficit rainfall during<br/>southwest and northeast monsoon periods, to determine the conditional probabilities for<br/>monsoon to be normal, excess and deficit when the monthly rainfall is normal, excess and<br/>deficit and to determine the assured monthly and weekly rainfall in the five agroclimatic<br/>zones of Kerala. Daily rainfall data from 1983 to 2019 collected from the five stations viz.<br/>Vellayani, Kumarakom, Vellanikkara, Pilicode and Ambalavayal representing southern<br/>zone, problem area zone, central zone, northern zone and high range zone respectively<br/>formed the database for the study.<br/>The daily rainfall data were converted to annual, seasonal, monthly and weekly<br/>rainfall data series for further analysis. Significant increasing trend is observed in annual<br/>rainfall at Vellayani. Non-significant increasing trend in annual rainfall is also observed<br/>at Vellanikkara, Pilicode and Ambalavayal. But, Kumarakom exhibited a non-significant<br/>negative trend for annual rainfall. Except the stations of Kumarakom and Vellanikkara,<br/>other stations have non-significant increasing trend in southwest monsoon rainfall. Only<br/>Vellayani has a non-significant increasing trend in northeast monsoon rainfall. All other<br/>stations exhibit declining trend for northeast monsoon rainfall over the period 1983-2019.<br/>The exploratory analysis showed that wide variation exists in rainfall over<br/>different agroclimatic zones. The rainfall variability was visually made possible by the<br/>use of box-and-whisker plots constructed for annual, seasonal, monthly and weekly<br/>rainfall over five stations. The boxplots explained the average and dispersion of rainfall<br/>data in terms of quartiles. In all the stations, annual, southwest monsoon and northeast<br/>monsoon rainfall did not follow normal distribution which was evident from the uneven<br/>boxes and dissimilar whisker lengths. A station-wise comparison showed that annual<br/>rainfall as well as southwest monsoon rainfall increased from south (Vellayani) to north<br/>(Pilicode) of Kerala and northeast monsoon rainfall declined from south to north. Outliers<br/>representing extreme rainfall events were also detected using boxplots which made the<br/>rainfall distribution skewed. At Ambalavayal, extreme annual rainfall (3093 mm) and<br/>extreme southwest monsoon rainfall (2380 mm) happened in 2018 and at Pilicode,<br/>extreme annual rainfall (4803 mm) occurred in 1994.The northeast monsoon witnessed<br/>extreme rainfall in 1992 (764 mm) and 2010 (950 mm), at Vellanikkara. The analysis of<br/>monthly rainfall using boxplots clearly depicted bimodal distribution at Vellayani and<br/>unimodal distribution at Pilicode. Thus, it was appropriate to use median and Inter<br/>Quartile Range (IQR) as the measures of central tendency and dispersion, rather than<br/>mean and standard deviation, as former measures were not affected by extreme<br/>observations.<br/>Conditional probabilities were estimated to determine whether the seasonal<br/>rainfall was excess, normal or deficient when monthly rainfall was excess, normal and<br/>deficient. Excess, normal and deficient rainfalls were defined in terms of quartiles for the<br/>purpose. At Vellayani, there was more than 50 per cent probability for the southwest<br/>monsoon to be in excess if the rainfall in the month of June was excess. At Kumarakom,<br/>there was a 60 per cent chance for receiving excess rainfall in southwest monsoon when<br/>July and September had excess rainfall. Rainfall in June and July determined excess<br/>rainfall in southwest monsoon at Vellanikkara with 70 per cent probability. There was<br/>70 per cent chance to receive excess rainfall during southwest monsoon at Pilicode when<br/>August or September received excess rainfall. Ambalavayal had experienced excess<br/>rainfall with 80 per cent possibility when July had excess rainfall. Similarly, each station<br/>had varying effects of rainfall in October and November towards northeast monsoon<br/>season. This analysis can provide information about when to take precautionary measures<br/>to anticipate the threat of floods and droughts in near future.<br/>The assured amounts of rainfall varied during different months and weeks in each<br/>station. Selection of crops (short duration varieties for low rainfall regions), cropping<br/>pattern and other decision making strategies for harvesting rainfall or drainage<br/>management can be made on the basis of assured rainfall in different months. At<br/>Vellayani, 23rd (4th June to 10th June) and 24th (11th June to 17th June) standard<br/>meteorological weeks (SMWs) are the rainiest weeks. The rainiest week is 28th SMW (9th<br/>July to 15th July) at Kumarakom and Ambalavayal, whereas, it is 24th SMW (11th June to<br/>17th June) at Vellanikkara and Pilicode. On farm operations and crop management plans<br/>like decision of times of sowing, irrigation, fertilizer application, harvesting, etc., could<br/>be executed on the basis of assured weekly rainfall during the different crop periods.
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical term or geographic name as entry element	Rainfall probability
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical term or geographic name as entry element	Agricultural Statistics
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical term or geographic name as entry element	Rainfall analysis
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical term or geographic name as entry element	Kerala
700 ## - ADDED ENTRY--PERSONAL NAME
Personal name	Laly John, C (Guide)
856 ## - ELECTRONIC LOCATION AND ACCESS
Uniform Resource Identifier	https://krishikosh.egranth.ac.in/handle/1/5810225366
942 ## - ADDED ENTRY ELEMENTS (KOHA)
Source of classification or shelving scheme	Dewey Decimal Classification
Item type	Theses

Holdings
Not for loan	Collection code	Home library	Current library	Shelving location	Date acquired	Full call number	Barcode	Date last seen	Koha item type
Not For Loan	Reference Book	KAU Central Library, Thrissur	KAU Central Library, Thrissur	Theses	01/12/2020	630.31 POO/RA PG	174935	01/12/2020	Theses