Characteristics of quasi-biennial oscillation over Kenya and their predictability potential for the seasonal rainfall

investigated using monthly zo.ta l wind com ponents from Nairob i (Kenya ) within the period1966-1987. RelatiHn.;;hips between the stra tospher ic eas terl y and westerly wino phases and t he seasona l ra infallanomalics were also iO\t,"..')t igatN.Res ults Irom spec tra l a nalysis indicated tho d ominance (If a 28 mon th s' period in the IllOal w ind comnoncn.The \'Crtical ra te of propagar ioa of both westerly and easterly wind phases was about - · 1.2 kmmonth.Results from statist ical analysis indicated signitica nr (at 5 '~~ level) association between rainfall anomalyclass (above normal. normal. a mi below normal) and east erly and westerl y wind phas...es.

Crop yield in India in relation to EI-Nino

ABSTRACT. Association between the EI- Nino events in the Pacific Ocean and the crop yields in India has been examined. Five districts,viz. Churu, Gwalior, Rewa, Palamau and Bankura located on the normal monsoon trough zone and cultivating altogether different, mostly rainfed crops, were selected for the study. Crop and seasonal rainfall data from 1951-88 were utilised in the analysis. The results indicate that the EI-Nino phenomenon does not exert much influence on the kharif. In wave models with cons crops in India.

Variability of southwest monsoon rainfall over West Bengal

Monthly and seasonal variations of southwest monsoon rainfall over the districts of Gangetic and Sub-Himalayan West Bengal are presented and their differences discussed. Latitudinal variations of monsoon rainfall are brought out. Decadal means of seasonal rainfall over plains are compared with those at higher elevations and northern latitudes. An attempt is made to study long term rainfall trends.

Assessment of Smallholder Farmers’ Adaptive Strategies on the Effects of Seasonal Rainfall Variability on Maize Yields in Nyeri County

Maize is the leading food crop produced in most parts of the world and a staple food crop in Kenya. Majority of the maize farmers are smallholders due to reduced land sizes as a result of land fragmentation. Maize farming is rain-fed making it more vulnerable to rainfall variability. Over the years, the farmers have increased their resilience and adaptive potential through indigenous knowledge so as to cope with the climate related risks. However, the increasing rainfall variability, frequency and more severe shocks likely surpass their current adaptive strategies. The study assessed existing adaptive strategies of the small-holder maize farmers in Kieni East sub-County in Nyeri Couny to the seasonal rainfall variability effects. The research adopted a mixed research design. Data was obtained from primary and secondary sources. Primary data was obtained using household structured questionnaires. Data was analyzed using descriptive methods and presented using charts and tables. SWOT analysis analyzed several underlying aspects affecting maize farmers in the sub-County. The study found that the farmers have several specific adaptive strategies to the effects of seasonal rainfall variability at their disposal which include but not limited to the use of varieties of maize seeds, seeking training, water harvesting, use of manure and fertilizers. Farmers also respond to rainfall variability by planting maize varieties that are early maturing and drought resistant as well as engaging in alternative farming activities and other economic activities.

Variations in meteorological floods during summer monsoon over India

In this study, rainfall data of 31 mteorological sub-divisioins in India for 113 years (1875-1987) have been used to develop a flood index and statistical properties of the Index are discussed. Relationship of the index with the seasonal rainfall, number of depressions and El-N/no phenomenon are examined. The study revealed that 1971-80 decade, had more number of flood years than the drought years. The flood index was found to be significantly related to flood situation over India. It IS difficult to associate any particular phase of the quasi-biennial oscillations (QBO) with occurrence of floods.

Characterization of Monsoonal Rainfall in the Sudano-Sahelian Zone of Northwestern Nigeria

Wavelet transform has been underutilized in characterization of rainfall (Real Onset Dates and Real Cessation Dates) in the study area. This study aims at the characterization of monsoonal rainfall. Daily rainfall data of four stations for the period 1981-2018 were collected from Nigerian Meteorological Agency. The Intra-seasonal Rainfall Monitoring Index (IRMI) was generated and used in determining the RODs and RCDs. The Mann–Kendall test was used to detect trends of the rainfall characteristics. Wavelet transform was used in modelling RODs and RCDs. Findings revealed that RODs vary between stations. There is low (0.3 Spearman’s Rank r) correlation between latitudes and Early Cessations (ECs) of rains. The Morlet wavelet analysis revealed that from 1999 to 2018, there were more of EOs and NOs especially in Kano station. We conclude that from 1981 to 2018 there has been a minimal increase in the retreat dates of rainfall in the study area.