Volume No. 7 Issue No.: 1A Page No.: 218-228 Jul-Sept. 2012

 

ANALYSIS OF TRENDS IN DRY SPELLS DURING RAINY SEASONS FOR MASVINGO AIRPORT AND ZAKA STATIONS IN MASVINGO PROVINCE, ZIMBABWE

 

Simba Farai Malvern*, Seyitini Luckywell, Murwendo Talent, Mapurisa Brain, Chayangira Juwawa, Matete Confess1, Chirima Justin2, Mashonjowa Emmanuel3 and Mufandaedza Jonathan4

1. Department of Physics, Geography and Environmental Science, Faculty of Science, Great Zimbabwe University (ZIMBABWE)
2. Department of Mathematics and Computer Science, Faculty of Science, Great Zimbabwe University (ZIMBABWE)
3. Department of Physics, Faculty of Science, University of Zimbabwe (ZIMBABWE)
4. Department of Biotechnology, Faculty of Science, Great Zimbabwe University (ZIMBABWE)

 

Received on : May 25, 2012

 

ABSTRACT

 

The study analyses trends in dryspell variables during rainy season for two stations in Masvingo province, a semi-arid region in Zimbabwe. The primary objectives of study firstly to investigate the general trends in frequency and severerity of dry spells, secondly to establish whether the occurrence of dry spells is random or it can be predicted and lastly to use the results to guide the decision making process on how to mitigate the problems caused by dry spells for two districts namely Zaka and Masvingo airport. Rainfall patterns have been erratic and failing to support crop production in the past two decades in rainfed farming. Incidences of droughts and floods have been prominent resulting in famines in many parts of Zimbabwe particularly Masvingo Province. Farmers now suffer the uncertainty of establishing the correct planting dates, as long dryspells or midseason droughts characterize the seasons. The Zimbabwe Meteorological Services Department (ZMSD) is not fully capacitated to predict seasonal distribution of rainfall but can forecast total amount to be received during the season. Climatic data for five stations in the province was collected from the ZMSD. An investigation on trends of SNDSP and SMDSL dryspell variables was undertaken using time series plots. A dryspell was defined by ten or more consecutive days of no rainfall during the rainfall season. Data randomness was investigated with Minitab auto-correlation functions. The analysis established increasing dryspell frequencies and severities and data for one station was found to be random. These results are critical in crafting of coping strategies like choosing planting dates, seed varieties and ways of harnessing groundwater for irrigation purposes among others and to enhance informed planning in crop production.

 

Keywords : Seasonal length, Dryspells, Rainfed, Floods, Droughts, Zaka and Masvingo airport

 

 

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