Rainfall Variability over Northern Zambia

Abstract

Aims: The main aimwas to establish, if any, a trend in the amount and distribution of annual rainfall climatologyover Zambia. Study Design: Diverse statistical methods representing approaches in long term rainfall climatology analysis were employed. Place and Duration of Study: Zambia Meteorological Department, Kabwe, Zambia and School of Atmospheric Sciences, Nanjing University of Information, Science and Technology, Nanjing, China, between September 2014 and December 2014. Methodology: In this paper, the amount and seasonal distribution of rainfall from 1960 to 2010 over Northern Zambia as observed by 7 Provincial Meteorological Stations scattered across the study area was studied. A relationship between the rainfall patterns and the El Nino Southern Oscillation (ENSO) was explored and found. Composite analysis was also employed. Results: The results showed that during the peak of the rainy season (October – April), the northwestern parts of the study area particularly Ndola, experiences more rainfall than any other area over Northern Zambia while during rainy season off peaks (May – September) Isoka receives more rainfall. During warm (cool) ENSO events, dry (wet) conditions generally occur over much of the summer rainfall. Conclusion: For agricultural tactical purposes, the start of the rain season has been identified as November with October being a transitional month while the end of the season is March and April being a month of transition. The strong link between ENSO and rainfall over Northern Zambia suggests that there is a practical usability in forecasting whenever it is established that an ENSO episode is in progress.