Rainfall Variability over Northern Zambia
Libanda Brigadier *
School of Atmospheric Sciences, Department of Applied Meteorology, Nanjing University of Information Science and Technology, 219 Ningliu Road, Nanjing, China and Meteorological Department, Box 80015, Kabwe, Zambia.
Nkolola Barbara
Department of Environmental Science and Engineering, School of Engineering, Nanjing University of Information Science and Technology, 219 Ningliu Road, China.
Musonda Bathsheba
Meteorological Department, Headquarters, Box 30200, Lusaka, Zambia.
*Author to whom correspondence should be addressed.
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.
Keywords: Rainfall variability, climatology, ITCZ, ENSO, Northern Zambia.