Analysis of spatio-temporal climate variability of a shallow lake catchment in Tanzania

Journal of Water and Climate Change

Isaac Larbi¹  Mwemezi J. Rwiza²  Latifa O. Nyembo² 

[1] Climate Change and Water Resources, West African Science Service Centre on Climate Change and Adapted Landuse (WASCAL), Universite d'Abomey Calavi (UAC), 03 BP 526 Cotonou, Benin;School of Materials, Energy, Water and Environmental Sciences (MEWES), The Nelson Mandela African Institution of Science and Technology (NM-AIST), P. O. Box, 447, Arusha, Tanzania;

关键词: mann-kendall test;    rain-dependency;    satellite climate product;    spatial climate variability;    standardized precipitation index;    water balance concept;   

DOI  :  10.2166/wcc.2020.197

来源: DOAJ

【 摘 要 】

This study analyzed the trends and spatio-temporal variability in rainfall and temperature, and the length of the rainy season (LRS) in the Lake Manyara catchment, Tanzania, covering a period between 1988 and 2018 using stations and satellite climate product. The Mann-Kendall statistical test, Sen's slope estimator, and inverse distance weighting interpolation techniques were used to detect the trends, magnitude of trends and spatial distribution of rainfall and temperature. A modified Stern's method and water balance concept were used for rainfall onset, cessation and LRS analysis, while a standardized precipitation index (SPI) was used to investigate the wetness or dryness of the area. The results showed high variability and decreasing trend (4 mm/y) in annual rainfall, and non-significant increasing trend for minimum and maximum temperature. Rainfall increased from the western to the northern part of the catchment whereas a reversal pattern was noticed for temperature. The SPI shows a signal of normal condition (about 65%) for all stations – with few years showing evidence of wetter and drier conditions. The LRS showed a decreasing trend indicating a potential negative influence on rain-dependent activities. There is a need, therefore, for adaptation measures such as improving water productivity and irrigation at the farm and catchment level.

【 授权许可】

Unknown