TITLE:
Estimation of Current Agricultural Drought in the District des Savanes (Northern Côte d’Ivoire)
AUTHORS:
Léréyaha Coulibaly, Kouadio Assemien François Yao, Ismaïla Ouattara, Moussa Ouedraogo, Seydou Diallo, Amidou Dao, Emile Gneneyougo Soro, Bamory Kamagate
KEYWORDS:
Agricultural Drought, SSWI, Soil Moisture, Trend, District des Savanes, Côte d’Ivoire
JOURNAL NAME:
Open Journal of Modern Hydrology,
Vol.16 No.1,
November
28,
2025
ABSTRACT: This study investigates the spatio-temporal variability of soil moisture in relation to drought estimation over the period 1981-2022 in the District des Savanes of Côte d’Ivoire. Hydro-climatic data were used to compute the Standardised Soil Water Index (SSWI) at a six-month cumulative time scale (SSWI-6). Stationarity and trend tests were applied to identify breakpoints (Pettitt test), monotonic trends (Mann-Kendall test), and the magnitude of these trends (Sen’s Slope) in the SSWI-6 series. In addition, the Inverse Distance Weighting (IDW) interpolation method was employed to assess the spatial variability of drought. Overall, the results reveal predominantly negative trends, indicating an intensification of agricultural drought since 1991. The period from 1995 to 2001 was characterized by particularly high rainfall across much of the district. However, a significant drought episode emerged in 1994 and became widespread across the district by 2010, except in the Korhogo region. The duration of the most frequent agricultural droughts exceeded five months, with prolonged episodes particularly affecting Boundiali, Ferkessédougou, and Kong. The findings highlight that the district has been highly exposed to recurrent droughts, although a slight recovery in soil moisture was observed between 1995 and 2001. Interannual variations of the index further revealed alternating dry and wet periods across the District des Savanes.