Remote Sensing of Droughts Impacts on Maize Prices Using SPOT-VGT Derived Vegetation Index

Abstract

Maize production in Kenya is usually affected by climate variability. Climate variability, further has implications for maize prices and national food security. The main objective of this study was to determine temporal fluctuations of maize prices in five (5) markets in Kenya; using NDVI values from SPOT-VEGETATION imagery of 1998–2010. The results show a weak relationship between maxNDVI and Kenyan maize wholesale price. Out of the five (5) markets analysed, only Kisumu (r2 = −0.11) shows a negative regression value; whereas, Nairobi (r2 = 0.29), Mombasa (r2 = 0.27), Nakuru (r2 = 0.44) and Eldoret (r2 = 0.05) portray a positive relationship. Overall, the findings of this study indicate that maize prices were high during drought periods (i.e. negative anomalies) and low during wet seasons (i.e. positive anomalies). The findings of this work underscores the potential for maize price monitoring using satellite derived vegetation indices, such as the normalised difference vegetation index towards providing valuable inputs to the food security modelling community. We however, recommend that, in the future, there is need to integrate a cumulative vegetation index (CVI) method to reduce any differences that could exist during analysing maize growing stage using vegetation index remote sensing techniques.