Comparative evaluation of NDVI strata and livelihood zones as spatial units of the practiced crop calendars

Abstract

ABSTRACT Properly mapping the spatial variability of the practiced crop calendars is useful for precise planning of agricultural activities. A seasonal calendar based on the livelihood zone (LHZ) map is widely employed as a crop calendar in Ethiopia. However, using the LHZ-based crop calendar for agricultural purposes may cause problems of doubtful accuracy, since non-ecological parameters are included in the LHZ map. This research was conducted in the central and southeastern parts of Ethiopia to compare the hypertemporal normalized difference vegetation index (NDVI) and LHZ-based stratification methods in explaining the spatial variability of the farmers’ actual crop calendar. A NDVI strata generated from SPOT-VGT and PROBA-V NDVI data of 16 years and the 2008 LHZ map of Ethiopia were processed to select sampling sites that represented three NDVI strata and four LHZs in common. Interview data were collected randomly from individual farmers on ploughing, planting and expected harvesting dates of teff (Eragrostis tef), wheat and barley (fields), and were analysed using non-parametric tests. The results revealed that the NDVI strata had greater spatial quality and precision than the LHZs in terms of uniqueness and internal homogeneity of the spatial units, indicating its suitability as a preferable alternative crop calendar.