Geo-Spatial Assessment of Vegetation Response to Drought in North Central Nigeria

摘要

The thrust of this paper is to examine the impact of drought risk on vegetation health in North Central Nigeria. The study applied remote sensing, Geographic information system (GIS) and statistical techniques as research methodologies. Monthly rainfall data which span through a period of 56 years (1960-2017) were obtained from Nigeria Meteorological Agency (NIMET) for analysis of variation and drought characterization using SPI. Consequently, drought risk maps were produced for three different periods: 2000-2005, 2005-2010 and 2010-2015. The study made use of the near real time data of Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua Normalized Difference Vegetation Index (NDVI) of 16 Day L3 Global 250 m resolution from 2000 to 2016 for analysis of vegetation health. The results of the study proved the efficacy of NDVI in highlighting areas that are currently under vegetation stress, reduction and drought. The states with reduced and low vegetation cover corresponded well to those with low rainfall hence, more vulnerable to drought risk. The summary of the NDVI results showed that Niger, plateau and Nasarawa states have low vegetation cover and are more vulnerable to drought risk.