The character of the sub-regional eco-climatic zones has possibly changed as suggested in the dwindling fortune of agricultural productivity, documented changes in vegetation and freshwater resources and rising poverty levels especially in the hitherto productive Northern Nigeria. To determine and map the changes, if any, in these eco-climatic characteristics is therefore important for general planning. This study is using rainfall and temperature data (1950-2006) to determine factors of rainfall effectiveness; onset dates, cessation dates, hydrologic growing season (HGS), monsoon quality index (MQI) and aridity index (AI); summarizing and ranking them using numerical identifiers for the interpretation of the various moisture situations, to assess the eco-climatic characteristics in the northern Nigeria. A multi-temporal database has been developed for the factors and classes have been defined using quantitative definitions for the time series. The point data have been transformed to spatial data and subjected to geospatial analysis. The results so far reveal variability in the effects of each factor on eco-climatic zonation and it is anticipated that integrating these derived climatic parameters and remotely sensed (vegetation dynamics) data using GIS techniques, is crucial for water management and attainment of food security. Key words: Eco-climatic, moisture effectiveness, surface, principal component analysis, environmental quality

Forests constitute a key component of the Earth system but the sustainability of the forest reserves in the semi-arid zone is a real concern since its vegetation is very sensitive to the climate fluctuation. The understanding of the mechanisms for the vegetation–climate interaction is poorly studied in the context of African Sahel. In this study, the characteristics of the vegetation response to the fluctuations of precipitation and temperature is determined for the forest reserve of Fina. Rainfall estimates, air temperature and NDVI were re-gridded to a same spatial resolution and standardized with respect to their respective long-term mean. Lag-correlations analysis was used to estimate lag times between changes of climate variables and vegetation response at both seasonal and interannual bases. Results show increasing tendency of NDVI started from the 1990s coinciding the recovery of the rainfall from the 1980s drought, and the obtained correlation (r = 0.66) is statistically significant (p value < 0.01). The strongest responses of vegetation to rainfall and temperature fluctuations were found after 30 and 15 days, respectively. Moreover, at a shorter time lag (e.g., 15 days), more pronounced vegetation responses to both rainfall and temperature were found in agriculturally dominated land while at a longer time lag (e.g., 30 days), a stronger response was observed in Bare-dominated land. The vegetation response to the climate fluctuation is modulated by the land-use/cover dynamics.

The highly variable rainfall and recurring drought in dry sub‐humid and semi‐arid regions constitute a major socio‐economic problem that influences people's livelihoods. Agricultural drought is the most common of all drought types and is the most challenging to track and forecast owing to its ease of occurrence and impact on socio‐economic sustainability. In Nigeria as is the case in large parts of sub‐Saharan Africa, drought frequency, intensity and effect have dominated the literature since the great Sahelian drought of the late 1960s and early 1970s. This study proposes a simple drought monitoring and early warning (EW) methodology based on an experiment over Kano, Nigeria, hinged on an Intra‐seasonal Rainfall Monitoring Index (IRMI, Usman and Abdulkadir, 2012) determined for each pentad, using daily rainfall totals for a period of 30 years. The onset dates and drought intensity levels were used to define EW statements at three levels: advisory, alert and emergency. An experimental application of the scheme identified and detected late initiation conditions of real monsoon onset (RMO) in those seasons that eventually witnessed disastrous rainfall situations. Generally, the result reveals that the years between 1970 and 1990 over Kano, Nigeria, which ended as years of severe drought or worse, showed enough signals of poor rainfall distribution (deficient moisture) at the beginning for the scheme to have enabled a very high degree of forecast accuracy. It is concluded that strict monitoring of the rainfall regime especially during its onset phase is capable of revealing danger signals in the rainfall regime early enough to enable mitigation. Such mitigation is critical for the management of agricultural productivity in the predominantly rainfall‐dependent farming systems in the Sudan‐Sahel zone as confirmed by earlier studies.

Forests constitute a key component of the Earth system but the sustainability of the forest reserves in the semi-arid zone is a real concern since its vegetation is very sensitive to the climate fluctuation. The understanding of the mechanisms for the interaction vegetation-climate is poorly studied in the context of African Sahel. In this study, the characteristics of the vegetation response to the fluctuations of precipitation and temperature is determined for the forest reserve of Fina. Rainfall estimates, air temperature and NDVI are used to establish the lag correlations between fluctuations of vegetation and climate variables at both seasonal and interannual bases. Results shows increasing tendency of NDVI started from the 1990s coinciding the recovery of the rainfall from the 1980s drought and the obtained correlation(r=0.66) is statistically significant (pvalue<0.01). The strongest responses of vegetation to rainfall and temperature fluctuations were found after 30 and 15 days, respectively. Moreover, at shorter time lag (e.g. 15 days) more pronounced vegetation responses to both rainfall and temperature were found in agricultural dominated land while at longer time lag (e.g. 30 days) stronger response was observed in Bare dominated land. The vegetation response to the climate fluctuation is modulated by the land use/cover dynamics. Keywords: NDVI, Rainfall, Air temperature, vegetation response, Fina Forest Reserve, Mali.

Agricultural intensification has been adopted as a viable option for Poverty eradication and hunger, attainment of food security, socio-economic wellbeing as well as sustainable livelihood across the West Africa sub-humid and semi-arid zones. Thus, there is need to identify and address the challenges of sustainable livelihoods in the agriculture-intensive semi-arid and dry sub-humid zones of West Africa. This was addressed through review of relevant literature and analysis of environmental parameters from recent research by the authors to unveil the environmental uncertainties that threaten the sustainability of agriculture and human livelihoods across the ecologically fragile regions of West Africa, using pointers from Nigeria. The research identified the fundamental challenges, adaptation and mitigation approaches to environmental constraints, and requirements for reducing risk, enhance agricultural resilience as well as livelihoods in the zones. This was based on the premise that primarily, the use of adequate and accurately derived environmental information is crucial for increased agricultural productivity, sustainability of economic diversification and human livelihoods and by implication, enhanced regional and national security.