Hydro-climatic changes in the Niger basin and consistency of local perceptions

Abstract

Since the 1970s, the Niger basin has been characterized by hydro-climatic changes which have significant impacts on local populations. These changes are not well documented as a result of a decreasing observation network for hydro-climatic data. Indigenous peoples' knowledge has increasingly been considered an important component in addressing these data gaps. We evaluated the consistency of indigenous perceptions and adaptive responses with rainfall and river discharge observations in the Niger basin. Socioeconomic data were collected from 239 households in 30 communities across two settlements in the Niger basin. Data on historical rainfall and river discharge from 1950 to 2010 were analyzed and the consistency with local perceptions was assessed. Generally, there was a high agreement between observations and perceptions, but impacts of climate change in the communities were dependent on social and environmental factors that can introduce differences in perception despite identical observations. Indigenous perceptions gave good indication of the most vulnerable sectors as well as communities who also displayed the greatest willingness to combat climate change. These results suggest that integration of indigenous perceptions into climate change science, especially in data scarce regions, is highly valuable.

Farmers’ Responses to Changing Hydrological Trends in the Niger Basin Parts of Benin

“…In the dry season, a Sahelian northeast trade wind, which brings cool and dry conditions, covers the whole basin. The highest temperatures of about 46 • C are experienced from March to April, while the lowest temperatures (about 16 • C) are observed in December and January, with an annual temperature mean of about 28 • C [8]. Precipitation amounts show wide variations from one year to another, as well as within the year.…”

“…Precipitation is very variable spatially and temporarily in the basin. The river dried up for several weeks at Malanville Hydrological Station (Figure 1) in 1985 as a result of low rainfall and runoff in 1984 [8,15]. Annual precipitation is concentrated in a single season from the middle of April to October.…”

“…Precipitation amounts show wide variations from one year to another, as well as within the year. Apart from the variability of the annual and seasonal rainfalls, the extremes of precipitation result in floods and droughts at different times and sometimes within the same year [8]. Table 1 and Figure 1 present the location of meteorological and hydrological stations.…”

“…The study of Aich et al [7] emphasized the danger of increasing catastrophic floods in some catchments of the Niger River Basin. This will aggravate the challenges of reported floods on rural farmers at the peak of the rainy season in the Niger Basin parts of Benin [8].The evidence of current and future flooding reported in the Niger Basin in Benin [7][8][9] readdresses the need for the development of sustainable coping strategies for changing hydrological trends.…”

Detecting Changes in Hydro-Climatic Variables during the Last Four Decades (1975-2014) on Downstream Kaduna River Catchment, Nigeria

“…In fact, temperature, evapo-transpiration and rainfall changes mainly influence the distribution of river flows and groundwater recharge [8]. With respect to climate variability and change impact on water resources, recent detected decreasing trend in water resources will continue in the future due to warming and rainfall declines [9] and a decrease in runoff is expected for 2050 [10].…”