Search

Climate variability and change greatly affect agricultural and water resource management over West Africa. This paper presents the current characteristics and projected change in regional crop water demand (CWD), irrigation requirement (IR), and water availability (WA) over West Africa. Observed and simulated daily rainfall, minimum temperature, maximum temperature, and evapotranspiration are used to derive the above agro-meteorological and hydrological variables. For future periods, high-resolution climate data from three regional climate models under two different scenarios, i.e., representative concentration pathway (RCP) 4.5 and 8.5, are considered. Evaluation of the characteristics of present-day CWD, IR, and WA indicated that the ensemble mean of the model-derived outputs reproduced the prevailing spatial patterns of CWD and IR. Moreover, the wetter part of the domain, especially along the southern coast, was correctly delineated from the drier northern regions, despite having biases. The ensemble model also simulated the annual cycle of water supply and the bimodal pattern of the water demand curves correctly. In terms of future projections, the outcomes from the study suggest an average increase in the CWD by up to 0.808 mm/day and IR by 1.244 mm/day towards the end of the twenty-first century, compared to the baseline period. The hot-spot areas, where there is higher projected increment in CWD and IR, are over Senegal, Southern Mali, and Western Burkina Faso. In most cases, WA is projected to decrease towards the end of the twenty-first century by −0.418 mm/day. The largest decline in WA is found to be over Guinea and most of the eastern parts of West Africa. Despite the current under-utilization of the existing groundwater resources, the threat of global warming in reducing future WA and increasing CWD suggested caution on the scale of irrigation schemes and management strategies. The outcomes from the study could be a crucial input for the agricultural and water managers for introducing effective measures to ensure sustainability of irrigated farm lands. [ABSTRACT FROM AUTHOR]

• Low and narrow level of adoption. Most of farmers not implementing technologies. • Farmer's, farm, and water community characteristics affect irrigation adoption. • Relative abundance of the resource discourages the adoption of technologies. • Irrigating the whole farm produces the largest negative effect on adoption. This paper examines the adoption of irrigation technologies and the underlying diversity in terms of intensity of adoption in 2 irrigated valleys in Central Chile. Results show a low and narrow range of adoption, with only 30 % of farmers adopting technologies. Through a Latent Class Analysis, 2 types of farmers were identified, a small group comprising moderate to intensive users, and a second one consisting of the majority of farmers mostly constrained in natural capital. Furthermore, the econometric analysis indicates that education, diversification, continuous access to water, and perception of water reliability increase the adoption. Conversely, higher water-land ratios, presence of community reservoirs, and earthen canals reduce the uptake. Overall, the dominance of fruit and horticulture production, access to agricultural credits, and full irrigation of the farm are the main drivers of adoption. The latter is a critical factor, indicating a relative abundance of water resources, which, alongside contextual characteristics, discourages farmers from implementing technologies. The low adoption rate, as well as the hindering factors, will challenge public and private organizations to design and implement policies aiming to improve water reliability and management. To generate incentives and increase awareness on the scarcity of the resource in the light of the predicted reductions in water availability because of climate change will be crucial as well. [ABSTRACT FROM AUTHOR]