Department of Physical Geography and Ecosystem Science, Lund University, SE-223 62, Lund, Sweden.
Centre for Environmental and Climate Research, Lund University, SE-223 62, Lund, Sweden.
Sci Rep. 2020 Feb 25;10(1):3393. doi: 10.1038/s41598-020-59943-y.
The climate of West Africa is expected to become more arid due to increased temperature and uncertain rainfall regimes, while its population is expected to grow faster than the rest of the world. As such, increased demand for food will likely coincide with declines in agricultural production in a region where severe undernutrition already occurs. Here, we attempt to discriminate between the impacts of climate and other factors (e.g. land management/degradation) on crop production across West Africa using satellite remote sensing. We identify trends in the land surface phenology and climate of West African croplands between 2000 and 2018. Using the combination of a an attribution framework and residual trend anlaysis, we discriminate between climate and other impacts on crop productivity. The combined effect of rainfall, land surface temperature and solar radiation explains approximately 40% of the variation in cropland productivity over West Africa at the 95% significance level. The largest proportions of croplands with greening trends were observed in Mali, Niger and Burkina Faso, and the largest proportions with browning trends were in Nigeria, The Gambia and Benin. Climate was responsible for 52% of the greening trends and 25% of the browning trends. Within the other driving factors, changes in phenology explained 18% of the greening and 37% of the browning trends across the region, the use of inputs and irrigation explained 30% of the greening trends and land degradation 38% of the browning trends. These findings have implications for adaptation policies as we map out areas in need of improved land management practices and those where it has proven to be successful.
由于温度升高和降雨模式不确定，预计西非的气候将变得更加干燥，而其人口增长速度将超过世界其他地区。因此，在这个已经严重营养不良的地区，对粮食的需求增加可能与农业生产的下降同时发生。在这里，我们试图利用卫星遥感来区分气候和其他因素（例如土地管理/退化）对西非作物生产的影响。我们确定了 2000 年至 2018 年期间西非耕地地表物候和气候的趋势。我们使用归因框架和残差趋势分析的组合，区分气候和其他因素对作物生产力的影响。降雨、地表温度和太阳辐射的综合影响在 95%的置信水平上解释了西非耕地生产力变化的大约 40%。在马里、尼日尔和布基纳法索，绿色化趋势的耕地比例最大，而在尼日利亚、冈比亚和贝宁，棕色化趋势的耕地比例最大。气候是绿色化趋势的 52%和棕色化趋势的 25%的原因。在其他驱动因素中，物候变化解释了该地区 18%的绿色化趋势和 37%的棕色化趋势，投入和灌溉的使用解释了 30%的绿色化趋势，土地退化解释了 38%的棕色化趋势。这些发现对适应政策具有影响，因为我们需要确定需要改进土地管理实践的地区以及已经证明成功的地区。
