Monitoring drought in Ghana using TAMSAT-ALERT: a new decision support system
Monitoring drought in Ghana using TAMSAT-ALERT: a new decision support system
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DOI：
10.1002/wea.3033
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发表时间：
2017-07-01
期刊：
影响因子：
1.9
通讯作者：
Otu-Larbi, Fred
中科院分区：
文献类型：
--
作者：
Brown, Matt;Black, Emily;Otu-Larbi, Fred
非洲约有8.86亿人依靠农业作为主要生存手段。因此，他们很容易受到季节性降雨量年复一年变化的影响，这可能导致农业干旱。农业干旱是由土壤含水量低决定的。土壤湿度不仅取决于降雨量，还取决于许多其他因素，包括土壤特性，最重要的是，取决于过去的土壤湿度。在这里，我们展示了随着生长季节的演变，预测技能可以从土地表面的当前状态（土壤的湿润或干燥程度）中获得。这种技术来自于陆面记忆--特定时间的土壤湿度在很大程度上取决于历史土壤湿度。通过将观测数据的陆面模式强制到“现在”，然后将气候数据向前推（表示未来可能的条件范围）我们表明，在生长季节结束前几周，有可能发生农业干旱。这个系统说明了从操作试验的结果塔马利在北方加纳。
Approximately 886 million people in Africa rely on agriculture as their main means of survival. They are therefore susceptible to changes in seasonal rains from year to year that can result in agricultural drought. Agricultural drought is determined by low soil moisture content. Soil moisture responds to rainfall, but also depends on many other factors, including the soil characteristics and, crucially, on the past soil moisture.Here we demonstrate that predictive skill can be gained from knowledge of the current state of the land surface – how wet or dry the soil is – as the growing season evolves. This skill arises from the land surface memory – the soil moisture content at a particular time depends to a large extent on the historical soil moisture.By forcing a land surface model with observed data up to a ‘present day’ and then forward in time with climatological data (to represent the range of possible future conditions) we show that it is possible to be confident of an ensuing agricultural drought several weeks before the end of the growing season. This system is illustrated using results from an operational trial for Tamale in northern Ghana.