Mapping smallholder cashew plantations to inform sustainable tree crop expansion in Benin

作者：Leikun Yin, Rahul Ghosh, Chenxi Lin, David Hale, Christoph Weigl, James Obarowski, Junxiong Zhou, J. L. Till, Xiaowei Jia, Nanshan You, Troy Mao, Vipin Kumar, Zhenong Jin · 发表于：Remote Sensing of Environment · 年份：2023 · DOI：10.1016/j.rse.2023.113695 · 被引用次数：43 · 研究领域：Land Use and Ecosystem Services、Remote Sensing in Agriculture

Cashews are grown by over 3 million smallholder farmers in >40 countries worldwide as a principal source of income. Expanding the area of cashew plantations and increasing productivity are critical to improving the livelihood of many smallholder communities. As the third largest cashew producer in Africa, Benin has nearly 200,000 smallholder cashew growers contributing 15% of the country's national export earnings. Expansion of the cashew industry is thus an essential economic driver and a governmental priority in Benin. However, a lack of information on where and how cashew trees grow across the country hinders decision-making that could support increased cashew production and poverty alleviation. By leveraging 2.4-m Planet Basemaps and 0.5-m aerial imagery, two newly developed deep learning algorithms, and large-scale ground truth datasets, we successfully produced the first-of-its-kind national map of cashew in Benin and characterized the expansion of cashew plantations between 2015 and 2021. In particular, we developed a SpatioTemporal Classification with Attention (STCA) model to map the distribution of cashew plantations with 2.4-m multi-temporal Planet Basemaps from 2019 to 2021, which can fully capture texture information from discriminative time steps during a growing season. The U-Net model was employed to map the distribution of cashew plantation with 0.5-m mono-temporal aerial imagery in 2015, which can achieve accurate and fast predictions even with limited train...