UAV-Based Mapping of Banana Land Area for Village-Level Decision-Support in Rwanda

Crop monitoring is crucial to understand crop production changes, agronomic practice decision-support, pests/diseases mitigation, and developing climate change adaptation strategies. Banana, an important staple food and cash crop in East Africa, is threatened by Banana Xanthomonas Wilt (BXW) disease. Yet, there is no up-to-date information about the spatial distribution and extent of banana lands, especially in Rwanda, where banana plays a key role in food security and livelihood. Therefore, delineation of banana-cultivated lands is important to prioritize resource allocation for optimal productivity. We mapped the spatial extent of smallholder banana farmlands by acquiring and processing high-resolution (25 cm/px) multispectral unmanned aerial vehicles (UAV) imageries, across four villages in Rwanda. Georeferenced ground-truth data on different land cover classes were combined with reflectance data and vegetation indices (NDVI, GNDVI, and EVI2) and compared using pixel-based supervised multi-classifiers (support vector models-SVM, classification and regression trees-CART, and random forest–RF), based on varying ground-truth data richness. Results show that RF consistently outperformed other classifiers regardless of data richness, with overall accuracy above 95%, producer’s/user’s accuracies above 92%, and kappa coefficient above 0.94. Estimated banana farmland areal coverage provides concrete baseline for extension-delivery efforts in terms of targeting banana farmers relative to their scale of production, and highlights opportunity to combine UAV-derived data with machine-learning methods for rapid landcover classification.

Reducing Underreporting by Aggregating Budgeted Time

ABSTRACT Underreporting, or reporting fewer hours than actually worked, is a prevalent behavior among auditors at all levels. Underreporting can result in negative consequences, such as tight budgets and reductions in future audit quality. In this paper, I propose a low-cost budget formatting procedure that reduces underreporting. Using an experiment, I document that individuals with higher underreporting incentives underreport less when given an aggregated budget relative to a disaggregated budget. When individuals have lower underreporting incentives, aggregating the budget has a smaller effect on underreporting. I also provide evidence of the process by performing a mediation analysis. In a second experiment, I examine a budget formatting procedure that reduces underreporting while also mitigating the loss of data richness that results from aggregation. This study provides important insights to audit firms, partners, managers, and regulators who rely on audit hours for budgets, measures of staff efficiency, and measures of audit quality.