Dry season forage assessment across senegalese rangelands using earth observation data

Autor: Lo, Adama, Diouf, Abdoul, Diedhiou, Ibrahima, Bassène, Cyrille, Leroux, Louise, Tagesson, Torbern, Fensholt, Rasmus, Hiernaux, Pierre, Mottet, Anne, Taugourdeau, Simon, Ngom, Daouda, Touré, Ibra, Ndao, Babacar, Sarr, Mamadou
Přispěvatelé: Centre de Suivi Ecologique [Dakar] (CSE), Environnement, Santé, Sociétés (ESS), Centre National de la Recherche Scientifique (CNRS), Université de Thiès, Département Performances des systèmes de production et de transformation tropicaux (Cirad-PERSYST), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Agroécologie et Intensification Durables des cultures annuelles (UPR AIDA), Lund University [Lund], University of Copenhagen = Københavns Universitet (UCPH), Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), FAO Animal Production and Health Division (FAO), Food and Agriculture Organization of the United Nations [Rome, Italie] (FAO), Département Environnements et Sociétés (Cirad-ES), Systèmes d'élevage méditerranéens et tropicaux (UMR SELMET), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD), 'Carbon sequestration and greenhouse gas emissions in (agro) silvopastoral ecosystems in the Sahelian CILSS states' (CaSSECS) project - European Union under the 'Development Smart Innovation through Research in Agriculture' (DeSIRA) Initiative FOOD/2019/410-169, Swedish National Space Agency SNSA 2021-00144 - 2021-00111, Swedish Research Council Formas Dnr. 2021-00644
Rok vydání: 2022
Předmět:
Zdroj: Frontiers in Environmental Science
Lo, A, Diouf, A A, Diedhiou, I, Bassène, C D E, Leroux, L, Tagesson, T, Fensholt, R, Hiernaux, P, Mottet, A, Taugourdeau, S, Ngom, D, Touré, I, Ndao, B & Sarr, M A 2022, ' Dry season forage assessment across senegalese rangelands using earth observation data ', Frontiers in Environmental Science, vol. 10, 931299 . https://doi.org/10.3389/fenvs.2022.931299
Frontiers in Environmental Science, 2022, 10, 15p. ⟨10.3389/fenvs.2022.931299⟩
ISSN: 2296-665X
Popis: Strengthening of feed security in the Sahel is urgently needed given the climate change and growing human population. A prerequisite to this is sustainable use of rangeland forage resources for livestock. Many studies have focused on the assessment of rangeland resources during the rainy season, while only a few have focused on the dry season which is the longest and most demanding period for livestock in Sahelian rangelands. The objective of this study is to develop remote sensing-based models for estimating dry season forage vegetation mass. To that end, 29 vegetation indices calculated from each of the MODIS-MCD43A4 (500 m), Landsat-8 (30 m), and Sentinel-2 (10 m) satellite products were used and tested against in situ data collected during three field-measurement campaigns in 2021 at eleven monitoring sites across Senegalese rangelands. Four statistical models were tested, namely, random forest, gradient boosting machines, and simple linear and multiple linear regressions. The two main vegetation mass variables modeled from remote sensing imagery were the standing herbaceous and litter dry mass (BH) and total forage dry mass (BT) with a dry mass of woody plant leaves added to BH. Overall, Sentinel-2 data provided the best performance for the assessment of BH with multiple linear regression (R2 = 0.74; RMSE = 378 kg DM/ha) using NDI5 (Normalized Difference Index5), GRCI (Green Residue Cover Index), SRI (Simple Ratio Index), TCARI (Transformed Chlorophyll Absorption in Reflectance Index), and DFI (Dead Fuel Index) indices. For BT, the best model was also obtained from Sentinel-2 data, including RVI3 (Ratio Vegetation Index3) (R2 = 0.78; RMSE = 496 kg DM/ha). Results showed the suitability of combining the red, green, blue, NIR, SWIR1, and SWIR2 bands in monitoring forage availability during the dry season. Our study revealed that the spectral richness of the optical sensor systems Sentinel-2, Landsat-8, and MODIS-MCD43A4 allowed for accurate assessments of dry-season forage mass of semi-arid rangelands. Adding to this, the high spatial and temporal resolution of Sentinel-2 satellite imagery makes this a promising data source for timely monitoring. These findings can support the monitoring of the animal feed balance in Sahelian countries and contribute to enhancing the resilience of pastoralism toward feed shortage through early warning systems.
Databáze: OpenAIRE
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