{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,14]],"date-time":"2026-07-14T18:50:13Z","timestamp":1784055013389,"version":"3.55.0"},"reference-count":108,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2024,9,18]],"date-time":"2024-09-18T00:00:00Z","timestamp":1726617600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Agropolis Foundation","award":["2001-032"],"award-info":[{"award-number":["2001-032"]}]},{"name":"Centre National d\u2019Etudes Spatiales (CNES)","award":["2001-032"],"award-info":[{"award-number":["2001-032"]}]},{"name":"IRD (Institut de Recherche pour le D\u00e9veloppement)","award":["2001-032"],"award-info":[{"award-number":["2001-032"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This study assesses the relative performance of Sentinel-1 and -2 and their combination with topographic information for plow agricultural land soil salinity mapping. A learning database made of 255 soil samples\u2019 electrical conductivity (EC) along with corresponding radar (R), optical (O), and topographic (T) information derived from Sentinel-2 (S2), Sentinel-1 (S1), and the SRTM digital elevation model, respectively, was used to train four machine learning models (Decision tree\u2014DT, Random Forest\u2014RF, Gradient Boosting\u2014GB, Extreme Gradient Boosting\u2014XGB). Each model was separately trained\/validated for four scenarios based on four combinations of R, O, and T (R, O, R+O, R+O+T), with and without feature selection. The Recursive Feature Elimination with k-fold cross validation (RFEcv 10-fold) and the Variance Inflation Factor (VIF) were used for the feature selection process to minimize multicollinearity by selecting the most relevant features. The most reliable salinity estimates are obtained for the R+O+T scenario, considering the feature selection process, with R2 of 0.73, 0.74, 0.75, and 0.76 for DT, GB, RF, and XGB, respectively. Conversely, models based on R information led to unreliable soil salinity estimates due to the saturation of the C-band signal in plowed lands.<\/jats:p>","DOI":"10.3390\/rs16183456","type":"journal-article","created":{"date-parts":[[2024,9,18]],"date-time":"2024-09-18T09:49:19Z","timestamp":1726652959000},"page":"3456","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Soil Salinity Mapping of Plowed Agriculture Lands Combining Radar Sentinel-1 and Optical Sentinel-2 with Topographic Data in Machine Learning Models"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-7148-4565","authenticated-orcid":false,"given":"Diego","family":"Tola","sequence":"first","affiliation":[{"name":"Programa de Doctorado en Recursos H\u00eddricos (PDRH), Universidad Nacional Agraria La Molina, Lima 15024, Peru"},{"name":"\u00c1rea de Ciencias Agr\u00edcolas, Pecuarias y Recursos Naturales (ACAPRN), Universidad P\u00fablica de El Alto, La Paz 10077, Bolivia"},{"name":"ESPACE-DEV, University Montpellier, IRD, University Antilles, University Guyane, University R\u00e9union, 34093 Montpellier, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fr\u00e9d\u00e9ric","family":"Satg\u00e9","sequence":"additional","affiliation":[{"name":"ESPACE-DEV, University Montpellier, IRD, University Antilles, University Guyane, University R\u00e9union, 34093 Montpellier, France"},{"name":"Instituto de Hidr\u00e1ulica e Hidrolog\u00eda (IHH), Universidad Mayor de San Andr\u00e9s, La Paz 10077, Bolivia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4025-6444","authenticated-orcid":false,"given":"Ramiro","family":"Pillco Zol\u00e1","sequence":"additional","affiliation":[{"name":"Instituto de Hidr\u00e1ulica e Hidrolog\u00eda (IHH), Universidad Mayor de San Andr\u00e9s, La Paz 10077, Bolivia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Humberto","family":"Sainz","sequence":"additional","affiliation":[{"name":"\u00c1rea de Ciencias Agr\u00edcolas, Pecuarias y Recursos Naturales (ACAPRN), Universidad P\u00fablica de El Alto, La Paz 10077, Bolivia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6537-0625","authenticated-orcid":false,"given":"Bruno","family":"Condori","sequence":"additional","affiliation":[{"name":"\u00c1rea de Ciencias Agr\u00edcolas, Pecuarias y Recursos Naturales (ACAPRN), Universidad P\u00fablica de El Alto, La Paz 10077, Bolivia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roberto","family":"Miranda","sequence":"additional","affiliation":[{"name":"Facultad de Agronom\u00eda, Universidad Mayor de San Andr\u00e9s, La Paz 10077, Bolivia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elizabeth","family":"Yujra","sequence":"additional","affiliation":[{"name":"Facultad de Agronom\u00eda, Universidad Mayor de San Andr\u00e9s, La Paz 10077, Bolivia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4324-5772","authenticated-orcid":false,"given":"Jorge","family":"Molina-Carpio","sequence":"additional","affiliation":[{"name":"Instituto de Hidr\u00e1ulica e Hidrolog\u00eda (IHH), Universidad Mayor de San Andr\u00e9s, La Paz 10077, Bolivia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8109-6010","authenticated-orcid":false,"given":"Renaud","family":"Hostache","sequence":"additional","affiliation":[{"name":"ESPACE-DEV, University Montpellier, IRD, University Antilles, University Guyane, University R\u00e9union, 34093 Montpellier, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1355-9060","authenticated-orcid":false,"given":"Ra\u00fal","family":"Espinoza-Villar","sequence":"additional","affiliation":[{"name":"Programa de Doctorado en Recursos H\u00eddricos (PDRH), Universidad Nacional Agraria La Molina, Lima 15024, Peru"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,18]]},"reference":[{"key":"ref_1","unstructured":"Omuto, C.T., Vargas, R.R., El Mobarak, A.M., Mohamed, N., Viatkin, K., and Yigini, Y. 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