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Costa Rica has approximately 1 500 km of coastline, with wetlands that offer a wide variety of ecosystem services, including coastal protection. The quantification of this service requires research in these wetlands, and for this, it is necessary to gather them in an inventory that includes their localization and basic characteristics. This type of inventory does not exist specifically for coastal wetlands in Costa Rica. Thus, the objective of this research is to create the first version of an inventory of wetlands that offers coastal protection in the country. The National Wetland Inventory (INH), and a 2005 mangrove cartography were used as the starting point. The coastal wetlands that were not included in these two sources were identified with a semiautomatic procedure, based on the analysis of vegetation indexes derived from a Sentinel 2 satellite image, and a manual delimitation using an orthophoto of 2017. The new inventory includes 464 coastal wetlands, from which 180 are not included in the INH. These new areas were characterized with the same information included in the INH to assure the compatibility between both databases. In addition, all 464 wetlands were characterized with some of the natural and anthropic conditions that might affect future research related to coastal protection. The result is a free access geographic database that includes the localization and general characteristics of the Costa Rican wetlands that offer coastal protection and could be used in future research not only in this topic, but in coastal studies in general. [ABSTRACT FROM AUTHOR]

Hydrothermal alteration was analyzed in the active Turrialba Volcano, Central Volcanic Range, Costa Rica. Principal component analysis (PCA) techniques were applied to Thematic Mapper (1986 and 2001) and MODIS/ ASTER airborne imagery (2003). Analyses were carried out using 4 input bands in PCA transformations to detect clays and iron oxides. The technique was adapted to MASTER sensor, selecting relevant bands for mineral detection. Argillic and limonitic zones were mapped for 1986, 2001 and 2003 images. Image analysis results are consistent with volcanic activity from 1986 to 2003. Graben area was characterized by an overlap of alterations (limonitic and argillized) along an N-S alignment. Multitemporal analysis showed enlargement of alteration area in Central and Southwestern craters. Reactivation of phreatic activity since 2010 developed in the same areas where increasing alteration was detected, thus validating results. This research contributes to the establishment of monitoring systems in volcanic areas based on remote sensing. [ABSTRACT FROM AUTHOR]