Detection and characterizacion of Colombian wetlands using Alos Palsar and MODIS imagery

Wetlands regulate the flow of water and play a key role in risk management of extreme flooding and drought. In Colombia, wetland conservation has been a priority for the government. However, there is an information gap neither an inventory nor a national baseline map exists. In this paper, we present a method that combines a wetlands thematic map with remote sensing derived data, and hydrometeorological stations data in order to characterize the Colombian wetlands. Following the adopted definition of wetlands, available spatial data on land forms, soils and vegetation was integrated in order to characterize spatially the occurrence of wetlands. This data was then complemented with remote sensing derived data from active and passive sensors. A flood frequency map derived from dense time series analysis of the ALOS PALSAR FBD /FBS data (2007-2010) at 50m resolution was used to analyse the recurrence of flooding. In this map, flooding under the canopy and open water classes could be mapped due to the capabilities of the L-band radar. In addition, MODIS NDVI profiles (2007-2012) were used to characterize temporally water mirrors and vegetation, founding different patterns at basin levels. Moreover, the Colombian main basins were analysed and typified based on hydroperiods, highlighting different hydrological regimes within each basin. The combination of thematic maps, SAR data, optical imagery and hydrological data provided information on the spatial and temporal dynamics of wetlands at regional scales. Our results provide the first validated baseline wetland map for Colombia, this way providing valuable information for ecosystem management

A Classification System for Colombian Wetlands: an Essential Step Forward in Open Environmental Policy-Making

Knowledge about the distribution and diversity of wetlands has become an essential tool for environmental management and policy-making. Yet, while recent estimates indicate that 27% of the area of Colombia is covered by wetlands and despite a number of regional studies, information about the diversity of wetlands nationally is scarce. In response, we present a national wetland classification system that is based on an ecological approach, from the perspective of wetland scientists, and which builds upon the assumptions underlying the flood pulse concept and hydrogeomorphic approach. Thus, the approach and structure of the Brazilian wetland classification system are used, with geomorphological adjustments made according to Colombia’s topography. The classification is hierarchical, multi-scale, functional, and organized according to four levels (system, macroregion, subsystem, and class), with the wetland diversity of Colombia represented nationally by 89 macrohabitats across marine-coastal, inland, and anthropogenic systems. The primary purpose of this classification is to provide integrated and organized information on the distribution and diversity of Colombian wetlands that will serve as a baseline for transparent environmental policy-making. © 2019, Society of Wetland Scientists