Historical landslides in Nicaragua—collection and analysis of data

The results of the first investigation on historical landslides that occurred in Nicaragua before 1990 are presented. The paper shows how the analysis of historical documents can provide important information about the type and the temporal and spatial distribution of landslide events, especially for countries where landslide investigation is a young discipline. The methodology included research of historical sources at national institutions, public libraries, international journals, the Internet, and the collection of original texts from newspapers and their transcription in analog format. Analysis and interpretation of the data was performed, followed up by the digitalization of landslide spatial locations using the software ArcGIS and the integration of the landslide attributes in a structured query language (SQL) server database. Finally, the analysis of the stored data was done using SQL interactive queries. The type and quality of the historical sources available are described. Limitations and problems, common in the preparation of any historical catalogue, and possible sources of error derived from the collection, interpretation, and storage of the data are discussed as well. One hundred thirty-five historical landslides were identified. The study shows that these events occurred mostly in combination with other natural phenomena. The collected data were used to construct a geo-referenced inventory of historical landslide events, including information about damage and human losses caused by them. The inventory provides the basis for a more comprehensive landslide hazard assessment in Nicaragua.[PUBLICATION ABSTRACT]