Military-engineered floods as defense from the enemy: a brief review and case study from WWI in Northern Italy

During the First World War, after the Austrian-Hungarians broke through the Caporetto front in the fall of 1917, the Italian Army established new defense positions in the Veneto plain along the Piave River. Subsequently, in 1918 the Italian Command made contingency plans for another Austrian-Hungarian offensive that might overrun this new Piave River defensive line. These new plans were based on a southern line called the Mincio-Po line and were based on engineering-controlled breaks along the mighty Adige and Fratta-Gorzone rivers, thus, creating a massive anthropogenic flood stretching from the Adriatic Sea in the east to almost the city of Mantua in the west. Although a few large scale anthropogenic induced floods have been used as desperate war-time measures, these activities are rare. Little is known of these secret plans to inundate the Adige River floodplain and almost nothing is known of the resulting impact to the population, infrastructure, and agricultural landscape. In this research we used a geo-historical approach (GIS, historical cartography, aerial imagery) to model the location and extent of the planned flood. Using a dasymetric approach we modeled the population distribution during 1918 and estimated the displaced population, agricultural, roads, railroads, and poultry impacted.