Geological risk assessment and mapping often require some data that are not easily available in developing countries. The goal of this work was to estimate geological zoning and related hazard, due to slope stability mostly for landsliding phenomena. The procedure was adopted in four key areas located in the northeastern part of Iraq (Duhok Governorate) along the Zagros Fold-thrust belt. From a geomorphologic point of view all the villages are located on the flanks of steep anticlines where slope deposits and large alluvial fans cover the foot slope. Field survey, improved with remote sensing imageries analysis, and Digital Elevation Model comparison are the methods integrated in the study. Once the geological setting and the geomorphological features and processes are mapped, the hazard classification of the territory is performed. The classification divides the areas in five hazard categories from low (zone 5) to very high (zone 2 and 1). Quaternary deposits (alluvial fan, slope and eluvial-colluvial deposits, are grouped in zone 5 if the slope angle is smaller than 20% and in zone 4 (moderate) for values larger than 20%. In these categories only the geomechanical properties of the terrains are taken into account for the potential hazard involving civil constructions and the infrastructures. Zone 3 (high hazard) is subjected to slope washing phenomena as gully erosion. The last two zones (2 and 1) are characterized by a very high hazard degree. Differences are in the kinematic of landslide phenomena are observed, with rock-falls in zone 2 and slides and debris flows in zone 1. For each the study area three maps are produced: a geological, a geomorphological and a hazard map, all in the 1:10000 scale map. The test areas correspond to the towns of Bamerne, Zawita, Ba’adrie and Al-Shikhan going from north to south. All the five hazard categories are present. The results of this study are at the basis of the master plans required from the local government in order to better design the development strategies for the cities. This approach may be a promising methodology for urban planning in developing countries since it only takes into account terrain attributes (slope) and the nature of the substrate (dividing the geological nature of the terrains only in bedrock and deposits).
Geotechnical Zoning for Urban Planning in Developing Countries (Duhok Governatorate, Iraq)
MELELLI, Laura
;
2017
Abstract
Geological risk assessment and mapping often require some data that are not easily available in developing countries. The goal of this work was to estimate geological zoning and related hazard, due to slope stability mostly for landsliding phenomena. The procedure was adopted in four key areas located in the northeastern part of Iraq (Duhok Governorate) along the Zagros Fold-thrust belt. From a geomorphologic point of view all the villages are located on the flanks of steep anticlines where slope deposits and large alluvial fans cover the foot slope. Field survey, improved with remote sensing imageries analysis, and Digital Elevation Model comparison are the methods integrated in the study. Once the geological setting and the geomorphological features and processes are mapped, the hazard classification of the territory is performed. The classification divides the areas in five hazard categories from low (zone 5) to very high (zone 2 and 1). Quaternary deposits (alluvial fan, slope and eluvial-colluvial deposits, are grouped in zone 5 if the slope angle is smaller than 20% and in zone 4 (moderate) for values larger than 20%. In these categories only the geomechanical properties of the terrains are taken into account for the potential hazard involving civil constructions and the infrastructures. Zone 3 (high hazard) is subjected to slope washing phenomena as gully erosion. The last two zones (2 and 1) are characterized by a very high hazard degree. Differences are in the kinematic of landslide phenomena are observed, with rock-falls in zone 2 and slides and debris flows in zone 1. For each the study area three maps are produced: a geological, a geomorphological and a hazard map, all in the 1:10000 scale map. The test areas correspond to the towns of Bamerne, Zawita, Ba’adrie and Al-Shikhan going from north to south. All the five hazard categories are present. The results of this study are at the basis of the master plans required from the local government in order to better design the development strategies for the cities. This approach may be a promising methodology for urban planning in developing countries since it only takes into account terrain attributes (slope) and the nature of the substrate (dividing the geological nature of the terrains only in bedrock and deposits).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.