ORIGINAL ARTICLE Evaluation of intrinsic vulnerability, hazard and risk mapping for karst aquifers, Khorein aquifer, Kermanshah province: a case study Mojgan Entezari 1 • Mojtaba Yamani 2 • Maryam Jafari Aghdam 1 Received: 14 April 2015 / Accepted: 5 November 2015 / Published online: 24 February 2016 Ó Springer-Verlag Berlin Heidelberg 2016 Abstract The Khorein karstic aquifer in the Kermanshah province (western Iran) plays a vital role in providing drinking and agricultural water for its surrounding com- munities. The aim of this research is to evaluate natural vulnerability, hazard and risk indices of the Khorein aquifer by cost action 620 proposed models, as well as to prioritize the aquifer surface concerning to protection measures and providing management strategies in order to its better protection. The results of the COP method rep- resent the high natural vulnerability of the region. Calcu- lation of the hazard index show that the military regions, telecom sites, the nomads’ habitation areas and quarries are situated in areas with low hazard index. Evaluation of the risk index and predict the aquifer contamination show that 75 % of the region extent is no or very low contamination risk, which this is due to low development of human activities in the top of the mass. This claim is confirmed by the presence of Escherichia coli bacteria in the aquifer water. The expansion of human activities in future toward the altitudes, can lead to further pollution of the aquifer. Continuous monitoring of the chemical characteristics of water, taking the recharge map, characterizing the areas with concentrated charge, determining the karstic landform limits, restricting the livestock activities on the anticline top, avoiding the construction activities close to the aquifer and improving the people and authorities public awareness level are the main necessary measures pertaining to man- age the Khorein aquifer. Keywords Intrinsic vulnerability  Hazard index  Risk index  COP method  Khorein aquifer Introduction Need to supplying the water to meet the needs of human societies and natural ecosystems is increasingly recognized globally (Gondwe et al. 2011). Karstic water resources are important water resources because they provide water for human consumption; so that, according to Ford and Wil- liams (2007), water requirements of *25 % of the world population supply from karstic waters. Karstic aquifers due to their hydrological characteristics are distinguished from the other aquifers (Ford and Williams 2007; Mudarra and Andreo 2011) and show a high sensitivity to contamination propagation. In karstic aquifers due to low storage capacity and fast water movement, interference of natural processes such as absorption, degradation and filtration has a little effect (Mudarra and Andreo 2011); thus the possibility of contamination propagation is high in such aquifers. Mila- novic´(2004) believes that one of the crucial problems pertaining to the regional planning and development in Karstic region is the Karstic aquifer protection. Protection of karst water resources is among the most important measures for karstic water resources management (Afrasiabian 2007). Over the past two decades, assessment of karstic water resources protection has become one of the main priority in many countries (Paul Novel et al. 2007). & Mojgan Entezari m.entezari@geo.ui.ac.ir Mojtaba Yamani myamani@ut.ac.ir Maryam Jafari Aghdam m.jafari.geo@gmail.com 1 Faculty of Geography, University of Isfahan, Hezar Jarib Boulevard, Isfahan, Iran 2 Faculty of Geography, University of Tehran, Enghelab Avenue, Tehran, Iran 123 Environ Earth Sci (2016) 75:435 DOI 10.1007/s12665-016-5258-5