The growth and evolution of sinkholes are a considerable proportion of the damage related to subsidence disaster in alluvial areas after ground water extraction for irrigation. In this research it was tried to study the evolution of the sinkholes from the birth point to the stabilization or final step. In the Eqlid-Abarkooh alluvial fan was selected an area about 300 km2 with giant sinkholes where consist; the city of Abarkooh, arable irrigated lands and desert rangelands. The major aspect on the study area was southwest to northeast where it ended to Abarkooh playa. For investigating the formation and evolution of these sinkholes in the study area, field observation for 2 years were done. Soil samples were taken from surface soils (0-25 cm) near and far of the sinkholes. Moreover, 4 soil samples were obtained from the deepest sinkhole as control sample in the study area. Chemical, physical and mechanical soil analyses were performed. Finally, the Ground Penetrating Radar (GPR) method were done for detection subsurface holes to depth of 4 m around the sinkholes. The chemical soil properties results include Electro Conductivity (EC) and the ratio of Ca2+/Mg2+ in lime which was important factors to formation of sinkholes changed from 2.05 to 19.3 dS/m, 0.15 to 6 respectively. The mechanical soil parameters such as Coefficient of Linear Extensibility (COLE) and Plasticity Index (PI) changed from 0.05 to 1.67, 0.99% to 15% respectively. According to sinkhole development, the results obtained that there was a relationship between diameter of sinkhole obtained from 0.6 to 15 m and groundwater extraction quantity changed from 0.18 to 18.14 m3/ha over 25 years. The groundwater level dropped 15 m and sinkhole volume variation obtained 0.014 to 2650 m3 over 25 years. Field discovery and google earth images showed that sinkholes were developed in 3 phases as (1) growth phase (2) mature and (3) steady phases up to about 25 years. The GPR results found some land breaks and a hole underground in the activation and growth phase of sinkhole evolution. Finally, according to some soil parameters and GPR results, the sinkhole hazard map was created in the study area.
