Electrical Survey Applications in Karstic Terrain (Resistivity & IP Survey); Cave Detection, Macro & Micro Rock Zonation for Rock Stability: A Case Study of Naisar Waterfall, Kashan, Iran

Naisar is a small village located ۲۳ km from the city of Kashan in Isfahan Province, Iran, and is famous due to the presence of a historical building known as Kooshk and a waterfall that attracts many national and international tourists. The rock present alongside the Naisar waterfall and below the historical building is highly karstified and unstable. The rock is a carbonate rock, mainly travertine, having intermixed impurities such as clay, sand, and gypsum, etc. It has undergone extensive weathering and erosion. It is assumed that the weathering and erosion of this host rock occur due to a dissolution process that takes place because of several factors, like changes in climate conditions and the continued exposure of the rock to underground water and waterfall water, making it more unstable day by day. The presence of highly karstic features, such as vugs, cracks, and caves, makes this area highly dangerous for both tourists and the residents of Naisar Village. In this study, a geophysical electrical resistivity survey was conducted to detect and characterize subsurface karst features in a highly karstified travertine formation located in an urban environment. The investigation aimed to identify the depth, geometry, and spatial distribution of karstic voids and weakened zones that pose potential risks to ground stability and urban infrastructure. Based on the interpretation of the resistivity data, the main karst features were delineated, and their geometrical characteristics were evaluated. Subsequently, macro‑ and micro‑zoning maps were developed to classify the study area according to the degree of karstification and relative stability. The results provide a practical framework for ground stability assessment and support decision‑making for urban planning, risk mitigation, and the design of appropriate stabilization and engineering measures in karst‑prone areas.

کلیدواژه ها:

Electrical Survey ، Karst ، Rock Zoning ، Naisar Waterfall ، Slope Studies