Urban Seismic Risk: "Impacts on Land Use Planning In Nablus City, Palestine"

The historical and instrumental earthquake studies in Palestine demonstrate that damaging earthquakes, mainly along the Jordan-Dead Sea fault, have caused in several cases severe devastation and many hundreds and sometimes thousands of fatal casualties. Therefore, it is of prime importance to search for seismic risk mitigation in the Palestinian urban areas. Land-use planning represents an attempt to reduce the number of conflicts and adverse environmental impacts in relation to both society and nature. It involves, in the first instance, the collection and evaluation of relevant data from which plans can be formulated. The aim of this work is the estimation of local site effects caused by the geological conditions and the evaluation of their influence on seismic ground motion. We divided this work into steps. In the first step, the H/V spectral ratio techniques were used to estimate empirically the site response function. Nablus area was analyzed using ambient vibration records from 17 sites over a ten-month period. In the second step, all available data for the Nablus area were collected and interpreted. In the third step the points where chosen and the data acquisition were made. The results show site–dependent variations in spectral amplitude, dominant frequency and amplification level. The study recommended that microtremor measurements should be done in detail for Nablus area, as well as adding an element of influence soil and the quality of the future master plans of the Nablus city, in particular, and most Palestinian cities in general. It has indicated that there is a negative relationship with the local geology, and the presence of site effect appears obviously in the study area (especially in the Valley part). Finally, the study stressed the need for a national policy for land usage that included avoiding building on landslide in the mountainous areas, having high control in construction, Number of stories, structure and use. The study aimed to help planners, decision makers and risk managers in Palestine to better understanding of the seismic risk in urban areas in order to reach a higher level of preparedness.