One of the most important problems in geotechnical projects is how to predict unstable areas. There are several methods to hazard potential delineation, generally include direct and indirect methods. In general, for some geotechnical problems, the hazard potential can be expressed by the terms of "very high, high, moderate, low, and very low". The evaluation using these terms as a qualitative assessment, enables the preparation of susceptibility maps at low cost for purposes such as land-use planning or regional risk assessment. This paper presents the investigation results of liquefaction zonation in Lorestan Province. This zonation is based on Forth Technical Committee manual for zonation on seismic geotechnical hazards (TC4). Three grades of approach to zonation can be used related to scale of mapping: Grade 1 or general zonation which is based on compilation and interpretation of existing information available from historic documents, published reports and other available databases, mapping in the range 1:1000,000 to 1:50,000. Grade 2 or detailed zonation, mapping to scales of about 1:100,000 to 1: 10,000, based on improving the Grade 1 zonation maps at moderate cost by making use of additional data such as aerial photographs or additional field studies. Grade 3 or rigorous zonation, which is a very detailed level of zonation, mapping in scales of 1:25,000 to 1:5,000. In this paper, Lorestan Province Liquefaction Potential is evaluated bases on Grade 1 and Grade 2 methods and mapped in scale of 1:250,000. Results of this zonation shows that the potential of seismic hazsrds of alluviums in this region varies from low to high, related to soil structure, level of ground water and Soil density.

Liquefaction appears in saturation conditions in sandy to silty unconsolidated soils. When seismic loads of earthquakes stresses on suitable masses of soils for liquefaction, these soils tend to reduce their volumes, this leads to liquids trap inside the soil and water in pores pressure increases, so effective shear stress decreases inside the soil and liquefaction appears. This phenomenon during an earthquake can lead to geomorphic changes on the surface of the earth and causes damages on human foundations. Recognizing and zonation of suitable areas for liquefaction alongside by determining risk potential areas can help us to reduce damages during an earthquake. In this research, by using IRS remotely sensed data and overlying digitized layers of geologic and seismic areas, underground water table level, and geomorphologic landform characteristics, a liquefaction zoning map were produced for Silakhor plain west of Iran which shows 7 class of potential risk areas. Based on this map, 7 percent of study area located on very high level risk of liquefaction, 21 percent on risk class 5, 5 percent on risk class 4, 4 percent on risk class 3, 5 percent on risk class 2, 30 percent on risk class 1 and 28 percent on class zero.

Physical expansion of cities, particularly those that have experienced unusual growth due to economic, social, and political transformations, has led to numerous problems. To this end, the purpose of this study was to investigate conditions of Birjand City regarding flooding and hazard zoning caused by this important natural event. The present study is applied regarding the objective and descriptive-analytic considering its methodology. The study was descriptive-analytic and performed through prediction of the scope of damages caused by floods and based on hazard zoning. Data gathered regarding land use, population density, features of existing watercourses, slope, residential and population density, CN coefficient, runoff, the age of buildings, open spaces, and other influencing components. Collected data were weighed after correction and conversion, and required maps were prepared after conducting paired comparisons and determination of eventual coefficients for each layer. AHP model and associated software, particularly Expert Choice, and ArcGIS, were used to determine final weights and coefficients. According to the results, given that development of Birjand City has been done on the sub-basin of the existing watercourse, all the city is exposed to the risk of flooding. However, southern and southeastern zones with almost 20% of the city area are subject to high and very high risk; northwestern and southeastern with 50% of the area are subject to average risk; and other zones of the city with less than 30% of area are subject to low and very low risk. As a result, the operation of flood control and flood warning systems in areas with greater vulnerability should be considered, while illegal occupation of flooding basins and watercourses should be dealt with.

The geological position and faults of Iran have caused earthquakes in the country throughout history. Assessing the seismic hazard of Tehran as the capital and its suburbs due to direct impact on the city of Tehran is very important from the viewpoint of earthquakes and the risks and possible damage caused by possible earthquakes to rehabilitate the more dangerous and vulnerable areas, as well as the creation of suitable facilities for the time of crisis. . . The hashtgerd range has high seismic activity due to its geographic proximity to Tehran. This is due to the construction of Hashtgerd new town, which has caused the extraordinary increase of human and urban densities in recent years to reduce the need of the region for more accurate and more rigorous surveying of seismicity. Risks make it special. In this research, using the conventional method of probabilistic seismic hazard analysis, the study area is located at 250 km radius of seismic studies and the estimated seismic riskiness of the area was estimated by analyzing the results. According to the study, the north and east of the region have higher fault densities. Also, according to the iso-acceleration map for a return period of 475 years, the maximum values are in the northern and northeastern strips as discrete zones and also in the southwest of Hashtgerd city in Najmabad area. The southern margin of the Alborz province generally has relatively less accelerated areas. The Hashtgerd city in the high danger zone ranges from 0. 38 g to 46 g. Also, the map for the return period of 2475 years indicates that the maximum values are in the south of Hashtgerd, and Hashtgerd is in the range with an acceleration range greater than 0. 68-0. 85g.

Today, the resiliency of the human centers, especially urban centersagainst the natural hazards such as earthquakes, is one of the mainchallenges in the targeted management of urban. One of the effectivestrategies in the control, containment and prevention of risks fromearthquakes is zoning of urban areas in terms of vulnerability. In thisregard, the purpose of this study was to determine the zoning andseismic active zones in the urban area of Urmia city. The seismic – tectonic situation and recorded seismic data surveyed in the currentstudy. Findings showed that there were seismic active zones in theUremia city area. The seismic effects and geo-tectonic resultsVerified, so the results marked that local geology condition would beeffective in earth motion. This research investigated the local geologyfeatures especially fault, geo units and seismic data in zoning ofseismic risk. Many methods are proposed by different researchers. Inthis study the SABTA (1987) method has been used for estimatingseismic risk by using most important parameters such as seismic, faultand geology data. The obtained results showed that the P. G. A measurevariation was from 0. 035 to 0. 33 which indicated the existence ofseismic activity in the study area.