JOURNAL OF NATURAL ENVIRONMENT HAZARDS
Year:2017 | Volume:5 | Issue:10|Papers Count:7

Earth's climate during the twentieth century, especially the past two decades, lost his balance and is more inclined to increase the temperature. This can cause hydrological anomalies, and problems in the agricultural sector will evaporate faster. In the present study, the occurrence of heat waves with different continuity in Kermanshah province with use Markov Chain and long-term statistics of daily maximum temperature is the 20- year period (1372-1391) has been performed. Statistical data daily maximum temperature for six synoptic stations in at least 20 years of continuous daily statistics was selected. And with an index on the statistical data of all stations, the maximum temperatures that were higher than the index, as the heat wave were introduced.After extracting the data from each station were divided into two categories: short-wave and long-term. They will then review process using Markov chain from identifying and duration of heat waves was analysed back.Results obtained showed that the heat wave occurred in Kermanshah province in July and August most of the incremental change in this period has. It is becoming more established, especially in 1380 reached its highest level. Finally, the estimated incidence of 1 to 9 days of heat waves the study was performed in plants.

Drought is a natural disaster, which its intensity and frequency of occurrence and the affected area and the amount of damage, is more important than other natural disasters. In this study, successive periods of meteorological and hydrological drought were investigated using SPI and SDI index in Sufi Chai and Mordagh Chai basins in the Southeast of Urmia Lake, and the time delay between the two occurrences was identified.Therefore, 10 rain gauges and 7 hydrometric station data was used. Range and area droughts in ArcGIS media were plotted according to the mean-square error minimum using methods of the kriging and IDW and also droughts trend was investigated by classic Mann-Kendall and modified Mann–Kendall droughts methods. The results showed that the occurrence of the two periods of severe and long-term meteorological drought has led to the simultaneous occurrence of hydrological drought in the basins. There is a significant correlation at 99% level between meteorological and hydrological droughts which is stronger for simultaneous occurrence and one month lag time. According to drought zoning maps, the Northwest region has more potential in the terms of frequency and severity of meteorological drought occurrence which is important in the water resources management.

As an indicator of the intensity of the heat temperature air is a basic element of understanding and view of the solar energy received by the Earth's irregular changes included extensive. Ice cold waves and one of the most important phenomena in Climatology is the study of daily temperature changes over time arises. The aim of this study was to analyze the spatial variability of core cooling in the North West of Iran during the various waves.For this purpose minimum temperature data and climatology station, 42 were the highest during the period of the country's Meteorological Agency. The day was considered as a cold wave that has a standard score equal to or less than 2 / -1. In accordance with this definition programming using MATLAB software environment days with cold wave extraction and analysis of spatial autocorrelation, Moran was studied and analyzed. The results of this study indicate that although core cooling waves of distributed heterogeneous spatial distribution have been but the major focus of this core cluster pattern in the eastern part of the study area is high. The results of the analysis showed that in the course of recent decades addition to the marked decline in the range of core cooling, The intensity of cooling cores for different durations, especially the continuation of five and six days has been reduced.

Forests as one of the important renewable natural resource play a vital role in maintaining the continuity of life and stability of ecosystems. Fires in forests and pastures destroy a vast part of the natural resources. Every year some of the forests in our country are destroyed in fire due to human negligence or natural causes. This study aimed to identify and analyze the most important factors affecting the fire control management at forests because the Golestan forest has had the most cases of fire and needs proper and effective fire control management. The research is descriptive-analytical. Data were collected using documentary and field methods and Swot model was used to determine the strengths, weaknesses opportunities and threats against the forests. To quantify the model, Analytical Hierarchy Process (AHP) model was used. The results of the study showed that. The measure of solidarity between devices with final weight (0.117), the measure of identifying the different parts of the forest and capabilities with final weight (0.099), the measure of constructing forest roads network with final weight (0.087) in opportunity group were identified as the most important factors influencing the fire control management at forests. Finally, some strategies are presented in order to deal with fire control management.

Map TOPSIS model shows the output from the South, Southwest and East regions of the very high-risk zones.According to calculations, the 17.86% of the high-risk zone 11.72% of the low risk and moderate risk was 27.49% in the area. According to the steep south-western areas of concentration are Runoff. Zoning maps and warning systems and rescue operations can have very good performance. To determine the risk of flood hazard areas in the watershed of Baghmlk of seven factors in order of priority are. Aspect, distance from drainage lines, slope, rainfall, height, build, and land use, was used the relative weight of Aspect (0/1933782) and the lowest weight Land Use (0/926625) have won and of very low to very high-risk areas were identified. According to calculations, the 17.86% of the high-risk zone, 24.15% in the range of 27.49% in high-risk areas with moderate risk 18.76 percent in areas with low risk and 11.27-percent limit of the study area is located at a very low risk.Analysis of the results suggests that map to the west, south, south-western and eastern part of the region, has the greatest potential risk of flooding are The main reason is that the eastern regions due to greater heights, the intervening seasonal river Abvalbas and more precipitation, higher runoff are susceptible to rise The seasonal river crossing from the West region Glal major role in creating and directing surface water seasonal floods during the rainy season in this area.

One of the main measures in order to financial and life damages reduction is a production of flood susceptibility mapping. In the current research, Shannon entropy has been studied to determine the flood probability and susceptibility mapping. In this research 211, flood locations were prepared.211 flood locations are divided into two categories based on random selection: 70 % for training and 30% for validation of final map. In the next step, 10 flood conditioning factors such as slope, plan curvature, distance from the river, altitude, rainfall, stream power index, topographic wetness index, lithology, land use and NDVI was selected. By using the Shannon entropy the weight of each factor in flooding have been determined. ROC curve has been drowned and area under the curve (AUC) was determined for validation of flood susceptibility mapping by success rate and prediction rate. The result showed that AUC for success rate in entropy model was 92.53% with a prediction accuracy of 91.42%. The high accuracy of the Shannon entropy model showed that this model is proper for flood susceptibility mapping.

Taftan volcano young to age Pliocene-Quaternary and a semi-active volcanic system is located 50 kilometers north of the city of Khash. According to population centers around the volcano and the earthquake of high magnitude in this area (earthquakes related to Saravan fault), study tectonic activity in this area is important. In the field of geomorphic indicators, it has been used for the study of tectonic activity. These indicators include the drainage basin asymmetry (Af), mountain front sinuosity (Smf), the slope of the valley (Sl), floor width to valley height (Vf), hypsometric integral (Hi). The index for evaluating relative active tectonic (Iat) basin and sub-basin of the study area were used. Based on the proposed model, recognized three tectonic zones in the study area: (zone with relatively high tectonic activity), this zone is observed only in two sub-basin, 4-B and 9-C, (zone of tectonic activity relative to average) the wide area of the region in this area, it is important that the structures can be noted in the northwest of Dargiaban, Iranshahr fault and fault Saadat-abad, (zone with relatively low tectonic activity) this zone has observations in two sub-basin only 5-C, 1-D, 9A and 8. By comparing and studying index in the range of Taftan volcano and its environment is composed mainly of flysch sediments. The result is that Taftan volcano eruptions of magma has been created in the past and the study area does not have a great impact on tectonic activity, the high indices in this section is affected by magmatic processes up to tectonic, but within the cone of the volcano, control structures such as faults and tectonic activity Saravan and Mirjaveh, Khan Mohammad wells, Saadat-abad and Dargiaban, Iranshahr and etc, and the presence of these faults in the area morphometric parameters are changed.