مطالب

Flash floods are considered to be one the worst kind of hazard. They are characterized by their suddenness, rarity, small scale, heavy rain and peak discharge, unpredictable, fast and violent movement. It has severe effects on human society in the form life losses, damages to property, roads, communication and on natural settings. Advances in hydrology, meteorology, engineering, using of GIS and remote sensing still not able to increase real time forecast. Researchers from developed countries have stressed to more focus to improve very short time an effective early warning system with collaboration of local communities for flash flood risk supervision. The data were combined with the Geographical Information System to analyze the temporal and spatial distribution of flood events in Salah Al-Din Governorate and Ramadan Valley. The analysis of the spatial distribution of the floods proves that most of the occurrences are recorded in the southern part of the study area. Most of the flooded areas in the study area are mainly pre-classified areas within the areas threatened by the flood due to the low level of its surface and its proximity to the course of the main valley (Wadi Jarnav), which flows into the Tigris River. The proposed method estimates the localization of sites prone to flood, and it may be used for flood hazard assessment mapping and for flood risk management. It was therefore, suggested that government agencies and policy makers should adopt this powerful technique for reliable and well synthesized information which is a vital component of flood risk assessment and planning.

The short resuscitation time for patients with asthma is one of the most urgent medical conditions with a high importance. In this study, the geographic information system (GIS) is used to analyze the access and transfer of emergency patients to health care centers (resuscitation, specialized, and health care services) to patients with respiratory problems with moderate and acute symptoms as the statistical sample. METHODS: Identifying the service area of the eligible health centers based on two factors of time and distance, the districts and streets covered by these centers were identified. Then, by spatial analysis, the appropriate service area available to the medical emergency centers and patients of this category was determined to facilitate their access to these areas. In addition, by calculating the time and distance cost matrix of the location of the patients with asthma attack relative to the treatment centers, the best treatment center for patient transfer was identified. After summarizing the appropriate model to calculate the service area for these patients, the spatial and descriptive data were collected in the study area (District 3 of Tehran, Iran) and their thematic maps were produced. Then, the time and distance matrix of transfer of patients was calculated for the spatial analysis and facilitation of their access to treatment centers related to respiratory diseases based on the two above factors. FINDINGS: Geospatial information system (GIS) and analysis of network access to appropriate respiratory care providers could save time and costs considerably. CONCLUSION: Establishment of time and location management systems for ambulances and identification of specific types of diseases at the moment of contact with the emergency departments of the medical care units can also play an important role in the rapid transfer of the patients to these centers.

This study investigates the effect of market inefficiency and environmental uncertainty on CEO risk taking. Prior research, however, have struggled to establish this relation empirically; moreover, some evidence points to the possibility that the CEO risk appetite is lower for firms active in inefficient markets. The opportunistic approach of managers leads to decisions about personal interests and imposing costs on shareholders by decreasing risk taking. In order to investigate the issue, data on companies listed in Tehran Stock Exchange, from 2008 to 2018, were extracted and a panel regression model was used to test the research hypotheses. Consistent with expected relation between market inefficiency, environmental uncertainty and CEO risk taking, the managers' risk taking decreases with respect to market inefficiency and environmental uncertainty. Managers may benefit from increased fluctuations in risk orientation, but are more sensitive than shareholders and have less restrictive choice that avoids higher risk.