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  • Natural Disaster Assessment
    BASNET Bhuwan, JOSHI Rajeev, SHARMA Ram Prasad, SUBEDI Rajan
    Journal of Resources and Ecology. 2024, 15(2): 431-438. https://doi.org/10.5814/j.issn.1674-764x.2024.02.017

    Landslides are the major problems of mountainous areas of Nepal basically due to its fragile geomorphology, intense rainfall, improper land management practices and rapid construction of hilly roads without applying necessary stabilization measures. There are huge loss of life and property, decline in ecosystem productivity and functionality and sedimentation on downstream areas due to frequent landslides. Multiple spatial factors like land use land cover, topography, road, drainage, geological setting and climatic factors like rainfall are found more associated with landslide occurrence and determine landslide susceptibility of the area. Understanding of landslide phenomenon and associated factors are crucial for adopting appropriate prevention, control and rehabilitation measures. This study was carried out in Singati sub-watershed of Sunkoshi River Basin with objectives to understand landslide hazards, associated factors and activities performed to minimize possible hazards with best strategy of minimizing hazards. Landslide assessments were made through identification and digitization of landslides using temporal Google image and field investigation. Where landslide hazard assessment and preparation of factor map was done by using GIS software and field observed data were analyzed and dimension of landslides were calculated. Along with, People perceptions on major effects of landslides on livelihood assets, were explore from associated household's questionnaire survey (n=60) using purposive sampling. And most causative factor of landslide on the perception of local people was calculated using nonparametric test (Friedman). From the field survey, a total of 46 landslides were surveys in different location of the study area. The total area of the landslide was found to be 4.77 km2. From the comparison matrix analysis using Friedman test, the study identified the main responsible factor for the occurrence of landslide are rural road, construction, slope factor rainfall and land use. The road factor up to 200 m area and 200-500 m distance from road covered the highest percentage of landslide hazard. Southeastern aspect with the slope class 30°-45° had the highest susceptibility to landslide. Dense forest was found to be more effected by landslide in comparison to other land use due to the construction of road in sloppy area inside the forest. Comparison the effects of landslide before and after the road construction about 80 percent of the respondent had the positive response on it.

  • Natural Disaster Assessment
    MASOUDI Masoud, TAHERI Zahra
    Journal of Resources and Ecology. 2024, 15(2): 439-447. https://doi.org/10.5814/j.issn.1674-764x.2024.02.018

    Drought is one of the main natural hazards affecting large areas’ economies and the environment. Therefore, it is necessary to study the different aspects of the drought on the land with several indices like the Standard Precipitation Index (SPI) index which can clarify the existing conditions for decisions and planning. The objective of this study was to analyze the spatial pattern of drought by SPI index in the Fars Province located in the Southern part of Iran. In this paper, according to the data from 42 stations in Fars Province, during 1990-2019, the pattern of drought hazard is evaluated. In the presented model, several drought hazard criteria were used including the maximum severity of drought in the period, the trend of drought, and the maximum number of sequential arid years. The final drought risk map was obtained with an arithmetic mean of 3 criteria: intensity, continuity, and trend. The three criteria maps and final hazard map were interpolated by the Inverse Distance Weightage (IDW) method and classified into five hazard classes none, slight, moderate, severe, and very severe. The obtained maps showed that the intensity, trend, and continuity of drought increases from the southeast to the northwest. The final vulnerability map shows that moderate hazard areas (36% of the region) observed in the Southern parts of the region are less widespread than areas under severe and very severe hazard (64% of the region) observed in the northern and central parts of the region. Preparation of these hazard maps may prove to be helpful for regional managers, and policymakers for environmental and agricultural strategies, not only in Iran but also in other countries facing this hazard.