Rudraprayag in Garhwal Himalayan division is one of the most vulnerable districts to landslides in India. Heavy rainfall, steep slope and developmental activities are important factors for the occurrence of landslides...Rudraprayag in Garhwal Himalayan division is one of the most vulnerable districts to landslides in India. Heavy rainfall, steep slope and developmental activities are important factors for the occurrence of landslides in the district. Therefore, specific assessment of landslide susceptibility and its accuracy at regional level is essential for disaster management and proper land use planning. The article evaluates effectiveness of frequency ratio, fuzzy logic and logistic regression models for assessing landslide susceptibility in Rudraprayag district of Uttarakhand state, India. A landslide inventory map was prepared and verified by field data. Fourteen landslide parameters and generated inventory map were utilized to prepare landslide susceptibility maps through frequency ratio, fuzzy logic and logistic regression models. Landslide susceptibility maps generated through these models were classified into very high, high, medium, low and very low categories using natural breaks classification. Receiver operating characteristics(ROC) curve, spatially agreed area approach and seed cell area index(SCAI) method were used to validate the landslide models. Validation results revealed that fuzzy logic model was found to be more effective in assessing landslide susceptibility in the study area. The landslide susceptibility map generated through fuzzy logic model can be best utilized for landslide disaster management and effective land use planning.展开更多
为了科学评估地质勘查活动对生态环境的影响,促进地质勘查与生态环境保护协调发展,本文探索建立了基于信息量法的评估方法体系:按照2 km×2 km标准划分青海省评价单元,假设每个评价单元高强烈度地质勘查活动影响面积为7850 m 2;分...为了科学评估地质勘查活动对生态环境的影响,促进地质勘查与生态环境保护协调发展,本文探索建立了基于信息量法的评估方法体系:按照2 km×2 km标准划分青海省评价单元,假设每个评价单元高强烈度地质勘查活动影响面积为7850 m 2;分别计算地物覆被类型、植被覆盖度、噪声影响、地表水资源环境四项单因子信息量,利用GIS叠加计算综合信息量;采用自然间断点分级法,将综合信息量划分为-1.55~1.72、1.72~3.48、3.48~4.70、4.70~6.04、6.04~9.14,对应的生态环境影响等级为轻微、较轻、一般、中等、严重。评估结果表明:轻微-较轻等级的面积为670086.5 km^(2),占青海省全域面积的94.6%,说明地质勘查活动对生态环境影响是有限的、可控的。在地质勘查过程中要加强环境本底调查,注重自然恢复能力,减少人为过渡治理,提升绿色勘查综合效益。该项评估为青海省地质勘查工作部署提供借鉴。展开更多
文摘Rudraprayag in Garhwal Himalayan division is one of the most vulnerable districts to landslides in India. Heavy rainfall, steep slope and developmental activities are important factors for the occurrence of landslides in the district. Therefore, specific assessment of landslide susceptibility and its accuracy at regional level is essential for disaster management and proper land use planning. The article evaluates effectiveness of frequency ratio, fuzzy logic and logistic regression models for assessing landslide susceptibility in Rudraprayag district of Uttarakhand state, India. A landslide inventory map was prepared and verified by field data. Fourteen landslide parameters and generated inventory map were utilized to prepare landslide susceptibility maps through frequency ratio, fuzzy logic and logistic regression models. Landslide susceptibility maps generated through these models were classified into very high, high, medium, low and very low categories using natural breaks classification. Receiver operating characteristics(ROC) curve, spatially agreed area approach and seed cell area index(SCAI) method were used to validate the landslide models. Validation results revealed that fuzzy logic model was found to be more effective in assessing landslide susceptibility in the study area. The landslide susceptibility map generated through fuzzy logic model can be best utilized for landslide disaster management and effective land use planning.
