Rawat Pradeep Kumar, Belho Khrieketouno, Rawat Mohan Singh
Department of Geography, Asian International Univesity, Imphal, Manipur, India.
Department of Geography, School of Sciences, Nagaland University, Lumami, 798627, Nagaland, India.
Environ Monit Assess. 2025 Feb 1;197(2):220. doi: 10.1007/s10661-025-13652-z.
The Eastern Himalaya region is highly susceptible to flood and other hydrological hazards due to frizzle geophysical setup, reshaping geomorphology, and heavy annual rainfall (1600-3200 mm). Despite that, anthropogenic activities have been enhancing this susceptibility which increases the intensity and impact of floods in terms of economic loss, human loss, and environmental degradation. Addressing this environmental problem, a geospatial technology-based case study of the Kohima district, Nagaland state (India), a part of the eastern Himalaya is presented here. Various experiential models are available for computing flood hazards; however, the geospatial technique-based analytic hierarchy process (AHP) method was applied in this study due to its robustness and high accuracy level. AHP integrates reclassified GIS layers of hazard-triggering factors and sub-factors by assigning relative weights 1-9 based on their corresponding impacts on flood occurrence. Overlay operation of reclassified GIS layer (causative factors and sub-factors) in ArcMap 10.8 software generated flood spatial variability map which shows four zones, namely low, moderate, high, and very high hazard zones, covers 23%, 35%, 28%, and 14% proportion of total area (978.96 km), respectively. The study poses a serious concern for the study area as most of the densely populated urban centers fall into moderate to very high flood hazard zones including the state capital city Kohima. So, to avert a worse flood disaster, a flood hazard zone study is the need of the hour. The present study can be used as a decision support system (DSS) for flood disaster risk reduction, infrastructural development, and land use planning in Kohima district.
由于其脆弱的地球物理环境、不断重塑的地貌以及每年充沛的降雨量（1600 - 3200毫米），东喜马拉雅地区极易遭受洪水和其他水文灾害。尽管如此，人为活动却一直在加剧这种易受灾性，从经济损失、人员伤亡和环境退化方面增加了洪水的强度和影响。为解决这一环境问题，本文呈现了一项基于地理空间技术的案例研究，该研究聚焦于印度那加兰邦科希马区，此地是东喜马拉雅地区的一部分。有多种经验模型可用于计算洪水灾害；然而，本研究采用了基于地理空间技术的层次分析法（AHP），因其具有稳健性和高精度。层次分析法通过根据危害触发因素和子因素对洪水发生的相应影响赋予1 - 9的相对权重，整合了重新分类的地理信息系统（GIS）图层。在ArcMap 10.8软件中对重新分类的GIS图层（成因因素和子因素）进行叠加操作，生成了洪水空间变异性地图，该地图显示了四个区域，即低、中、高和极高危险区，分别占总面积（978.96平方公里）的23%、35%、28%和14%。该研究对研究区域构成了严重关切，因为大多数人口密集的城市中心都位于中度至极高洪水危险区内，包括该邦首府科希马市。因此，为避免更严重的洪水灾害，开展洪水危险区研究迫在眉睫。本研究可作为科希马区洪水灾害风险降低、基础设施发展和土地利用规划的决策支持系统（DSS）。
