伊犁河流域春季融雪型洪水危险性评价与区划

Risk Evaluation of the Spring Snowmeit Flood in River Basin and It's Mapping

将春季融雪型洪水发生最为频繁的伊犁河流域作为研究区,选取高程、坡度、地形起伏度、与水系距离、土地利用/覆被、冬季积雪深度作为春季融雪型洪水的影响因子,利用GIS技术和信息量模型定量计算了春季融雪型洪水的危险性,并基于总信息量最终将研究区域划分为极高度、高度、中度、低度和极低度等5个等级危险区。研究表明:春季融雪型洪水灾害主要沿河谷地带发生,并且与冬季积雪深度、农田等分布相一致,灾害点与危险性区划具有很好的空间相关性,运用信息量模型开展春季融雪型洪水危险性区划具有较好的科学客观性和业务应用价值,可为该区内的春季融雪型洪水精细化预报提供有力的技术支撑,可为防灾减灾决策服务提供参考依据。

This paper evaluates the risk of the spring snowmelt flooding,which is often occured in the Ili River Basin,based on GIS technology,information quantity model and impact factors including elevation,topographic relief degree,slope,distance from the river system,land use/cover types and winter snow depth.According to the final comprehensive information quantity,the spring snowmelt flooding hazard may be divided into five grades：very high,high,moderate,low and very low.Results show that the spring snowmelt floods concentrated mainly along the zonal river valley in the Ili River Basin,and are consistent with the distribution of winter snow-belt and farmland.The site number of spring snowmelt flooding hazards is positively correlated with the hazard grades.It is shown that the method based on the information quantity,and the mapping of spring snowmelt flood hazard zones is objective and has a better business value.The study may provide a technical support for a fine forecast of the spring snowmelt flood,and a valid basis to prevent from the spring snowmelt flood.