传统旱涝评估多从单一因素角度来研究,而忽略了下垫面的特性如农业用地对旱涝事件形成的影响.基于昌化江流域内 20 个气象站点 1970-2019 年逐日降雨数据,结合遥感提取的 30 m DEM和遥感解译的土地利用数据,应用降水 Z指数对流域内的旱涝等级进行划分.运用下垫面数据修正分析结果,评估流域旱涝面积时空变化特征,分别划分流域的易旱、易涝区.结果表明:流域冬春季节干旱问题较其它季节突出,但整体上干旱面积呈明显下降趋势;流域内夏秋季雨涝问题较为严重,且总体雨涝面积呈上升趋势.全年干旱易发区与秋季雨涝易发区较为集中分布于流域下游;总体昌化江流域旱涝灾害有逐年缓解趋势.
Temporal and spatial distribution of drought and flood in Changhua River Basin in arid region of Hainan Island considering the influence of underlying surface
Traditional assessments of drought and flood events have primarily focused on a single factor,neglecting the influence of underlying surface characteristics,such as the impact of agricultural land,on the occurrence of these events.Using the daily precipitation data of 21 meteorological stations in the Changhua River Basin from 1970 to 2019,the 30 m resolution DEM data and land use data were extracted by remote sensing,etc.,the precipitation Z index was used to evaluate the drought and flood levels in the Changhua River Basin and revised the analysis results by using underlying surface data to evaluate the spatio-temporal characteristics of the drought and flood area in the Changhua River Basin.The drought-prone areas and flood-prone areas in the Changhua River Basin were divided.The results showed that the drought problem in the Changhua River Basin in winter and spring was more prominent than that in other seasons,but the overall arid area showed an obvious downward trend.The summer and autumn flood problem in the basin was more serious,and the overall flood area was on the rise.The drought-prone areas and the autumn flood-prone areas were more concentrated in the lower reaches of the basin.The overall drought and flood disasters in the Changhua River Basin tended to be alleviated year by year.
drought and floodspatial and temporal distributionunderlying surface correctionChanghua River BasinHainan Island
万方数据
维普
