自然资源遥感2024，Vol.36Issue(3)：117-127,11.DOI:10.6046/zrzyyg.2023097
基于Copula函数的千米尺度综合干旱指数构建与应用
Construction and application of a comprehensive drought index based on Copula function on a kilometer scale:A case study of Chongqing,China
摘要
Abstract
Drought is identified as one type of the most serious natural disasters affecting agricultural production,and developing a comprehensive drought index holds practical significance for the assessment of drought in various districts and counties in Chongqing.By coupling the soil moisture and precipitation Z-index data downscaled using the XGBoost algorithm and using the Copula function,this study developed a gridded comprehensive drought index CSDIM-A on a kilometer scale with the boundaries of various districts and counties of Chongqing as the spatial division criteria and decades of a month as time units.Using this index,this study assessed the spatiotemporal characteristics of drought and performed an experimental demonstration of the index using Chongqing as the study area.The results indicate that the downscaling enhanced the spatial continuity of remote sensing-based products,thus providing support for the subsequent construction of a comprehensive drought index on a kilometer scale.The generalized extreme value distribution and the t location-scale distribution applied to the fitting of the data distributions of soil moisture and precipitation in most districts and counties of Chongqing,respectively,while the Frank-copula function suited for the fitting of the joint distribution of binary variables on a scale of a month decade.As validated based on soil moisture content,CSDIM-A can more effectively reflect drought than the precipitation Z-index,with its spatial distribution in various districts and counties consistent with the actual drought data.This indicates that the CSDIM-A can be used as a reference for drought assessment.关键词
干旱/土壤水分/降水Z指数/降尺度/综合干旱指数Key words
drought/soil moisture/precipitation Z-index/downscaling/comprehensive drought index分类
信息技术与安全科学引用本文复制引用
杨辰飞,吴田军,王长鹏,杨丽娟,骆剑承,张新..基于Copula函数的千米尺度综合干旱指数构建与应用[J].自然资源遥感,2024,36(3):117-127,11.基金项目
内蒙古自治区科技重大专项项目"现代牧区草地高效生产与家畜优化利用技术研发与示范"(编号:2021ZD0045)、国家自然科学基金项目"地块作物生长的光学与SAR遥感同步观测响应机制研究"(编号:42071316)、国家重点研发计划项目"地理空间智能核心技术与软件系统"(编号:2021YFB3900905)、第三次新疆综合科学考察项目"新疆遥感动态监测系统及时序信息反演"(编号:2021xjkk1400)、国家自然科学基金项目"贝叶斯低秩矩阵分解算法研究"(编号:12001057)和重庆市农业信息中心项目"农业产业数字化地图"(编号:21C00346)共同资助. （编号:2021ZD0045）
