湖北省径流影响因子识别及分区建模策略研究

Identification of Runoff Influencing Factors and Zoning-Based Modeling Strategy in Hubei Province

摘要: 为揭示湖北省径流变异特征及提升水文模拟精度，本研究以210个“县套四级区”为单元，基于2001~2023年数据，构建了融合随机森林与多元线性回归的“筛选–验证–量化”分析框架。研究表明：降水(P)、潜在蒸发量(Ew)和归一化植被指数(NDVI)是驱动湖北省径流变异的三个核心影响因子。其中，降水为第一主导因子，其贡献度超过60%；潜在蒸发量表现出显著的负效应，贡献度介于25%~30%之间；NDVI的影响则呈现明显的区域异质性。各因子的贡献度空间分异规律显著：降水贡献由东南向西北递减，NDVI影响由南向北递减，而蒸发影响则自西向东递增。不同因子组合模型的适应性存在时空尺度差异。基于此，本研究提出了适用于五类典型区域的差异化径流建模策略，以期为区域水资源精准管理与模拟预测提供科学依据。

Abstract: To reveal the characteristics of runoff variation and improve the accuracy of hydrological simulation in Hubei Province, this study established a “screening-verification-quantification” analytical framework integrating Random Forest and Multiple Linear Regression. The analysis was based on data from 2001 to 2023, taking 210 “county-nested fourth-level watersheds” as basic units. The results indicate that precipitation (P), potential evapotranspiration (Ew), and the Normalized Difference Vegetation Index (NDVI) are the three core factors driving runoff variation. Among them, precipitation is the primary dominant factor, with a contribution exceeding 60%; potential evapotranspiration shows a significant negative effect, contributing 25%~30%; and the impact of NDVI exhibits notable regional heterogeneity. The spatial contribution distribution of each factor follows distinct patterns: the contribution of precipitation decreases from southeast to northwest, and the influence of NDVI decreases from south to north, while the impact of evapotranspiration increases from west to east. The adaptability of models with different factor combinations varies across spatial and temporal scales. Accordingly, this study proposes differentiated runoff modeling strategies for five types of regions, aiming to provide a scientific basis for precise regional water resources management and simulation forecasting.