Gridded Time-Series Runoff Dataset in Mainland Southeast Asia (2001-2020) using NRCS-CN Framework - A Reproducible Workflow

This dataset provides a data-driven, gridded time-series estimation of direct runoff derived using the NRCS-CN (Natural Resources Conservation Service - Curve Number) rainfall-runoff method across mainland Southeast Asia (MSEA), covering major river basins including the Irrawaddy, Salween, Mekong, Red River and Chao Phraya for the period 2001-2020. To address the scarcity of in-situ hydrological observations and the limited availability of regionally consistent runoff products, this raster dataset was developed using globally available geopspatial inputs within a computationally efficient CN-based framework. The dataset contains stacked continuous monthly runoff rasters based on two precipitation datasets (CHIRPS and ERA5-Land) and three initial abstraction ratios (λ = 0.20, 0.05 and 0.01), tested on major river basins in MSEA. In addition, the datasest package also includes detalied runoff generating scripts implementing NRCS-CN method using CN lookup table values for three initial abstraction ratios and three antecedent runoff conditions (ARC) i.e., ARC I (dry), ARC II (average) and ARC III (wet). These scripts enable researchers to reproduce the runoff estimation workflow and generate gridded runoff estimation using alternative λ values or precipitation datasets. The provided framework can also be adapted to evaluate runoff sensitivity and support pixel-wise runoff estimation in other geographic regions worldwide where in-situ hrdrological observations and continuous spatio-temporal monitoring are limited.