全球变化下澜沧江-湄公河流域水量平衡模拟

流域水文模型是区域水资源评价的重要工具，基于普林斯顿全球气象驱动数据集和澜沧江-湄公河流域（简称：澜湄流域）八个水文站实测资料，分析了澜湄流域不同区间的水文特性，采用RCCC-WBM模型（Water Balance Model developed by Research Center for Climate Change，RCCC-WBM）开展了区间径流及水量平衡模拟研究。结果表明：1）澜湄流域不同区间气候水文差异显著，上游气温低且年内变幅大，下游气温高年内变幅小；尽管不同区间降水、径流的年内分配特征总体一致，但径流的年内分布峰值大多滞后降水峰值一个时段。2）RCCC-WBM模型能够较好地模拟出澜湄流域不同区间的径流过程，率定期和验证期的月径流模拟效率系数（Nash-Sutcliffe Efficiency，NSE）均在60%以上，总量模拟误差（Relative Error，RE）也均控制在±10%以内，模型具有较好的区域适应性。3）模拟的土壤含水量都具有先衰减后增加再衰减的年内分配特征；不同季节径流和蒸发耗散的水源不同，降水是汛期水分耗散的主要来源，而土壤含水量是非汛期径流和蒸发消耗的主要水源。

Simulations of the water balance components of the sub-regions in the Lancang-Mekong River Basin in the context of global climate change

Catchment hydrological models are of vital importance in regional water resource assessments.In this study,based on the Princeton Meteorological Forcing Dataset and the recorded runoff data at eight hydrometric stations on the Lancang-Mekong River,the hydrological characteristics of the eight sub-regions were analyzed.The regional runoffs,as well as other key water balance components,were successfully simulated using an RCCC-WBM model.The obtained results revealed that the Lancang-Mekong River Basin was characterized by high differences in hydro-meteorological features.For example,the temperature levels in the upper reaches were much lower.However,those areas displayed larger ranges of seasonal variations.Meanwhile,the temperature levels in the middle and lower reaches were higher,with narrow variation ranges in seasonal temperatures.In addition,the seasonal patterns of the runoff were generally consistent with that of the precipitation,with one-month lags in runoff peaks occurring.This study''s RCCC-WBM model was able to effectively simulate the monthly runoff patterns for the sub-regions of the Lancang-Mekong River Basin,with Nash-Sutcliffe coefficients over 60% in both the calibration and validation periods.The model achieved a relative error of runoff volume varying in a range of ±10%,which indicated the suitability of the model for studying catchments.The seasonal patterns of the simulated soil moisture were found to be characterized by first decreasing trends and then increasing trends,followed with decreases again due to influencing effects of seasonal variations in precipitation and evaporation.The main water sources for the runoff yields and the actual evaporation consumption values were observed to change with the different seasons.It was determined in this study that precipitation was the main source of the runoff yields and evaporation during the flooding seasons,while soil moisture played an important role in providing resources for both consumption processes during the dryer seasons.