基于SWAT的北江流域蓝绿水评估及其干旱响应

为探究北江流域的水资源状况及其在不同程度干旱下的变化特征,利用SWAT模型模拟北江流域径流过程,并在此基础上评估北江流域的蓝绿水资源时空变化及其对干旱的响应特征。研究表明:北江流域水资源以蓝水为主,多年平均蓝水量为1 149.08 mm,绿水量为981.08 mm,绿水系数为0.48; 1966—2010年间,北江流域蓝绿水无显著变化趋势,空间分布上蓝水表现为南多北少,而绿水则与之相反;蓝水对干旱的响应更敏感,重度干旱下,北江流域的蓝水量较多年平均值分别减少16.94%,流域内的水资源分配模式由以蓝水为主转变为以绿水为主,绿水系数达0.53。从蓝水和绿水的角度研究北江流域的水资源状况及其干旱响应特征,可以为流域水资源管理提供依据,增强应对干旱风险、保障流域水安全的能力。

Evaluation of Blue Water and Green Water in Beijiang River Basin and Their Responses to Droughts Based on SWAT Model

The aim of this study is to explore the status of water resources and its variation characteristics in Beijiang river basin in the presence of different degrees of drought. The streamflow in Beijiang river basin was simulated using SWAT model, and on this basis, the temporal and spatial variation characteristics of blue water and green water and their responses to droughts were evaluated. Results unraveled that: (1) Blue water accounted for the main part in the water resources in Beijiang river basin, with the average annual blue water reaching 1 149.08 mm, green water 981.08 mm, and green water coefficient 0.48. (2) From 1966 to 2010, blue water and green water experienced no significant changes, whereas in spatial scale, blue water distributed more in the south than that in the north, and the opposite for green water. (3) Blue water was more sensitive to drought than green water. Under severe droughts, the blue water in Beijiang river basin dropped by 16.94% from annual average, and the pattern of water resource distribution changed from blue water dominated to green water taking a lead, with the green water coefficient of 0.53. The research findings will be beneficial for the formulation of water resources management strategies, the designation of drought risk response measures and the guarantee of water security in the basin.