漠阳江流域水环境容量的时空分布特征研究

Temporal and Spatial Distribution Characteristic Research of Water Environmental Capacity in Moyang River Basin

针对实测径流资料较缺乏的漠阳江流域,通过流域水文模型HSPF(hydrological simulation programFortran)模拟各支流和子流域详细的径流时空特征,利用一维稳态水质数学模型计算不同时间和空间上化学需氧量(COD)和氨氮的水环境容量。结果表明:1)在漠阳江流域,HSPF模型对年与月径流模拟的相对误差小于15%,Nash-Sutcliffe系数大于0.9;水质模型的相对误差在10%左右,Nash-Sutcliffe系数大于0.8;2)在90%,50%和10%保证率下,漠阳江流域COD的环境容量分别为16.45,21.84和24.97万t,氨氮的环境容量分别为0.51,0.88万t和1.14万t;受径流季节波动影响,枯水期与丰水期季节水环境容量差异明显;1月份的水环境容量及其变差最小,6月份的水环境容量及其变差最大;3)空间分布上,漠阳江干流流域承载力较大,一级与二级支流的承载力较小。因此,在水文资料缺乏的流域,可基于HSPF模型模拟的水文条件,开展水环境容量的时空分布分析,为水环境容量总量控制方案的制定提供指导。

This study takes Moyang River basin, which is lack of hydrologic data, as the research object to simulate the temporal and spatial distribution of water flow through HSPF （hydrological simulation program- Fortran） model, and calculates the temporal and spatial distribution of chemical oxygen demand （COD） and ammonia nitrogen water environmental capacity using one-dimensional steady-state water quality mathematical model. Results show that 1） HSPF model＇s yearly and monthly hydrological errors are below 15%, Nash-Sutcliffe coefficient is over 0.9; the relative error of the water quality model is around 10%, Nash-Suteliffe coefficient over 0.8. 2） Under 90%, 50% and 10% assurance rate, COD capacity of Moyang River basin is 164500 t, 218400 t and 249700 t respectively, and ammonia nitrogen is 5100 t, 8800 t and 11400 t respectively. Affected by seasonal runoff fluctuations, difference of water environment capacity between dry season and wet season is obvious. The variation of water environment capacity in January is minimum and June the maximum. 3） Bearing capacity of main stream of Moyang River is larger than that of the primary and secondary tributaries. Therefore, in some basins where hydrological data is lack, HSPF model can be applied to simulate the hydrology, analysis time and space distribution of water environmental capacity, and provide guidance for the establishment of total amount control scheme of water environmental capacity.