干旱地区区域内部洪水资源调配研究——以天津市南北水系沟通工程为例

依据历史水文数据和区域水资源现状,阐述了20世纪以来天津市湿地萎缩的趋势和成因,论述了该地区进行汛期洪水资源存储的必要性和可能性。实施境内区域水资源的优化调配,建设南北水系沟通工程引北部富余雨洪水南调入北大港水库,是天津市洪水资源利用体系的重要组成部分。基于Newton-Raphson方法和松弛算法建立一维河网非恒定流水动力学模型,对西线调水工程拟建路线和30 m3/s和50 m3/s两种方案进行数值计算,结果表明:该工程线路可以实现自流调水,调水过程平稳且线路沿程控制水位较低。分析工程实施对环境影响,通过加强水质监测、合理选择调水时机、及时修复施工所占用土地等措施,可减弱工程对环境的不良影响。

Research on Internal Flood Resource Utilization in Arid Area——North-South Water System Connecting Engineering in Tianjin

The development trend and causes of wetlands degradation in Tianjin since last century were exposited based on the historical hydrographic dates and regional water resources present status,then the necessity of implement flood resource utilization storage was discussed.Implementing optimization of water resource and developing north-south water system connecting engineering to divert the redundant runoff into Beidagang reservoir is the significant constituent of flood resource utilization system in Tianjin.Based on Newton-Raphson interation method and relaxation algorithm,a one-dimensional unsteady hydrodynamics numerical model for drafted water transfer channel line and schemes of the connecting engineering were established.The calculation results showed that the water gravity transfer process was relative stable and control water-levels fluctuation of cross-sections along water transfer channel was in reliable safety situation.Finally,unfavorable effect on water environment,coastal inlet sediment and used land caused by engineering execution was discussed.Utilizing several countermeasures of intensifying water quality monitoring,reasonable water transfer time decision could be made,the adverse effect on environment caused by the water diversion engineering could be weakened.