基于SWAT模型定量分析自然因素与人为因素对水文系统的影响——以漳卫南运河流域为例

Quantitative Analysis of the Impact of Natural Factors and Human Factors on Hydrological System Using the SWAT Model:The Zhangweinan Canal Basin Case

"干旱"是由大尺度的气候变化所引起的水分亏缺现象,"水资源短缺"则是因人类长期对水资源不可持续利用引起的水资源亏缺现象。前者无法被水资源管理系统规避,后者则受水资源管理方针政策的影响。然而,通常一个地区由干旱与水资源短缺引起的水分亏缺经常同时发生而且难以区分。因此,论文提出了一种可以定量区分自然因素(干旱)和人为因素(水资源短缺)对水文系统影响的框架,并以漳卫南运河流域为研究对象,利用SWAT模型模拟结果(无人为影响情景下)和观测数据(自然因素和人为因素共同作用结果),对研究区1976—1995年的日径流量序列进行了初步对比和差异性分析。结果表明:1)经率定和验证的SWAT模型能够有效模拟漳卫南运河流域的径流过程;2)无论是丰水年还是枯水年,水资源短缺现象均导致了夏季径流洪峰时期的消失;3)人为因素是引起漳卫南运河流域水文系统发生变化的主要原因,并且人为因素影响造成的径流损失量是自然因素造成径流损失量的4倍。论文提出的框架可以定量化分析自然因素和人为因素对水文系统的相对影响,有助于水资源管理者制定适应干旱与水资源短缺状况的管理政策。

Drought is a natural hazard caused by large-scale climatic variability and cannot be prevented by local water management. Water scarcity refers to the water shortage caused by long-term unsustainable use of water resources, which can be influenced by water management policies. Clarifying drought and water scarcity is not trivial, since they often occur simultaneously. In this paper, we propose an observation-modeling framework to separate natural（drought） and human（water scarcity） effects on the hydrological system. Taking the Zhangweinan Canal Basin as study area, we carry out the preliminary comparison and difference analysis on the scenario simulation results of the SWAT model（without human influence） and observed data（with natural factors and human influence） of daily runoff series during 1976-1995. The result shows that： 1） The calibrated and validated SWAT model can effectively simulate the runoff process. 2） Water scarcity resulted in the disappearance of the peak flood period in summer, even in relatively wet years. 3） Human factors are the main reason that caused the loss of runoff in Zhangweinan Canal Basin. The impact of human factors on the hydrological system was, on average, four times as high as the impact of natural factors.The proposed observation-modeling framework helps water managers in water-stressed regions quantify the relative impact of drought and water scarcity and make decisions regarding drought and water scarcity condition.