黄河流域水循环研究的进展和展望

Advances on the research into the mechanism of hydrological cycle in Yellow River catchment

总结了黄河流域水循环研究的进展 ,指出缺乏立足于水循环整体的机理过程的探讨及缺乏较成熟的流域水文模型是已有研究的不足。为能更好地模拟水文过程对各种作用力的响应 ,今后研究的方向将是建立既考虑垂向水分和能量传输 (如降水 ,蒸发 ,感热 ) ,又考虑水平向的地表水分运动 (汇流 )和地下水基流过程的黄河流域的分布式水文模型。模型将结合遥感信息与地面资料 ,建立与区域大气环流模式 (GCM )的接口 ,辅之以野外生态试验小区、径流试验场和室内试验的资料 。

The advances on the research into the mechanism of hydrological cycle in Yellow River drainage basin are generalized from four aspects. Firstly, it is shown that the researches on hydrological processes have mainly focused on the single aspects such as precipitation, evaporation, infiltration, interception and runoff. Further studies should focus on the coupling between vertical water transfer and horizontal water movement, with special attention to the prominent characteristics of Yellow River such as man made dry out and high silt content. Secondly, the research results at several hydrological field experimental stations and hydrological laboratories are generalized. These stations and laboratories accumulated a large amount of hydrological data of the Yellow River over years. Unfortunately, most of these stations and laboratories ceased to run in the1960s. A new hydrological experimental laboratory, based on an old laboratory, is available soon to explore the key links in the hydrological cycle in Yellow River drainage basin. Appealing is to the government for reforming more old and/or establishing new hydrological experimental installments. They are one of the most important aspects to basic hydrological research Thirdly, the hydrological models used in operational Yellow River flood forecasting are listed. As Yellow River is mostly located in semi arid and arid climatic zone, the hydrological scenarios of the river are very complicated with high spatial variability. Sometimes the empirical method can get better results of hydrological forecasting than hill slope and or conceptual models. Because distributed model can well consider spatial variability, it is worthy to try to establish a distributed model over the Yellow River. The model will couple vertical and horizontal water transfer and movement, be parameterized by making use of remote sensing and field experimental data and interfaced with Global Circulation Model. The model is established for exploring the mechanism of hydrological cycle in Yellow River diainage basin and simulating the responses on land use/land cover change and other environmental changes. Last but not least, the scale problem, which is another key to explore the mechanism of hydrological cycle of Yellow River, is discussed. It rises because theories of many hydrological processes such as infiltration, evaporation, overland flow, sediment transport and subsurface water movement have been developed at small space-time scales. However, predictions are required at much larger space and time scales. These include the scale of large catchments where not only are the basic theories questionable but other processes or controls on spatial and temporal heterogeneity come into play. In essence, the scale problem is a search for connections between nonlinear hydrological theories developed for small scales, and the large scale hydrology of complex natural systems. Representing spatial and temporal variability in models, exploring the existence of natural time and space scales and statistical downscaling are specially needed in Yellow River drainage basin.