黄河流域水循环要素变化趋势分析

根据月降水、径流资料进行水循环要素分解,并应用Mann-Kendall方法分析了7个主要的水循环要素的变化趋势。分析表明:对于兰州控制断面而言,地表径流有明显的减少趋势,而其它水循环要素变化的趋势并不十分明显。但是,对于花园口控制断面而言,天然径流、地表径流和地下径流减少的趋势十分明显,而降水、蒸散发、壤中流和土壤水分通量也都呈减少趋势,但变化并不突出。进一步的研究表明了用水量的增加、降水减少以及径流系数减小与黄河流域水循环变化的关系。水循环是水资源科学评价与合理开发利用基本依据,黄河流域地处半干旱地区水循环具有垂向运动的特征,蒸发旺盛。因此,对黄河流域来说,应从其水循环的特征,考虑用水结构的调整。

Trend analysis of hydrological components in the Yellow River basin

This paper attempts to detect the trends of hydrologic cycle components in the concerned region.The hydrologic components are separated from monthly precipitation and natural runoff series based on the schemes proposed herein.Mann-Kendall method has been applied to detect the trends of the hydrologic components.For the Lanzhou station,only surface runoff(RS)showed a decreasing trend.As for the Huayuankou station,the results showed that RN,RS and RG have a strong decreasing trend,while the decreasing trend of the other components is not significant enough.Furthermore,impacts of human activities,climatic changes and annual runoff coefficient change on hydrologic cycle components have been discussed.The study suggests that increasing water resources development and utilization may be the most important factors for the frequent drying-up in the main course of the Yellow River.Moreover,the similarities of the trends in precipitation and natural runoff suggest a linkage exists between climatic change and hydrologic cycle change.With regard to intensified human activities and climatic change,knowledge about the regional hydrologic cycle change should be seen as the base for searching for an adaptation strategy in water resources use.The Yellow River basin,located in the semi-humid,semi-arid and arid climatic zones,is characterized by vertical hydrological cycle,which means a strong evapotranspiration.Thus,it is important to control that part of water consumption through adjustment of water utilization.Water-saving agriculture must be one of the most important ways to alleviate water resources deficit in the region.Therefore,industrial structure adjustment should also be under consideration for sustainable development in the basin.