中国东北地区典型流域水文变化特性及其对气候变化的响应

以辽河的主要水源区太子河流域为对象,分析近50 a来流域的降水径流变化特性,采用水文模拟方法,研究了河川径流量及土壤含水量对气候变化的响应。结果表明:近50 a来实测径流量总体呈现减少趋势;20世纪80年代以来,气候因素对河川径流量的绝对影响量呈现增加趋势;降水增加比减少对河川径流量的影响明显,土壤含水量对降水减少的响应更加敏感,气候暖干化趋势将非常不利于东北地区的水资源利用和农业生产。

Hydrological Characteristics and Its Responses to Climate Change for Typical River Basin in Northeastern China

Global warming caused by increasing concentration of carbon dioxide and other trace gases in atmosphere has become evident. It has concluded that the earth surface air temperature increased by about 0.74℃ during 1905-2005. Surface air temperature change in China keeps well agreement with that of globe, which has risen by about 0.5-0.8℃ during the last 100 years, particularly, rising rate in the latest 50 years slightly exceeds the corresponding value of globe. Water resource in China is scarce, especially in the northeastern part of China, where is the main food source area of China as well. With the rapid development of agriculture and industry, as well as population growth, China has been undergoing increasingly stress of water resources. During the last two decades, recorded runoffs in the major rivers, which are located in the northern China, have been dramatically decreasing. As a result, conflict between water supply and demand in these areas has been becoming more significant, which has attracted great attention from both the relevant authorities and the general public. Global warming is likely to change precipitation patterns and raise the frequency of extreme events; in further, will affect many sectors of natural environment and human endeavor. Water is considered to be the most critical sector associated with climate change impacts. Climate change is estimated to alter timing and magnitude of runoff, consequently, which has significant implication for the existing water resources system as well as for future water resources planning and management. Climate change may bring adverse effect on food security of China through aggravating the severe situation of shortage in water resources of the northeastern China. Quantitative estimates for hydrological effects of climate change are essential. Taking Taizihe River basin as a case, which is main water source of Liaohe River, its variation characteristics of runoff and precipitation in the past 50 years were analyzed. Based on naturalization of runoff adopting a snowmelt-based water balance model (SWBM model), hydrological responses to climate change were studied. The results indicate that recorded runoff at Xiaolinzi hydrometric station has been decreasing during 1954-2005. Since the 1980s, climate-induced runoff reduction presents increase trend. The increase in precipitation could exert higher effect on stream flow than decrease in precipitation does, while soil moisture is more sensitive to rainfall reduction. Climatic aridification will extremely be not conducive to sustainable utilization of water resources and agricultural production for the northeastern China.