黄河重要水源补给区甘南高原气候变化及其对生态环境的影响

利用甘南高原黄河重要水源补给区气候资料和生态观测资料及统计资料,分析研究区域气候变化特征及其草原湿地生态环境效应。结果表明,甘南高原黄河重要水源补给区降水量年际变化呈下降趋势,降水量的年际变化存在6~7a、15a的周期振荡特征。甘南高原黄河重要水源补给区气温年际变化呈上升趋势,增温速度大于全国增温速度。1980年之后持续偏暖,草地年干燥指数变化呈显著上升趋势。气候变化是草原生态退化的自然诱发因素,而超载过牧、滥采滥挖、人为破坏、生物链失衡等环境蠕变是造成生态退化的人为因素,二者共同作用导致黄河首曲草原湿地水资源锐减、生物多样性减少、生态环境退化。

Climatic changes and eco-environmental effects in the Yellow River important water source supply area of Gannan Plateau

Using main meteorological and eco-environmental observational data in the Yellow River important water source supply area of Gannan Plateau, the climatic change characteristics and eco-environmental effects of this study area were analyzed. The results show that the interannual variation of precipitation tended to decrease, and the variability is -22.6--9.6 mm/10a. In the 1980s the sudden change phenomenon in precipitation took place, in addition the 6-7a and 15a main periods of oscillation exist in most parts of the study area; temperature displays a remarkable increasing trend with an increasing rate higher than that of the whole country, in terms of seasonal changes, the increasing rate of winter is higher than that of the other seasons, in the 1970s the sudden change phenomenon in temperature took place with a persistent ascendant trend after 1980; water resource shows a significant descendant trend, the valley precipitation presents a remarkable positive correlation with the water resource, and the valley drought index presents a remarkable negative correlation with the water resource, the decreasing precipitation and increasing drought index result in a decrease in water resource; theoretically the domestic animal capacity of the regional savageness grassland is 428.82 ten thousand sheep, but in fact the over loading rate reaches 96.39% ; climate changes is the natural factor for plain ecological degradation, but overgrazing, excessive tree felling and grass cutting, artificial destruction, biological chain unbalance and so on are the artificial factors for plain ecological degradation, water resource sharp decrease, diversity of biology decrease and eco-environment degradation are the combined effects of the above two factors in the Yellow River important water source supply area of Gannan Plateau.