青海湖流域水位和农牧业特征对气候暖湿化特征的响应研究

Water Level and Agriculture and Husbandry Characteristics in Qinghai Lake Basin:The Response to Climate Warming and Wetting

为揭示青海湖水位变化及农牧业特征对气候暖湿化的响应,通过分析流域气象、水位以及草地NDVI变化、建立水位评估模型,计算各因素贡献率,定量评估各要素对湖水位和农牧业的影响。结果表明:流域气候呈显著暖湿化趋势,降水量总体呈弱的增加态势,但2001—2015年增加显著并在2003发生突变;流域内平均气温、最低气温和最高气温均呈显著的升高趋势(P<0.01);湖水位从1961年开始,下降趋势显著,速率为-0.5 m/10 a(P<0.01);2004—2015年连续上升,上升速率达1.44 m/10 a(P<0.01)并在2004年发生了突变;前一年降水量、流量及蒸发量对水位影响大,贡献率大小依次为流量、降水量和蒸发量。因此,2001—2015年的15年里降水量增加及其导致的河流径流量增加可能是水位上涨的主要原因。

The paper aims to reveal the response of water level change and agriculture and husbandrycharacteristics in Qinghai Lake basin to climate warming and wetting. By analyzing the variation of weather,water level and NDVI of grassland in the basin, the authors built a water level assessment model, calculatedthe contribution rate of each factor, and quantitatively assessed the influence of each factor on the water leveland agriculture and animal husbandry. The results showed that： the basin climate had a significant warmingand wetting trend, and the total precipitation had a weak increase trend, and precipitation increasedsignificantly in recent 15 years and had a mutation in 2003; the average, the lowest and highest temperature inbasin had a significant increase（P〈0.01）; the water level declined significantly since 1961 with a rate of-0.5 m/10 a（P〈0.01）; the water level had a continuous rise in 2004-2015 with a rate of 1.44 m/10 a（P〈0.01）and had a mutation in 2004; the amount of precipitation, flow and evaporation in the previous year had greatinfluence on the water level, and the contribution rate followed the order of flow, precipitation and evaporation.Therefore, the increase of precipitation in recent 15 years and the increase of river runoff resulting fromprecipitation may be the main reason of water level rise.