民勤荒漠绿洲干旱影响因子及驱动机制研究

探究荒漠绿洲系统中气象、水文、农业、社会经济及综合干旱形成的原因,可为干旱环境与水循环研究以及生态系统的恢复与建设提供理论依据。基于主成分分析法,选取21个指标,对甘肃民勤荒漠绿洲的干旱驱动机制进行多层面和多角度解析。结果表明,研究期内蒸发量和平均温度是引起气象干旱的主要因素,累计方差贡献率为86.853%;水文干旱受制于民调水量和出库水量,累计方差贡献率为92.190%;农业干旱主要是由耕地面积与有效灌溉面积增大所致,累计方差贡献率为86.179%;工业用水与万元工业增加值用水量成为社会经济干旱的驱动要素,累计方差贡献率为87.582%。综合干旱层面提取4个主成分,其累计方差贡献率为98.255%,准确反映干旱环境的形成原因,年蒸发量、平均湿度、地表供水量、地下水开采量、地下水位、出库水量、民调水量、上游来水量、水利财政支出等因素是民勤荒漠绿洲干旱的主要驱动力来源,其对干旱的影响程度排序为:地下水开采量出库水量地表供水量民调水量年蒸发量平均湿度上游来水量地下水位水利财政支出。

Driving Factors and Mechanism of Drought in Minqin Desert Oasis

A comprehensive exploration of factors (meteorological, hydrological, agricultural, social and economic) that lead to drought in a desert oasis system can lay the foundation for study of arid environments and the water cycle. In this investigation, the Minqin desert oasis in Gansu Province was selected as a case study and the driving factors and mechanism producing drought in a desert oasis was explored, aiming to provide a theoretical basis for restoring desert oasis ecosystems. Using principal component analysis, 21 indicators of meteorology, hydrology, agriculture and the social economy were selected to study the mechanism producing draughts in the Minqin desert oasis from multiple aspects. Evaporation and temperature were the primary factors driving meteorological drought in the oasis during the study period, contributing a cumulative variance of 86.853%. Hydrological drought was attributed primarily to public water transfer volume and reservoir discharge volume, contributing a cumulative variance of 92.190%. Agriculture drought was mainly due to the increase in arable land and irrigation area, contributing a cumulative variance of 86.179%. Industrial water consumption and the 10,000-yuan added value of industrial water consumption have become the primary drivers of socio-economic drought, contributing a cumulative variance of 87.582%. The cumulative variance contributed by the four principal components extracted from the comprehensive drought level analysis was 98.255%, accurately reflecting the reasons an arid environment formed. The degree of impact among the nine primary drought factors were ranked as follows: groundwater extraction volume > reservoir water supply > surface water supply > public transfer water volume > annual evaporation > average humidity > upstream water supplementation > groundwater level > water conservancy financial expenditure. This comprehensive analysis indicates that numerous factors affect draught intensity and reflect the complexity of draught cycles in desert oasis ecosystems.