辽西风沙半干旱区旱作农田水资源研究

Study of Farmland Water Resources in the Sandy and Windy Semi-Drought Area of Western Liaoning Orovince

辽西风沙半干旱区年降水量多为二、三年左右的丰枯交替,并有持续4年以上的连续干旱,尤其是1980年以后连续干旱的年份较多。区域内春旱严重,夏季降水明显集中,秋季水分收支基本平衡。以土壤水分季节变化情况可分为:冬季土壤水分凝聚、冻结、累积阶段,春季解冻、返浆、土壤水分大量蒸散阶段,夏季土壤水分大量累积阶段,秋季土壤水分缓慢蒸发阶段。

The abundance and pinch of the rainfall alternate every two or three years in the Sand and Wind Semi-Drought Area of Liaoning province and the arid climate may last for 4 years sometimes. The dry condition became more and more severe after 1980. In the Sand and Wind semi-Drought Area, in spring the arid climate is very severe, in summer the rainwater is abundant, and in autumn the income and expenses of soil water is balanceable. The change of soil water with time could be divided into four phases-the phase of sil water agglomerating, freezing up and accumulating in winter; the phase of soil water fast vaporizing in spring; the phase of soil water accumulating in summer; and the phase of soil water slowly vaporizing in the autumn.