石羊河流域史前曾存在大面积的终闾湖泊———猪野泽。自西汉开拓河西以后的两千多年以来,受人类活动影响,石羊河流域土地覆盖发生了显著的变化。灌溉农田取代了天然绿洲,而且面积逐步扩大,农业用水急剧增加,猪野泽逐渐退缩成许多小湖,并于近代干涸。在假设人类活动（主要是灌溉）对水资源未加利用的条件下（理想状态）,通过确定流域的水量收支和改进水量平衡模型,对石羊河流域现代自然条件下“终闾湖”的面积进行了模拟重建,得出现代终闾湖的面积至少应为５８０ｋｍ^２。

A large terminal lake Zhuyeze once existed in Shiyang River Drainage Basin in prehistoric period.Since Western Han Dynasty (about 2010 years ago),the landcover of this area has changed greatly because of human activities.The irrigated farmlands replaced the natural oases and increased gradually,while the water was increasingly used for agricultural purpose.Zhuyeze shrank into many small lakes that dried up gradually.In this article the area of the “close lake”under modern natural conditions is calculated following water budget principle by deciding water income and outcome,supposed that the water resource in the drainage basin was not utilized by human being.The area of the modern terminal lake under natural conditions should be about 580km².