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黑河流域地处西北干旱区,水资源短缺是限制其中游绿洲农业发展、下游生态环境保护的首要原因。该流域的中游绿洲农业用水约占总用水量的80%,因此农业节水对流域发展至关重要。在干旱区绿洲农业节水探索中,众多学者主张通过节水技术来提高用水效率,而关于农业种植结构调整对农业节水影响的定量研究较少。本文采用2012年黑河流域蒸散发数据、土地利用数据、降水数据和农业经济统计数据,定量分析黑河中游主要作物需水特征和用水效率差异,尝试从调整作物种植结构角度为其绿洲农业节水提供依据。结果表明:(1)研究区4种主要作物中,玉米生长期需水量最大,其次为小麦、油菜和大麦;(2)考虑降水补给,发现大麦和油菜生长需水可很大程度上依赖降水,而小麦和玉米则需要灌溉,且玉米灌溉需水量远超小麦;(3)作物用水效率由高到低依次为大麦、油菜、小麦和玉米。从用水效率角度而言,考虑种植区位,在黑河中游适当扩大小麦种植规模更有利于提高中游农业用水效率。
Heihe River Basin is located in the arid region of Northwest China. The shortage of water resources is the primary reason for limiting the development of agriculture and the ecological environment in the lower reaches of the oasis. The middle reaches of the basin of agricultural water use about 80% of the total water consumption, agricultural water saving is therefore crucial for the development of the basin. In the exploration of water saving in oasis agriculture in arid area, many scholars advocate using water-saving technology to improve water use efficiency. However, there are few quantitative research about the impact of agricultural planting structure adjustment on agricultural water saving. Based on the data of evapotranspiration, land use, precipitation and agricultural economy in the Heihe River basin in 2012, this paper quantitatively analyzed the water demand characteristics and water use efficiency of main crops in the middle reaches of the Heihe River. It attempted to provide the oasis agriculture water-saving by adjusting crop planting structure in accordance with. The results showed that: (1) Among the four main crops in the study area, the water demand of maize was the largest in the growing period, followed by wheat, rape and barley; (2) Considering the recharge of precipitation, we found that the water requirement for growth of barley and rapeseed largely depends on precipitation , While wheat and corn need to be irrigated, and the demand for water for irrigation of corn is much higher than that of wheat. (3) The water use efficiency of crops is, in descending order, barley, rapeseed, wheat and corn. From the water efficiency point of view, considering the planting location, the appropriate expansion of wheat planting in the middle reaches of Heihe River is more conducive to improving the efficiency of agricultural water use in the middle reaches.