民勤三项农业节水措施的相对潜力估算

该研究利用FAO-56推荐的灌溉指标法，计算民勤农田灌溉需水量，并通过设定情景，在可比条件下探讨《石羊河流域综合环境治理规划》中提出的3项措施在压缩农业用水方面的潜力。结果表明，在相同气候条件和传统灌溉方式下，民勤县主要农作物2006年灌溉需水量比1973年增加0.22亿m3；其中播种面积增加与种植结构调整都是促进用水因素，种植结构调整的贡献率高于60%。在相同气候条件和不改变种植结构的情况下，玉米和棉花采用膜下滴灌方式可压缩用水0.55亿m3。基于规划目标和情景分析，仅依靠压减耕地面积达不到规划要求的节水目标；具有节水潜力的是膜下滴灌等节水灌溉技术。

Estimation of relative potential of three agricultural water-saving measures in Minqin Oasis

Irrigation water requirements for Minqin county under several planting scenarios were calculated with the FAO-56 recommended method, to make an assessment of the water-saving potential of three measures which were proposed by Shiyang River Rehabilitation Plan under comparable conditions. The results indicated that with the same climatic conditions and traditional surface irrigation, the four main crops in Minqin County in 2006 required more irrigation water than in 1973 by 2.2×107 m3. Both adjustment of planting structure and expansion of planting area contributed positively to the water increase, while the former contributed more than 60%. If drip irrigation was adopted to corn and cotton in 2006, 5.5×107 m3 of water would be saved. The objectives of the rehabilitation plan were also evaluated in the paper. It is difficult to achieve the goal of saving water only by reducing farmland area. In contrast, water-saving irrigation technology has great potential in reducing irrigation water requirements.