区域灌溉需水量时空变化特征及其影响因素研究——以鲁西北地区为例

Spatiotemporal Variation in Crop Demand for Irrigation Water and Its Determinants: Take Northwest Shandong Province as an Example

【目的】探寻鲁西北地区灌溉需水量时空分布特征及影响因素。【方法】选取冬小麦为研究对象,利用Penman-Monteith公式对鲁西北地区灌溉需水量进行计算,应用Mann-Kendall突变检验法分析其变化趋势,得出鲁西北地区灌溉需水量的时间分布规律,使用反距离权重插值法得出灌溉需水量空间分布规律,并利用Pearson相关分析法对各气象因素对灌溉需水量的影响程度进行分析比较。【结果】(1)鲁西北地区的年平均灌溉需水量为339 mm,年际变化呈上升趋势;(2)灌溉需水量空间变化呈带环状分布,各生育期内规律不相同;(3)相对湿度和日照时数是影响鲁西北地区灌溉需水量较为重要的因素,分别呈极强负相关与较强正相关。【结论】鲁西北地区冬小麦灌溉需水量逐年缓慢上升,由东北到西南递增;各站点降水量在播种期、返青期和拔节期内均不满足需水要求,需要人工灌溉补给。

【Objective】Agricultural production in most regions in northern China relies on irrigation. Understanding spatiotemporal variation of the demand of different crops for water is critical to improving agricultural management.Taking the northwest Shandong province as an example, this paper studies the change in its demand for irrigation.【Method】We took winter wheat as the model plant, and calculated its water demand based on the Penman-Monteith formula. Spatiotemporal variation in the water demand was analyzed using the Mann-Kendall mutation test, the inverse distance weighting and the interpolation method. The factors that affect the water demand was calculated using the Pearson correlation analysis method.【Result】(1)Annual average irrigation water demand of the winter wheat is 339 mm, but has been increasing.(2)Spatially, distribution of irrigation water demand is ring-shaped across the studied region, with the shape of the rings varying with growth season.(3)The relative humidity and sunshine duration are the factors that affect the irrigation water most, with the former negatively correlated while the latter positively correlated with the irrigation water demand, both at significant level.【Conclusion】The irrigation water demand of winter wheat in northwest Shandong province has been increasing.Spatially, it increases from the northeast to the southwest. Precipitation cannot meet the demand of the wheat during its seeding, returning green and elongation stages. Topping up the soil water by irrigation is hence required.