石羊河流域春小麦灌溉需水量时空分布研究

The Study of Temporal and Spatial Distribution of Spring Wheat Irrigation Water Requirement in Shiyang River Basin

根据石羊河流域1960-2004年的气象资料,利用FAO的CROPWAT模型计算石羊河流域春小麦生育期多年平均蒸发蒸腾量、有效降水量和灌溉需水量;利用GIS建立流域空间和属性数据库,分析春小麦灌溉需水量空间分布规律。结果显示,春小麦蒸发蒸腾量、灌溉需水量空间分布趋势为从北往南逐渐降低,生育期降水量由北到南逐渐增大,其中春小麦多年平均蒸发蒸腾量为353.55-452.60 mm,生育期有效降水量为45.13-168.16 mm,雨养条件下石羊河流域春小麦产量减幅为27.90%-65.30%。因此,为保证春小麦产量需进行补充灌溉。利用CROPWAT模型计算,石羊河流域春小麦多年平均灌溉需水量为202.79-407.47 mm。

According to the meteorological data from 1960 to 2004 in Shiyang River Basin,the CROPWAT model and GIS were adopted to analyse the temporal and spatial distribution of average annual evapotranspiration,effective rainfall and irrigation water requirement of Spring wheat.The results showed that the tendency of spatial distribution of evapotranspiration and effective rainfall decreasd gradually from north to south in Shiyang River Basin,and the effective rainfall showed a opposite tendency.The average annual evapotranspiration of wheat was between 353.55 and 452.60mm,the effective rainfall was from 45.13 to 168.16mm and the yield of wheat would reduce from 27.90 percent to 65.30 percent under rain-fed condition.Therefore,in order to guarantee the production of spring wheat,it is significant to provide supplemental irrigation to wheat,and the average annual irrigation water demand which calculated by CROPWAT model is from 202.79 to 407.47mm in Shiyang River Basin.