气候变化背景下松嫩平原玉米灌溉需水量估算及预测

开展农作物需水规律研究对于干旱半干旱区域旱作物节水灌溉和水分管理实践具有重要意义。以松嫩平原玉米为研究对象,研究玉米生育期需水量规律及灌溉需水量。结果表明:(1)历史时期和未来气候变化情景下,松嫩平原玉米全生育期和L~(mid)时段灌溉需水量等值线沿西南—东北方向递减,其中全生育期和L~(mid)时段2000s灌溉需水量临界等势线(灌溉需水量为0的等势线)分别比1970s北移70.2km和53.4km,全生育期和L~(mid)时段2040s灌溉需水量临界等势线分别比2010s北移30.9km和55.2km。(2)历史时期和气候变化情景下玉米全生育期灌溉需水量随年代呈波动增加趋势,其中前者以29.1mm/(10a)速度增加,后者以17.5mm/(10a)速度增加。(3)未来温度和降雨量变化对玉米需水量的贡献率为波动上升趋势,与1970s相比,2000s温度和降雨量变化对玉米需水量的贡献率为22.1%,增加6.8亿m~3灌溉水量;2040s温度和降雨量变化对玉米需水量的贡献率为38.3%,增加12.6亿m~3灌溉水量。

Estimation and prediction of maize irrigation water requirement based on climate change in Songnen Plain, NE China

It is important to study crop water requirement rule for water-saving irrigation and water regulation management of dry land crops in arid and semi-arid regions. In this study, the maize water requirement was estimated by means of McCloud model and Penman-Monteith model, and the amount of irrigation water in maize field was estimated by water balance approach in Songnen Plain, NE China. The main results are shown below:(1) both in historical period and projected climate change scenario, the maize irrigation water amount contour lines during the whole growth period and L_mid periods decreased along southwest to northeast geographically, and the same irrigation water amount contour line moved north with the progression of decades. Compared with 1970s, the zero equipotential line of irrigation water requirement during the whole growth period and L_mid period in 2000s moved to north by 70.2 km and 53.4 km, respectively. Compared with 2010s, the zero equipotential line of irrigation water requirement during the whole growth and L_mid periods in 2040s moved to north by 30.9 km and 55.2 km, respectively. (2) The maize irrigation water requirement during the whole growth period increased volatility coupled with the progression of decades both in historical conditions and in projected climate change scenarios, and the rate of the increase was 29.1 mm/(10a) in historical period and 17.5 mm/(10a) in projected climate change scenarios. (3) Compared with 1970s, contribution of climate change to the maize irrigation water requirement was 22.1% in 2000s and 38.3% in 2040s, namely an increase of 6.8×10⁸ m³ in irrigation water requirement in 2000s and an increase of 12.6×10⁸ m³ in irrigation water requirement in 2040s.