基于MS-PT的天山北坡农业灌溉用水时空格局估算及影响因素分析

Estimation of spatial and temporal pattern of agricultural irrigation water use based on MS-PT Algorithm and analysis of influence factors on the northern slope of the Tianshan Mountains

基于土壤水分平衡方程和遥感数据,利用改进后基于卫星的Priestley-Taylor算法(MS-PT),估算了2018—2020年天山北坡0.1°×0.1°空间分辨率下的农业灌溉用水量,通过与定额法所得到的估算结果进行对比,并采用通量塔数据对关键结果——蒸散发量进行了验证.结果表明:研究区内灌溉时间主要为每年的4—9月,其中7月份灌溉用水达到峰值,3年平均年灌溉用水量为98.90亿m^(3)/a,与定额法估算的结果(94.58亿m^(3)/a)相近.同时,在乌苏市、沙湾县、玛纳斯县以及呼图壁县等农业较为发达的地区,农业灌溉用水量相对较大.此外,农作物的种植结构及种植面积是影响天山北坡农业灌溉用水量的主要因素.

Based on the soil water balance equation,remote sensing data and Modified Satellite-Based Priestley-Taylor(MS-PT)algorithm,agricultural irrigation water use at 0.1°×0.1°spatial resolution on the northern slope of Tianshan Mountains during 2018—2020 was estimated,which was compared with the estimated results of each county obtained by the quota method.The key result,evapotranspiration,was verified by using flux tower data.The results showed that irrigation of the study area was mainly from April to September,and the irrigation water use in July was the highest.Three-year average irrigation water use was 9.890 billion m^(3)/a,which was similar to the estimated result of the quota method(9.458 billion m^(3)/a).At the same time,in the areas with relatively developed agriculture,like Wusu City,Shawan County,Manas County and Hutubi County,the agricultural irrigation water use was relatively large.What's more,the planting structure and the planting area of crops were main factors affecting agricultural irrigation water use on the northern slope of the Tianshan Mountains.