西藏燕麦主要种植区灌溉定额空间分布及影响因素

燕麦为西藏自治区典型牧草之一,由于种植区地域辽阔,灌溉试验结果受限,西藏燕麦主要种植区的灌溉定额尚不明确。本文在西藏燕麦主要种植区内选取28个典型站点进行资料收集,遵循农业气候相似原则进行区域划分,基于水量平衡法揭示了西藏燕麦主要种植区灌溉定额的空间分布特征,并根据统计学原理分析了其影响因素。研究表明:燕麦主要种植区的灌溉定额呈由西藏中部至东部呈现先递增后递减的趋势,50%水文年下的燕麦灌溉定额在56~265 mm之间变化。降雨量是影响研究区内燕麦灌溉定额的主要因素(R²为0.515),ET₀次之(R²为0.152);其它气象因素中,日照时数对研究区燕麦灌溉定额影响较大(R²为0.462),且呈正相关关系;相对湿度对燕麦灌溉定额影响较小。西藏燕麦主要种植区的灌溉定额及其空间分布可为西藏自治区灌溉用水管理提供支撑。

Analysis of spatial distribution and its influencing factors of oat irrigation quota in Tibet region

Oat is one of the typical herbages in Tibet region.Due to the vast growing area,the irrigation test results are limited,and the irrigation quota of the main growing area of Oat in Tibet is not clear.In this paper,28 typical stations were selected to collect data in the main oat growing areas in Tibet,and the regions were divided according to the principle of agro-climate similarity.Based on the water balance method,the spatial distribution characteristics of irrigation quota in the main oat growing areas in Tibet were revealed,and the influencing factors were analyzed according to the statistical principle.The results show that the irrigation quota of oat growing areas increased firstly and then decreased from central to eastern Tibet,and the irrigation quota of oat varies from 50 mm to 270 mm in 50% hydrological years.Rainfall is the main factor affecting irrigation quota of oat in the study area (R²=0.515),and ET₀ is the second factor (R²=0.152).Among other meteorological factors,sunshine duration has a significant effect on oat irrigation quota in the study area (R²=0.462),and there is a positive correlation.Relative humidity has little effect on oat irrigation quota.The irrigation quota and spatial distribution of oat growing areas in Tibet can provide support for irrigation water management in Tibet region.