中国主要天然草地产草量气象预测方法

Grass yield meteorological prediction method for main natural grasslands in China

中国天然草地主要分布于北方干旱半干旱及青藏高原高寒气候区,牧草生长受着气象条件的极大制约。本文在构建的牧草生长气象条件指数的基础上,利用1994—2005年牧业气象站的牧草观测资料,通过相关分析,确定了影响牧草产量的关键气象条件指数和影响时段,建立了产草量预报模式。结果表明:2个主要草地年最高产草量与牧草生长季3—9月气象条件指数密切相关,其中北方干旱半干旱草地产草量与气象条件指数的相关时段为3—8月且整个时段相关程度均较高;青藏高原草地相关时段为3—5月、8—9月且后者与气象条件的相关程度高于前者;2个主要草地鲜草产量与气象条件的相关程度高于干草产量。所建产草量预报模式经过历史拟合和外推预报检验,准确率较高,可以满足应用需要。

Natural grassland in China is mainly distributed in North China drought and semidrought regions and in high altitude and cold Qinghai-Tibet Plateau. Its grass growth is greatly influenced by meteorological conditions. In this paper, a meteorological condition index reflecting the influences of precipitation, air temperature and sunlight on the grass growth were developed, and its relationship with the grass yield of main natural grasslands in China was analyzed, based on the grass biomass observation data from animal husbandry meteorological stations in 1994- 2005. For the main natural grasslands in China, there was a close relationship between the meteorological condition index and the grass yield during the growth period from March to September. The fresh and dry grass yields of North China natural grasslands had close correlations with the meteorological condition index from March to August, and a high correlation coefficient was obtained in the periods of time from March to May and from August to September in Qinghai-Tibet Plateau natural grasslands, with a higher correlation coefficient between the fresh and dry grass yields and the meteorological condition index from August to September than from March to May. Comparing with dry grass yield, the fresh grass yield in the two main grassland regions had a higher correlation with the meteorological condition index. Historical simulation and extensive prediction examination showed that using this meteorological condition index to predict grass yield had a higher accuracy, being available in operational prediction.