Abstract:

Database of precipitation amount in the area of Yantai from 10 monitoring stations was gathered and analyzed in the method of moving-average, linear tendency rate and so on, in order to study the changing patterns of precipitation and its effect to the yield of local main crops. Characteristic of local precipitation from 1961 to 2008 was raised, and in the process annual dynamic variation, distribution and evaluation of precipitation amount was put forward too. The effect of precipitation amount to agricultural yield was analyzed through the method of comparative analysis. The results showed that a downward trend in the variation of precipitation amount in the lately 48 years, the same trend of precipitation was found in the growing season of winter wheat and the sum of total precipitation in this period was 221 mm, which was less than the necessary amount in average. The variation of precipitation during the growing season of autumn corn also showed obvious decreasing trend, while the total quantity could meet the requirement of the crop. The relative variability of the summer precipitation which might cause more frequent drought or flood disaster influenced the sustainable development of agriculture.