基于降水资源特征分析的西北半干旱区小流域种植业结构的调整——以定西市九华沟流域为例

Adjustment of the Small Watershed Planting Structure in Northwest Semiarid Regions Based on the Analysis of the Precipitation Resource Characteristics

根据研究区降水少、变率大、旱灾频繁的基本规律,特别是降水季节分配不均、有效性差的降水资源特征,得出西北半干旱地区降雨对作物产量的影响不仅与年降雨量的多寡相关,而且与降雨的时空分布有极大关系。分别就夏粮作物、秋粮作物单产量与年降雨量和作物生长期降雨量的相关程度,讨论了九华沟流域种植业结构的调整。

According to the basic laws of less precipitation, high variable rate, frequent droughts in the study area, especially, the characteristics of precipitation resources （the uneven seasonal distribution of the precipitation and poor effectiveness）, a conclusion was drawn that the effects of precipitation in northwest semiarid areas on the crop yield was not only related to the amount of annual rainfall, but it was also related to the space and time distribution of precipitation. The adjustment of planting structure in Jiuhuagou Watershed was discussed according to the size of the correlation coefficient between the single yield of summer crops and autumn crops and annual precipitation and the rainfall precipitation in the growth period of crops.