三江源区气候变化特征及其对天然牧草影响分析——以河南县为例

CHARACTERISTICS OF CLIMATE CHANGE IN SANJIANG SOURCE AREA AND ITS IMPACT ON NATURAL PASTURE——Take the Henan area as an example

根据三江源区河南县牧业试验站1994~2017年天然牧草观测数据和同期气象资料,分析了河南县地区气候变化特征、气候变化与天然牧草长势及其产量的关系,探讨了该地区牧草发育期、高度、覆盖度及产量对气候变化的响应。结果表明,近24a来,该地区年平均气温为0.3℃,气候倾向率以0.66℃/10a,呈显著上升趋势;年平均降水量为566.2mm,气候倾向率以27.7mm/10 a,呈增加趋势;年平均日照时数为2559.8h,倾向率以58.9h/10a,呈增加趋势;年平均蒸发量为1193.0mm,气候倾向率以62.0mm/10a,呈下降趋势;干燥指数变化倾向率以0.2/10a,呈下降趋势;影响该地区牧草返青期的主要因素是热量条件,返青期出现时间与5d滑动日平均气温稳定≥3℃初日基本一致,黄枯期出现时间与5d滑动日平均气温稳定≥10℃的终日相吻合;近24a来,随着温度升高,降水增多,光照条件充足,使该地区的牧草返青期提前,黃枯期推迟,生长期延长,高度有所增高,覆盖度有不明显减小,牧草产量有所增加。为相关部门及单位合理利用草地资源及退化草地的恢复和重建提供参考。

Based on the observation data from animal husbandry meteorological observation station in Sanjiang source area,from 1994 to 2017,the relationship between climate change and natural forage growth and its yield in Henan area was analyzed,the response of forage growth period,height,coverage and yield to climate change in this area was discussed as well. The result showed： The average annual temperature in this area was 0.3,and the climate tendency increased 0.66 C/10 a,the annual average precipitation was 566.2 mm,the climate tendency increased with 27. 7 mm/10 a; the annual average sunshine time is 2559. 8 h,the tendency rate increased with 58.9 h/10 a year,the annual average evaporation was 1193.0 mm,the tendency rate decreased with62.0 mm/10 a,and the tendency of dry index change tended to decrease with 17. 2/10 a in last 24 years. The main factor affected turning green period of herbage was heat condition in this area,the emergence time of returning green period was basically the same as that initial day of 5 d moving average temperature stably above3℃. In the last 24 years,with the increase of temperature,precipitation and light,the herbage in the area was early in the turning green period,the yellow dry period was delayed and the growth period extended,the height increased,although the coverage was not obviously reduced,the yield of herbage increased. It would provide a basic reference for relevant departments and units to make rational use of grassland resources and restore and rebuild degraded grassland.