黑河莺落峡站年径流长期预报模型研究

Models for Long-term Forecast of Annual Runoff at Yin Lou-xia Station of Heihe River

通过分析黑河莺落峡站出山径流变化规律,并将年径流系列按照频率25%及75%为界,划分成3种情况:即多水年xi>55.0,中水年42.1≤xi≤55.0,小水年xi<42.1。计算其状态转移概率得出:年径流过程从某一状态转移至其他状态的可能性都有,但其转移概率的最大值达81.8%。由此可知,年径流的变化过程不仅有随机性,而且有很强的相依性。通过多年对站年径流预报工作的实践,经过各种方法的比较检验,认为建立前期大气环流因子与年平均流量的预报模型和建立年平均流量的时间序列组合模型,其逐年预报的精度较高,经过误差评定分析,两个模型均为甲级方案,检验预报时性能较稳定,能对莺落峡站年平均流量进行有效预报,为黑河流域调水提供技术支撑。

Having analyzed the changing regularity of out-mountainous runoff at the Yin Luo-xia station on the Heihe River, we took frequency 25% and 75% of annual flow as dividing standards and classified the runoff series into three types： high-flow year with xi〉55.0, moderate-flow year with 42.1≤ xi≤55.0, and low-flow year with xi〈42.1. The calculated shifting frequency showed that annual flow has all sorts of possibility from a state to another state, but the largest shifting frequency reached 81.8%. It can be known that the changing processes of annual flow are random and dependent as well. Forecasting practice and model comparing test all proved that there are two models： the model of annual runoff based on prophase atmospheric current factors and the model of annual runoff time series, which have high forecasting accuracy and stable capability. The models can provide technological support for water adjustment of Heihe River.