环境变化对黄河中游汾河径流情势的影响研究

Impacts of environmental change on runoff in Fenhe river basin of the middle Yellow River

20世纪70年代后我国许多河流的径流量呈下降的趋势。在这些趋势变化中,如何区分人类活动及气候变化的影响是当前流域水文研究的热点和难点。提出了区分人类活动和气候变化影响的分析思路以及定量计算方法。介绍了SIMHYD概念性降水径流模型,并应用黄河中游汾河流域“天然”时期的水文、气象资料率定了模型参数,通过水文模拟还原了人类活动影响期间的天然径流量,进而分析了汾河流域径流情势的变化原因。结果表明:SIMHYD降水径流模型对汾河流域天然月径流过程具有良好的模拟效果;就1970-1999年的平均状况而言,气候因素和人类活动对径流的影响量分别占径流减少总量的35.9%和64.1%,人类活动是汾河流域径流减少的主要因素。

Runoff in many rivers in China have presented decreasing trend over the past decades. How to identify the effects of eliraate change and human activities in the trend variation are a current hot topic, a diffieuhy problem as well. An assessment method to quantitatively distinguish the effects of climate change and human activities was put forward in the paper. SIMHYD rainfall runoff model was briefly introduced and calibrated with ＂natural＂ hydro-meteorological data in Fenhe River basin. Based on simulation of natural runoff in human-disturbed period with hydrological model, causes of runoff variation were analyzed. And results show that SIMHYD rainfall runoff model has good performance for natural monthly discharge simulation. On average, 35.9% and 64.1% of total annual runoff reduction from 1970 - 1999 were induced by climate change and human activities respectively. Human activities are main reasons of runoff reduction in Fenhe River basin.