52 a来秦岭南北径流变化对比及影响因素

运用集中期、M-K突变检验法、径流系数等数理统计方法，基于1960-2011年马渡王与南宽坪径流数据及气象数据，对比分析灞河与金钱河流域径流变化特征，揭示秦岭南北气候变化差异得出：（1）52 a来灞河与金钱河年均径流深变化趋势相似，金钱河年径流深的变异程度大于灞河；（2）灞河与金钱河流域径流与降水在年内分配上存在滞后效应，秦岭南北从流域降水开始经过停蓄、漫流、河槽集流，然后汇流至金钱河河道大概需要20 d 左右的时间；（3）秦岭南北气候因子突变的时间点具有一致性，均发生在1990年左右，该突变可能是由于大尺度的气候变化导致局部地区自然环境变化引起的；（4）径流变化的下降趋势是降水、气温、植被变化和人类活动综合作用的结果。20世纪90年代末的径流突变主要原因是气候变化引起的，人类活动对其影响十分微小，因此，某些明显的突变现象是由于大的气候变化引起的，人类活动的影响是一个长期的过程，所以对自然资源应采取开发与治理同时进行。

Runoff variation and its influencing factors compared between south and north of Qinling Mountains during 50 years

This paper contrasts runoff change and main influence factors of Bahe River and Jinqianhe River on north and south slopes of the Qinling Mountains，aims to reveal the difference in hydrology and climatology change in the north and south Qinling Mountains，to provide a quantitative analysis data base for the climate change research of the Qinling Mountains region. Based on runoff、precipitation data of Maduwang and Nankuanping Stations from 1960 to 2011，the mathematical statistical methods such as concentration period，M-K mutation，runoff coefficient were used and compared runoff variation of Bahe River basin and Jinqianhe River basin and revealled the difference in environmental change of the south and north Qinling Mountains. The conclusions are as follows：（1） The trend of variation in annual mean runoff depthes of Bahe and Jinqianhe River basins basically was similar during the last 52 years，the runoff change reflected a wave rise from 1960s to 1990s，after 1990s it showed an obvious fluctuation decline trend. The annual runoff depth variation of Jinqianhe River was greater than that of Bahe River. （2） The annual runoff variation tendency of Jinqianhe and Bahe Rivers was consistent in the last 50 years，the runoff is mainly concentrated in summer and autumn seasons，the runoff and precipitation have a lag effect in the Qinling Mountains river basins；it takes about 20 d from the basin precipitation beginning for rainwater storage stopping，overflowing，river tunnel collecting，and then converging to rives of the north and south Qinling Mountains. （3） The time mutation points of the runoff in the Qinling Mountains were characterized by consistency，they all occurred in 1990 or so，the mutation is not caused by local human activities，but due to the larger scale climate change which leads to a change in the local natural environment. （4） The runoff depth decreased significantly after mutation than before mutation in Bahe River and Jinqianhe River basins from 1960 to 2011，the precipitation showed a trend of decrease as a whole in Bahe River and Jinqianhe River basins，indicating that the precipitation is one of factors affecting the runoff depth. Their runoff coefficients had a downward trend，meaning that part of rainfall converting to runoff becomes less and less in the north and south Qinling Mountains，the part of rainoff that is intercepted by plants or filled into depresses，infiltration and evaporation increased，this is due to the increased temperatures increasing vegetation activity，thus making the runoff a decline trend. （5） During recent 50 years，the Jinqianhe River was affected by human activity are much smaller than the Bahe River. The runoff coefficients and double mass curve method were used to analyze quantitatively runoff change effect factors，the conclusion shows that the combination of climate change and human activities influences the runoff variation. The mutations of runoff in the late 1990s was mainly caused by climate change. In fact，some obvious mutation phenomenon is caused by the heavy climate change，the impact of human activities on the natural environment is slow in time，and the process of governance also requires a lot of time and money，so the development and management for natural resource should be taken simultaneously.