• 论文 •

### Impacts of Climatic Factors on Runoff Coefficients in Source Regions of the Huanghe River

CHEN Liqun1,5, LIU Changming1,2, LI Yanping3, WANG Guoqiang4

1. 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
2. College of Water Sciences, Beijing Normal University, Beijing 100875, China;
3. Department of Foreign Languages, China University of Petroleum, Beijing 102249, China;
4. Department of Civil and Environmental Engineering, University of Yamanashi, Yamanashi 400-8511, Japan;
5. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
• 收稿日期:2006-05-28 修回日期:2006-10-30 出版日期:2007-03-20 发布日期:2011-12-15
• 通讯作者: CHEN Liqun.E-mail:yeliqun304@163.com E-mail:yeliqun304@163.com
• 基金资助:

Under the auspices of the Major State Basic Research Development Program of China (No.G19990436-01);the Na-tional Natural Science Foundation of China (No.40471127)

### Impacts of Climatic Factors on Runoff Coefficients in Source Regions of the Huanghe River

CHEN Liqun1,5, LIU Changming1,2, LI Yanping3, WANG Guoqiang4

1. 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
2. College of Water Sciences, Beijing Normal University, Beijing 100875, China;
3. Department of Foreign Languages, China University of Petroleum, Beijing 102249, China;
4. Department of Civil and Environmental Engineering, University of Yamanashi, Yamanashi 400-8511, Japan;
5. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
• Received:2006-05-28 Revised:2006-10-30 Online:2007-03-20 Published:2011-12-15

Runoff coefficients of the source regions of the Huanghe River in 1956-2000 were analyzed in this paper. In the 1990s runoff of Tangnaihai Hydrologic Station of the Huanghe River experienced a serious decrease, which had at-tracted considerable attention. Climate changes have important impact on the water resources availability. From the view of water cycling, runoff coefficients are important indexes of water resources in a particular catchment. Kalinin baseflow separation technique was improved based on the characteristics of precipitation and streamflow. After the separation of runoff coefficient (R/P), baseflow coefficient (Br/P) and direct runoff coefficient (Dr/PM) were estimated. Statistic analyses were applied to assessing the impact of precipitation and temperature on runoff coefficients (including Dr/PM, Br/P and R/P). The results show that in the source regions of the Huanghe River, mean annual baseflow coefficient was higher than mean annual direct runoff coefficient. Annual runoff coefficients were in direct proportion to annual pre-cipitation and in inverse proportion to annual mean temperature. The decrease of runoff coefficients in the 1990s was closely related to the decrease in precipitation and increase in temperature in the same period. Over different sub-basins of the source regions of the Huanghe River, runoff coefficients responded differently to precipitation and temperature. In the area above Jimai Hydrologic Station where annual mean temperature is-3.9oC, temperature is the main factor in-fluencing the runoff coefficients. Runoff coefficients were in inverse relation to temperature, and precipitation had nearly no impact on runoff coefficients. In subbasin between Jimai and Maqu Hydrologic Station Dr/PM was mainly affected by precipitation while R/P and Br/P were both significantly influenced by precipitation and temperature. In the area be-tween Maqu and Tangnaihai hydrologic stations all the three runoff coefficients increased with the rising of annual precipitation, while direct runoff coefficient was inversely proportional to temperature. In the source regions of the Huanghe River with the increase of average annual temperature, the impacts of temperature on runoff coefficients be-come insignificant.

Abstract:

Runoff coefficients of the source regions of the Huanghe River in 1956-2000 were analyzed in this paper. In the 1990s runoff of Tangnaihai Hydrologic Station of the Huanghe River experienced a serious decrease, which had at-tracted considerable attention. Climate changes have important impact on the water resources availability. From the view of water cycling, runoff coefficients are important indexes of water resources in a particular catchment. Kalinin baseflow separation technique was improved based on the characteristics of precipitation and streamflow. After the separation of runoff coefficient (R/P), baseflow coefficient (Br/P) and direct runoff coefficient (Dr/PM) were estimated. Statistic analyses were applied to assessing the impact of precipitation and temperature on runoff coefficients (including Dr/PM, Br/P and R/P). The results show that in the source regions of the Huanghe River, mean annual baseflow coefficient was higher than mean annual direct runoff coefficient. Annual runoff coefficients were in direct proportion to annual pre-cipitation and in inverse proportion to annual mean temperature. The decrease of runoff coefficients in the 1990s was closely related to the decrease in precipitation and increase in temperature in the same period. Over different sub-basins of the source regions of the Huanghe River, runoff coefficients responded differently to precipitation and temperature. In the area above Jimai Hydrologic Station where annual mean temperature is-3.9oC, temperature is the main factor in-fluencing the runoff coefficients. Runoff coefficients were in inverse relation to temperature, and precipitation had nearly no impact on runoff coefficients. In subbasin between Jimai and Maqu Hydrologic Station Dr/PM was mainly affected by precipitation while R/P and Br/P were both significantly influenced by precipitation and temperature. In the area be-tween Maqu and Tangnaihai hydrologic stations all the three runoff coefficients increased with the rising of annual precipitation, while direct runoff coefficient was inversely proportional to temperature. In the source regions of the Huanghe River with the increase of average annual temperature, the impacts of temperature on runoff coefficients be-come insignificant.