THE IMPACT OF METEOROLOGICAL DROUGHT ON STREAMFLOW IN THE JINGHE RIVER BASIN OF CHINA

Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environment and human life. Drought can be categorized as meteorological, agricultural, hydrological or socio-economic drought. Among the different categories of drought, hydrological drought, especially streamflow drought, has been given more attention by governments, researchers and the public in recent years. Identifying the occurrence of streamflow drought and issuing early warning can provide timely information for effective water resources management. Hydrological drought has some relationships with meteorological drought in different areas. In this study, meteorological drought is detected by using the Standardized Precipitation Index (SPI), whereas streamflow drought is detected by the Standardized Runoff Index (SRI). Comparative analyses of frequency, magnitude, onset and duration are conducted to identify the impact of meteorological drought on streamflow drought. This study focuses on the Jinghe River Basin in Northwest China. It mainly provided the following findings. (1) 11 meteorological droughts and 6 streamflow droughts were indicated during 1970 to 1990 after pooling using IC (Inter-event time and volume Criterion) method. (2) Streamflow drought in Jinghe River Basin lagged meteorological drought for about 127 days. (3) The frequency of streamflow drought in Jinghe River Basin was less than meteorological drought. However, the average duration of streamflow drought is longer. (4) The magnitude of streamflow drought is greater than meteorological drought. These results not only play an important theoretical role in understanding relationships between different drought categories, but also have practical implications for streamflow drought prevention and regional water resources management