Based on the data measured in the Jinghe River Basin (JRB) between 1965 and 2014 (including daily precipitation

runoff and concentration)

the spatio-temporall characteristics of hyper-concentrated flow were analyzed. Flows with daily concentration greater than 100 kg/m3 were identified as hyper-concentrated flows. Analysis showed that

the occurrences of hyper-concentrated flows in the JRB can be grouped into three periods

which were 1965—1978

1979—1990 and 2006—2014. Hyper-concentrated flows occurred frequently before 1978

and the occurrence decreased dramatically after 2006. Moreover

the JRB is divided into two parts

the north and the south part

where the temporal distributions of hyper-concentrated flows had different characteristics. For the north part

the sediment yield modus decreased with the increasing drainage area

while the runoff modus increased with increasing drainage area. For the south part

the modus of the runoff and sediment yield both might increase with the increasing drainage area. The temporal characteristics of hyper-concentrated flow were the same in the south and north part

JRB. So

the complex effect sizes during the first period changed to linear relation gradually. Analysis indicates that hyper-concentrated flows are effectively controlled by water and soil conservation practices in the JRB.