Precipitation projection over Daqing River Basin (North China) considering the evolution of dependence structures

Understanding dynamic future changes in precipitation can provide prior information for nonpoint source pollution simulations under global warming. However, the evolution of the dependence structure and the unevenness characteristics of precipitation are rarely considered. This study applied a two-stage bias correction to daily precipitation and max/min temperature data in the Daqing River Basin (DQRB) with the HadGEM3-RA climate model. Validated from 1981 to 2015, future scenarios under two emission paths covering 2031-2065 and 2066-2100 were projected to assess variations in both the amount and unevenness of precipitation. The results suggested that, overall, the two-stage bias correction could reproduce the marginal distributions of variables and the evolution process of the dependence structure. In the future, the amount of precipitation in the plains is expected to increase more than that in the mountains, while precipitation unevenness, as measured by relative entropy, shows a slight increase in the mountains and a decrease in the plains, with enhanced seasonality. Conditioned on rising temperatures, high-/low-intensity precipitation tends to intensify/weaken precipitation unevenness. Additionally, the potential application of the bias correction method used herein and the possible impacts of uneven precipitation on nonpoint source pollution are given for further analyses. This study can provide useful information for future nonpoint source pollution simulations in the DQRB.

Jumping ability is related to change of direction ability in elite handball players

PURPOSE

This study investigated the relationship between vertical and horizontal jumping ability and change of direction (COD) to measure athletic performance in 51 elite male handball players.

SCOPE

Countermovement jump (CMJ), peak power, and standing long jump (SLJ) were measured. Participants performed a 20-m sprint test (time measured at 5, 10, and 20 m) and a zigzag test (COD: 135°, 90°, and 45°). The COD deficit, an index of the time required for COD, was calculated. The correlations between CMJ height and zigzag test times were relatively large (at 135°, r =  - 0.607; at 90°, r =  - 0.594; at 45°, r =  - 0.613; p < 0.01), whereas those between CMJ height and COD deficit were moderate (at 135°, r =  - 0.399, p < 0.01; at 90°, r =  - 0.350, p < 0.05; at 45°, r =  - 0.323, p < 0.05). SLJ showed a negative moderate correlation with COD deficit (at 135°, r =  - 0.439, p < 0.01; at 90°, r =  - 0.469, p < 0.01; at 45°, r =  - 0.380, p < 0.01).

CONCLUSIONS

This study is the first to analyse SLJ ability and COD deficit parameters of handball players. We found that SLJ ability is moderately related to COD time and deficit; therefore, SLJ measurement may be a useful predictor of athletic performance.