Variations of precipitation characteristics during the period 1960–2014 in the Source Region of the Yellow River, China

Abstract

Precipitation, a natural feature of weather systems in the Earth, is vitally important for the environment of any region. Under global climate change condition, the characteristics of precipitation have changed as a consequence of enhanced global hydrological cycle. The source region of the Yellow River (SRYR), locating within the Qinghai-Tibet Plateau, is sensitive to the global climate change due to its complex orography and fragile ecosystem. To understand the precipitation characteristics and its impacts on the environment in the region, we studied the characteristics of rainy days and precipitation amount of different precipitation classes, such as light (0-5 and 5-10 mm), moderate (10-15, 15-20 and 20-25 mm) and heavy (≥25 mm) rains by analyzing the precipitation data of typical meteorological stations in the SRYR during the period 1961-2014, as well as the trends of persistent rainfall events and drought events. Results showed that annual average precipitation in this area had a non-significant (P>0.05) increasing trend, and 82.5% of the precipitation occurred from May to September. Rainy days of the 0-5 mm precipitation class significantly decreased, whereas the rainy days of 5-10, 10-15, and 20-25 mm precipitation classes increased and that of ≥25 mm precipitation class decreased insignificantly. The persistent rainfall events of 1-or 2-day and more than 2-day showed an increasing trend, with the 1-or 2-day events being more frequent. Meanwhile, the number of short drought periods (≤10 days) increased while long drought periods (>10 days) decreased. Since the 0-5 mm precipitation class had a huge impact on the grasslands productivity; the 5-10, 10-15, and 20-25 mm precipitation classes had positive effects on vegetation which rely on the deep soil water through moving nutrients and water into the root zone of these vegetation or through the plant-microbe interactions; the ≥25 mm precipitation class contributed to the floods; and more persistent rainfall events and fewer long drought events inferred positive effects on agriculture. Thus, these results indicate grassland degradation, less risk of floods, and the upgrading impact of climate change on agriculture. This study may provide scientific knowledge for policymakers to sustain the eco-environmental resources in the SYSR.

Precipitation Variations under a Changing Climate from 1961–2015 in the Source Region of the Indus River

“…The double mass curve method disclosed a straight line at all stations, showing no breakpoints, which confirms the reliability of the precipitation time series. [39,40] also confirmed such results by using the double mass curve method in their studies conducted in the Yellow River basin, China.…”

“…For the analysis of different characteristics of precipitation in the SRIR, the daily precipitation rate was divided into different classes, e.g., 0-10 mm day −1 precipitation was described as light precipitation, 10.1-25 mm day −1 precipitation was described as moderate precipitation, while precipitation greater than 25 mm day −1 was described as heavy precipitation. A similar classification of daily precipitation has been used by different researchers for the analysis of precipitation in different regions [12,13,[40][41][42].…”

“…Most of the precipitation in the study area took place as light and heavy precipitation. According to Iqbal [40], precipitation with a duration of 1-2 days was demarcated as short-duration wet spells, and precipitation with a duration of more than 2 days was defined as long-duration wet spells. Gong [41] used short-and long-duration precipitation to examine the continuation of precipitation events.…”

Differential changes in precipitation and runoff discharge during 1958–2017 in the headwater region of Yellow River of China

“…A simulation study by Li et al (2012) suggested that a decline in precipitation, especially in the summer season, is a primary driver of decreasing runoff in the upper reach of Yellow River, while temperature rises may play a secondary role. Iqbal et al (2018) mentioned that the short drought significantly increased (periods without rain for ≤ 10 d) in SRYR, which might result in low soil moisture and hinder the runoff process. Lan et al (2010) also attributed the changes in runoff in the headwater region of Yellow River more to the influence of precipitation than temperature.…”

Deterministic and probabilistic projections and their credibility in analyzing future precipitation variations in the Yellow River Basin, China

“…The vulnerable natural system in the YRB is of interest to researchers worldwide because it reflects the evolution of water resources under climate change and human activity in the future (Wu et al 2016;Wang et al 2019b). Moreover, the precipitation in the YRB has changed in time and space for decades (Lu et al 2014;Zhang et al 2014Zhang et al , 2019Iqbal et al 2018;Zhao et al 2019), arousing many concerns and prompting research on future precipitation change as well as its impact on hydrology and water resources. The GCMs provide scenario determination and forcing data, forming the basis of climate change projection.…”