scholarly journals Spatial and Temporal Variability in the Precipitation Concentration in the Upper Reaches of the Hongshui River Basin, Southwestern China

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Ya Huang ◽  
Hao Wang ◽  
Weihua Xiao ◽  
Li-hua Chen ◽  
Deng-hua Yan ◽  
...  
Keyword(s):  
River Basin ◽  
Temporal Variability ◽  
Water Resource Management ◽  
Statistical Characteristics ◽  
Southwestern China ◽  
Spatial And Temporal Variability ◽  
Drought Risk ◽  
Precipitation Concentration ◽  
Atmospheric Circulation Indices ◽  
Concentration Indices

The statistical characteristics of precipitation play important roles not only in flood and drought risk assessments but also in water resource management. This paper implements a statistical analysis to study the spatial and temporal variability in precipitation in the upper reaches of the Hongshui River basin (UHRB), southwestern China, by analysing time series of daily precipitation from 18 weather stations during the period of 1959 to 2015. To detect precipitation concentrations and the associated patterns, three indices, the precipitation concentration index (PCI), precipitation concentration degree (PCD), and precipitation concentration period (PCP), were used. The relationships between the precipitation concentration indices (PCI, PCD, and PCP) and geographic variables (latitude, longitude, and elevation), large-scale atmospheric circulation indices, and summer monsoon indices were investigated to identify specific dependencies and spatial patterns in the precipitation distribution and concentration. The results show that high PCI values were mainly observed in the northeastern portion of the basin, whereas low PCI values were mainly detected in the southwest. The Mann-Kendall test results demonstrate that the majority of the UHRB is characterized by nonsignificant trends in the PCI, PCD, and PCP from 1959 to 2015. The PCP results reveal that rainfall in the UHRB mainly occurs in summer months, and the rainy season arrives earlier in the eastern UHRB than in the western UHRB. Additionally, the PCD results indicate that the rainfall in the western UHRB is more dispersed throughout the year than that in the eastern UHRB. Compared with other geographical factors, longitude is the most important variable that governs the spatial distribution and variations in annual precipitation and the precipitation concentration indices. Due to a combination of topography, the Indian subtropical high, and monsoon weakening, precipitation may be more concentrated in one period, especially in the eastern part of the basin, which increases the risk of drought.

scholarly journals Links between East Coast Lows and the spatial and temporal variability of rainfall along the eastern seaboard of Australia

2016 ◽  
Vol 66 (2) ◽  
pp. 162
Author(s):  
Anthony S. Kiem ◽  
Callum Twomey ◽  
Natalie Lockart ◽  
Garry Willgoose ◽  
George Kuczera ◽  
...  
Keyword(s):  
Temporal Variability ◽  
East Coast ◽  
Water Security ◽  
Rainfall Simulation ◽  
Spatial And Temporal Variability ◽  
Drought Risk ◽  
Urban Water ◽  
Catchment Scale ◽  
Duration Magnitude ◽  
Eastern Seaboard

East Coast Lows (ECLs) are intense low-pressure systems which occur over the subtropical east coasts of southern and northern hemisphere continents. ECLs are typically associated with gale force winds, large seas, storm surges, heavy rainfall and flooding. While ECL impacts are typically seen as negative the rainfall associated with ECLs is also very important for urban water security within the heavily populated eastern seaboard of Australia (ESA). This study investigates historical ECLs to gain insights into the timing, frequency, intensity and location of ECL occurrence as well as the magnitude and spatial extent of ECL impacts on rainfall. The different characteristics and impacts associated with different ECL sub-types are highlighted and it is proposed that this spatial and temporal variability in ECL behaviour at least partially explains why the ESA is hydroclimatically different to the rest of Australia and why different locations within the ESA have such different rainfall patterns—and therefore different levels of flood and drought risk. The-se insights are critical to the objectives of the New South Wales government funded Eastern Seaboard Climate Change Initiative (ESCCI), in particular Project 5 which focuses on the water security impacts of ECLs. The results of this work will be used to produce climate-informed stochastic daily rainfall simulations that are more realistic than existing stochastic rainfall simulation methods at preserving the statistics important for catchment-scale hydrology (e.g. clustering of extreme events, long-term persistence, frequency/duration/magnitude of wet and dry spells). These simulated rainfall sequences, that incorporate the spatial and temporal hydroclimatic variability caused by ECLs and other climate phenomena, are important inputs into the hydrological models used to determine current and future urban water security within the ESA.

Sign in / Sign up

Export Citation Format

Share Document