Analysis on Runoff Variation Trend and Characteristics in Duhe River

2021 ◽  
Vol 10 (04) ◽  
pp. 426-434
Author(s):  
绍峰 顾
Keyword(s):  
Variation Trend ◽  
Runoff Variation

scholarly journals Research on runoff variation trend and hydrological situation variation in Wujiang River Basin

2021 ◽  
Vol 826 (1) ◽  
pp. 012004
Author(s):  
Guo Wei ◽  
Shao Jun ◽  
Ou Yangshuo ◽  
Yao Liqiang ◽  
Wu Guangdong ◽  
...  
Keyword(s):  
River Basin ◽  
Variation Trend ◽  
Runoff Variation ◽  
Wujiang River

scholarly journals Performance Evaluation of a Two-Parameters Monthly Rainfall-Runoff Model in the Southern Basin of Thailand

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1226
Author(s):  
Pakorn Ditthakit ◽  
Sirimon Pinthong ◽  
Nureehan Salaeh ◽  
Fadilah Binnui ◽  
Laksanara Khwanchum ◽  
...  
Keyword(s):  
Exchange Rate ◽  
Rainfall Runoff ◽  
Management Planning ◽  
Runoff Variation ◽  
Groundwater Exchange ◽  
Monthly Runoff ◽  
Rainfall Runoff Model ◽  
Two Parameters ◽  
Runoff Model

Accurate monthly runoff estimation is crucial in water resources management, planning, and development, preventing and reducing water-related problems, such as flooding and droughts. This article evaluates the monthly hydrological rainfall-runoff model’s performance, the GR2M model, in Thailand’s southern basins. The GR2M model requires only two parameters: production store (X1) and groundwater exchange rate (X2). Moreover, no prior research has been reported on its application in this region. The 37 runoff stations, which are located in three sub-watersheds of Thailand’s southern region, namely; Thale Sap Songkhla, Peninsular-East Coast, and Peninsular-West Coast, were selected as study cases. The available monthly hydrological data of runoff, rainfall, air temperature from the Royal Irrigation Department (RID) and the Thai Meteorological Department (TMD) were collected and analyzed. The Thornthwaite method was utilized for the determination of evapotranspiration. The model’s performance was conducted using three statistical indices: Nash–Sutcliffe Efficiency (NSE), Correlation Coefficient (r), and Overall Index (OI). The model’s calibration results for 37 runoff stations gave the average NSE, r, and OI of 0.657, 0.825, and 0.757, respectively. Moreover, the NSE, r, and OI values for the model’s verification were 0.472, 0.750, and 0.639, respectively. Hence, the GR2M model was qualified and reliable to apply for determining monthly runoff variation in this region. The spatial distribution of production store (X1) and groundwater exchange rate (X2) values was conducted using the IDW method. It was susceptible to the X1, and X2 values of approximately more than 0.90, gave the higher model’s performance.

scholarly journals Recent shrinkage and hydrological response of Hailuogou glacier, a monsoon temperate glacier on the east slope of Mount Gongga, China

2010 ◽  
Vol 56 (196) ◽  
pp. 215-224 ◽  
Author(s):  
Qiao Liu ◽  
Shiyin Liu ◽  
Yong Zhang ◽  
Xin Wang ◽  
Yingsong Zhang ◽  
...  
Keyword(s):  
Daily Rainfall ◽  
Annual Runoff ◽  
Aerial Photographs ◽  
Flow Measurements ◽  
Runoff Variation ◽  
Runoff Change ◽  
Weather Stations ◽  
Local Water ◽  
Total Discharge ◽  
Daily Total

AbstractTemperate glaciers are more sensitive to climate changes than polar or continental glaciers, and can drive remarkable runoff variation in local water catchments. Here we present recent glacier shrinkage and runoff change for Hailuogou glacier, a typical monsoon temperate glacier on the east slope of Mount Gongga (Minya Konga), China. The surface area of Hailuogou glacier has decreased by 3.5% (0.92 km2) between 1966 (aerial photographs) and 2007 (ASTER images). Flow measurements at a stream gauge about 500 m down-glacier commencing in 1994 display a remarkable increase in annual runoff (mostly during July–September) since 1999. Annual runoff over the same period in a nonglacierized but forested subcatchment (9.17 km2) did not experience significant change. By separating the daily rainfall component from the daily total discharge, monthly catchment water-balance series were calculated for the period 1994–2005, which shows an increasing trend of glacier storage loss. We concluded that air-temperature rise (with a trend of +0.2°C (10 a)−1 between 1988 and 2005, recorded at nearby weather stations) has had an increased effect on glacier mass loss and river runoff change during the past 20 years.

scholarly journals Investigation on the Mathematical Relation Model of Structural Reliability and Structural Robustness

2021 ◽  
Vol 26 (2) ◽  
pp. 26
Author(s):  
Qi-Wen Jin ◽  
Zheng Liu ◽  
Shuan-Hai He
Keyword(s):  
Structural Damage ◽  
Structural Reliability ◽  
Relational Model ◽  
Engineering Practice ◽  
Variation Trend ◽  
Evaluation Indexes ◽  
Structural Robustness ◽  
Mathematical Relation ◽  
Relation Model ◽  
Random Variation

Structural reliability and structural robustness, from different research fields, are usually employed for the evaluative analysis of building and civil engineering structures. Structural reliability has been widely used for structural analysis and optimization design, while structural robustness is still in rapid development. Several dimensionless evaluation indexes have been defined for structural robustness so far, such as the structural reliability-based redundancy index. However, these different evaluation indexes are usually based on subjective definitions, and they are also difficult to put into engineering practice. The mathematical relational model between structural reliability and structural robustness has not been established yet. This paper is a quantitative study, focusing on the mathematical relation between structural reliability and structural robustness so as to further develop the theory of structural robustness. A strain energy evaluation index for structural robustness is introduced firstly by considering the energy principle. The mathematical relation model of structural reliability and structural robustness is then derived followed by a further comparative study on sensitivity, structural damage, and random variation factor. A cantilever beam and a truss beam are also presented as two case studies. In this study, a parabolic curve mathematical model between structural reliability and structural robustness is established. A significant variation trend for their sensitivities is also observed. The complex interaction mechanism of the joint effect of structural damage and random variation factor is also reflected. With consideration of the variation trend of the structural reliability index that is affected by different degrees of structural damage (mild impairment, moderate impairment, and severe impairment), a three-stage framework for structural life-cycle maintenance management is also proposed. This study can help us gain a better understanding of structural robustness and structural reliability. Some practical references are also provided for the better decision-making of maintenance and management departments.

scholarly journals Current status and variation trend of seagrass beds in coastal water of Son Tra peninsula, Da Nang city

2021 ◽  
Vol 21 (2) ◽  
pp. 183-189
Author(s):  
Hoa Nguyen Xuan ◽  
Nhu Thuy Nguyen Nhat ◽  
Hieu Nguyen Trung
Keyword(s):  
Species Composition ◽  
Coastal Water ◽  
Shoot Density ◽  
Current Status ◽  
Seagrass Beds ◽  
Variation Trend ◽  
Halophila Ovalis ◽  
Density And Biomass ◽  
Size And Structure

Species composition of seagrasses in coastal water of Son Tra peninsula was less diverse, with three species identified. Halophila ovalis was dominant. The seagrass beds are mainly distributed in Bai Nom and Bai But, with a total area of about 1 ha. The seagrass beds had been seriously degraded in both size and structure. Approximately 9 ha of seagrass beds (90% of total area) disappeared compared with data of 2005. Halophila ovalis had only been distributed at a depth of 2–3 m. Coverage, shoot density, and biomass of seagrass beds had also decreased.

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