scholarly journals Regression equations to estimate seasonal flow duration, n-day high-flow frequency, and n-day low-flow frequency at sites in North Dakota using data through water year 2009

Author(s):  
Tara Williams-Sether ◽  
Tara A. Gross
Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 212 ◽  
Author(s):  
Zhipeng Xu ◽  
Wenfei Liu ◽  
Xiaohua Wei ◽  
Houbao Fan ◽  
Yizao Ge ◽  
...  

Fruit tree planting is a common practice for alleviating poverty and restoring degraded environment in developing countries. Yet, its environmental effects are rarely assessed. The Jiujushui watershed (261.4 km2), located in the subtropical Jiangxi Province of China, was selected to assess responses of several flow regime components on both reforestation and fruit tree planting. Three periods of forest changes, including a reference (1961 to 1985), reforestation (1986 to 2000) and fruit tree planting (2001 to 2016) were identified for assessment. Results suggest that the reforestation significantly decreased the average magnitude of high flow by 8.78%, and shortened high flow duration by 2.2 days compared with the reference. In contrast, fruit tree planting significantly increased the average magnitude of high flow by 27.43%. For low flows, reforestation significantly increased the average magnitude by 46.38%, and shortened low flow duration by 8.8 days, while the fruit tree planting had no significant impact on any flow regime components of low flows. We conclude that reforestation had positive impacts on high and low flows, while to our surprise, fruit tree planting had negative effects on high flows, suggesting that large areas of fruit tree planting may potentially become an important driver for some negative hydrological effects in our study area.


2020 ◽  
Author(s):  
Qining Shen ◽  
Zhentao Cong

<p>It is widely recognized that urbanization has a significant impact on streamflow characteristics. However, the influences of economic development, increasing population and positioning of urban development on streamflow regimes is still not fully understood. This study aims to clarify these influences by analyzing 134 catchments in China and 1064 catchments in the United State. Urbanization metrics were derived from gridded GDP dataset, gridded population dataset and land use/land cover datasets, while the streamflow characteristics were calculated using annual streamflow and mean daily discharge data. The statistical analysis indicated that the rate of change in rainfall-runoff ratio is positively related to the growth rate of GDP and urban area both in China and the U.S., but this relationship was not found in population growth rate. Increasing the extent of urbanized area increased high and low flow frequency in Kansas metropolitan region as well as San Antonio metropolitan region, while reduced low flow frequency in Atlanta metropolitan region. In addition, urban expansion also enhanced streamflow flashiness. Compared to down-stream development, up-stream development increased high flow volume in Atlanta metropolitan region and Kansas metropolitan region, while decreased high flow volume in San Antonio metropolitan region and low flow volume in all study metropolitan regions. The findings in this study provide a sight for future researches in hydrological variation due to urbanization.</p>


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