[1]ZHANG Xifeng,SHEN Dong,TANG Jialiang,et al.Scale Effects on Characteristics of Runoff Processes and Nitrogen Losses in a Small Agricultural Catchment in Purple Soil Region[J].Research of Soil and Water Conservation,2018,25(02):72-80.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
25
Number of periods:
2018 02
Page number:
72-80
Column:
Public date:
2018-04-03
- Title:
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Scale Effects on Characteristics of Runoff Processes and Nitrogen Losses in a Small Agricultural Catchment in Purple Soil Region
- Author(s):
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ZHANG Xifeng1, SHEN Dong2, TANG Jialiang1, WANG Rui1, XUE Fei1
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1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Ministry of Water Resources, Chengdu 610041, China;
2. Mianyang Normal University, Mianyang, Sichuan 621000, China
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- Keywords:
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hydrology; scale effects; runoff process; purple soil; nitrate nitrogen
- CLC:
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X522
- DOI:
-
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- Abstract:
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In order to elucidate the nitrogen loss mechanisms and runoff process in agricultural catchments in hilly purple soil region. Synchronized monitoring on runoff process and nitrogen transport was carried out during three storm events at four cascading small watershed, which are Surong, Jieliu, Daxing and Wan’an catchments. In addition, we analyzed the regulation of nitrogen transportation and scales effects of runoff process. The results showed that the peak discharge had the quick response to rainfall in smaller catchments while delayed and smoothed peak discharge appeared in lower reaches at Daxing and Wan’an stations; total nitrogen (TN), nitrate nitrogen (NO3-N) concentration in the process of rainfall showed the obvious characteristics in the two stage, the drastic fluctuations in the runoff production, and concentration rise in flow withdraw. Compared with Surong station, TN concentrations in larger catchments decreased obviously, NO3-N was the main form of nitrogen loss. According to NCF-NCL curve, short and heavy rain is more likely to produce the ‘first flush’ effect, however, cascading small watershed showed the significant reduction in storm. The subsurface flow and groundwater flow which carries a large number of NO3-N controlled receding process line, and continuously added nitrogen load in the water, showing the ‘end flush’ effect. Regressed empirical equations between cumulated TN load and watershed area were obtained, which could be used to provide reference for estimating nitrogen losses in the similar watersheds.