Acta Geographica Sinica ›› 2020, Vol. 75 ›› Issue (5): 1065-1078.doi: 10.11821/dlxb202005013

• Climate Change and Surface Process • Previous Articles     Next Articles

Multi-time scale analysis of water conservation in a discontinuous forest watershed based on SWAT model

LIN Feng1,2, CHEN Xingwei2(), YAO Wenyi3, FANG Yihui4, DENG Haijun2, WU Jiefeng5, LIN Bingqing2   

  1. 1.Key Laboratory of Soil Erosion Process and Control on the Loess Plateau, Ministry of Water Resources, Zhengzhou 450003, China
    2.School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
    3.Yellow River Institute of Hydraulic Research, Zhengzhou 450003, China
    4.Information Management and Engineer Department, Fujian Business University, Fuzhou 350012, China
    5.Research Center of Water Resources and Environment, Sun Yat-Sen University, Guangzhou 510275, China
  • Received:2019-05-14 Revised:2020-02-10 Online:2020-05-25 Published:2020-07-25
  • Contact: CHEN Xingwei E-mail:cxwchen215@fjnu.edu.cn
  • Supported by:
    The Foundation of the Key Laboratory of Soil Erosion Process and Control on the Loess Plateau, Ministry of Water Resources(2017003);National Natural Science Foundation of China(41877167)

Abstract:

A method has been developed based on the Soil and Water Assessment Tool (SWAT) to quantitatively evaluate the water conservation function of forests and its multi-time scale characteristics in a discontinuous forest watershed. Using this method, we have divided hydrological response units (HRU) based on the spatial distribution of forests, and derived a formula to quantify the water conservation in discontinuous forest watershed based on the water balance method. Here we take the Jinjiang River Basin in southeast coastal China as an example. We constructed SWAT model under land use conditions in 2006 and analyzed the temporal variation of forest water conservation in the study river basin under precipitation conditions from 2002 to 2010. The results show that (1) the SWAT model of the study area is of high accuracy, and the hydrological response unit can accurately reflect the distribution of forest patches when the area threshold is zero. The model provides a new method for evaluation of forest water conservation function in the discontinuous forest watershed using a distributed hydrological model. (2) The annual conservation of forest water in the Jinjiang River Basin was 271.41-565.25 mm. The annual conservation function of forest water is relatively stable, and there was no runoff regulation between consecutive years. The monthly conservation ranged from -29.15 mm to 154.59 mm, which is positive for most months of the year. The forest water conservation was positive in extreme precipitation period, and negative in extremely dry period. This demonstrates the function of forest water conservation in retaining rainwater in wet periods to decrease flood in the river and supplying water in dry periods to supplement the flow at the daily scale was more effective than that at the monthly scale.

Key words: forest water conservation, water balance method, distributed hydrological model, Jinjiang River Basin