An Improved Model for Investigating Dual Effects of Vegetation Density Variations and Groundwater Level Fluctuations on
- PDF / 2,124,700 Bytes
- 16 Pages / 595.276 x 790.866 pts Page_size
- 102 Downloads / 171 Views
GENERAL WETLAND SCIENCE
An Improved Model for Investigating Dual Effects of Vegetation Density Variations and Groundwater Level Fluctuations on Water Transport and Dissipation in Raised Field Wetlands Yunlong Zhang 1,2 & Xuan Wang 1,2
&
Dan Liu 1,2 & Yujun Yi 1,2 & Chunhui Li 2 & Qiang Liu 1 & Yanpeng Cai 1,3
Received: 25 July 2019 / Accepted: 7 February 2020 # Society of Wetland Scientists 2020
Abstract An improved model for investigating dual effects of vegetation density variations and groundwater level fluctuations on water transport and dissipation in the soil-plant-atmosphere continuum (SPAC) of raised field wetlands was developed through combining the HYDRUS and the dual crop coefficient models. The results showed the following: (1) the improved model was reliable for soil water and evapotranspiration simulation. For soil water, the coefficient of determination (R2) was above 0.68, the Nash-Sutcliffe efficiency coefficient (NSE) was above 0.53, and the relative deviation (Re) was below 6%. For evapotranspiration, R2, NSE and Re were 0.83, 0.83 and 12.3%, respectively. (2) For the evapotranspiration, both vegetation densities variations and groundwater level fluctuation would affect it. (3) For 0%–60% density, the groundwater level fluctuation mainly contributed to changes in evaporation rather than transpiration. For 80%–100% density, it was transpiration. (4) For the soil water supplement and drainage, under different densities, the main water replenishment source in the same month was almost identical, but the main water drainage approach was inconsistent. (5) For the soil water balance, groundwater level fluctuations had an influence on it, while vegetation density variations did not. This study can provide an method for analyzing water transport in SPAC. Keywords Improved HYDRUS model . Dual crop coefficient models . Vegetation density . Groundwater level . Water transport and dissipation
Introduction In semi-arid areas, water resources are relatively scarce and ecosystems are fragile and highly prone to degradation, maintaining and restoring ecosystem health in semi-arid areas is important (Chesson et al. 2004; Cortina et al. 2011). Wetlands have an irreplaceable role in regulating climate, conserving water, and protecting biodiversity in such areas. Evapotranspiration is one of main ways of lose water of
* Xuan Wang [email protected] 1
State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing 100875, China
2
Key Laboratory for Water and Sediment Sciences of Ministry of Education, Beijing Normal University, Beijing 100875, China
3
Beijing Engineering Research Center for Watershed Environmental Restoration and Integrated Ecological Regulation, School of Environment, Beijing Normal University, Beijing, China
wetlands, which affects water balance and the stability of wetland ecosystems. Therefore, in soil-vegetation-atmosphere continuum (SPAC) of wetland, it is of great significance to study the evapotranspiration response to vegetation, groundwater and other cond
Data Loading...
