Simulation Of Water And Heat Transfer At Ecotone Between Oasis And Desert

This study concerned the Groundwater-Soil-Vegetation-Atmosphere-Continuum on oasis-desert ecotone regions. It is one of emphases and difficulties on GSVAC and its research extent is very shallow. The main reason is the complexity of Groundwater-Soil-Vegetation-Atmosphere Continuum on oasis-desert ecotone regions and the limitation of the human cognition technique. Ecological processes of arid regions consist of water process, soil process, and biologic process. The water process is the cardinal line of ecological process in arid regions. Therefore, this study developed the innovation research by applying mathematical utility based on the water sciences.Water consumption of typical population were simulated based on the Groundwater-Soil-Vegetation-Atmosphere Continuum theory by using MODIS's and experimental data at the field station in Sangong River Watershed of Chinese Academy of Sciences (CAS) in the North slope of Tianshan.The research about Groundwater-Soil-Vegetation-Atmosphere Continuum (GSVAC) model on oasis-desert ecotone is important to maintaining the balance of the ecological system in arid regions. Groundwater-Soil-Vegetation-Atmosphere Continuum (GSVAC) model on oasis-desert ecotone is mainly consisting of the groundwater-soil subsystem and the vegetation-atmosphere subsystem. The exchange mode of Groundwater-Soil-Vegetation-Atmosphere Continuum (GSVAC) model is established according to the principles of conservation of mass, balance of water, and flow continuity. Vegetation transpiration, ground surface evaporation, vegetation canopy temperature, vegetation canopy vapor pressure, sensible heat flux, latent heat flux, and ground surface heat flux in the vegetation-atmosphere subsystem, and water-absorbing capacity, soil temperature distribution, and water-containing distribution in the groundwater-soil subsystem were calculated by using GSVAC model.As far as the solution of model, which unable to be calculated directly because of the complexity of Groundwater-Soil-Vegetation-Atmosphere Continuum (GSVAC) model that were consist of coupling variables with water and temperature. Therefore, the water and heat transformation of Groundwater-Soil-Vegetation-AtmosphereContinuum (GSVAC) model were calculated by using finite difference method in this paper. A computer program of Groundwater-Soil-Vegetation-Atmosphere Continuum (GSVAC) model with GUI interface is designed and developed by using Visual Basic language in succession. It can be used to calculate the vegetation transpiration, ground surface evaporation, temperature and vapor pressure of vegetation canopy, sensible heat flux, latent heat flux, ground surface heat flux, water-absorbing capacity, soil temperature distribution, and water-containing distribution.The experimental data, which were obtained at the field station in Sangong River Watershed of CAS, is used to validation the models of GSVAC and RNN (Regression Neural Network), the results show that the simulated values of GSVAC model are very close to the measured values, with that of RNN model are rather too close to the measured values. Those models and methods presented in this paper are demonstrated to have a certain reliability. Whereafter, sensitive analysis is carried out on the model, the result indicated that the parameters, which are air temperature, air vapor pressure, vegetation coverage, leaf area index (LAI), ground surface water-containing, and ground surface heat, influence greatly to GSVAC model than other parameters.Calculating method of Groundwater-Soil-Vegetation-Atmosphere Continuum (GSVAC) model to the vegetation water consumption of large area have been presented at the end of this paper. Firstly, dividing of the whole area into different type small area will be carry out according to vegetation height, vegetation coverage, leaf area index, and groundwater depth. Secondly, calculating of the vegetation water consumption will be carry out in the small area respectively. Lastly, the vegetation water consumption of the whole area will be obtained through accumulating...