Study On Coupling Simulation Of Water Carbon Process In Desert Riparian Forest Ecosystem And Integration Of Web Services

In the past 30 years,with the continuous development of oasis cities in arid area,the problems and contradictions of water shortage and low vegetation coverage had become increasingly prominent.It was urgently needed to effectively coordinate and mitigate the multiple contradictions between vegetation restoration,water resources supply,and climate change.The scientific and integrated management of water and carbon resources in arid area was an effective way to solve the contradiction and the water-carbon coupling model can provide important decision support for it.The upstream area of the mainstream of Tarim River and Yanqi Basin,the typical arid region,had been selected as the research object.Based on the study of the theoretical framework and operating mechanism of the Wa SSI-C model(Water Supply Stress Index-Carbon model)and according to the characters of natural geography and the environment in the study area,the model of calculating the melt of glaciesrs had been added to improve the applicability of the Wa SSI-C model.Using SPPS software and Matlab genetic algorithm GUI,the running parameters of the model had been calibrated.On this basis,the study period had been divided into calibration(2000-2009)and validation(2010-2015)periods,and the data of measured runoff,MODIS evapotranspiration(ET)and total ecosystem productivity(GEP)in the study area had been statistically analyzed.After that,the precision of the simulation of the model had been evaluated using the coefficient of determination(R~2)and the efficiency coefficient(NS)and the spatial distribution characteristics of resources of water and carbon of the study area had been discussed using the technique of GIS Spatial Analysis.Finally,a general Web service system of Wa SSI-C model had been designed and implemented.The research results of the article were as follows:(1)The operation parameters of the WaSSI-C model can be calibrated through the combination of SPSS software and Matlab genetic algorithm tool GUI.(2)In the Yanqi Basin,The R~2 of calibration and verification period for the total runoff of the study area were 0.80 and 0.77 respectively,and NS was 0.77 and 0.69 respectively;The R~2 for ET were 0.82 and0.79 respectively,NS was 0.80 and 0.76 respectively;The R~2 for GEP were 0.88 and 0.87,NS were 0.87and 0.82.It shown that the applicability of the improved Wa SSI-C model in Yanqi Basin was excellent.(3)In the upper area of the mainstream of the Tarim River,the R~2 of calibration and verification period for the total runoff of the basin were 0.72 and 0.68 respectively,and NS was 0.71 and 0.67 respectively;The R~2 for ET were 0.60 and 0.64 respectively,NS was 0.60 and 0.56 respectively;The R~2 for GEP were0.68 and 0.61,NS were 0.66 and 0.69.The two evaluation indexes of the simulation results were all maintained at 0.6 and above,except for the NS of verification period for ET.So it can be seen that the model can well simulate the dynamic changes of water and carbon resources in the upstream area of the mainstream of Tarim River.(4)The simulation results shown that the water and carbon resources in Yanqi basin and the upper area of the mainstream of the Tarim River possessed obvious spatial heterogeneity.Among them,the spatial distribution of the runoff in the Yanqi basin had shown the characteristics of higher in the West and lower in the east and higher in the north and lower in the South.The distribution of ET and GEP had shown the characteristics of higher in the middle and lower in the around.The distribution of ET and GEP in the upper area of the mainstream of the Tarim River had shown the distribution characteristics of higher in the West and lower in the east,and the distribution of runoff was opposite.(5)The WaSSI-C model universal Web service system can provide effective tool support for arid regions.The core functions of the Wa SSI-C model were almost all covered by the Wa SSI-C model general web service system in this paper.The system had successfully realized the online visualization of Wa SSI-C model.And the operation mode of the system was based on the process,so it was easy to understand and had a merit of friendly human-machine interaction.