Study On Runoff And Sediment Simulation And Estuarine Tidal Flat Response Under The Influence Of Changing Environment

Water resources are the key between the natural environment and human society.Climate change directly affects the spatial and temporal distribution,intensity and total change of precipitation.Human activities have changed land use that water cycle process was affected.The transformation of forests dominated by artificial eucalyptus forests is fundamentally changing the spatial and temporal distribution characteristics of land use in Guangxi,China in the past two decades.Artificial eucalyptus planting patterns with climate change directly affect runoff and sediment fluxes at the basin scale.Changes in runoff and sediment will have a profound impact on the estuarine ecosystem.This paper makes significant trend test,mutation test and cycle analysis on hydrological observation data,in order to assess hydrological nonstationarity.Based on land use data and remote sensing data to monitoring land use change,vegetation cover change,and disturbance changes and built the SWAT model before and after planting eucalyptus plantations.The varying of SWAT model parameters in the changing environment of climate and underlying surface changes have been discussed in this paper.We spatially expanded the parameters of the SWAT model,based on hydrological similarity,in order to calculate runoff and sediment into the sea.Finally,we analyzed the changes in the estuary based on sea level data and remote sensing image data.The results show that precipitation increase weakly and evaporation decrease significantly.The surface of basin was mainly characterized by an increase in vegetation cover caused by artificial eucalyptus planting.Under the influence of vegetation interception and eucalyptus growth,the runoff and sediment concentration showed the decreased and significant decreased trend respectively.Due to changes in the surface and hydrological consistency in the basin,the SWAT model parameters showed time varying and pseudo-variation.The runoff and sediment concentration into the sea is declining due to climate change and changes in the surface of the basin.The impact of climate change and human activities on the estuary is lagging...