Study On The Impact Of Wetland Pattern Changes In Tumen River Basin On Main Greenhouse Gas Emissions

Global warming caused by the increase in the concentration of greenhouse gases CO₂and CH₄is the main topic of global climate change research today.As an important carbon reservoir of terrestrial ecosystems,the spatial characteristics of wetland will affect the emission of greenhouse gases.However,the area of wetland has been greatly reduced by human activities.Therefore,it is very important to ascertain that the impact of wetland pattern changes on greenhouse gas emissions.This paper chooses herb swamps,shrub swamps,forest swamps,and paddy fields in the Tumen River Basin as the research target.Furthermore,object-oriented classification combined with a random forest algorithm used as the main method of image classification,and characteristics of landscape pattern was analyzed.Cumulative greenhouse gas emissions data from field observation and characteristics of greenhouse gas emissions pattern was analyzed.Furthermore,the LUSD model was used to predict 2026 and 2036 wetland spatial distribution,and the impact of wetland landscape pattern on greenhouse gas emissions was analyzed from 1996 to2036.The main conclusions are as follows:(1)During the period from 1996 to 2016,the total area of wetlands was greatly reduced,and the reduced wetlands were mainly transformed into woodlands and dry-land.The wetland landscape became more complex,the fragmentation of the landscape deepened,and the shape of landscape patches became more complex.(2)Regardless of time scale or spatial scale,summer CO₂and CH₄emissions are the largest,and the soil temperature has the greatest impact on CO₂emissions,and above-ground biomass has the greatest impact on CH₄emissions.(3)The prediction results of the LUSD model show that the area of wetland growth in the Tumen River Basin in 2026 and 2036 is mainly converted from dry land.(4)As the area of wetland increases,the cumulative emissions of CO₂and CH₄also increase.Among them,the Gaya River Basin has the largest annual cumulative emissions of CO₂and CH₄,and the Mijiang River Basin has the smallest cumulative annual emissions of CO₂and CH_4,and the CO₂emission flux in the same year is greater than the CH₄ emission flux.