Carbon Emission Effects Of Land Use And Its Temporal And Spatial Patterns In Hohhot

Since the 21 st century,the global warming caused by the rapid increase of carbon dioxide emissions has become more and more obvious.Land use is one of the two sources of carbon emissions.Research on land use carbon emissions has important practical significance to improving the scientific use of land resources and land use efficiency,as well as developing a good ecological environment and building green cities.This paper uses Hohhot city as the research area,with remote sensing images of Hohhot in 1990,2001,2010 and 2016,data set of 1:10,0000(Harmonized World Soil Database version 1.1)(HWSD)dataest and socio-economic datas are the main data sources.The carbon emission measurement model and carbon absorption coefficient method are used to estimate the total carbon emissions and carbon absorption of the four periods in Hohhot.The InVEST model is used to estimate the carbon stocks in the study area,carbon emission risk index indicators and carbon emission effect evaluation index are introduced.The spatial analysis of ArcGIS software interpolation and natural break point is used to realize the carbon emission risk to Hohhot.Spatial visualization of assessment indicators for carbon emission effects.Finally,the linear programming method is used to optimize the land use structure to determine thequantity structure of each land use type.The results show that:(1)The city construction land is mainly distributed in the central area of the urban area,and gradually expands from the west to the east.The conversion between land use types is more severe.The forest land and construction land use types expansion is more severe.The forest land and construction land show a clear expansion trend,and the dynamic degree is large.The cultivated land and unused land area are drastically reduced.The growth rate of construction land area is the most obvious.(2)The degree of carbon emission risk gradually increases with time,showing a clear upward trend.The carbon source mainly comes from construction land and cultivated land,and the construction land occupies a large proportion.Forest land and grassland are the main types of carbon absorption land use;the spatial distribution of carbon emission risk is consistent with the land use distribution,and the carbon emissions are corresponding to the expansion of construction land.The area of high risk area expands to the east and south,and other land types correspond to relatively low value areas.(3)The differences of carbon footprint and ecological deficit in different regions of municipal districts show an increasing trend year by year,both of which belong to the ecological pressure area.Moreover,the ecological pressure index varies greatly,and the carbon emission pressure system circulates excessively.Among them,the ecological pressure inyuquan area is the highest,which is a high ecological pressure area,and the new urban area is the lowest.(4)The linear programming method was adopted to establish the optimization model with the goal of minimizing carbon emissions and maximizing carbon reserves.By comparing the two optimization results,the area proportion of land use types remained basically the same,indicating that the results of the two optimization schemes were highly reliable and could be used as the basic targets of future low-carbon optimization in the research area.