红沙泉露天煤矿碳储量时空动态变化分析

Spatiotemporal dynamic change analysis of carbon storage in desertification open-pit mine

明确矿区碳储量的演变规律及其对采矿活动的响应机制,是在碳达峰、碳中和“双碳”目标背景下推进矿区低碳减排和绿色高质量发展的重要手段。以土地利用/覆被为基础,利用InVEST模型评估新疆红沙泉矿区2007—2020年的碳储量变化,探究采矿扰动下土地利用变化对固碳功能的影响,构建景观指数-采煤面积-碳储量耦合协调度模型探寻3者的发展协调程度,并利用景观生态功能贡献率量化矿业景观的影响范围。结果表明:(1)2007—2020年,红沙泉矿区未利用地以1.95 km^(2)/a的速度持续缩减,工矿用地和交通运输用地分别以1.68,0.16 km^(2)/a的速度持续扩张且2者的土地利用动态度最高(分别为79.86%,46.25%),其余地类变化并不明显;(2)2007—2020年,红沙泉矿区碳储量以6550.769 t/a的速率呈持续下降的趋势,累计减少固碳8.516×10^(4)t,其减小区域主要位于矿区北部,表现为北部未利用地(碳密度为96.34 t/hm^(2))逐渐被不断扩张的工矿用地(碳密度为53.48 t/hm^(2))斑块状分割侵占;草地和未利用地向工矿用地转移是造成碳储量下降的主要原因;(3)景观尺度上,红沙泉矿区景观破碎化加重(斑块数目NP、斑块密度PD、形状指数LSI的增幅分别为194,1.185,6.856,聚合度AI的降幅为0.104),生物多样性SHDI和均匀度SHEI上升(增幅为0.445,0.236);斑块尺度上,工矿用地和交通运输用地的景观向聚集化有序性发展,而草地和未利用地向破碎化无序型发展;景观指数、采煤面积与碳储量的耦合协调度呈不断减小趋势,由2007年的0.948(优质协调)下降为2020年的0.602(初级协调);(4)距离红沙泉矿区矿业景观15 km内,距离越远,平均单位面积碳储量越高;矿区碳储量敏感区可分为3级:极敏感区(0~7 km)、敏感区(7~15 km)、不敏感区(15 km以外)。该研究能够定量反映矿区固碳功能及其与景观格局、采煤面积的耦合机制,以及矿业景观的影响范围,可为矿区实施低碳高质量发展提供思路,促进矿区精准服务于碳达峰、碳中和“双碳”目标。

To clarify the evolution law of carbon storage in mining area and its response mechanism to mining activities is an important means to promote low-carbon emission reduction and green high-quality development of mining area under the background of carbon peak and carbon neutral“double carbon”goal.Based on land use/cover,the InVEST model was used to evaluate the change of carbon storage in the Hongshaquan Mining area of Xinjiang from 2007 to 2020,explore the impact of land use change on carbon sequestration function under mining disturbance,and establish the coupling coordination degree model of landscape index,coal mining acreage and carbon storage for exploring the development coordination degree of three parameters above.The influence range of mining landscape is quantified using the contribution rate of landscape ecological function.The results show that:(1)From 2007 to 2020,the unused land in the Hongshaquan mining area continued to shrink at a rate of 1.95 km^(2)/a,and the industrial and mining land and transportation land continued to expand at a rate of 1.68 km^(2)/a and 0.16 km^(2)/a,respectively.The dynamic degree of land use is the highest(79.86%and 46.25%respectively),and the other land types have not changed significantly.(2)From 2007 to 2020,the carbon storage of the Hongshaquan Mining area showed a trend of continuous decline at the rate of 6550.769 t/a,and the cumulative reduction of carbon sequestration was 8.516×10^(4)t.The change of carbon storage space was mainly weakened in the north,showing that the unused land with carbon density of 96.34 t/hm^(2)in the north was gradually invaded by the expanding industrial and mining land with carbon density of 53.48 t/hm^(2).The main reason for the decline of carbon storage was the transfer of grassland and unused land to industrial and mining land.(3)On the landscape scale,the landscape fragmentation of the Hongshaquan mining area increased(patch number NP,patch density PD and shape index LSI increased by 194,1.185 and 6.856,respectively,while the convergence AI decreased by 0.104),and biodiversity SHDI and uniformity SHEI increased(0.445 and 0.236).On the patch scale,the landscape of industrial and mining land and transportation land tended to be clustered and orderly,while grassland and unused land tended to be fragmented and disordered.The coupling coordination degree of landscape index,coal mining area and carbon storage is in a weakening trend as a whole,from 0.948(high-quality coordination)in 2007 to 0.602(primary coordination)in 2020.(4)Within 15 km from the mining landscape of the Hongshaquan Mining area,the farther the distance,the higher the average carbon storage per unit area.The carbon storage sensitive area in the mining area can be divided into three levels:extremely sensitive area(0-7 km),sensitive area(7-15 km)and insensitive area(beyond 15 km).This study can quantitatively reflect the carbon sequestration function of the mining area and its coupling mechanism with landscape pattern and coal mining area,as well as the influence range of mining landscape.Also,it can provide ideas for the implementation of low-carbon and high-quality development of the mining area,and promote the precise service of the mining area to achieve carbon peak and carbon neutral“dual carbon”goals.