博斯腾湖流域景观破碎化时空特征及其成因

Spatiotemporal Characteristics and Causes of Landscape Fragmentation in Bosten Lake Basin

以博斯腾湖流域为研究区,运用景观格局指数、主成分分析法,定量分析研究区2000-2020年的景观破碎化的时空变化特征,并采用地理探测器模型探讨研究区景观破碎化的驱动机制。结果表明:1)2000-2020年,研究区边缘密度(ED)由2000年的5.787 m/km^(2)增至2020年的6.859 m/km^(2),增加1.072 m/km^(2);蔓延度指数(CONTAG)由75.970%增加至79.596%,增加3.626%;分离度指数(DIVISION)由0.361增加到0.626;香农多样性指数(SHDI)由0.689减少到0.606。2)2000-2020年,景观破碎化程度较为严重的地区集中在焉耆县、博湖县、库尔勒市以及轮台县的西南部;和硕县东部以及尉犁县东南部破碎化程度相对较低。2000-2010年,高度等级面积增加较为明显,面积比增加5.30%;极低等级面积减小较为明显,面积比减小3.21%;2010-2020年,低度等级面积增加较为明显,面积比增加1.48%;极低等级面积减小较为明显,面积比减小2.37%。3)研究区景观破碎化受到自然、社会等因素影响,高程(X2)对景观破碎化的驱动力相对最大,因子平均贡献率为0.195;年降水量(X4)和年均气温(X5)对景观破碎化的驱动较强,因子平均贡献率分别为0.127和0.110;人口密度(X8)对景观破碎化的驱动力相对最小,因子平均贡献率为0.045。

Taking the Bosten Lake Basin as the study area,based on the landscape pattern index and principal component analysis,the spatial and temporal pattern characteristics of landscape fragmentation in the study area from 2000 to 2020 were quantitatively analyzed,and the causes of spatial and temporal differentiation of landscape fragmentation in the study area were discussed by using the geographical detector model.The results showed that 1)between 2000 and 2020,the edge density(ED)of the study area increased from 5.787 in 2000 to 6.859 m/km^(2) in 2020 with an increase of 1.072 m/km^(2).The spread index(CONTAG)increased from 75.970%to 79.596%,with a total increase of 3.626%.The DIVISION index increased from 0.361 to 0.626.The Shannon diversity index(SHDI)decreased from 0.689 to 0.606.2)The degree of landscape fragmentation in the basin from 2000 to 2020,from the perspective of space,the regions with more serious fragmentation were concentrated in Yanqi County,Bohu County,Korla City and the southwest of Luntai County.The degree of fragmentation in the east of Heshuo County and the southeast of Weili County was relatively low.From the time scale,the area with high landscape fragmentation degree increased significantly between 2000 and 2010,with an increment of 5.30%in area ratio.The area with very low landscape fragmentation degree decreased obviously,with an decrement of 2.37%in area ratio.3)Landscape fragmentation in the study area was affected by natural and social factors,and elevation(X2)was the largest driving force for landscape fragmentation,with an average contribution rate of 0.195.Annual precipitation(X4)and annual average temperature(X5)had strong driving effects on landscape fragmentation,and the average contribution rates of the factors were 0.127 and 0.110,respectively.Population density(X8)had the weakest driving force on landscape fragmentation,and the average contribution rate of the factor was 0.045.