黄河源区玛多县土地利用和生态系统服务价值的演变

黄河源区玛多县作为"世界的一方净土",开展土地利用变化及生态系统服务功能量化评价,以期为保障黄河流域乃至全国生态安全提供支撑。以黄河源区玛多县为研究案例,统计了2005—2015年玛多县土地利用类型转移矩阵、土地利用变化动态度,计量了2005—2015年玛多县生态系统服务价值演变特征。结果表明:(1)10年间玛多县土地利用结构变化显著,高覆盖度草地、建设用地面积分别增加了38.30%和3.85倍,低覆盖度草地、林地分别降低了44.29%和86.55%。(2)10年间林地、低覆盖度草地的单一土地利用动态度分别为-8.65%、-4.43%,高覆盖度草地、中覆盖度草地的单一土地利用动态度分别为3.83%、2.83%,土地利用类型演变表现为从林地、低覆盖度草地向高覆盖度草地、中覆盖度草地的转移;前期(2005—2010年)林地、低覆盖度草地迅速减少,后期(2010—2015年)建设用地急速扩张。(3)10年间玛多县生态系统服务价值(ESV)呈增长趋势,从2005年的911.24×10~8元增长到2015年938.87×10~8元;单项生态系统服务价值中水文调节的ESV贡献量最大,在53.70%—55.24%之间。(4)10年间水域面积比例在8.21%—8.31%之间波动,ESV贡献量约占生态系统服务价值均在50%左右,未利用土地和高覆盖度草地的ESV贡献量分别为16.85%—17.26%和13.78%—18.50%,低覆盖度草地的ESV减少了44.29%。

Land use change and evolution of ecosystem service value in Maduo County of source region of the Yellow River

Maduo County in the Yellow River source area is a "purified land of the world". Carrying out quantitative research on land use change and ecosystem service functions can provide support for ensuring ecological security in the Yellow River Basin and the whole country. Taking the Maduo County of Source Region of the Yellow River as a research case, we counts the transfer matrix of land use types and the land use change, and measures the evolution characteristics of its ecosystem service value (ESV) in Maduo County from 2005 to 2015. The results showed that (1) the land use structure of Maduo County has changed significantly in past 10 years. The area of high coverage grassland and construction land increased by 38.30% and 3.85 times, respectively. The area of low-coverage grassland and forests decreased by 44.29% and 86.55%, respectively. (2) The single land use change of forests and low coverage grassland were -8.65% and -4.43%, respectively. The single land use change of high coverage grassland and medium coverage grassland were 3.83% and 2.83% respectively during the 10 years. Therefore, the evolution of land use type mainly presents the transfer from forests and low coverage grassland to high coverage grassland and medium coverage grassland. In the early stage (2005-2010), the woodland and low coverage grassland decreased rapidly. In the later stage (2010-2015), the construction land expanded rapidly. (3) The ESV in Maduo County was growing from 911.24×10⁸ yuan in 2005 to 938.87×10⁸ yuan in 2015. The single ESV of hydrology regulation contributed to 53.70%-55.24%. (3) The proportion of water area fluctuated between 8.21% and 8.31% in 10 years. Its ESV contribution accounted for about 50% of the total ecosystem service value. The ESV contribution of unutilized land and high coverage grassland were 16.85%-17.26% and 13.78%-18.50%,respectively. The ESV of low coverage grassland decreased by 44.29%.