基于LUCC追踪分析的生态系统服务价值时空变化研究--以博斯腾湖流域为例

Spatio-temporal variation of ecosystem service value based on LUCC trajectories:a case study of Bosten Lake Watershed

【目的】为了更好地揭示生态系统服务价值时空变化特征及趋势,加强对生态系统服务价值(ESV)空间变化描述。【方法】该研究以博斯腾湖流域为例,结合使用逐像元的追踪分析、趋势分析等方法,试探究土地利用/覆盖变化(LUCC)对生态系统服务价值的影响。【结果】(1)博斯腾湖流域主要的土地利用类型是荒漠,其次是草甸和裸地。研究期内,水田、荒漠、草甸、湿地、水域、旱地、建设用地面积增加;草原、灌木、裸地、针叶、阔叶、冰川积雪面积减少,2005−2010年综合土地利用动态度最大。(2)2000−2018年博斯腾湖流域未发生变化的土地即稳定型占流域总面积的60.43%,中等变化型、回归型和激烈变化型多分布于人类活动较强的绿洲地区。(3)2000−2018年博斯腾湖流域ESV总体上呈现波动增长趋势,流域ESV主要由草甸、水域和湿地构成,水域、旱地、草甸和草原是流域ESV变化的主要贡献因子和敏感因子,其中草原为负向贡献因子。(4)博斯腾湖流域ESV呈西北高、东南低,高值(博斯腾湖)点缀在低值区的空间分布特征。有明显增大与明显减少趋势的地区均分布于博斯腾湖周围湿地,流域北部大部分ESV呈轻度增加趋势,绿洲区轨迹等级和ESV变化趋势从城市至绿洲边缘呈:中等变化型(ESV轻度减少)−渐变型(ESV轻度增加)−中等变化型(ESV轻度减少)环状相间结构。【结论】该研究发现博斯腾湖流域南部土地利用轨迹等级、ESV变化趋势均高于北部的空间差异,并采用土地利用追踪分析与ESV趋势变化相结合的方式,揭示了绿洲城市的土地利用冲突现状及ESV时空变化,对博斯腾湖流域土地利用调控和生态环境保护提供参考。

[Objective]The research on the impact of land use change and ecosystem service value under the background of global warming and increasing human vitality has become a hot topic in the current ecosystem change research.This paper aims to reveal the spatio-temporal variation characteristics and trends of ecosystem service value and facilitate to the traditional spatial statistical methods such as hot spot analysis to describe the insignificant fluctuation in ecosystem service value(ESV).[Method]In this study,pixel based tracking analysis,trend analysis and other methods were combined to test the impact of LUCC(land use and land cover change)on ESV in the Bosten Lake Watershed.[Result](1)Desert was the predominant land use type in the Bosten Lake Watershed,followed by meadow and bare land.During the study period,the area of paddy field,desert,meadow,wetland,water area,dry land and construction land showed increasing trend.Grassland,shrubland,bare land,coniferous,broadleaf,glacier snow showed decreasing trend,from 2005–2010,the dynamic level of comprehensive land use was most significant.(2)From 2000 to 2018,the stable type accounted for 60.43%of the total area in the Bosten Lake Watershed,and the moderate change type,regression type and intense change type were mainly distributed in the oasis areas owing to intense human activities.(3)From 2000 to 2018,the ESV of the Bosten Lake Watershed showed a fluctuating growth trend.The ESV of the watershed was mainly composed of meadows,water area and wetlands.Water area,dry land,meadow and grassland were the main contributors and sensitive factors of ESV changes in the watershed,besides,grassland was negative contributing factor.(4)The ESV of the Bosten Lake Watershed was higher in the northwest than in the southeast,with high values(Bosten Lake)dotted in the low-value areas.The areas of significant increasing and decreasing trends were mainly distributed in the wetland around Bosten Lake.ESV in the northern part of the basin showed a slight increasing trend.The trajectory level and ESV change trend of the oasis area from the city to the edge of the oasis as ranked:medium change type(slightly decreased ESV)-gradient type(slightly increased ESV)-moderate variation type(slightly decreased ESV)ring-shaped interphase structure.[Conclusion]This study demonstrates that the spatial difference of land use trajectory level and ESV change trend in the southern part are higher than in the northern part,combination of land use tracking analysis and the ESV trend change reveal the current status of land use conflicts and model distribution of the ESV spatiotemporal changes in oasis cities,provides a reference for land use management and ecological environment protection in the Bosten Lake Watershed.