基于遥感转型期唐山主城区地类变化的NPP响应

NPP response of land type changes in Tangshan main urban area based on Remote Sensing in the transition period

[方法]研究以唐山市“南湖生态修复工程”建设的关键时间节点为研究时序,利用分层分类方法和CASA估算模型对唐山土地利用变化及由此产生的NPP时空变化进行量化研究。[结果]1996年后单位面积NPP人工绿地大于农用地;主城区农用地减少1.2 km^2、人工绿地增加13.5 km^2,单位面积NPP增加1.76gC·m^-2、NPP总量增加299t;南湖区域农用地减少2.2 km^2、人工绿地增加3.9 km^2,南湖区域单位面积NPP增加6.95gC·m^-2、总量增加104t;NPP高值区分布与农业用地、人工绿地的空间分布吻合度较高,且呈月牙状分布在建设用地周围;研究期间南湖区域单位面积NPP均高于研究区,NPP高值区逐步聚集至南湖及其东部耕地保护区域。[结论]研究区NPP总量受农用地影响较大,但单位面积人工绿地NPP贡献大于农用地;南湖区域生态修复提高了研究区NPP均值水平,有效地加速了研究区NPP总量增长。研究结果可为城市转型和生态建设提供决策支持和理论指导。

[Methods]The key time nodes of the“South Lake Ecological Restoration Project”in Tangshan City as the research time series.The stratified classification method and the CASA estimation model were used to quantify the land use change in Tangshan and the resulting spatiotemporal changes of NPP.[Results]After 1996,the artificial green land per unit area of NPP was larger than that of agricultural land;Agricultural land in the main urban area decreased by 1.2km^2,artificial green space increased by 13.5km^2,unit area NPP increased by 1.76 gC·m^-2,and total NPP increased by 299t;Agricultural land in Nanhu region decreased by 2.2km^2,artificial green space increased by 3.9km^2,unit area of Nanhu region increased by 6.95 gC·m^-2 and total amount increased by 104t;The distribution of NPP high value area has a high degree of coincidence with the spatial distribution of agricultural land and artificial green land,and it is distributed around the construction land in a crescent shape;During the study period,NPP per unit area in Nanhu area was all higher than that in the study area,and the high-value NPP areas gradually gathered in Nanhu and its eastern cultivated land protection area.[Conclusion]The total amount of NPP in the research area is greatly affected by agricultural land,and the contribution of NPP to artificial green land per unit area is greater than that of agricultural land;The ecological restoration of Nanhu improves the average level of NPP in the research area and effectively accelerates the growth of the total NPP in the research area.The research results can provide decision support and theoretical guidance for urban transformation and ecological construction.