基于DInSAR的洪河国家级自然保护区沼泽水位相对变化量监测研究

水文是沼泽形成、发育和演化的决定性因素.目前,沼泽水位的监测仍然以实地观测为主,需要花费大量的人力和物力.以洪河国家级自然保护区为研究区,利用2007年6?10月星载相控阵L波段合成孔径雷达(phase array type L-band synthetic aperture radar,L-band PALSAR)数...

Monitoring of Relative Variation of Water Level of Marshes in Honghe National Nature Reserve Using DInSAR Technique

Hydrological situation determines the formation,development and evolution of the wetlands.At present,field observation still has been a main approach for monitoring water level change of the wetlands,which usually need to spend a lot of manpower and material resources.In this paper,the technique of differential interferometry synthetic aperture radar(DInSAR)was utilized to extract the phase of surface deformation of the marshes in Honghe National Nature Reserve using L-band PALSAR images from June to October in 2007,C-band Sentinel-1A SAR images from June to October in 2015.The relative water level variation was calculated in this study,the empirical estimation formulas of water level variation were provided based on remote sensing technique,and the annual water-level variation was monitored in the study area.This paper explored the differences of interferometric coherence of shallow water marshes and deep water marshes during different periods.Variance and regression analysis were used to implement accuracy assessment and significance test of water level variation using empirical estimation formulas and field measurement from three scales of hydrological observation stations,shallow water marshes and deep water marshes,respectively.The results showed that growth phases and cluster spatial patterns of vegetation had an effect on the interferometric coherence of the marshes.The interferometric coherence of study area from August to October was better than that from June to July.The interferometric coherence of shallow water marshes was higher than that of deep water marshes,and the interferometric coherence coefficients of shallow water marshes were 10%-35%more than those of deep water marshes.The water level variation of marshes obtained by DInSAR techniquein agreement with field measurement.The larger ones of water level variation in the shallow water marshes were from June to July and from September to October,the differennce between the mmaximum and the minimum of water level was over 0.7 m.