基于遥感影像的黄河三角洲植被时空演化特征分析
Analysis of Temporal and Spatial Evolution Characteristics of Vegetation in the Yellow River Delta Based on Remote Sensing Image

基于黄河三角洲1998年、2008年和2018年的Landsat TM/OLI遥感影像数据，在ENVI5.1和ArcGIS10.2.2的支持下分析了黄河三角洲植被时空演化特征。研究结果表明：1998年到2018年这20年间本研究区的林地植被覆盖面积一直稳定在第三位，1998年植被覆盖面积第一位是芦苇及灌木植被，第二位是为耕地植被，2008年和2018年植被覆盖面积第一位变为耕地植被，第二位变为芦苇及灌木植被。从1998年到2018年，植被覆盖度面积变化最大的是极低植被覆盖度，面积减少了298.79 km2，其次是高植被覆盖度，面积增加了289.92 km2。该研究区NDVI总体上呈中部高，周边低，黄河河道、黄河故道高，沿海低的分布格局。较高等级的植被覆盖度主要分布在研究区内部，少量分布在河口地区，较低等级的植被覆盖度主要分布在北部、东南部的沿海滩涂上，以及水体、盐田及养殖池处，与NDVI分布趋于一致，较高等级的植被覆盖度由中部向西南、东南方向扩散，较低等级的植被覆盖度由东北部的盐田及养殖池向西扩散。通过转移矩阵计算得出，黄河三角洲1998年到2018年，芦苇及灌木植被、林地植被和耕地植被三者在空间上相互转移，其中芦苇及灌木植被和耕地植被之间的相互转移较为明显。
Based on the Landsat TM/OLI remote sensing image data of the Yellow River Delta in 1998, 2008 and 2018, the temporal and spatial evolution characteristics of vegetation in the Yellow River Delta are analyzed with the support of ENVI5.1 and ArcGIS10.2.2. The results show that during the 20 years from 1998 to 2018, the forest land vegetation coverage in the study area has been stable in the third place. In 1998, the first vegetation coverage was reed and shrub vegetation, and the second was cultivated land vegetation. In 2008 and 2018, the first vegetation coverage became cultivated land vegetation, and the second became reed and shrub vegetation. From 1998 to 2018, the largest change in the area of vegetation coverage was the extremely low vegetation coverage, with an area decrease of 298.79 km2, followed by the high vegetation coverage, with an area increase of 289.92 km2. The NDVI in the study area is generally high in the middle, low around, high in the Yellow River channel and the old yellow river channel, and low along the coast. The higher level vegetation coverage is mainly distributed in the study area, and a small amount is distributed in the estuary area. The lower level vegetation coverage is mainly distributed on the coastal beaches in the north and southeast, as well as water bodies, salt fields and aquaculture ponds, which is consistent with the distribution of NDVI. The higher level vegetation coverage diffuses from the middle to the southwest and southeast. The lower vegetation coverage spreads westward from the salt field and aquaculture pond in the northeast. According to the calculation of transfer matrix, from 1998 to 2018, reed and shrub vegetation, forest vegetation and cultivated land vegetation in the Yellow River Delta transferred to each other in space, among which the mutual transfer between reed and shrub vegetation and cultivated land vegetation was more obvious.