基于GEE的大青山国家级自然保护区NDVI变化及影响因素分析

doi:10.12118/j.issn.1000-6060.2022.584

Abstract

Abstract:

In recent years, China has made great progress in the construction and management of national nature reserves such as the Daqingshan National Nature Reserve in Inner Mongolia. However, the associated ecological benefits have not been effectively assessed. The purpose of this study is to assess whether the establishment of the Daqingshan National Nature Reserve has contributed to the ecological recovery and improvement of the area. Examining changes in vegetation dynamics can be an effective tool for regional ecological engineering assessment, and this study analyzes such changes using the normalized difference vegetation index (NDVI). Based on the Google Earth Engine (GEE) cloud platform, the study uses Landsat remote sensing imagery to extract NDVI data for the nature reserve for the years 1995 to 2020. Spatial and temporal variation in NDVI and variation drivers before and after the establishment of the reserve were analyzed using Pearson correlation, residual analysis and the Lindeman-Merenda-Gold (LMG) model. A decreasing NDVI trend was identified during the 1995—2008 period in 69.04% of the studied area, while an increasing NDVI trend was identified during the 2008—2020 period in 94.98% of the studied area. These results indicate that the quality of vegetation in the study area has improved significantly since it became a national nature reserve. Negative impacts from human activities and climatic warming during the 1995—2008 period led to decreases in NDVI in the studied area, with climate warming being the dominant factor. An increase in precipitation and positive impacts from human activities drove increases in NDVI in the studied area during the 2008—2020 period, with positive human impacts arising from ecological-environmental protection engineering implementation being the main reasons for vegetation recovery during this period. The selection of Landsat remote sensing images and the use of the GEE integrated computing environment enabled the study to obtain vegetation monitoring data over a long time span and at a high spatial resolution. Spatiotemporal variation in vegetation was also more accurately portrayed using the NDVI measure, thereby enriching the technical means for long time-sequence and small region-scale vegetation monitoring. The results of this study provide clear evidence of the ecological benefits brought by the establishment of the Daqingshan National Nature Reserve. At the same time, the study provides basic information and technical support for future ecological-environmental management decisions concerning the protected area.

Key words: Google Earth Engine, NDVI, climate change, human activities, National Nature Reserve

AI Liya, WANG Yongfang, GUO Enliang, YIN Shan, GU Xiling. NDVI change and its influencing factors of Daqingshan National Nature Reserve based on GEE[J].Arid Land Geography, 2023, 46(8): 1279-1290.

Figures/Tables 13

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年份		分区	非显著减少		显著减少		稳定不变		非显著增加		显著增加
年份		分区	面积/km²	占比/%	面积/km²	占比/%	面积/km²	占比/%	面积/km²	占比/%	面积/km²	占比/%
1995—2008	核心区		659.86	60.26	89.11	8.14	138.99	12.69	193.20	17.64	13.79	1.26
	缓冲区		526.21	64.97	53.80	6.64	93.96	11.60	126.92	15.67	8.99	1.11
	实验区		1196.10	60.29	159.49	8.04	197.22	9.94	393.49	19.83	37.57	1.89
	保护区		2382.17	61.26	302.40	7.78	430.17	11.06	713.61	18.35	60.35	1.55
2008—2020	核心区		35.56	3.25	1.07	0.10	46.96	4.29	678.99	62.01	332.37	30.35
	缓冲区		19.62	2.42	0.76	0.09	23.80	2.94	472.64	58.36	293.06	36.19
	实验区		28.86	1.45	1.97	0.10	36.39	1.83	1046.07	52.73	870.58	43.88
	保护区		84.04	2.16	3.80	0.10	107.15	2.76	2197.70	56.51	1496.01	38.47

年份		分区	显著负相关		非显著负相关		显著正相关		非显著正相关
年份		分区	面积/km²	占比/%	面积/km²	占比/%	面积/km²	占比/%	面积/km²	占比/%
1995—2008	核心区		0.14	0.01	28.07	2.56	173.66	15.86	893.08	81.56
	缓冲区		0.37	0.05	18.62	2.30	136.84	16.90	654.05	80.76
	实验区		0.37	0.02	45.86	2.31	410.48	20.69	1527.15	76.98
	保护区		0.87	0.02	92.56	2.38	721.02	18.54	3074.25	79.06
2008—2020	核心区		0.13	0.01	45.09	4.12	209.50	19.13	840.23	76.74
	缓冲区		0.16	0.02	30.37	3.75	158.57	19.58	620.78	76.65
	实验区		0.34	0.02	54.32	2.74	587.35	29.61	1341.86	67.64
	保护区		0.63	0.02	129.77	3.34	955.50	24.57	2802.80	72.08

年份		分区	显著负相关		非显著负相关		显著正相关		非显著正相关
年份		分区	面积/km²	占比/%	面积/km²	占比/%	面积/km²	占比/%	面积/km²	占比/%
1995—2008	核心区		449.04	41.01	623.33	56.93	0.12	0.01	22.46	2.05
	缓冲区		335.83	41.47	459.06	56.68	0.24	0.03	14.76	1.82
	实验区		838.55	42.27	1101.95	55.55	0.22	0.01	43.15	2.17
	保护区		1623.42	41.75	2184.33	56.17	0.58	0.01	80.37	2.07
2008—2020	核心区		0.08	0.01	134.77	12.31	26.26	2.40	933.84	85.29
	缓冲区		0.11	0.01	98.12	12.12	17.38	2.15	694.27	85.72
	实验区		0.38	0.02	309.42	15.60	17.67	0.89	1656.41	83.49
	保护区		0.57	0.01	542.34	13.95	61.30	1.58	3284.50	84.46

残差趋势	1995—2008年		2008—2020年
残差趋势	面积/km²	占比/%	面积/km²	占比/%
抑制	671.34	33.84	55.35	2.79
无影响	289.46	14.59	51.40	2.59
促进	1023.07	51.57	1877.12	94.62

NDVI change and its influencing factors of Daqingshan National Nature Reserve based on GEE

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