Spatiotemporal Dynamics of Ecological Condition in Qinghai-Tibet Plateau Based on Remotely Sensed Ecological Index
The eco-system in the Qinghai-Tibet Plateau (QTP) is extremely fragile, and highly vulnerable to climate change. Knowledge of the changes in the ecological conditions is vital to mitigate the impact of climate change. In this study, we investigated the trend of ecological conditions of the QTP using...
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MDPI AG
2022-08-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/14/17/4234 |
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| author | Jiaxi Cao Entao Wu Shuhong Wu Rong Fan Lei Xu Ke Ning Ying Li Ri Lu Xixi Xu Jian Zhang Junliu Yang Le Yang Guangchun Lei |
| author_facet | Jiaxi Cao Entao Wu Shuhong Wu Rong Fan Lei Xu Ke Ning Ying Li Ri Lu Xixi Xu Jian Zhang Junliu Yang Le Yang Guangchun Lei |
| author_sort | Jiaxi Cao |
| collection | DOAJ |
| description | The eco-system in the Qinghai-Tibet Plateau (QTP) is extremely fragile, and highly vulnerable to climate change. Knowledge of the changes in the ecological conditions is vital to mitigate the impact of climate change. In this study, we investigated the trend of ecological conditions of the QTP using the remotely sensed ecological index (RSEI), which is the first PCA (principal component analysis) axis of the four indexes derived from the MODIS (Moderate resolution Imaging Spectroradiometer) images captured in the growing season of 2000–2020. The four indexes, i.e., NDVI (normalized difference vegetation index), heat (land surface temperature, LST), wetness (tasseled cap wetness index, WET) and dryness (normalized difference impervious surface index, NDBSI), were calculated on the Google Earth Engine platform. Using land use cover change (LUCC) data, long-term meteorological records and the supplementary annual livestock production, we explored the drivers of spatiotemporal changes in the RSEI. The results show the following points: (1) the ecological conditions of the QTP have remarkable spatiotemporal variations. There were two ecological degradation periods, one of them occurred in the central region during 2005–2010, mainly attributed to the rising temperatures and decreasing precipitation. The other occurred during 2015–2020, driven primarily by overgrazing in the southwest. From 2000 to 2005, it was a period of rapid ecological restoration in the ecologically fragile northeast region. (2) The contribution rate of pc1 was stable at 60%, while the contribution rate of pc2 remained below 40%, indicating that pc1 demonstrated most of the characteristics of the four indexes. The correlation coefficients between NDVI and WET with pc1 are both positive, while LST and NDBSI have negative correlation coefficients, i.e., negative effects. This is consistent with the actual situation. (3) Overgrazing caused grass degradation in the southwest area of the QTP, which might be the main reason for the poor ecological conditions (i.e., low RSEI value) during 2015–2020. (4) Temperature and precipitation showed an increasing trend during the study period. A warmer and wetter climate is expected to have profound impacts on the ecosystems in QTP and practices should be concentrated on identifying climate-sensitive ecosystem components and designating adaptative options. |
| first_indexed | 2024-03-10T01:18:49Z |
| format | Article |
| id | doaj.art-39123fa218bb494ea3707466a0469684 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-10T01:18:49Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-39123fa218bb494ea3707466a04696842023-11-23T14:03:09ZengMDPI AGRemote Sensing2072-42922022-08-011417423410.3390/rs14174234Spatiotemporal Dynamics of Ecological Condition in Qinghai-Tibet Plateau Based on Remotely Sensed Ecological IndexJiaxi Cao0Entao Wu1Shuhong Wu2Rong Fan3Lei Xu4Ke Ning5Ying Li6Ri Lu7Xixi Xu8Jian Zhang9Junliu Yang10Le Yang11Guangchun Lei12School of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Statistics, Jilin University of Finance and Economics, Jilin 130117, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaSchool of Ecological and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaThe eco-system in the Qinghai-Tibet Plateau (QTP) is extremely fragile, and highly vulnerable to climate change. Knowledge of the changes in the ecological conditions is vital to mitigate the impact of climate change. In this study, we investigated the trend of ecological conditions of the QTP using the remotely sensed ecological index (RSEI), which is the first PCA (principal component analysis) axis of the four indexes derived from the MODIS (Moderate resolution Imaging Spectroradiometer) images captured in the growing season of 2000–2020. The four indexes, i.e., NDVI (normalized difference vegetation index), heat (land surface temperature, LST), wetness (tasseled cap wetness index, WET) and dryness (normalized difference impervious surface index, NDBSI), were calculated on the Google Earth Engine platform. Using land use cover change (LUCC) data, long-term meteorological records and the supplementary annual livestock production, we explored the drivers of spatiotemporal changes in the RSEI. The results show the following points: (1) the ecological conditions of the QTP have remarkable spatiotemporal variations. There were two ecological degradation periods, one of them occurred in the central region during 2005–2010, mainly attributed to the rising temperatures and decreasing precipitation. The other occurred during 2015–2020, driven primarily by overgrazing in the southwest. From 2000 to 2005, it was a period of rapid ecological restoration in the ecologically fragile northeast region. (2) The contribution rate of pc1 was stable at 60%, while the contribution rate of pc2 remained below 40%, indicating that pc1 demonstrated most of the characteristics of the four indexes. The correlation coefficients between NDVI and WET with pc1 are both positive, while LST and NDBSI have negative correlation coefficients, i.e., negative effects. This is consistent with the actual situation. (3) Overgrazing caused grass degradation in the southwest area of the QTP, which might be the main reason for the poor ecological conditions (i.e., low RSEI value) during 2015–2020. (4) Temperature and precipitation showed an increasing trend during the study period. A warmer and wetter climate is expected to have profound impacts on the ecosystems in QTP and practices should be concentrated on identifying climate-sensitive ecosystem components and designating adaptative options.https://www.mdpi.com/2072-4292/14/17/4234ecological condition evaluationalpine environmentMODISclimate changeadaptive managementRSEI |
| spellingShingle | Jiaxi Cao Entao Wu Shuhong Wu Rong Fan Lei Xu Ke Ning Ying Li Ri Lu Xixi Xu Jian Zhang Junliu Yang Le Yang Guangchun Lei Spatiotemporal Dynamics of Ecological Condition in Qinghai-Tibet Plateau Based on Remotely Sensed Ecological Index Remote Sensing ecological condition evaluation alpine environment MODIS climate change adaptive management RSEI |
| title | Spatiotemporal Dynamics of Ecological Condition in Qinghai-Tibet Plateau Based on Remotely Sensed Ecological Index |
| title_full | Spatiotemporal Dynamics of Ecological Condition in Qinghai-Tibet Plateau Based on Remotely Sensed Ecological Index |
| title_fullStr | Spatiotemporal Dynamics of Ecological Condition in Qinghai-Tibet Plateau Based on Remotely Sensed Ecological Index |
| title_full_unstemmed | Spatiotemporal Dynamics of Ecological Condition in Qinghai-Tibet Plateau Based on Remotely Sensed Ecological Index |
| title_short | Spatiotemporal Dynamics of Ecological Condition in Qinghai-Tibet Plateau Based on Remotely Sensed Ecological Index |
| title_sort | spatiotemporal dynamics of ecological condition in qinghai tibet plateau based on remotely sensed ecological index |
| topic | ecological condition evaluation alpine environment MODIS climate change adaptive management RSEI |
| url | https://www.mdpi.com/2072-4292/14/17/4234 |
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