{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,19]],"date-time":"2025-12-19T15:52:56Z","timestamp":1766159576347,"version":"build-2065373602"},"reference-count":47,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2024,12,7]],"date-time":"2024-12-07T00:00:00Z","timestamp":1733529600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Basic Research Project of Yunnan Province","award":["202401AT070366","XDA26050301-01"],"award-info":[{"award-number":["202401AT070366","XDA26050301-01"]}]},{"name":"Strategic Priority Research Program of the Chinese Academy of Sciences","award":["202401AT070366","XDA26050301-01"],"award-info":[{"award-number":["202401AT070366","XDA26050301-01"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJGI"],"abstract":"<jats:p>Non-photosynthetic vegetation (NPV) significantly impacts ecosystem degradation, drought, and wildfire risk due to its flammable and persistent litter. Yet, the accurate estimation of NPV in heterogeneous landscapes, such as dry\u2013hot valleys, has been limited. This study utilized multi-source time-series remote sensing data from Sentinel-2 and GF-2, along with field surveys, to develop an NDVI-DFI ternary linear mixed model for quantifying NPV coverage (fNPV) in a typical dry\u2013hot valley region in 2023. The results indicated the following: (1) The NDVI-DFI ternary linear mixed model effectively estimates photosynthetic vegetation coverage (fPV) and fNPV, aligning well with the conceptual framework and meeting key assumptions, demonstrating its applicability and reliability. (2) The RGB color composite image derived using the minimum inclusion endmember feature method (MVE) exhibited darker tones, suggesting that MVE tends to overestimate the vegetation fraction when distinguishing vegetation types from bare soil. On the other hand, the pure pixel index (PPI) method showed higher accuracy in estimation due to its higher spectral purity and better recognition of endmembers, making it more suitable for studying dry\u2013hot valley areas. (3) Estimates based on the NDVI-DFI ternary linear mixed model revealed significant seasonal shifts between PV and NPV, especially in valleys and lowlands. From the rainy to the dry season, the proportion of NPV increased from 23.37% to 35.52%, covering an additional 502.96 km\u00b2. In summary, these findings underscore the substantial seasonal variations in fPV and fNPV, particularly in low-altitude regions along the valley, highlighting the dynamic nature of vegetation in dry\u2013hot environments.<\/jats:p>","DOI":"10.3390\/ijgi13120440","type":"journal-article","created":{"date-parts":[[2024,12,9]],"date-time":"2024-12-09T08:17:49Z","timestamp":1733732269000},"page":"440","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Estimation of Non-Photosynthetic Vegetation Cover Using the NDVI\u2013DFI Model in a Typical Dry\u2013Hot Valley, Southwest China"],"prefix":"10.3390","volume":"13","author":[{"given":"Caiyi","family":"Fan","sequence":"first","affiliation":[{"name":"Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5866-6321","authenticated-orcid":false,"given":"Guokun","family":"Chen","sequence":"additional","affiliation":[{"name":"Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China"},{"name":"Yunnan Key Laboratory of Quantitative Remote Sensing, Kunming University of Science and Technology, Kunming 650093, China"},{"name":"Yunnan International Joint Laboratory for Integrated Sky-Ground Intelligent Monitoring of Mountain Hazards, Kunming 650093, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ronghua","family":"Zhong","sequence":"additional","affiliation":[{"name":"Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, China"},{"name":"Yunnan Key Laboratory of Soil Erosion Prevention and Green Development, Yunnan University, Kunming 650500, China"},{"name":"Yuanjiang Dry\u2013Hot Valley Water and Soil Conservation Observation and Research Station of Yunnan Province, Yunnan University, Kunming 650500, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yan","family":"Huang","sequence":"additional","affiliation":[{"name":"Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qiyan","family":"Duan","sequence":"additional","affiliation":[{"name":"Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ying","family":"Wang","sequence":"additional","affiliation":[{"name":"Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"He, J., Lyu, D., He, L., Zhang, Y., Xu, X., Yi, H., Tian, Q., Liu, B., and Zhang, X. 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