MétaCan
Menu
Back to cohort
Record W2359905814

Relationship between NDVI and Precipitation and Temperature in Middle Asia during 1982-2002

2009· article· en· W2359905814 on OpenAlex
Yu Bohua

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

aboutThe title or abstract carries a Canadian signal from the geographic lexicon.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

Venuenot available
Typearticle
Languageen
FieldEnvironmental Science
TopicEnvironmental and Agricultural Sciences
Canadian institutionsnot available
Fundersnot available
KeywordsNormalized Difference Vegetation IndexAridLand coverSteppeDeciduousVegetation (pathology)CruPhysical geographyGeographyEnvironmental scienceClimatologyEvergreenPrecipitationClimate changeLand useEcologyMeteorologyGeology
DOInot available

Abstract

fetched live from OpenAlex

The five countries in Middle Asia lie in the center of Eurasia. Most part of this region is arid and semi-arid zone with sparse vegetation cover. The study of the vegetation dynamics and environmental change in this region is important to the research of environment and climate in China. This paper explored the vegetation dynamics and its relationship with major climatic factors in middle Asia by using AVHRR-NDVI dataset at 8km spatial resolution and CRU climate data set at 0.5° spatial resolution between 1982 and 2002. These two datasets were unified to the same spatial resolution of 8km and Alberta geographic projection. The trend analysis showed that 53 percent of the land cover was relatively stable, with a very small NDVI change of ±0.005 NDVI per year. These regions, especially the two large deserts, were mainly in the center of Middle Asia. Forty percent of the land had a NDVI up-trend of more than 0.0005 NDVI per year, which was mainly in the north and south of Middle Asia, while only 6 percent of the land had a NDVI down-trend of less than 0.0005 NDVI per year. The analysis on land cover types indicated that evergreen forest and alpine grass (steppe) were among the best up-trend group with NDVI gains more than 0.0014 and 0.0009 per year, while the p values are 0.001 and 0.001 respectively. There were no obvious changes in deciduous forest, grass, crop and steppified desert. To investigate the possible driving forces, correlation analysis was conducted between AVHRR-NDVI and major climatic factors, which are precipitation and temperature. In 49 percent of the area, especially in the forest steppe in north Middle Asia, annual average AVHRR-NDVI was closely related to the annual precipitation, especially that in spring and summer. Only 17.78 percent of the area is related to the annual average temperature with a validation coefficient of more than 0.05. Annually speaking, the positive correlation coefficient of evergreen forest, alpine grass with the annual average temperature is relatively low, with the correlation coefficients of 0.432 and 0.557 as well as p value of 0.052 and 0.009 respectively. The positive correlation coefficient of crop and grass with annual precipitation are comparatively low with R values of 0.511and 0.476 as well as p values of 0.018 and 0.029 respectively. The R value between NDVI and precipitation for deciduous forest was 0.415 in summer and 0.461 in winter, while the p value was 0.01 in summer and 0.461 in winter. The positive correlation coefficient of re-vegetated desert cover with precipitation in spring is relatively lower with the R value of 0.415 and the p value of 0.0061.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.018
Threshold uncertainty score0.188

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.012
GPT teacher head0.196
Teacher spread0.184 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Quick stats

Citations9
Published2009
Admission routes1
Has abstractyes

Explore more

Same topicEnvironmental and Agricultural SciencesFrench-language works237,207