Analyzing phenological changes with remote sensing data in Central Asia
نویسندگان
چکیده
Based on NOAA/AVHRR NDVI biweekly time-series data, the start and end of the growing season of Central Asia from 1982 to 2006 were estimated. Trend analysis results indicate an earlier green-up and a later dormancy over the entire area during the study period. For seven main vegetation types, the largest advance of greenup onset (0.597 days/year) occurs in cropland and the longest delay of dormancy (1.109 days/year) in open shrubland. The smallest advance (0.164 days/year) occurs in evergreen needleleaf forest and delay (0.443 days/year) in crop/natural vegetation mosaic. These results imply enhanced vegetation activity in the Central Asia region over last decades.
منابع مشابه
Analyzing the Spatial Pattern of Drought in Central and South Zagros Using Remote Sensing Indicators
Introduction: As a complex phenomenon occurring due to a long period of poor precipitation, drought causes water scarcity in the soil and the hydrological system via hydrological, bringing about long-term consequences which may lead to severe economic, environmental, and social problems worldwide. Droughts are classified into four types: meteorological (rainfall), agricultural (soil’s moisture)...
متن کاملReconstructing the Spatio-Temporal Development of Irrigation Systems in Uzbekistan Using Landsat Time Series
The expansion of irrigated agriculture during the Soviet Union (SU) era made Central Asia a leading cotton production region in the world. However, the successor states of the SU in Central Asia face on-going environmental damages and soil degradation that are endangering the sustainability of agricultural production. With Landsat MSS and TM data from 1972/73, 1977, 1987, 1998, and 2000 the exp...
متن کاملEstimating runoff precipitation and providing land use maps and agriculture levels in different periods of time, using remote sensing technology in Roud Zard basin area
Today, remote sensing technology is used in all scientific and informing fields around the world, and it has achieved to very satisfying results. In the present study, by using remote sensing technology and application of satellite photographs the coefficient of curve number was estimated with high accuracy and pick discharge of the flood was calculated with a good accuracy. In this study, i...
متن کاملReview: advances in in situ and satellite phenological observations in Japan.
To accurately evaluate the responses of spatial and temporal variation of ecosystem functioning (evapotranspiration and photosynthesis) and services (regulating and cultural services) to the rapid changes caused by global warming, we depend on long-term, continuous, near-surface, and satellite remote sensing of phenology over wide areas. Here, we review such phenological studies in Japan and di...
متن کاملEnvironmental Drivers of NDVI-Based Vegetation Phenology in Central Asia
Through the application and use of geospatial data, this study aimed to detect and characterize some of the key environmental drivers contributing to landscape-scale vegetation response patterns in Central Asia. The objectives of the study were to identify the variables driving the year-to-year vegetation dynamics in three regional landscapes (desert, steppe, and mountainous); and to determine ...
متن کامل