Subjects: Geosciences >> Geography submitted time 2022-05-09 Cooperative journals: 《干旱区科学》
Abstract：Abstract: Land use/land cover (LULC) is an important part of exploring the interaction between natural environment and human activities and achieving regional sustainable development. Based on the data of LULC types (cropland, forest land, grassland, built-up land, and unused land) from 1990 to 2015, we analysed the intensity and driving factors of land use/cover change (LUCC) in the Yarlung Zangbo River, Nyang Qu River, and Lhasa River (YNL) region, Qinghai-Tibet Plateau of China, using intensity analysis method, cross-linking table method, and spatial econometric model. The results showed that LUCC in the YNL region was nonstationary from 1990 to 2015, showing a change pattern with fast-slow-fast and U-shaped. Built-up land showed a steady increase pattern, while cropland showed a steady decrease pattern. The gain of built-up land mainly came from the loss of cropland. The transition pattern of LUCC in the YNL region was relatively single and stable during 19902015. The transition pattern from cropland and forest land to built-up land was a systematic change process of tendency and the transition pattern from grassland and unused land to cropland was a systematic change process of avoidance. The transition process of LUCC was the result of the combined effect of natural environment and social economic development in the YNL region. This study reveals the impact of ecological environment problems caused by human activities on the land resource system and provides scientific support for the study of ecological environment change and sustainable development of the Qinghai-Tibet Plateau.
Subjects: Geosciences >> Space Physics submitted time 2017-03-10
Abstract： High-energy electron precipitation in the high latitude regions enhances the ionization of the atmosphere, and subsequently increases the atmospheric conductivities and the vertical electric field of the atmosphere near the ground as well. The high-energy electron flux (HEEF) data measured by the Feng-Yun III meteorological satellite are analyzed together with the data of near-surface atmospheric vertical electric field measured at the Russian Vostok Station. Three HEEF enhancements are identified and show that when the HEEF increases to a certain level, the local atmospheric vertical electric field near the ground can increase substantially than usual. The time of the response of the electric field to the HEEF enhancement is about 3.7 to 4 days (delay time).
Peer Review Status:
Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2017-01-22
Abstract： High-energy electron precipitation in the high latitude regions enhances the ionization of the atmosphere, and subsequently increases the atmospheric conductivities and the vertical electric field of the atmosphere near the ground as well. The High-Energy Electron Flux (HEEF) data measured by the Fengyun-3 meteorological satellite are analyzed together with the data of nearsurface atmospheric vertical electric field measured at the Russian Vostok Station. Three HEEF enhancements are identified and it is shown that when the HEEF increases to a certain level, the local atmospheric vertical electric field near the ground can increase substantially than usual. The response time of the electric field to HEEF enhancement is about 3.7 to 4 days.
Peer Review Status:Awaiting Review
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