Oasis cities are deeply affected by human activities in arid and semi-arid regions.Vegetation is an important repository in the carbon cycle of oasis urban ecosystems.The continuous expansion of urban has a disproport...Oasis cities are deeply affected by human activities in arid and semi-arid regions.Vegetation is an important repository in the carbon cycle of oasis urban ecosystems.The continuous expansion of urban has a disproportionate impact on the carbon sequestration capacity of vegetation.Till now,studies have been conducted to quantify the impact of urbanization on vegetation carbon sequestration capacity,the mechanism of such impact remains unclear and lacks systematic investigations,especially in oasis urban.Understanding the impact mechanism greatly benefits the sustainable development of oasis urban and regional carbon neutrality.To fill this knowledge gap,we design a theoretical framework to analyze the impact of urbanization on vegetation carbon sequestration capacity by isolating the direct and indirect impacts in Urumqi,China.Some results based on Landsat images indicated that the Impervious Surface Areas(ISAs)expanded by 436.98 km2 during 2000-2019.The Net Primary Productivity(NPP)calculated using the Vegetation Photosynthesis Model(VPM)was directly caused by the loss of 51.45 Gg C(1 Gg=109 g).Another important finding proved that the direct carbon loss caused by urbanization did not change the upward trend of the total carbon sequestration capacity of vegetation,but only slowed down this upward trend by 20.86%.Our results provide new insights into urban vegetation carbon sinks and contribute to a better understanding of the uncertainty of urbanization toward carbon neutrality.This study will provide scientific data support and suggestions for the sustainable development of oasis cities and the regional carbon budget.展开更多
水资源利用在在干旱地区的整个绿洲都市化期间总是是很重要的，与在矛盾和协作之间的城市的开发适应。作为一个盒子，水利用的合作改编和城市的生长拿 Urumqi 城市被在水供应和绿洲城市之间的相互作用模仿“ s 阐述人口，经济和环境。...水资源利用在在干旱地区的整个绿洲都市化期间总是是很重要的，与在矛盾和协作之间的城市的开发适应。作为一个盒子，水利用的合作改编和城市的生长拿 Urumqi 城市被在水供应和绿洲城市之间的相互作用模仿“ s 阐述人口，经济和环境。在不同都市化阶段，合作改编能不同地被代表，它能被五个阶段总结：基本协作，膨胀协作，膨胀矛盾，适应矛盾，和适应协作。水消费的费用，水使用和效率的比例是主要影响因素帮助合作改编。展开更多
Croplands are decreasing due to the expansion of urban areas into rural communities and to some extent due to sand accumulations. Increases in population numbers, new development, in addition to the accumulation of sa...Croplands are decreasing due to the expansion of urban areas into rural communities and to some extent due to sand accumulations. Increases in population numbers, new development, in addition to the accumulation of sand and soil salinity are the major driving force leading to abandonment and shrinking of cropland. The aim of this study was to investigate and assess to what extent agricultural lands are affected by urban development in the Al Hassa oasis, Eastern region in Saudi Arabia by employing Landsat time series data of years 1988, 2000 and 2017 as the main source of information. A set of ground truth, control points (GCPs) was also used besides population census data. Unsupervised classifications approach, Normalized Difference Vegetation Index (NDVI) and change detection methods were used here. Urban area during 2000-2017 exhibits much higher increase compared to 1988-2000, while the arable lands declined to −3.4% in 1988-2000 and increased to 22% during 2000-2017. The data analysis results provided new accurate numerical information supported by a graphical representation in regard to the decrease and increase in urban and agricultural lands. Therefore the findings of this study should be considered by decision maker for improving and development the agriculture activities in rural and urban communities.展开更多
基金supported by the National Natural Science Foundation of China[grant numbers 42090012,41771452,41771454]the National Key Research and Development Program of China[grant number 2018YFB0505401]+2 种基金03 special research and 5G project of Jiangxi Province in China[grant number 20212ABC03A09]Zhuhai industry university research cooperation project of China[grant number ZH22017001210098PWC]Natural Science Foundation of Sichuan[grant number 2022NSFCSC1124].
文摘Oasis cities are deeply affected by human activities in arid and semi-arid regions.Vegetation is an important repository in the carbon cycle of oasis urban ecosystems.The continuous expansion of urban has a disproportionate impact on the carbon sequestration capacity of vegetation.Till now,studies have been conducted to quantify the impact of urbanization on vegetation carbon sequestration capacity,the mechanism of such impact remains unclear and lacks systematic investigations,especially in oasis urban.Understanding the impact mechanism greatly benefits the sustainable development of oasis urban and regional carbon neutrality.To fill this knowledge gap,we design a theoretical framework to analyze the impact of urbanization on vegetation carbon sequestration capacity by isolating the direct and indirect impacts in Urumqi,China.Some results based on Landsat images indicated that the Impervious Surface Areas(ISAs)expanded by 436.98 km2 during 2000-2019.The Net Primary Productivity(NPP)calculated using the Vegetation Photosynthesis Model(VPM)was directly caused by the loss of 51.45 Gg C(1 Gg=109 g).Another important finding proved that the direct carbon loss caused by urbanization did not change the upward trend of the total carbon sequestration capacity of vegetation,but only slowed down this upward trend by 20.86%.Our results provide new insights into urban vegetation carbon sinks and contribute to a better understanding of the uncertainty of urbanization toward carbon neutrality.This study will provide scientific data support and suggestions for the sustainable development of oasis cities and the regional carbon budget.
基金supported by the National Natural Science Foundation of China(Grant No.40371041).
文摘水资源利用在在干旱地区的整个绿洲都市化期间总是是很重要的，与在矛盾和协作之间的城市的开发适应。作为一个盒子，水利用的合作改编和城市的生长拿 Urumqi 城市被在水供应和绿洲城市之间的相互作用模仿“ s 阐述人口，经济和环境。在不同都市化阶段，合作改编能不同地被代表，它能被五个阶段总结：基本协作，膨胀协作，膨胀矛盾，适应矛盾，和适应协作。水消费的费用，水使用和效率的比例是主要影响因素帮助合作改编。
文摘Croplands are decreasing due to the expansion of urban areas into rural communities and to some extent due to sand accumulations. Increases in population numbers, new development, in addition to the accumulation of sand and soil salinity are the major driving force leading to abandonment and shrinking of cropland. The aim of this study was to investigate and assess to what extent agricultural lands are affected by urban development in the Al Hassa oasis, Eastern region in Saudi Arabia by employing Landsat time series data of years 1988, 2000 and 2017 as the main source of information. A set of ground truth, control points (GCPs) was also used besides population census data. Unsupervised classifications approach, Normalized Difference Vegetation Index (NDVI) and change detection methods were used here. Urban area during 2000-2017 exhibits much higher increase compared to 1988-2000, while the arable lands declined to −3.4% in 1988-2000 and increased to 22% during 2000-2017. The data analysis results provided new accurate numerical information supported by a graphical representation in regard to the decrease and increase in urban and agricultural lands. Therefore the findings of this study should be considered by decision maker for improving and development the agriculture activities in rural and urban communities.
