The ecosystem is important because it is the life sustaining system for human survival.Three ecosystem characteristics are:regional particularities,ecosystem complexity and conventional cultural particularities.This p...The ecosystem is important because it is the life sustaining system for human survival.Three ecosystem characteristics are:regional particularities,ecosystem complexity and conventional cultural particularities.This paper develops a remote sensing based dynamic model to assess grassland ecosystem service values involving multidisciplinary knowledge.The ecological value of grassland ecosystems is focused on using a remote sensing technique in the model,and setting up the framework for a dynamic assessing model.The grassland ecological services condition and value in 1985 is used as the benchmark.The dynamic model has two adjusting indicators:biomass and price index.The biomass is simulated using the CASA(Carnegie-Ames-Stanford Approach) model.The price index was obtained from statistics data published by the statistical bureau.Results show that the grassland ecosystem value in Gansu Province was 28.36 billion Chinese Yuan in 1985,140.37 billion in 1999 and 130.86 billion in 2002.展开更多
Urban greenspace has a profound impact on public health by purifying the air,blocking bacteria,and creating activity venues.Due to people's different position,the greenspace exposure to different age groups change...Urban greenspace has a profound impact on public health by purifying the air,blocking bacteria,and creating activity venues.Due to people's different position,the greenspace exposure to different age groups changes at various times.In this study,we combined NDVI(normalized difference vegetation index)and GVI(green view index)green indices with mobile signaling big data to evaluate the greenspace exposure of 3 age groups in Shanghai at different times.A dynamic assessment model for greenspace exposure has been adopted in this study.April 2021 and April 2022 were selected as the study periods,representing the non-lockdown period and the lockdown period,respectively.The results indicate that greenspace exposure changes slightly during the lockdown period.During lockdown,the NDVI exposure in the age groups of 31 to 50,51,and above was higher than that during non-lockdown.However,the NDVI exposure of people aged 0 to 30 during lockdown is lower than that during non-lockdown.The GVI exposure of people aged 51 and above is lower than that of the other age group.Whether it is under lockdown or not,from 8:00 to 17:00,the NDVI exposure showed a slightly higher value than at other hours.The value of GVI exposure fluctuates steadily during 6:00 to 24:00.This study enriches the evaluation dimensions of urban greenspace exposure.展开更多
Based on the citrus temperature, precipitation, sunlight and climate risk degree, the article divides subtropics of China into three types： the low risk region, the moderate risk region and the high risk region. The ...Based on the citrus temperature, precipitation, sunlight and climate risk degree, the article divides subtropics of China into three types： the low risk region, the moderate risk region and the high risk region. The citrus temperature risk increases with increasing latitude （except for the western mountainous area of subtropics of China）. The citrus precipitation risk in the central part of subtropics of China is higher than that in the northern and western parts. The distributions of citrus sunlight risk are not consistent to those of the citrus precipitation risk. The citrus climate risk is mainly influenced by temperature. There is latitudinal zonal law for the distribution of the climate risk, that is, the climate risk increases with increasing latitude At the same time the climate risk in mountainous area is high and that in eastern plain area is low. There are differences in the temporal and spatial changes of the citrus climate. In recent 46 years, the citrus climate risk presents a gradual increasing trend in subtropics of China, especially it has been increasing fast since the 1980s. Because of the global warming, the low risk region in the eastern and southern parts has a gradual decreasing trend, however, the high risk region in the northern and western parts has an increasing trend and the high risk region has been extending eastward and southward. The article analyses the distribution of the citrus climate risk degree of reduction rates of 〉10%, 〉20% and 〉30% in subtropics of China, and studies their changes in different time periods. Results show that the risk is increasing from southeast to northwest.展开更多
基金supported by the CAS (Chinese Academy of Sciences) Action Plan for West Development Project "Watershed Allied Telemetry Experimental Research (WATER)"(grant number:KZCX2-XB2-09)the Global Change Research Program of China (2010CB951403)+2 种基金WP6 of FP7 topic ENV.2007.4.1.4.2 "Improving observing systems for water resource management"the National Natural Science Foundation of China (grant number:41071227)the Major Research Plan "Integrated Research on the Eco-Hydrological Process of Heihe Basin" of National Natural Science Foundation of China,topic (grant number:91025001)
文摘The ecosystem is important because it is the life sustaining system for human survival.Three ecosystem characteristics are:regional particularities,ecosystem complexity and conventional cultural particularities.This paper develops a remote sensing based dynamic model to assess grassland ecosystem service values involving multidisciplinary knowledge.The ecological value of grassland ecosystems is focused on using a remote sensing technique in the model,and setting up the framework for a dynamic assessing model.The grassland ecological services condition and value in 1985 is used as the benchmark.The dynamic model has two adjusting indicators:biomass and price index.The biomass is simulated using the CASA(Carnegie-Ames-Stanford Approach) model.The price index was obtained from statistics data published by the statistical bureau.Results show that the grassland ecosystem value in Gansu Province was 28.36 billion Chinese Yuan in 1985,140.37 billion in 1999 and 130.86 billion in 2002.
基金supported by the National Key R&D Program of China(2022YFC3802600 and 2022YFC3802603)China National Forestry and Grassland Administration,Forestry and Grassland Science and Technology Youth Talent Project(2024132024)
文摘Urban greenspace has a profound impact on public health by purifying the air,blocking bacteria,and creating activity venues.Due to people's different position,the greenspace exposure to different age groups changes at various times.In this study,we combined NDVI(normalized difference vegetation index)and GVI(green view index)green indices with mobile signaling big data to evaluate the greenspace exposure of 3 age groups in Shanghai at different times.A dynamic assessment model for greenspace exposure has been adopted in this study.April 2021 and April 2022 were selected as the study periods,representing the non-lockdown period and the lockdown period,respectively.The results indicate that greenspace exposure changes slightly during the lockdown period.During lockdown,the NDVI exposure in the age groups of 31 to 50,51,and above was higher than that during non-lockdown.However,the NDVI exposure of people aged 0 to 30 during lockdown is lower than that during non-lockdown.The GVI exposure of people aged 51 and above is lower than that of the other age group.Whether it is under lockdown or not,from 8:00 to 17:00,the NDVI exposure showed a slightly higher value than at other hours.The value of GVI exposure fluctuates steadily during 6:00 to 24:00.This study enriches the evaluation dimensions of urban greenspace exposure.
基金National Natural Sciences Foundation of China,No.40771033Special Item Funds of Climate Change Supported by China Meteorological Administration,No.CCSF-09-11
文摘Based on the citrus temperature, precipitation, sunlight and climate risk degree, the article divides subtropics of China into three types： the low risk region, the moderate risk region and the high risk region. The citrus temperature risk increases with increasing latitude （except for the western mountainous area of subtropics of China）. The citrus precipitation risk in the central part of subtropics of China is higher than that in the northern and western parts. The distributions of citrus sunlight risk are not consistent to those of the citrus precipitation risk. The citrus climate risk is mainly influenced by temperature. There is latitudinal zonal law for the distribution of the climate risk, that is, the climate risk increases with increasing latitude At the same time the climate risk in mountainous area is high and that in eastern plain area is low. There are differences in the temporal and spatial changes of the citrus climate. In recent 46 years, the citrus climate risk presents a gradual increasing trend in subtropics of China, especially it has been increasing fast since the 1980s. Because of the global warming, the low risk region in the eastern and southern parts has a gradual decreasing trend, however, the high risk region in the northern and western parts has an increasing trend and the high risk region has been extending eastward and southward. The article analyses the distribution of the citrus climate risk degree of reduction rates of 〉10%, 〉20% and 〉30% in subtropics of China, and studies their changes in different time periods. Results show that the risk is increasing from southeast to northwest.
