【目的】本研究旨在获得潜江市不同稻作模式温室气体排放和固碳情况,以评价不同稻作模式的绿色发展潜力。【方法】首先,利用随机森林对遥感影像进行分类,获得了潜江市各稻作模式分布数据,结合气象、土壤、作物管理数据库,利用校正和验...【目的】本研究旨在获得潜江市不同稻作模式温室气体排放和固碳情况,以评价不同稻作模式的绿色发展潜力。【方法】首先,利用随机森林对遥感影像进行分类,获得了潜江市各稻作模式分布数据,结合气象、土壤、作物管理数据库,利用校正和验证后的DNDC模型进行区域模拟,获得潜江市甲烷(CH_(4))和氧化亚氮(N_(2)O)两种温室气体排放量及土壤有机碳变化量(dSOC)。其次,在DNDC模型中设置情景分析,假设目前稻虾模式由不同稻作模式变迁而来,利用相关指标的变化评价稻虾模式在潜江地区的绿色发展潜力。【结果】各项指标表明,校正后DNDC模型对CH_(4)和N_(2)O模拟效果良好。2019年潜江市每1 km^(2)范围内主要稻作模式CH_(4)和N_(2)O排放量及全年dSOC总量变化区间分别为0.40kg~64043.34 kg,0.002kg~227.08 kg和0.18 kg C~35835.27 kg C。潜江市全年单位面积CH_(4)和N_(2)O排放量均表现为稻虾模式最小,分别为394.50kg·hm^(-2),1.43kg·hm^(-2),单位面积dSOC表现为稻虾模式最大为274.30 kg C·hm^(-2),稻闲模式最小,为204.95 kg C·hm^(-2)。当潜江市稻虾模式转变为其他主要模式后,其周年CH_(4)排放总量增加2.31%~11.25%,N_(2)O排放总量增加11.49%~67.09%,dSOC减少9.95%~22.81%。【结论】本研究中,稻麦模式表现为CH_(4)排放最大,稻油模式的N_(2)O排放最大,两者固碳能力中等;稻闲模式由于只有一季种植,温室气体排放小于稻旱轮作模式,但其固碳能力较差;稻虾模式的减排和固碳能力相较于稻闲与稻旱轮作模式强,具有更高的绿色发展潜力,但其仍具有减排空间。展开更多
Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-sour...Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-source data, an effective model named the Spatial Production Allocation Model （SPAM） which integrates arable land distribution, administrative unit statistics of crop data, agricultural irrigation data and crop suitability data, was used to get a series of spatial distributions of rice area and production with 10-km pixels at a national scale -it was applied from the early 1980s onwards and used to analyze the pattern of spatial and temporal changes. The results show that significant changes occurred in rice in China during 1980-2010. Overall, more than 50% of the rice area decreased, while nearly 70% of rice production increased in the change region during 1980-2010. Spatially, most of the increased area and production were in Northeast China, especially, in Jilin and Heilongjiang; most of the decreased area and production were located in Southeast China, especially, in regions of rapidly urbanization in Guangdong, Fujian and Zhejiang. Thus, the centroid of rice area was moved northeast approximately 230 km since 1980, and rice production about 320 km, which means rice production moved northeastward faster than rice area because of the significant rice yield increase in Northeast China. The results also show that rice area change had a decisive impact on rice production change. About 54.5% of the increase in rice pro- duction is due to the expansion of sown area, while around 83.2% of the decrease in rice production is due to contraction of rice area. This implies that rice production increase may be due to area expansion and other non-area factors, but reduced rice production could largely be attributed to rice area decrease.展开更多
This paper presents a scenario-based assessment of global future food security. To do that,the socio-economic and climate change scenarios were defined for the future and were linked to an integrated modeling framewor...This paper presents a scenario-based assessment of global future food security. To do that,the socio-economic and climate change scenarios were defined for the future and were linked to an integrated modeling framework. The crop yields simulated by the GIS-based Environmental Policy Integrated Climate （EPIC） model and crop areas simulated by the crop choice decision model were combined to calculate the total food production and per capita food availability,which was used to represent the status of food availability and stability. The per capita Gross Domestic Product （GDP） simulated by IFPSIM model was used to reflect the situation of food accessibility and affordability. Based on these two indicators,the future food security status was assessed at a global scale over a period of approximately 20 years,starting from the year 2000. The results show that certain regions such as South Asia and most African countries will likely remain hotspots of food insecurity in the future as both the per capita food availability and the capacity of being able to import food will decrease between 2000 and 2020. Low food production associated with poverty is the determining factor to starvation in these regions,and more efforts are needed to combat hunger in terms of future actions. Other regions such as China,most Eastern European countries and most South American countries where there is an increase in per capita food availability or an increase in the capacity to import food between 2000 and 2020 might be able to improve their food security situation.展开更多
Understanding crop patterns and their changes on regional scale is a critical re- quirement for projecting agro-ecosystem dynamics. However, tools and methods for mapping the distribution of crop area and yield are st...Understanding crop patterns and their changes on regional scale is a critical re- quirement for projecting agro-ecosystem dynamics. However, tools and methods for mapping the distribution of crop area and yield are still lacking. Based on the cross-entropy theory, a spatial production allocation model （SPAM） has been developed for presenting spa- tio-temporal dynamics of maize cropping system in Northeast China during 1980-2010. The simulated results indicated that （1） maize sown area expanded northwards to 48~N before 2000, after that the increased sown area mainly occurred in the central and southern parts of Northeast China. Meanwhile, maize also expanded eastwards to 127°E and lower elevation （less than 100 m） as well as higher elevation （mainly distributed between 200 m and 350 m）; （2） maize yield has been greatly promoted for most planted area of Northeast China, espe- cially in the planted zone between 42°N and 48°N, while the yield increase was relatively homogeneous without obvious longitudinal variations for whole region; （3） maize planting density increased gradually to a moderately high level over the investigated period, which reflected the trend of aggregation of maize cultivation driven by market demand.展开更多
文摘【目的】本研究旨在获得潜江市不同稻作模式温室气体排放和固碳情况,以评价不同稻作模式的绿色发展潜力。【方法】首先,利用随机森林对遥感影像进行分类,获得了潜江市各稻作模式分布数据,结合气象、土壤、作物管理数据库,利用校正和验证后的DNDC模型进行区域模拟,获得潜江市甲烷(CH_(4))和氧化亚氮(N_(2)O)两种温室气体排放量及土壤有机碳变化量(dSOC)。其次,在DNDC模型中设置情景分析,假设目前稻虾模式由不同稻作模式变迁而来,利用相关指标的变化评价稻虾模式在潜江地区的绿色发展潜力。【结果】各项指标表明,校正后DNDC模型对CH_(4)和N_(2)O模拟效果良好。2019年潜江市每1 km^(2)范围内主要稻作模式CH_(4)和N_(2)O排放量及全年dSOC总量变化区间分别为0.40kg~64043.34 kg,0.002kg~227.08 kg和0.18 kg C~35835.27 kg C。潜江市全年单位面积CH_(4)和N_(2)O排放量均表现为稻虾模式最小,分别为394.50kg·hm^(-2),1.43kg·hm^(-2),单位面积dSOC表现为稻虾模式最大为274.30 kg C·hm^(-2),稻闲模式最小,为204.95 kg C·hm^(-2)。当潜江市稻虾模式转变为其他主要模式后,其周年CH_(4)排放总量增加2.31%~11.25%,N_(2)O排放总量增加11.49%~67.09%,dSOC减少9.95%~22.81%。【结论】本研究中,稻麦模式表现为CH_(4)排放最大,稻油模式的N_(2)O排放最大,两者固碳能力中等;稻闲模式由于只有一季种植,温室气体排放小于稻旱轮作模式,但其固碳能力较差;稻虾模式的减排和固碳能力相较于稻闲与稻旱轮作模式强,具有更高的绿色发展潜力,但其仍具有减排空间。
基金National Natural Science Foundation, No.41171382 National Basic Program of China （973 Program）, No.2010CB951502
文摘Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-source data, an effective model named the Spatial Production Allocation Model （SPAM） which integrates arable land distribution, administrative unit statistics of crop data, agricultural irrigation data and crop suitability data, was used to get a series of spatial distributions of rice area and production with 10-km pixels at a national scale -it was applied from the early 1980s onwards and used to analyze the pattern of spatial and temporal changes. The results show that significant changes occurred in rice in China during 1980-2010. Overall, more than 50% of the rice area decreased, while nearly 70% of rice production increased in the change region during 1980-2010. Spatially, most of the increased area and production were in Northeast China, especially, in Jilin and Heilongjiang; most of the decreased area and production were located in Southeast China, especially, in regions of rapidly urbanization in Guangdong, Fujian and Zhejiang. Thus, the centroid of rice area was moved northeast approximately 230 km since 1980, and rice production about 320 km, which means rice production moved northeastward faster than rice area because of the significant rice yield increase in Northeast China. The results also show that rice area change had a decisive impact on rice production change. About 54.5% of the increase in rice pro- duction is due to the expansion of sown area, while around 83.2% of the decrease in rice production is due to contraction of rice area. This implies that rice production increase may be due to area expansion and other non-area factors, but reduced rice production could largely be attributed to rice area decrease.
基金National Basic Research Program of China (973 Program),No.2010CB951504National Natural Science Foundation of China,No.40930101+1 种基金No.40971218Foundation for National Non-Profit Scientific Institution,Ministry of Finance of China,No.IARRP-2010-02
文摘This paper presents a scenario-based assessment of global future food security. To do that,the socio-economic and climate change scenarios were defined for the future and were linked to an integrated modeling framework. The crop yields simulated by the GIS-based Environmental Policy Integrated Climate （EPIC） model and crop areas simulated by the crop choice decision model were combined to calculate the total food production and per capita food availability,which was used to represent the status of food availability and stability. The per capita Gross Domestic Product （GDP） simulated by IFPSIM model was used to reflect the situation of food accessibility and affordability. Based on these two indicators,the future food security status was assessed at a global scale over a period of approximately 20 years,starting from the year 2000. The results show that certain regions such as South Asia and most African countries will likely remain hotspots of food insecurity in the future as both the per capita food availability and the capacity of being able to import food will decrease between 2000 and 2020. Low food production associated with poverty is the determining factor to starvation in these regions,and more efforts are needed to combat hunger in terms of future actions. Other regions such as China,most Eastern European countries and most South American countries where there is an increase in per capita food availability or an increase in the capacity to import food between 2000 and 2020 might be able to improve their food security situation.
基金Foundation： National Natural Science Foundation of China, No.41171328, No.41201184, No.41101537 National Basic Program of China, No.2010CB951502
文摘Understanding crop patterns and their changes on regional scale is a critical re- quirement for projecting agro-ecosystem dynamics. However, tools and methods for mapping the distribution of crop area and yield are still lacking. Based on the cross-entropy theory, a spatial production allocation model （SPAM） has been developed for presenting spa- tio-temporal dynamics of maize cropping system in Northeast China during 1980-2010. The simulated results indicated that （1） maize sown area expanded northwards to 48~N before 2000, after that the increased sown area mainly occurred in the central and southern parts of Northeast China. Meanwhile, maize also expanded eastwards to 127°E and lower elevation （less than 100 m） as well as higher elevation （mainly distributed between 200 m and 350 m）; （2） maize yield has been greatly promoted for most planted area of Northeast China, espe- cially in the planted zone between 42°N and 48°N, while the yield increase was relatively homogeneous without obvious longitudinal variations for whole region; （3） maize planting density increased gradually to a moderately high level over the investigated period, which reflected the trend of aggregation of maize cultivation driven by market demand.
