Green manure use in China has declined rapidly since the 1980 s with the extensive use of chemical fertilizers.The deterioration of field environments and the demand for green agricultural products have resulted in mo...Green manure use in China has declined rapidly since the 1980 s with the extensive use of chemical fertilizers.The deterioration of field environments and the demand for green agricultural products have resulted in more attention to green manure.Human intervention and policy-oriented behaviors likely have large impacts on promoting green manure planting.However,little information is available regarding on where,at what rates,and in which ways（i.e.,intercropping green manure in orchards or rotating green manure in cropland） to develop green manure and what benefits could be gained by incorporating green manure in fields at the county scale.This paper presents the conversion of land use and its effects at small region extent（CLUE-S） model,which is specifically developed for the simulation of land use changes originally,to predict spatial distribution of green manure in cropland and orchards in 2020 in Pinggu District located in Beijing,China.Four types of land use for planting or not planting green manure were classified and the future land use dynamics（mainly croplands and orchards） were considered in the prediction.Two scenarios were used to predict the spatial distribution of green manure based on data from 2011：The promotion of green manure planting in orchards（scenario 1） and the promotion of simultaneous green manure planting in orchards and croplands（scenario 2）.The predictions were generally accurate based on the receiver operating characteristic（ROC） and Kappa indices,which validated the effectiveness of the CLUE-S model in the prediction.In addition,the spatial distribution of the green manure was acquired,which indicated that green manure mainly located in the orchards of the middle and southern regions of Dahuashan,the western and southern regions of Wangxinzhuang,the middle region of Shandongzhuang,the eastern region of Pinggu and the middle region of Xiagezhuang under scenario 1.Green manure planting under scenario 2 occurred in orchards in the middle region of Wangxinzhuang,and croplands in most regions of Daxingzhuang,southern Pinggu,northern Xiagezhuang and most of Mafang.The spatially explicit results allowed for the assessment of the benefits of these changes based on different economic and ecological indicators.The economic and ecological gains of scenarios 1 and 2 were 175691 900 and143000 300 CNY,respectively,which indicated that the first scenario was more beneficial for promoting the same area of green manure.These results can facilitate policies of promoting green manure and guide the extensive use of green manure in local agricultural production in suitable ways.展开更多
In order to study the county scale land use structure during the rapid urbanization and more accurately grasp the dynamic process of land use and cover change,we combine GIS technology with CLUE-S model to research th...In order to study the county scale land use structure during the rapid urbanization and more accurately grasp the dynamic process of land use and cover change,we combine GIS technology with CLUE-S model to research the spatial pattern change of land use in Yongchuan District of Chongqing City. The results show that the forest and farmland were main land use types going through changes in Yongchuan District during 2000-2010,accounting for more than 90% of the total area in each year; during 2000- 2010,the urban area was significantly increased,an increase of 16. 11%,and the urban area during 2005- 2010 was changed more dramatically than during 2000- 2005; forest area was slightly increased and farmland area was reduced by 1660 ha in 10 years. We set three scenarios on land use change in Yongchuan District for simulation and compare the predicted results. It can be concluded that driven by rapid urbanization,the change in land use landscape pattern in Yongchuan District is mainly focused on forest and farmland,the urban area is substantially increased,and the forest area also shows an increasing trend while the farmland area is reduced accordingly. Under ecological protection scenarios,the land use type having a protective effect on the ecological environment achieves better control effect.展开更多
基金supported by the Special Fund for Agroscientific Research in the Public Interest,China(20110300501-01)the Special Fund for First-Class University (4572-18101510)
文摘Green manure use in China has declined rapidly since the 1980 s with the extensive use of chemical fertilizers.The deterioration of field environments and the demand for green agricultural products have resulted in more attention to green manure.Human intervention and policy-oriented behaviors likely have large impacts on promoting green manure planting.However,little information is available regarding on where,at what rates,and in which ways（i.e.,intercropping green manure in orchards or rotating green manure in cropland） to develop green manure and what benefits could be gained by incorporating green manure in fields at the county scale.This paper presents the conversion of land use and its effects at small region extent（CLUE-S） model,which is specifically developed for the simulation of land use changes originally,to predict spatial distribution of green manure in cropland and orchards in 2020 in Pinggu District located in Beijing,China.Four types of land use for planting or not planting green manure were classified and the future land use dynamics（mainly croplands and orchards） were considered in the prediction.Two scenarios were used to predict the spatial distribution of green manure based on data from 2011：The promotion of green manure planting in orchards（scenario 1） and the promotion of simultaneous green manure planting in orchards and croplands（scenario 2）.The predictions were generally accurate based on the receiver operating characteristic（ROC） and Kappa indices,which validated the effectiveness of the CLUE-S model in the prediction.In addition,the spatial distribution of the green manure was acquired,which indicated that green manure mainly located in the orchards of the middle and southern regions of Dahuashan,the western and southern regions of Wangxinzhuang,the middle region of Shandongzhuang,the eastern region of Pinggu and the middle region of Xiagezhuang under scenario 1.Green manure planting under scenario 2 occurred in orchards in the middle region of Wangxinzhuang,and croplands in most regions of Daxingzhuang,southern Pinggu,northern Xiagezhuang and most of Mafang.The spatially explicit results allowed for the assessment of the benefits of these changes based on different economic and ecological indicators.The economic and ecological gains of scenarios 1 and 2 were 175691 900 and143000 300 CNY,respectively,which indicated that the first scenario was more beneficial for promoting the same area of green manure.These results can facilitate policies of promoting green manure and guide the extensive use of green manure in local agricultural production in suitable ways.
基金Supported by National Natural Science Foundation of China(41171442)
文摘In order to study the county scale land use structure during the rapid urbanization and more accurately grasp the dynamic process of land use and cover change,we combine GIS technology with CLUE-S model to research the spatial pattern change of land use in Yongchuan District of Chongqing City. The results show that the forest and farmland were main land use types going through changes in Yongchuan District during 2000-2010,accounting for more than 90% of the total area in each year; during 2000- 2010,the urban area was significantly increased,an increase of 16. 11%,and the urban area during 2005- 2010 was changed more dramatically than during 2000- 2005; forest area was slightly increased and farmland area was reduced by 1660 ha in 10 years. We set three scenarios on land use change in Yongchuan District for simulation and compare the predicted results. It can be concluded that driven by rapid urbanization,the change in land use landscape pattern in Yongchuan District is mainly focused on forest and farmland,the urban area is substantially increased,and the forest area also shows an increasing trend while the farmland area is reduced accordingly. Under ecological protection scenarios,the land use type having a protective effect on the ecological environment achieves better control effect.
