The quality of cultivated land has an important influence on agricultural output, food security, sustainable development and the ability of using cultivated land resources. As the trend of cultivated land quality is g...The quality of cultivated land has an important influence on agricultural output, food security, sustainable development and the ability of using cultivated land resources. As the trend of cultivated land quality is getting more and more attention, in order to strengthen the management of cultivated land quality, improve the precision of cultivated land quality and other achievements, and maintain the current situation of cultivated land quality and other achievements. For this paper, taking A county of Guangxi Zhuang Autonomous Region as an example, with the support of GIS, the paper studies the grade and grade renewal of cultivated land by using the superposition method, studies the grade and grade change of regional cultivated land and its spatial distribution, grasps the status quo change of cultivated land and the grade and grade change of cultivated land caused by the quality construction of cultivated land in the year, and then provides scientific data for land use plan, land consolidation and cultivates land protection.展开更多
Sustainable use of natural resources is different from sustainable development. As the most important natural resource, sustainable use of land resource is the essential guarantee of sustainable development. The natur...Sustainable use of natural resources is different from sustainable development. As the most important natural resource, sustainable use of land resource is the essential guarantee of sustainable development. The nature of sustainable use of land resource is to retain the quantity and productivity of land resource from generation to generation.The evaluation of sustainable use of land resource is an important method to ensure land use to get onto the sustainable track. Furthermore, building index system is the key of the evaluation. In view of tendency of the evaluation indexes chosen so widely, the evaluation indexes should include only three kinds in the researches on the evaluation of sustainable use of land resource. The first is the stock and structure index of land resource, viz. Areas quantity structure of land resources. In China, it is especially paid attention to the per person index of land quantity and rate between cultivated land and farmland. The second is the productive index of land, which includes the productivity, potentiality, stability and renewal situation of land. The third is the sustained index of land environment. On the evaluation research of area level, we should lay particular emphasis on statistic indexes. With a case of Guangxi Zhuang Autonomous Region in China, the evaluation index system of sustainable land use in county area has been built in this thesis. Using the weighted average method to calculate the means of sustainable land use in each county, according to the land using situation, all counties in the autonomous region have been divided into three types. (1) Sustainable Pattern contains 18 counties, which have higher land resource productivity, stronger sustained abilities of land environment .The economic benefits of land using in these counties are obviously higher. These counties have gotten highly intensive farming, and they are all in the good circumstance. (2) Basically Sustained Pattern contains 48 counties, which productivity of land resource is of middle level. In part of counties and cities, the stock of land resource inclines to lower level, but their land using potentialities are still greater. Through changing land using pattern, these counties can rapidly enter in a good circumstance. (3) Critically Sustained Pattern contains 14 counties, which are mostly in the karst mountain areas. They have less stock of land resource, lower productivity and more extensive cultivation. The productivity of land renewing has been hindered, so it urgently need to be renovated. At last, the writers have explored the basic ways of sustainable use of land resource in Guangxi, China — (1) Retain the stock of land resource and strictly manage farmland uses. (2) Strengthen the value accounting of land resource, and control the farmland occupation of non agricultural construction. (3) Depend on technology advanced, optimize the land using structure, and promote the productive level. (4) Carry out land management all round, and improve the ecological environment of land resource. (5) Enhance evaluation researche and land monitoring, and promote the sustainable utilization level of land resource.展开更多
Based on the data concerning detailed survey on land in the year 2009 and land change in the year 2010 in Rong County,a mountainous region of Sichuan Province,by using quantitative geographical model,we conduct quanti...Based on the data concerning detailed survey on land in the year 2009 and land change in the year 2010 in Rong County,a mountainous region of Sichuan Province,by using quantitative geographical model,we conduct quantitative analysis of the status quo of land use in Rong County in terms of land use diversification,land use centralization,land use combination type,land use geographic significance and comprehensive use degree of land use.The results show some characteristics as follows.Firstly,land use in study area displays prominent characteristic of diversification;there is a high degree of completeness land use type;there is a great similarity among towns.Secondly,there is limited combination number of land use type;mostly the combination number of the towns is 2-3;the holistic function of regional land is fragile;the proportion of farmland areas is big,reaching 40.09%;the land use type of 21 towns is farmland.Thirdly,the towns with prominent characteristic of diversification of land use in Rong County,have low degree of centralization of land use and relatively big combination number of land use type,and vice versa.Fourthly,the type and quantity of agricultural land resources with geographical significance are relatively complete with nothing missing;it abounds in untapped land,but the overall index values of land use are all smaller than 300,with low overall use degree of land.展开更多
Based on a partial postcranial skeleton collected from the Lower Cretaceous Napai Formation of Guangxi, China, we erect a new sauropod taxon, Fusuisaurus zhaoi gen. et sp. nov. The holotype specimen consists of the le...Based on a partial postcranial skeleton collected from the Lower Cretaceous Napai Formation of Guangxi, China, we erect a new sauropod taxon, Fusuisaurus zhaoi gen. et sp. nov. The holotype specimen consists of the left ilium, left pubis, anterior caudals, most of the dorsal ribs and distal end of the left femur. Fusuisaurus zhaoi is diagnosed by a unique combination of character states among the known sauropods. It displays several synapomorphies of Titanosauriformes but lacks many derived features seen in other titanosauriforms, suggesting that the new taxon represents the basalmost known titanosauriform and providing new evidence that Titanosauriformes originated from Asia. A size comparison suggests that Fusuisaurus zhaoi is among the largest Early Cretaceous sauropods, providing an important addition to the Early Cretaceous Chinese sauropod diversity.展开更多
文摘The quality of cultivated land has an important influence on agricultural output, food security, sustainable development and the ability of using cultivated land resources. As the trend of cultivated land quality is getting more and more attention, in order to strengthen the management of cultivated land quality, improve the precision of cultivated land quality and other achievements, and maintain the current situation of cultivated land quality and other achievements. For this paper, taking A county of Guangxi Zhuang Autonomous Region as an example, with the support of GIS, the paper studies the grade and grade renewal of cultivated land by using the superposition method, studies the grade and grade change of regional cultivated land and its spatial distribution, grasps the status quo change of cultivated land and the grade and grade change of cultivated land caused by the quality construction of cultivated land in the year, and then provides scientific data for land use plan, land consolidation and cultivates land protection.
文摘Sustainable use of natural resources is different from sustainable development. As the most important natural resource, sustainable use of land resource is the essential guarantee of sustainable development. The nature of sustainable use of land resource is to retain the quantity and productivity of land resource from generation to generation.The evaluation of sustainable use of land resource is an important method to ensure land use to get onto the sustainable track. Furthermore, building index system is the key of the evaluation. In view of tendency of the evaluation indexes chosen so widely, the evaluation indexes should include only three kinds in the researches on the evaluation of sustainable use of land resource. The first is the stock and structure index of land resource, viz. Areas quantity structure of land resources. In China, it is especially paid attention to the per person index of land quantity and rate between cultivated land and farmland. The second is the productive index of land, which includes the productivity, potentiality, stability and renewal situation of land. The third is the sustained index of land environment. On the evaluation research of area level, we should lay particular emphasis on statistic indexes. With a case of Guangxi Zhuang Autonomous Region in China, the evaluation index system of sustainable land use in county area has been built in this thesis. Using the weighted average method to calculate the means of sustainable land use in each county, according to the land using situation, all counties in the autonomous region have been divided into three types. (1) Sustainable Pattern contains 18 counties, which have higher land resource productivity, stronger sustained abilities of land environment .The economic benefits of land using in these counties are obviously higher. These counties have gotten highly intensive farming, and they are all in the good circumstance. (2) Basically Sustained Pattern contains 48 counties, which productivity of land resource is of middle level. In part of counties and cities, the stock of land resource inclines to lower level, but their land using potentialities are still greater. Through changing land using pattern, these counties can rapidly enter in a good circumstance. (3) Critically Sustained Pattern contains 14 counties, which are mostly in the karst mountain areas. They have less stock of land resource, lower productivity and more extensive cultivation. The productivity of land renewing has been hindered, so it urgently need to be renovated. At last, the writers have explored the basic ways of sustainable use of land resource in Guangxi, China — (1) Retain the stock of land resource and strictly manage farmland uses. (2) Strengthen the value accounting of land resource, and control the farmland occupation of non agricultural construction. (3) Depend on technology advanced, optimize the land using structure, and promote the productive level. (4) Carry out land management all round, and improve the ecological environment of land resource. (5) Enhance evaluation researche and land monitoring, and promote the sustainable utilization level of land resource.
基金Supported by National Technology Support Program (2006BAJ05A13)National Technology Support Program (2007BAD89B15 )Technology Support Program of Sichuan Province (2009NZ0051)
文摘Based on the data concerning detailed survey on land in the year 2009 and land change in the year 2010 in Rong County,a mountainous region of Sichuan Province,by using quantitative geographical model,we conduct quantitative analysis of the status quo of land use in Rong County in terms of land use diversification,land use centralization,land use combination type,land use geographic significance and comprehensive use degree of land use.The results show some characteristics as follows.Firstly,land use in study area displays prominent characteristic of diversification;there is a high degree of completeness land use type;there is a great similarity among towns.Secondly,there is limited combination number of land use type;mostly the combination number of the towns is 2-3;the holistic function of regional land is fragile;the proportion of farmland areas is big,reaching 40.09%;the land use type of 21 towns is farmland.Thirdly,the towns with prominent characteristic of diversification of land use in Rong County,have low degree of centralization of land use and relatively big combination number of land use type,and vice versa.Fourthly,the type and quantity of agricultural land resources with geographical significance are relatively complete with nothing missing;it abounds in untapped land,but the overall index values of land use are all smaller than 300,with low overall use degree of land.
文摘Based on a partial postcranial skeleton collected from the Lower Cretaceous Napai Formation of Guangxi, China, we erect a new sauropod taxon, Fusuisaurus zhaoi gen. et sp. nov. The holotype specimen consists of the left ilium, left pubis, anterior caudals, most of the dorsal ribs and distal end of the left femur. Fusuisaurus zhaoi is diagnosed by a unique combination of character states among the known sauropods. It displays several synapomorphies of Titanosauriformes but lacks many derived features seen in other titanosauriforms, suggesting that the new taxon represents the basalmost known titanosauriform and providing new evidence that Titanosauriformes originated from Asia. A size comparison suggests that Fusuisaurus zhaoi is among the largest Early Cretaceous sauropods, providing an important addition to the Early Cretaceous Chinese sauropod diversity.
