The ＂Grain for Green Project＂ initiated by the governments since 1999 were the dominant contributors to the vegetation restoration in the agro-pastoral transitional zone of northern China. Climate change and human a...The ＂Grain for Green Project＂ initiated by the governments since 1999 were the dominant contributors to the vegetation restoration in the agro-pastoral transitional zone of northern China. Climate change and human activities are responsible for the improvement and degradation to a certain degree. In order to monitor the vegetation variations and clarify the causes of rehabilitation in the Shaanxi-Gansu-Ningxia Region, this paper, based on the MODIS-NDVI and climate data during the period of 2000-2009, analyzes the main charac- teristics, spatial-temporal distribution and reasons of vegetation restoration, using methods of linear regression, the Hurst Exponent, standard deviation and other methods. Results are shown as follows. （1） From 2000 to 2009, the NDVI of the study area was improved progres- sively, with a linear tendency being 0.032/10a, faster than the growth of the Three-North Shelter Forest Program （0.007/10a） from 1982 to 2006. （2） The vegetation restoration is characterized by two fast-growing periods, with an ＂S-shaped＂ increasing curve. （3） The largest proportion of the contribution to vegetation restoration was observed in the slightly improved area, followed by the moderate and the significantly improved area; the degraded area is distributed sporadically over southern part of Ningxia Hui Autonomous Region as well as eastern Dingbian of Shaanxi province, Huanxian and Zhengyuan of Gansu province. （4） Climate change and human activities are two driving forces in vegetation restoration; more- over anthropogenic factors such as ＂Grain for Green Project＂ were the main causes leading to an increasing trend of NDVI on local scale. However, its influencing mechanism remains to be further investigated. （5） The Hurst Exponent of NDVI time series shows that the vegetation restoration was sustainable. It is expected that improvement in vegetation cover will expand to the most parts of the region.展开更多
The Late Cenozoic stratigraphic sequence and its information of tectonic evolution are obtained here through the detailed petrostratigraphic and magnetostratigraphic study and research of stratigraphic contact and sed...The Late Cenozoic stratigraphic sequence and its information of tectonic evolution are obtained here through the detailed petrostratigraphic and magnetostratigraphic study and research of stratigraphic contact and sedmentary faces of the Cenozoic strata profile, Hejiakouzi area, Ningxia Hui Autonomous Region. The intense Cenozoic tectonic deformation began at 10Ma BP in the Haiyuan-Tongxin Syntaxis, the northeastern margin of Qinghai-Xizang Plateau, and a few deformation events occurred during Late Cenozoic Era.展开更多
In China, 10 ethnic minorities with a combined population of over 20 million people are followers of Islam. In Ningxia Hui Autonomous Region, the population is nearly 6 million, a-mong which the Islamic population is ...In China, 10 ethnic minorities with a combined population of over 20 million people are followers of Islam. In Ningxia Hui Autonomous Region, the population is nearly 6 million, a-mong which the Islamic population is about 2 million. In China as a whole, more than 20 million people enjoy eating food prepared according to Islamic guidelines, known as hal'al food.展开更多
开展陕甘宁红色旅游流网络结构特征研究,可以指导目的地旅游网络结构优化,推动红色旅游高质量发展。运用地理信息技术系统(geographic information system,GIS)技术、社会网络分析等方法,对陕甘宁红色旅游流整体网络特征、网络节点特征...开展陕甘宁红色旅游流网络结构特征研究,可以指导目的地旅游网络结构优化,推动红色旅游高质量发展。运用地理信息技术系统(geographic information system,GIS)技术、社会网络分析等方法,对陕甘宁红色旅游流整体网络特征、网络节点特征进行系统研究。结果表明,陕甘宁红色旅游流网络结构松散,密度低,呈现典型的“核心-边缘”特征;红色旅游流网络凝聚特征显著,地域集中性强,跨区域合作有待强化;延安革命纪念馆等关键节点功能地位突出,网络极化效应显著;核心节点对周边节点存在“虹吸效应”。研究进一步从构建多极化红色旅游流网络体系、推动红色旅游与相关业态协调发展和创新融合等方面就推动陕甘宁红色旅游流网络优化提出了相关对策建议。展开更多
The Weining Beishan area of Ningxia Hui Autonomous Region is located at on the western edge of the Helanshan tectonic belt,which is a tectonic joint among Alxa Block,Ordos Block,and North Qilian orogenic belt.However,...The Weining Beishan area of Ningxia Hui Autonomous Region is located at on the western edge of the Helanshan tectonic belt,which is a tectonic joint among Alxa Block,Ordos Block,and North Qilian orogenic belt.However,the tectonic evolution of this area remains unclear due to the lack of magmatic information.This paper conducted researches on geochronology,geochemistry,and Sr-Nd-Hf isotopes of the diorite porphyrites exposed in the Weining Beishan area.The zircon U-Pb dating yields two ages of 145.0±1.1 and 146.2±1.5 Ma,and the whole-rock geochemical data indicate that the diorite porphyrites are metaluminous to weakly peraluminous and high-K calc-alkaline series.The characteristics of highly initial^(87)Sr/^(86)Sr ratios(0.70816 to 0.71047),negativeε_(Nd)(t)(−8.9 to−8.4),and negativeε_(Hf)(t)(−13.8 to−21.2)indicate that the diorite porphyrites originated from partial melting of the middle-lower ancient crust related to the North China Craton.Combined with the regional geology,we suggested that partial melting was triggered by a tectonic activity of deep faults cutting through the crust under the regional stress transformation from compressing to extension during the Late Jurassic–Early Cretaceous,which is probably related to the westward subduction of the Paleo-Pacific Plate.展开更多
基金National Natural Science Foundation of China, No.41171090 No.40871052
文摘The ＂Grain for Green Project＂ initiated by the governments since 1999 were the dominant contributors to the vegetation restoration in the agro-pastoral transitional zone of northern China. Climate change and human activities are responsible for the improvement and degradation to a certain degree. In order to monitor the vegetation variations and clarify the causes of rehabilitation in the Shaanxi-Gansu-Ningxia Region, this paper, based on the MODIS-NDVI and climate data during the period of 2000-2009, analyzes the main charac- teristics, spatial-temporal distribution and reasons of vegetation restoration, using methods of linear regression, the Hurst Exponent, standard deviation and other methods. Results are shown as follows. （1） From 2000 to 2009, the NDVI of the study area was improved progres- sively, with a linear tendency being 0.032/10a, faster than the growth of the Three-North Shelter Forest Program （0.007/10a） from 1982 to 2006. （2） The vegetation restoration is characterized by two fast-growing periods, with an ＂S-shaped＂ increasing curve. （3） The largest proportion of the contribution to vegetation restoration was observed in the slightly improved area, followed by the moderate and the significantly improved area; the degraded area is distributed sporadically over southern part of Ningxia Hui Autonomous Region as well as eastern Dingbian of Shaanxi province, Huanxian and Zhengyuan of Gansu province. （4） Climate change and human activities are two driving forces in vegetation restoration; more- over anthropogenic factors such as ＂Grain for Green Project＂ were the main causes leading to an increasing trend of NDVI on local scale. However, its influencing mechanism remains to be further investigated. （5） The Hurst Exponent of NDVI time series shows that the vegetation restoration was sustainable. It is expected that improvement in vegetation cover will expand to the most parts of the region.
文摘The Late Cenozoic stratigraphic sequence and its information of tectonic evolution are obtained here through the detailed petrostratigraphic and magnetostratigraphic study and research of stratigraphic contact and sedmentary faces of the Cenozoic strata profile, Hejiakouzi area, Ningxia Hui Autonomous Region. The intense Cenozoic tectonic deformation began at 10Ma BP in the Haiyuan-Tongxin Syntaxis, the northeastern margin of Qinghai-Xizang Plateau, and a few deformation events occurred during Late Cenozoic Era.
文摘In China, 10 ethnic minorities with a combined population of over 20 million people are followers of Islam. In Ningxia Hui Autonomous Region, the population is nearly 6 million, a-mong which the Islamic population is about 2 million. In China as a whole, more than 20 million people enjoy eating food prepared according to Islamic guidelines, known as hal'al food.
文摘开展陕甘宁红色旅游流网络结构特征研究,可以指导目的地旅游网络结构优化,推动红色旅游高质量发展。运用地理信息技术系统(geographic information system,GIS)技术、社会网络分析等方法,对陕甘宁红色旅游流整体网络特征、网络节点特征进行系统研究。结果表明,陕甘宁红色旅游流网络结构松散,密度低,呈现典型的“核心-边缘”特征;红色旅游流网络凝聚特征显著,地域集中性强,跨区域合作有待强化;延安革命纪念馆等关键节点功能地位突出,网络极化效应显著;核心节点对周边节点存在“虹吸效应”。研究进一步从构建多极化红色旅游流网络体系、推动红色旅游与相关业态协调发展和创新融合等方面就推动陕甘宁红色旅游流网络优化提出了相关对策建议。
文摘The Weining Beishan area of Ningxia Hui Autonomous Region is located at on the western edge of the Helanshan tectonic belt,which is a tectonic joint among Alxa Block,Ordos Block,and North Qilian orogenic belt.However,the tectonic evolution of this area remains unclear due to the lack of magmatic information.This paper conducted researches on geochronology,geochemistry,and Sr-Nd-Hf isotopes of the diorite porphyrites exposed in the Weining Beishan area.The zircon U-Pb dating yields two ages of 145.0±1.1 and 146.2±1.5 Ma,and the whole-rock geochemical data indicate that the diorite porphyrites are metaluminous to weakly peraluminous and high-K calc-alkaline series.The characteristics of highly initial^(87)Sr/^(86)Sr ratios(0.70816 to 0.71047),negativeε_(Nd)(t)(−8.9 to−8.4),and negativeε_(Hf)(t)(−13.8 to−21.2)indicate that the diorite porphyrites originated from partial melting of the middle-lower ancient crust related to the North China Craton.Combined with the regional geology,we suggested that partial melting was triggered by a tectonic activity of deep faults cutting through the crust under the regional stress transformation from compressing to extension during the Late Jurassic–Early Cretaceous,which is probably related to the westward subduction of the Paleo-Pacific Plate.
