In the summer of 1998, a rarely severe flooding disaster occurred in the whole basin of the Changjiang(Yangtze) River, which caused enormous losses. By 22nd of August, 29 provinces, autonomous regions and municipaliti...In the summer of 1998, a rarely severe flooding disaster occurred in the whole basin of the Changjiang(Yangtze) River, which caused enormous losses. By 22nd of August, 29 provinces, autonomous regions and municipalitieswere involved, 21. 2 million ha of land were inundated, 223 million people were affected, 3004 people were killed and4. 97 million buildings were collapsed. The estimated direct loss of the country accounted to 166. 6 billion yuan (RMB).The main reason of the disaster is the unusual climate but the unreasonable land utilization the aggravated the disaster.This paper consists of two parts. One part analysed the unreasonable land utilization, including the neglect of forest landprotection, which caused the forest land area to decrease by 440 thousand ha in the whole country every year, the enclosing of lakes for cultivation, which decreased the area of lakes located along the banks of the Changjiang River from 17 200km2 at the beginning of the founding of the People’s Republic of China to 6531 km2 in 1983, the changing of functions oflakes, which reduced the volume of storage exceedingly, for example, only 5 spots of lakes were used for storing water inWuhan City, and the slow progress of the construction of flood diversion and storage area, which would cause huge lossesonce flood was diverted. The other part explored the strategy of land utilization on the supplying of land for flood controlprojects, such as embankment, drainage installation, flood diversion and storage area, and on tapping the potentialsthrough narrowing and amalgamgting the range of rural residential quarters and small towns, reclaiming reserved resources, transforming middle and low productive fields, attaching importance to land arrangement and recultivation, and adjusting contracted fields partially, to ensure the sustainable and stable growth of the region.展开更多
Due to its great strategic significance in integrating regional coordinated development and enhancing the rise of Central China, urban agglomeration in the middle reaches of Changjiang （Yangtze） River has attracted ...Due to its great strategic significance in integrating regional coordinated development and enhancing the rise of Central China, urban agglomeration in the middle reaches of Changjiang （Yangtze） River has attracted much attention from both theoretical and practical aspects. Such research into the area＇s economic network structure is beneficial for the formation of an urban- and regional-development strategy. This paper constructs an economic tie model based on a modified gravitation model. Subsequently, referring to social network analysis, the paper empirically studies the network density, network centrality, subgroups and structural holes of the middle reaches of Changjiang River＇s urban agglomeration economic network. The findings are fourfold： （1） an economic network of urban agglomeration in the middle reaches of Changjiang River has been formed, and economic ties between the cities in this network are comparatively dense; （2） the urban agglomeration in the middle reaches of Changjiang River can be divided into four significant subgroups, with each subgroup having its own obvious economic communications, while there is less economic-behavioral heterogeneity among subgroups - this is especially true for the two subgroups that exist in the Poyang Lake Ecological Economic Zone; （3） an economy pattern driven by the central cities of Wuhan, Changsha and Nanchang has emerged in the urban agglomeration of the middle reaches of Changjiang River, while these three capital cities have exerted great radiation abilities to their surrounding cities, the latter are less able to absorb resources from the former （4） the Wuhan Metropolitan Areas and the Poyang Lake Ecological Economic Zone have more structural holes than the Ring of Changsha, Zhuzhou and the Xiangtan City Clusters, meaning that cities at the periphery of these two areas are easily constrained by central cities. The Ring of Changsha, Zhuzhou and the Xiangtan City Clusters have fewer structural holes; thus, the cities in this area will not face as many constraints as those in the other two areas.展开更多
Skarns of magmatic origin, or magmatic skarns as called, are formed by crystallization of skarnic magma injecting into structural fissures. They occur in various rocks (rock formations), mainly in form of veins. Usual...Skarns of magmatic origin, or magmatic skarns as called, are formed by crystallization of skarnic magma injecting into structural fissures. They occur in various rocks (rock formations), mainly in form of veins. Usually, they possess massive structure and cumulative texture. They mainly consist of calc silicate, without or with minor water bearing silicates. The typical minerals in it include alkali feldspar, calcite and anhydrite. Some silicate melt inclusions and high temperature, high salinity poly phase inclusions can be seen in the crystals of their host minerals. The particular members of the magmatic skarns are transitional skarn and skarnic pegmatite. The magmatic skarn and the congenetic alkali rich diorite usually collaborate in a conjugating and complementary manner. They probably are the products of calcic contamination, degassing, desilicification and separation in melt state of deep seated (high level magma chamber) alkali rich intermediate acid magma.展开更多
Based on the data of NCEP, OLR and rainfall of China, we studied the influences of the East Asian winter monsoon activities on the precipitation during the raining season over China by correlation analysis and composi...Based on the data of NCEP, OLR and rainfall of China, we studied the influences of the East Asian winter monsoon activities on the precipitation during the raining season over China by correlation analysis and composite analysis. The result shows that annual and interdecadal change of East Asian winter monsoon is distinct. It is strong from 1950s to the middle of 1980s but weak after the middle of 1980s. The effect of abnormal winter monsoon on the precipitation during raining season is significant over the middle and lower reaches of the Changjiang River basin. It is revealed that the precipitation will increase when preceding winter monsoon is weak but decrease when preceding winter monsoon is strong. In this paper, some appropriate reasons are given to explain the abnormal rainfall by analyzing the distribution of SSTA and the variation of summer circulation. It is pointed out definitely that the variation of SSTA and summer circulation is a primary cause for abnormal rainfall over the middle and lower reaches of the Changjiang River.展开更多
文摘In the summer of 1998, a rarely severe flooding disaster occurred in the whole basin of the Changjiang(Yangtze) River, which caused enormous losses. By 22nd of August, 29 provinces, autonomous regions and municipalitieswere involved, 21. 2 million ha of land were inundated, 223 million people were affected, 3004 people were killed and4. 97 million buildings were collapsed. The estimated direct loss of the country accounted to 166. 6 billion yuan (RMB).The main reason of the disaster is the unusual climate but the unreasonable land utilization the aggravated the disaster.This paper consists of two parts. One part analysed the unreasonable land utilization, including the neglect of forest landprotection, which caused the forest land area to decrease by 440 thousand ha in the whole country every year, the enclosing of lakes for cultivation, which decreased the area of lakes located along the banks of the Changjiang River from 17 200km2 at the beginning of the founding of the People’s Republic of China to 6531 km2 in 1983, the changing of functions oflakes, which reduced the volume of storage exceedingly, for example, only 5 spots of lakes were used for storing water inWuhan City, and the slow progress of the construction of flood diversion and storage area, which would cause huge lossesonce flood was diverted. The other part explored the strategy of land utilization on the supplying of land for flood controlprojects, such as embankment, drainage installation, flood diversion and storage area, and on tapping the potentialsthrough narrowing and amalgamgting the range of rural residential quarters and small towns, reclaiming reserved resources, transforming middle and low productive fields, attaching importance to land arrangement and recultivation, and adjusting contracted fields partially, to ensure the sustainable and stable growth of the region.
基金National Natural Science Foundation of China, No.41371182 Key Project of Hunan Social Science Foundation, No. 12ZDB01 Entrusting Project of Hunan Social Science Foundation Base, No. 12JD 12
文摘Due to its great strategic significance in integrating regional coordinated development and enhancing the rise of Central China, urban agglomeration in the middle reaches of Changjiang （Yangtze） River has attracted much attention from both theoretical and practical aspects. Such research into the area＇s economic network structure is beneficial for the formation of an urban- and regional-development strategy. This paper constructs an economic tie model based on a modified gravitation model. Subsequently, referring to social network analysis, the paper empirically studies the network density, network centrality, subgroups and structural holes of the middle reaches of Changjiang River＇s urban agglomeration economic network. The findings are fourfold： （1） an economic network of urban agglomeration in the middle reaches of Changjiang River has been formed, and economic ties between the cities in this network are comparatively dense; （2） the urban agglomeration in the middle reaches of Changjiang River can be divided into four significant subgroups, with each subgroup having its own obvious economic communications, while there is less economic-behavioral heterogeneity among subgroups - this is especially true for the two subgroups that exist in the Poyang Lake Ecological Economic Zone; （3） an economy pattern driven by the central cities of Wuhan, Changsha and Nanchang has emerged in the urban agglomeration of the middle reaches of Changjiang River, while these three capital cities have exerted great radiation abilities to their surrounding cities, the latter are less able to absorb resources from the former （4） the Wuhan Metropolitan Areas and the Poyang Lake Ecological Economic Zone have more structural holes than the Ring of Changsha, Zhuzhou and the Xiangtan City Clusters, meaning that cities at the periphery of these two areas are easily constrained by central cities. The Ring of Changsha, Zhuzhou and the Xiangtan City Clusters have fewer structural holes; thus, the cities in this area will not face as many constraints as those in the other two areas.
文摘Skarns of magmatic origin, or magmatic skarns as called, are formed by crystallization of skarnic magma injecting into structural fissures. They occur in various rocks (rock formations), mainly in form of veins. Usually, they possess massive structure and cumulative texture. They mainly consist of calc silicate, without or with minor water bearing silicates. The typical minerals in it include alkali feldspar, calcite and anhydrite. Some silicate melt inclusions and high temperature, high salinity poly phase inclusions can be seen in the crystals of their host minerals. The particular members of the magmatic skarns are transitional skarn and skarnic pegmatite. The magmatic skarn and the congenetic alkali rich diorite usually collaborate in a conjugating and complementary manner. They probably are the products of calcic contamination, degassing, desilicification and separation in melt state of deep seated (high level magma chamber) alkali rich intermediate acid magma.
基金East Asia winter monsoon and Yunnan summertime drought and floods and their interdecadal anomalies a project of the Yunnan Province Science Foundation a Yunnan Province Foundation project (97D022G)
文摘Based on the data of NCEP, OLR and rainfall of China, we studied the influences of the East Asian winter monsoon activities on the precipitation during the raining season over China by correlation analysis and composite analysis. The result shows that annual and interdecadal change of East Asian winter monsoon is distinct. It is strong from 1950s to the middle of 1980s but weak after the middle of 1980s. The effect of abnormal winter monsoon on the precipitation during raining season is significant over the middle and lower reaches of the Changjiang River basin. It is revealed that the precipitation will increase when preceding winter monsoon is weak but decrease when preceding winter monsoon is strong. In this paper, some appropriate reasons are given to explain the abnormal rainfall by analyzing the distribution of SSTA and the variation of summer circulation. It is pointed out definitely that the variation of SSTA and summer circulation is a primary cause for abnormal rainfall over the middle and lower reaches of the Changjiang River.
