1999年 第9卷 第3期
1999, 9(3): 193-198.
摘要:
In the summer of 1998, an exceptionally serious flood, with the characteristics of high water level, large volume of flow, long duration and serious losses caused by the disaster, occurred in the Nenjiang River basin and the Songhua River basin. Greater flood peak occurred three times in the trunk stream of the Nenjiang River for the floods occurred in its tributaries one after another. At Jiangqiao Hydrometric Station, the water level was 141.90 m and the rate of flow was 12000 m3/s. The flood is ranged to a catastrophic one, which occurs once in 50 years. Ranged to a catastrophic flood at Qiqihar Hydrometric Station that occurs once in 400 years, its water level, 0.89 m higher than the former all time highest, was 149.30 m and the corresponding rate of flow was 14800 m3/s. The water level that exceeded the all time highest lasted for 7 days. At Harbin Hydrometric Station, the water level, 0.59 m higher than the former all time highest, was 120.89 m and the corresponding rate of flow was 17400 m3/s. The water level that exceeded the all time highest lasted for 9 to 10 days. The flood here is ranged to a catastrophic one, which occurs once in 150 years. The flood of the Nenjiang River damaged 456×104ha of crops and 115×104 rooms and the direct loss of economy exceeded 40 billion yuan(RMB). The main reasons of the flood are great rainfall, long flood season, unreasonable land use, regional ecological environment degradation and lack of water control projects. It is obvious that the following measures are greatly needed: the comprehensive management of the river basins; the formulation of development planning of the river basins, especially the water control projects; the development of agriculture based on ecological security.
In the summer of 1998, an exceptionally serious flood, with the characteristics of high water level, large volume of flow, long duration and serious losses caused by the disaster, occurred in the Nenjiang River basin and the Songhua River basin. Greater flood peak occurred three times in the trunk stream of the Nenjiang River for the floods occurred in its tributaries one after another. At Jiangqiao Hydrometric Station, the water level was 141.90 m and the rate of flow was 12000 m3/s. The flood is ranged to a catastrophic one, which occurs once in 50 years. Ranged to a catastrophic flood at Qiqihar Hydrometric Station that occurs once in 400 years, its water level, 0.89 m higher than the former all time highest, was 149.30 m and the corresponding rate of flow was 14800 m3/s. The water level that exceeded the all time highest lasted for 7 days. At Harbin Hydrometric Station, the water level, 0.59 m higher than the former all time highest, was 120.89 m and the corresponding rate of flow was 17400 m3/s. The water level that exceeded the all time highest lasted for 9 to 10 days. The flood here is ranged to a catastrophic one, which occurs once in 150 years. The flood of the Nenjiang River damaged 456×104ha of crops and 115×104 rooms and the direct loss of economy exceeded 40 billion yuan(RMB). The main reasons of the flood are great rainfall, long flood season, unreasonable land use, regional ecological environment degradation and lack of water control projects. It is obvious that the following measures are greatly needed: the comprehensive management of the river basins; the formulation of development planning of the river basins, especially the water control projects; the development of agriculture based on ecological security.
1999, 9(3): 199-205.
摘要:
Oasis is a kind of special ecological landscape of arid land. In the past two decades, certain progress has been made in research on Chinese oases and a series of achievements have been attained on system of oasis, evolution of oasis, maintenance and construction of oasis, regulation and control of oasis, sustainable development of oasis. To establish the science of Chinese Oasis is pressingly necessary for the development of arid land on a large scale and the opportunity is coming. We should specify the object of study and the nature of this science, and push forward it to more advanced level so that we could occupy the international leading position in this field.
Oasis is a kind of special ecological landscape of arid land. In the past two decades, certain progress has been made in research on Chinese oases and a series of achievements have been attained on system of oasis, evolution of oasis, maintenance and construction of oasis, regulation and control of oasis, sustainable development of oasis. To establish the science of Chinese Oasis is pressingly necessary for the development of arid land on a large scale and the opportunity is coming. We should specify the object of study and the nature of this science, and push forward it to more advanced level so that we could occupy the international leading position in this field.
1999, 9(3): 206-212.
摘要:
Urban social geography and its subfield—urban social spatial differentiation have been developed since the 1960s. In China, with the development of urban geography during the 1970s and prosperity in the 1980s, its study fields have been expanded, the research technology and theory have been renewed. There are two main sub methodologies of urban social space study: ecological and comparative methodologies. Since Beijing, Shanghai, Guangzhou metropolitans are located at the window of China to overseas, it is reasonable to chose them as the main research regions, and the study on them has been strengthened since the 1980s. The research fields can be classified into five sub fields: (1) social structure transformation and economic transit; (2) the change of cognition and behavior differentiation; (3) the relation between culture transformation and space differentiation in organization; (4) land use differentiation and the transit of planning method; (5) material environment differentiation. We should strengthen the study of internal relation between resident space structure changing with time and space, and landuse; the division of a consumer and provision markets which can further understand the mechanism of social spatial differentiation; the effect of resident segregation; what's its benefits which can be accepted by community; and, how to the study result of community replacement, state house distribution policy and management into the social practice.
Urban social geography and its subfield—urban social spatial differentiation have been developed since the 1960s. In China, with the development of urban geography during the 1970s and prosperity in the 1980s, its study fields have been expanded, the research technology and theory have been renewed. There are two main sub methodologies of urban social space study: ecological and comparative methodologies. Since Beijing, Shanghai, Guangzhou metropolitans are located at the window of China to overseas, it is reasonable to chose them as the main research regions, and the study on them has been strengthened since the 1980s. The research fields can be classified into five sub fields: (1) social structure transformation and economic transit; (2) the change of cognition and behavior differentiation; (3) the relation between culture transformation and space differentiation in organization; (4) land use differentiation and the transit of planning method; (5) material environment differentiation. We should strengthen the study of internal relation between resident space structure changing with time and space, and landuse; the division of a consumer and provision markets which can further understand the mechanism of social spatial differentiation; the effect of resident segregation; what's its benefits which can be accepted by community; and, how to the study result of community replacement, state house distribution policy and management into the social practice.
1999, 9(3): 213-220.
摘要:
As a constant and active factor affecting population migration, marriage has long been neglected. This paper brings to light of the social significance of marriage migration and makes an inquiry into its characteristics, patterns and mechanism. It is thought the marriage plays an important role in hastening population migration. While compared with other forms of population migration, marriage migration is distinctive, showing its own characteristics, such as irreversibility in direction, shorter distance, age long continuity, regional dispersal, gentler fluctuation in number, sexual imbalance, and multiple factors at work. Although the manifestation of marriage migration is complicated, its patterns are clear, that is: pattern 1, women to men's habitation; pattern 2, men to women's habitation; and pattern 3, men and women to a third place. It is thought that both the characters and the patterns of marriage migration are determined by its mechanism, because marriage migration is not only a kind of biological action but also a kind of social action, the former of which determines whether it happens, while the latter of which determines how it does. The difference of men's and women's social status, that of cities and country, and that of developed and backward areas may result in abnormality of marriage migration, while the socio biological feedback of sexual imbalance and regional environmental deterioration can give rise to some self adjusting mechanism. In the end of the paper, based on a sample analysis, it concludes four tendencies towards marriage migration in China: (1) pair migration is emerging; (2) the changing trend of urban and rural regional relationship of marriage is contrary; (3) urban “island effect” in marriage is weakening; and (4) the potential energy between developed and less developed areas is still strong.
As a constant and active factor affecting population migration, marriage has long been neglected. This paper brings to light of the social significance of marriage migration and makes an inquiry into its characteristics, patterns and mechanism. It is thought the marriage plays an important role in hastening population migration. While compared with other forms of population migration, marriage migration is distinctive, showing its own characteristics, such as irreversibility in direction, shorter distance, age long continuity, regional dispersal, gentler fluctuation in number, sexual imbalance, and multiple factors at work. Although the manifestation of marriage migration is complicated, its patterns are clear, that is: pattern 1, women to men's habitation; pattern 2, men to women's habitation; and pattern 3, men and women to a third place. It is thought that both the characters and the patterns of marriage migration are determined by its mechanism, because marriage migration is not only a kind of biological action but also a kind of social action, the former of which determines whether it happens, while the latter of which determines how it does. The difference of men's and women's social status, that of cities and country, and that of developed and backward areas may result in abnormality of marriage migration, while the socio biological feedback of sexual imbalance and regional environmental deterioration can give rise to some self adjusting mechanism. In the end of the paper, based on a sample analysis, it concludes four tendencies towards marriage migration in China: (1) pair migration is emerging; (2) the changing trend of urban and rural regional relationship of marriage is contrary; (3) urban “island effect” in marriage is weakening; and (4) the potential energy between developed and less developed areas is still strong.
1999, 9(3): 221-227.
摘要:
Situated in the hinterland of the Qinghai Xizang Plateau, the eco environment of the source regions of the Changjiang (Yangtze) River and the Huanghe(Yellow) River are getting worse in recent years and has attracted increasing attention of researchers around the world. This paper discusses several major problems concerning the eco environment of the source regions. The authors hold that the two eco environment extents of the source region of the Changjiang River should be demarcated with the confluence of the Deng'ailongqu River to Zhidoi as its boundary, or 1.15×104 km2 larger than the hydrological source area; while that of the Huanghe River should be delimited with Medotangumaxia in Darlag County as its limit, or 1.84×104 km2 larger than the hydrological source area. The eco environment of the source regions with vegetation, soil, wetland, lake and river as the main elements, has always been affected by climatic changes, freeze thaw processes (including frozen soil freeze thaw processes and glacial snow cover freeze thaw processes), rodent damage and human activities. From an evaluation angle of fragile ecosystem, a study index system is established and several important issues for future research are suggested.
Situated in the hinterland of the Qinghai Xizang Plateau, the eco environment of the source regions of the Changjiang (Yangtze) River and the Huanghe(Yellow) River are getting worse in recent years and has attracted increasing attention of researchers around the world. This paper discusses several major problems concerning the eco environment of the source regions. The authors hold that the two eco environment extents of the source region of the Changjiang River should be demarcated with the confluence of the Deng'ailongqu River to Zhidoi as its boundary, or 1.15×104 km2 larger than the hydrological source area; while that of the Huanghe River should be delimited with Medotangumaxia in Darlag County as its limit, or 1.84×104 km2 larger than the hydrological source area. The eco environment of the source regions with vegetation, soil, wetland, lake and river as the main elements, has always been affected by climatic changes, freeze thaw processes (including frozen soil freeze thaw processes and glacial snow cover freeze thaw processes), rodent damage and human activities. From an evaluation angle of fragile ecosystem, a study index system is established and several important issues for future research are suggested.
1999, 9(3): 228-235.
摘要:
The Yarlung Zangbo River basin is a spacial zone in the south of Xizang, the types, distribution and causes of desertified lands have special features. The type, area, distribution and damage of desertification land in the Yarlung Zangbo River basin are firstly analysed in detail by using latest investigation information. According to the classification criteria of desertified land types and grades, the desertified land in the Yarlung Zangbo River basin can be divided into three grades and five types: fixed sand (dune) land, semi bare sand and gravel land, semi-fixed sand (dune) land, base sand and gravel land, and shifting sand (dune) land. The desertified lands in the basin are mainly distributed in the wide valley floor and tributary junction area. The main factors affecting desertification are fragile eco environment, climate warming and drying and over exploitation of land resources. The man made factors leading to desertification in the Yarlung Zangbo River basin are over cutting and over grazing, dominated by over-grazing.
The Yarlung Zangbo River basin is a spacial zone in the south of Xizang, the types, distribution and causes of desertified lands have special features. The type, area, distribution and damage of desertification land in the Yarlung Zangbo River basin are firstly analysed in detail by using latest investigation information. According to the classification criteria of desertified land types and grades, the desertified land in the Yarlung Zangbo River basin can be divided into three grades and five types: fixed sand (dune) land, semi bare sand and gravel land, semi-fixed sand (dune) land, base sand and gravel land, and shifting sand (dune) land. The desertified lands in the basin are mainly distributed in the wide valley floor and tributary junction area. The main factors affecting desertification are fragile eco environment, climate warming and drying and over exploitation of land resources. The man made factors leading to desertification in the Yarlung Zangbo River basin are over cutting and over grazing, dominated by over-grazing.
1999, 9(3): 236-242.
摘要:
So called free economic region is a special region without jurisdiction of customs, delimited by one country. There are mainly four types of free economic region, that is, commercial type of free economic region—free port, industrial type of free economic region—export processing area, integrated commercial and trade type of free economic region—free trade zone, and scientific and technological type of free economic region—scientific industrial park. With the development of free economic region of different countries, besides free economic region within one country, there appear transnational border free economic region established by two or multiple countries. Analysing favorable factors and unfavorable factors to establish the free economic region for China and Russia, for example, China and Russia have land boundary line of 4282.7 km; China and Russia may strengthen overall cooperation in politics, military, economy, science and technology, culture, etc. making full use of geographical factors of the two countries, borders; there is a strong complementarity in resources, labour force etc. for China and Russia; strengthening the Sino Russian economic trade cooperation is needed, the authors proposed a conception and selected four comparative ideal locations for establishing the Sino Russian border free economic region: Manzhouli Zabaikalye Free Economic Region, Heihe Blagoveshchensk Free Economic Region, Suifenhe Pogranichnyy Free Economic Region, Hunchun Hasan Free Economic Region. Finally the principles and patterns for establishing free economic region are discussed.
So called free economic region is a special region without jurisdiction of customs, delimited by one country. There are mainly four types of free economic region, that is, commercial type of free economic region—free port, industrial type of free economic region—export processing area, integrated commercial and trade type of free economic region—free trade zone, and scientific and technological type of free economic region—scientific industrial park. With the development of free economic region of different countries, besides free economic region within one country, there appear transnational border free economic region established by two or multiple countries. Analysing favorable factors and unfavorable factors to establish the free economic region for China and Russia, for example, China and Russia have land boundary line of 4282.7 km; China and Russia may strengthen overall cooperation in politics, military, economy, science and technology, culture, etc. making full use of geographical factors of the two countries, borders; there is a strong complementarity in resources, labour force etc. for China and Russia; strengthening the Sino Russian economic trade cooperation is needed, the authors proposed a conception and selected four comparative ideal locations for establishing the Sino Russian border free economic region: Manzhouli Zabaikalye Free Economic Region, Heihe Blagoveshchensk Free Economic Region, Suifenhe Pogranichnyy Free Economic Region, Hunchun Hasan Free Economic Region. Finally the principles and patterns for establishing free economic region are discussed.
1999, 9(3): 243-249.
摘要:
A complex history of the Late Pleistocene vegetation and environmental changes for the northern part of the deciduous forest is revealed in an exceptionally well dated pollen diagram from Dongganchi in Beijing area. In 15800-14700 a B.P., the arbors and aquatic plants were sparse, and the climate was cold and dry. In 14700-13400 a B.P., forest growth was limited, it was dominated by conifers, presumably in responded to a cooling climate. Aquatic plants became abundant. During 13400 to 12600 a B.P., there was a widespread development of coniferous and broad leaved mixed forest, aquatic plants decreased which corresponded to climate gradually becoming warming and dry. In 12600-11400 a B.P., there was alternation of coniferous and broad leaved mixed forest, so were aquatic plants. From 11400 to 9600 a B.P., the decreasing of trees and increasing of herbs and shrubs suggested an opening up of the vegetation in responded to cooling, probably corresponded to Younger Dryas from 10600 to 10300 a B.P. About 9600-7270 a B.P., the climate changed from cooler and dry to warmer and humid. About 7270-3390 a B.P., the coniferous and the broad leaved mixed forest increased, it was in responding to the “climatic optimum". About 3390-1000 a B.P., climate became cooler and dry. After 1000 a B.P., there was a severe fluctuation, indicating the temperature drop and the environmental deterioration.
A complex history of the Late Pleistocene vegetation and environmental changes for the northern part of the deciduous forest is revealed in an exceptionally well dated pollen diagram from Dongganchi in Beijing area. In 15800-14700 a B.P., the arbors and aquatic plants were sparse, and the climate was cold and dry. In 14700-13400 a B.P., forest growth was limited, it was dominated by conifers, presumably in responded to a cooling climate. Aquatic plants became abundant. During 13400 to 12600 a B.P., there was a widespread development of coniferous and broad leaved mixed forest, aquatic plants decreased which corresponded to climate gradually becoming warming and dry. In 12600-11400 a B.P., there was alternation of coniferous and broad leaved mixed forest, so were aquatic plants. From 11400 to 9600 a B.P., the decreasing of trees and increasing of herbs and shrubs suggested an opening up of the vegetation in responded to cooling, probably corresponded to Younger Dryas from 10600 to 10300 a B.P. About 9600-7270 a B.P., the climate changed from cooler and dry to warmer and humid. About 7270-3390 a B.P., the coniferous and the broad leaved mixed forest increased, it was in responding to the “climatic optimum". About 3390-1000 a B.P., climate became cooler and dry. After 1000 a B.P., there was a severe fluctuation, indicating the temperature drop and the environmental deterioration.
1999, 9(3): 250-257.
摘要:
Employing the regression equations relating mean annual runoff to mean annual temperature and mean annual precipitation derived with modern data, palaeorunoff values were calculated from palaeoclimatic information for three localities in the eastern part of the North China Plain (37-41°N, 115-120°E) during the last 12000 years. These results present a general pattern of temporal and spatial variations of the Holocene palaeorunoff occurring in this region. The annual runoff was the highest during 8000-3000 a B.P., the second high during 12000-8000 a B.P., and the lowest during 3000-0 a B.P. Spatially the annual runoff was the highest at the downstream area of the Luanhe River in the north, the second highest at the area around Beijing in the middle, and the lowest at the area around Xingtai in the southwest. These results were further compared to other palaeohydrological reconstruction achieved by other researchers or with other methods, which usually indicates the similar trend of hydrological changes for this region.
Employing the regression equations relating mean annual runoff to mean annual temperature and mean annual precipitation derived with modern data, palaeorunoff values were calculated from palaeoclimatic information for three localities in the eastern part of the North China Plain (37-41°N, 115-120°E) during the last 12000 years. These results present a general pattern of temporal and spatial variations of the Holocene palaeorunoff occurring in this region. The annual runoff was the highest during 8000-3000 a B.P., the second high during 12000-8000 a B.P., and the lowest during 3000-0 a B.P. Spatially the annual runoff was the highest at the downstream area of the Luanhe River in the north, the second highest at the area around Beijing in the middle, and the lowest at the area around Xingtai in the southwest. These results were further compared to other palaeohydrological reconstruction achieved by other researchers or with other methods, which usually indicates the similar trend of hydrological changes for this region.
1999, 9(3): 258-264.
摘要:
Experiment researches have proven that there is an obvious phenomenon of abrupt geothermal anomaly in volcanic region in the forewarning period of volcano eruption, which is closely related to the geological structure, the cause, the scale and the type of volcano etc. On the other hand, this kind of geothermal anomaly is an important sign to monitor volcano activity by thermal infrared remote sensing techniques. This paper discusses the feature of abrupt geothermal anomaly, the transmission mechanism of geothermal anomaly and the radiation transmission mechanism of heat field of terrene in volcanic region. By analyzing mechanism of terrene temperature rising by way of conduction and convection of heat, we have presented the transmission equation of atmosphere for thermal infrared radiation based on the effective radiation of objects. The related problems of noise interference in the processes of transmission for thermal infrared radiation will be discussed in the later paper.
Experiment researches have proven that there is an obvious phenomenon of abrupt geothermal anomaly in volcanic region in the forewarning period of volcano eruption, which is closely related to the geological structure, the cause, the scale and the type of volcano etc. On the other hand, this kind of geothermal anomaly is an important sign to monitor volcano activity by thermal infrared remote sensing techniques. This paper discusses the feature of abrupt geothermal anomaly, the transmission mechanism of geothermal anomaly and the radiation transmission mechanism of heat field of terrene in volcanic region. By analyzing mechanism of terrene temperature rising by way of conduction and convection of heat, we have presented the transmission equation of atmosphere for thermal infrared radiation based on the effective radiation of objects. The related problems of noise interference in the processes of transmission for thermal infrared radiation will be discussed in the later paper.
1999, 9(3): 265-273.
摘要:
In order to make a thorough investigation about relationship between population increase and cultivated land decrease along with economic development over recent years in Guangdong province, this paper aims to study the relationship between the changes in cultivated land and the rapid economic development in Guangdong Province of China using GIS. The spatial database of administrative boundary in the province is captured and stored in GIS and then several county based statistics produced by the National Statistical Bureau of China are linked to the spatial data. In the study, the correlation analysis between decrease of cultivated land in some metropolitan counties and population increase is conducted. Besides, similar analysis is carried out between decrease of cultivated land in the Zhujiang (Pearl) River Delta Region and gross industrial output. The result of the analysis is presented in GIS with the boundary data to show the spatial distribution and trend of the phenomenon. Some measures of conserving cultivated land in the province in order to achieve a sustainable development are also proposed.
In order to make a thorough investigation about relationship between population increase and cultivated land decrease along with economic development over recent years in Guangdong province, this paper aims to study the relationship between the changes in cultivated land and the rapid economic development in Guangdong Province of China using GIS. The spatial database of administrative boundary in the province is captured and stored in GIS and then several county based statistics produced by the National Statistical Bureau of China are linked to the spatial data. In the study, the correlation analysis between decrease of cultivated land in some metropolitan counties and population increase is conducted. Besides, similar analysis is carried out between decrease of cultivated land in the Zhujiang (Pearl) River Delta Region and gross industrial output. The result of the analysis is presented in GIS with the boundary data to show the spatial distribution and trend of the phenomenon. Some measures of conserving cultivated land in the province in order to achieve a sustainable development are also proposed.
1999, 9(3): 274-278.
摘要:
The chemistry of water samples collected in May of 1997 from snow, lakes, rivers, and spring on the north side of Mt. Qomolangma is reported. The pH value is between 7.35-8.52, the order of which is: lake water>river water>snow. All the samples are alkalinity. The pH values of the surface snow samples are relatively higher than the other China's glacial regions. The conductivity of the samples is low, varying between 34.8-194 μs/cm. The conductivity values and total concentrations of the samples on the same glacier usually increase with decreasing altitude, but ones of the surface snow samples are converse for topographical causes. The anions are determined, the SO42- concentration is the highest in river and lake samples; in the surface snow samples, the Cl- concentration is the highest. Among the cations of all the samples, the Ca2+ concentration is the highest. The relationships between SO42- , Mg2+, F-, Ca2+, conductivity and the total concentrations show the increasing trend. On the other side, the conductivity, F-, Ca2+, the total concentration, SO42- and Mg2+ of the river water samples all increase with decreasing altitude.
The chemistry of water samples collected in May of 1997 from snow, lakes, rivers, and spring on the north side of Mt. Qomolangma is reported. The pH value is between 7.35-8.52, the order of which is: lake water>river water>snow. All the samples are alkalinity. The pH values of the surface snow samples are relatively higher than the other China's glacial regions. The conductivity of the samples is low, varying between 34.8-194 μs/cm. The conductivity values and total concentrations of the samples on the same glacier usually increase with decreasing altitude, but ones of the surface snow samples are converse for topographical causes. The anions are determined, the SO42- concentration is the highest in river and lake samples; in the surface snow samples, the Cl- concentration is the highest. Among the cations of all the samples, the Ca2+ concentration is the highest. The relationships between SO42- , Mg2+, F-, Ca2+, conductivity and the total concentrations show the increasing trend. On the other side, the conductivity, F-, Ca2+, the total concentration, SO42- and Mg2+ of the river water samples all increase with decreasing altitude.
1999, 9(3): 279-283.
摘要:
The basic theory of fractal is introduced and applied. Because the changes and development of drainage landform are affected by many complex factors, the process is a nonlinear change, but the definite method could not explain this phenomenon for along time. However, the nonlinear science method such as the fractal theory has been applied to many fields and the researchers obtained more satisfactory results by means of nonlinear method instead of linear method. This paper discussed the quantitative index such as fractal dimension of the river networks, main channels and furrow networks on the drainage geomorphy system. And the calculating method, the separating principle on the fractal dimension have are studied. Finally, the fractal dimensions of the furrow and main channel have been obtained according to the experimental data, and the significance of the value of fractal dimension is discussed. It is believed that the slope erosive growth is more complicated than that of main channel districts, and the value of the fractal dimension of river networks would reflect the extricated degree of the growth and geomorphic erosive stages of the drainage.
The basic theory of fractal is introduced and applied. Because the changes and development of drainage landform are affected by many complex factors, the process is a nonlinear change, but the definite method could not explain this phenomenon for along time. However, the nonlinear science method such as the fractal theory has been applied to many fields and the researchers obtained more satisfactory results by means of nonlinear method instead of linear method. This paper discussed the quantitative index such as fractal dimension of the river networks, main channels and furrow networks on the drainage geomorphy system. And the calculating method, the separating principle on the fractal dimension have are studied. Finally, the fractal dimensions of the furrow and main channel have been obtained according to the experimental data, and the significance of the value of fractal dimension is discussed. It is believed that the slope erosive growth is more complicated than that of main channel districts, and the value of the fractal dimension of river networks would reflect the extricated degree of the growth and geomorphic erosive stages of the drainage.
THE PRECIPITATION INFILTRATION AND RUNOFF RECHARGING EXPERIMENT OBSERVATION IN THE TAKLIMAKAN DESERT
1999, 9(3): 284-288.
摘要:
This is a certain quantity of available groundwater resources in the form of freshwater lens according to the survey and drilling experiment along the oil transporting highway in the Taklimakan Desert, which is the second largest moving desert in the world, located in the northwest part of China. As the primary freshwater sources, local precipitation in the heartland of Taklimakan Desert, not only forms the runoff on the clayey ground, but also feeds the groundwater. After the analysis of historic records of the rainfall and the formation of clayey sediments, the precipitation infiltration and runoff recharging experiment was conducted, a natural rainfall runoff process was observed and recorded. The studied area referred to this paper is located in the middle part of the desert, within 6 km wide and 60 km long along the new oil transporting highway. This paper reveals that in the center of the desert an event of storm (4 mm) can be considered as the critical value of the runoff produced on the clayey ground. The rainfall infiltration coefficients on the sand dunes are over 0.46 for the erosion side, thus, rainstorms and runoffs as main fresh water sources feed the ground water directly.
This is a certain quantity of available groundwater resources in the form of freshwater lens according to the survey and drilling experiment along the oil transporting highway in the Taklimakan Desert, which is the second largest moving desert in the world, located in the northwest part of China. As the primary freshwater sources, local precipitation in the heartland of Taklimakan Desert, not only forms the runoff on the clayey ground, but also feeds the groundwater. After the analysis of historic records of the rainfall and the formation of clayey sediments, the precipitation infiltration and runoff recharging experiment was conducted, a natural rainfall runoff process was observed and recorded. The studied area referred to this paper is located in the middle part of the desert, within 6 km wide and 60 km long along the new oil transporting highway. This paper reveals that in the center of the desert an event of storm (4 mm) can be considered as the critical value of the runoff produced on the clayey ground. The rainfall infiltration coefficients on the sand dunes are over 0.46 for the erosion side, thus, rainstorms and runoffs as main fresh water sources feed the ground water directly.
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