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1.
Dating data, altitude of Neolithic sites, climatic changes from sedimentary records and previous research results were collected and analyzed to detect possible connections between climatic changes and human activities in the Changjiang River Delta in the Neolithic Age. The results indicated that hydrological changes greatly impacted the human activities in the study region. Low-lying geomorphology made the floods and sea level changes become the important factors affecting human activities, especially the altitude change of human settlements. People usually moved to higher places during the periods characterized by high sea level and frequent floods to escape the negative influences from water body expansion, which resulted in cultural hiatus in certain profiles. However, some higher-altitude settlements were not the results of climatic changes but the results of social factors, such as religious ceremony and social status. Therefore, further research will be necessary for the degree and types of impacts of climatic changes on human activities in the study area at that time.  相似文献   

2.
Based on the theory of geo-economy, under the new situation of global economy, information network and China‘s entry into WTO, also with the holding of APEC (in 2001) and the International Exposition in the near future, the Changjiang (Yangtze) River Delta is striding toward the spectacular international multi-polar situation and becomes one of core regions with high-speed development. Facing the ocean and world all along, leading the progressive tides of the age and scintillating the splendor of the nation, she does advance with time. Through a long period of irrigation projects construction and intensive operation of lands in previous agricultural society, the artificial wetland ecosystem with a positive cycle had ever been formed in this region. At present, environmental pollution and urban expansion resulted from post-industrialization are being rectified. The delta will be the paradigm of industrial and agricultural modernization along the sustainable development road. With the rapid development of urbanization,she has been one of the regions with the highest density population and high urbanization level. Taking the Changjiang River estuary and the Hangzhou Bay as two parts, she is continuously strengthening and adjusting her interior structure, expanding mothball space and constructing the oriental modem ″logistics center“ to link the whole world. The butterfly-style urban system of the Changjiang River Delta is flying, probably engendering earthshaking “butterfly effect“.  相似文献   

3.
陈宝冲THECHANGEOFTHEGENERALFORMANDTHETRANSPORTOFTHEWATER,LOADANDSALTABOUTTHENORTH-BRANCHOFTHECHANGJIANGRIVERMOUTH¥ChenBaochong(N...  相似文献   

4.
The general trend of three elements (precipitation, runoff and evaporation) of the water balance of the Changjiang River Basin is discussed from the regional distribution of the mean annual values of view, i.e. isogram. The distribution of precipitation is non-uniform. The distribution of runoff mainly supplied from precipitation is more uniform than that of precipitation. The distribution of the evaporation from land is much more uniform than that of precipitation and runoff. Time distribution of these three elements shows the characteristics of comparatively distinct yearly variation and few variation between years. The relationship between precipitation and runoff, and between precipitation and evaporation in the humid region in the Changjiang River is analyzed. The slopes of their straight line correlation are nearly equal. The internal relationship between variables should be paid attention to, otherwise, a pseudo correlation may be resulted in. The paper provides the method of quantitative computa  相似文献   

5.
1 Introduction Economic development in any country or region entails a long process of structural change in production as GDP and income per capita rise. In addition, economic de- velopment requires a long period of structural transfor- mation in materials inputs through reallocating natural resources (Cipolla, 1962). Land, as a crucial element and a key factor of production, is always the best witness of such transformations. In China, one of the largest countries in the world, 13.5% of its…  相似文献   

6.
From the point of view of urban consumption behavior, urban fresh water consumption could be classified as three types, namely, direct, indirect and induced water consumption. A calculation approach of urban fresh water consumption was presented based on the theory of urban basic material consumption and the input-output method, which was utilized to calculate urban fresh water consumption of China, and to analyze its structural change and causes. The results show that the total urban fresh water consumption increased 561.7×109m3, and the proportion to the total national fresh water resources increased by 20 percentage points from 1952 to 2005. The proportion of direct and induced water consumption had been continuously rising, and it increased by 15 and 35 percentage points separately from 1952 to 2005, while the proportion of indirect water consumption decreased by 50 percentage points. Urban indirect water consumption was mainly related to urban grain, beef and mutton consumption, and urban induced water consumption had a close relationship with the amount of carbon emission per capita. Finally, some countermeasures were put forward to realize sustainable utilization of urban fresh water resources in China. Foundation item: Under the auspices of Key Project of National Natural Science Foundation of China (No. 40535026)  相似文献   

7.
Using field hydrological data, the relationship between the mixing of salt water and fresh water and the tidal range/ high tidal level in the Changjiang (Yangtze) River estuary is discussed, and the transporting and concentrating of suspended sediment in the estuary were also analysed in respect to the circulation, flocculation and stratified interface resulting from mixing.The calculation results by two-dimentional box model have confirmed the effects of the circulation on the concentrating of suspended sediment in the estuary. The conclusions derived from this work have deepened the understanding on the mixing in the Changjiang River estuary and are of significance in bo'th theory and practice.  相似文献   

8.
近47年白银市气候变化及其对农业生产的影响分析   总被引:1,自引:0,他引:1  
利用白银市4个代表站逐日平均气温、逐日地面最低温度,分别得到≥0℃初终日期、初终霜冻日期以及利用逐月平均气温、平均最高气温、平均最低气温和逐月降水资料,对白银市近47a的气候变化特征进行分析,同时分析了气候变化对农业生产的影响,为充分利用变化了的农业气候资源,减少不利因素带来的影响提出了对策和建议。  相似文献   

9.
Sea level rise could increase the salinity of an estuary by altering the balance between fresh water and salt water. The implications of sea level rise for increasing salinity have been examined in the Changjiang (Yangtze) River estuary. By correlative analysis of chlorinity, discharge and tidal level and calculation of two-dimensional chlorinity, distribution of the Changjiang River estuary, the changes of the intensity and lasting hours of salt water intrusion at Wusong Station and the changes of chlorinity distribution in the South Branch of the Changjiang River estuary have been estimated when future sea level rises 50-100 cm. The intensity of salt water intrusion in the future will be far more serious than current trend.  相似文献   

10.
Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded: 1) The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2) The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3) The western and eastern boundaries of the suitable agricul~re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.  相似文献   

11.
In this paper, Shunde City is selected as a typical region standing for the Zhujiang Delta because of its excellent location and dike-pond system. There are three main characters of agricultural land use in this region. First, the most typical land use form is dike-pond system. It is a special form of artificial ecosystem of land-water interaction. Second, sandy field is also an important land type in this region. Third, land use is greatly influenced by export-oriented economy. Recently, with economic reforming and the opening up of the Zhujiang Delta, the structure of agricultural land use has been changed greatly. The area of mulberry dike has decreased and a variety of planting crops has increased. Various structure of dike-pond farming has emerged in the Zhujiang Delta such as “fruit dike-fish pond”, “flower dike-fish pond”, “grass dike-fish pond”, “vegetable dike-fish pond”. The area of water has slightly increased and its development tends to modernization due to the use of modern equipment and advanced breeding ways. The area for “three high” (high yield, high quality and high efficiency) agriculture has increased greatly.  相似文献   

12.
Spectrum analyses of water quality time series have been carried out for five hydrometric stations including Wuhan hydrometric station of the Changjiang(Yangtze) River, etc. The fluctuations of Ca2+, Mg2+ and HCO 3 concentrations in river water under different physical geography conditions have about two-year cycle which is corresponding to hydrometeorological quasi-biannual-oscillation (QBO). Na+, Cl SO 4 2− have about two-year cycle in the area lightly affected by human activities while two-year cycle doesn’t exist in the area heavily affected by human activities. All the fluctuations of major ions have about three-month cycle. The river diseharge fluctuation accounts for 43.9%, 45.1%, 54.3%, 33.9%, 30.3% and 42.7% of the variance of Ca2+, Mg2+, HCO 3 , Na+, Cl, SO 4 2− , respectively, at Wuhan from 1962 to 1985. According to the spectrum characteristic of major ions, the duration of the time series has to be at least 13 years for trend analysis of monthly water quality data. Foundation item: Under the auspices of the National Natural Science Foundation of China (No. 49671017). Biography: XIA Xing-hui(1971-), female, a native of Hunan Province, Ph. D. Her research interest includes environmental chemistry.  相似文献   

13.
1 INTRODUCTION The Changjiang (Yangtze) Delta and its neighboring regions mentioned in this article is located in the lower reaches of the Changjiang River, whose north, east, south and west adjacent places are Xingtongyang Canal, Huanghai Sea, East China Sea, Qiantang River, Hangzhou Bay and Nanjing, Zhenjiang respectively. These regions belong to Jiangsu Province, Zhejiang Province and Shanghai City in administrative division, being one of the economic developed regions. The …  相似文献   

14.
Investigations from August, 1985 to July , 1986 showed that the high concentration area of PO4-P , SiO3-Si and NO3-N gradually reduced with the reduction of the area of the Changjiang River diluted water from summer, autumn to winter , and that the seasonal distributions and variations of the nutrients concentrations were mainly controlled by the river flow and were also related to the growth and decline of phytoplankton . The conservation of SiO3-Si and NO3-N in the estuary in the flood season was poorer than that in the dry season .. The behaviour of PO4-P in the estuary shows that aside from -biological removal, buffering of PCU-P is possible in the estuary . The highest monthly average concentrations and annual average concentrations in the river mouth were respectively 0.88 and 0.57 umol/L for PO4-P,191.5 and 96.2 umol/L for SiO3-Si, and 81.6 and 58.6 umol/L for NOs-N . The Changjiang's annual transports of PO4-P , SiO3-Si and NO3-N to the sea were about 1.4×104tons , 204.4×104 tons and 63.6×104  相似文献   

15.
This paper explains the meaning of investment circumstance, and analyses the overall feature of investment circumstances of the Changjiang River Delta zone and clears about its targets’ system. Then the authors use “polytarget comprehensive value evaluation rule” to make comprehensive classification appraisal of the investment circumstance of the five regions including Shanghai, Ning (Nanjing)-Zhen (Zhenjiang)-Yang(Yangzhou), Su(Suzhou)-Xi(Wuxi)-Chang(Changzhou)-Tong(Nantong), Hang(Hangzhou)-Jia(Jiaxing)-Hu(Huzhou), Ning(Ningbo)-Shao(Shaoxing)-Zhou(Zhoushan)etc., which have similar region feature and district join together due to the long-term development of society and economy among these regions.  相似文献   

16.
THEINVESTMENTCIRCUMSTANCESANDITSCLASSIFICATIONAPPRAISALOFCHANGJIANGRIVERDELTAXuGang(许刚)SheZhixiang(佘之祥)NanjingInstituteofGeog...  相似文献   

17.
In recent years,wetland ecological water requirements (EWRs) have been estimated by using hydrological and functional approaches,but those approaches have not yet been integrated for a whole ecosystem.This paper presents a new method for calculating wetland EWRs,which is based on the response of habitats to water level,and determines water level threshold through the functional integrity of habitats.Results show that in the Huanghe (Yellow) River Delta water levels between 5.0 m and 5.5 m are required to maintain the functional integrity of the wetland at a value higher than 0.7.One of the dominant plants in the delta,Phragmites australis,tolerates water level fluctuation of about ± 0.25 m without the change in wetland functional integrity.The minimum,optimum and maximum EWRs for the Huanghe River Delta are 9.42×106 m3,15.56×106 m3 and 24.12×106 m3 with water levels of 5.0 m,5.2 m and 5.5 m,corresponding to functional integrity indices of 0.70,0.84 and 0.72,respectively.A wetland restoration program has been performed,which aims to meet these EWRs in attempt to recover from losses of up to 98% in the delta's former wetland area.  相似文献   

18.
(翁齐浩)THERELATIONSHIPBETWEENTHEENVIRONMENTALCHANGEOFTHEZHUJIANGRIVERDELTAINHOLOCENEANDITSCULTURALORIGINSANDPROPAGATION¥WengQih...  相似文献   

19.
The northeastern China, the United States, and the western Europe are important agricultural regions both on the global and regional scales. The western Europe has a longer history of agricultural land development than the eastern United States. These two regions have changed from the deforestation and reclamation phase in the past to the current land abandonment and reforestation phase. Compared with the two regions, large-scale land exploitation has only been practiced in the northeastern China during the last century. After a short high-intensity deforestation and reclamation period, agricultural and forest lands are basically in a dynamic steady state. By comparing domestic and international agro-forestry development and considering the ecological environment and socio-economic benefits that can be derived from agro-forestry, this paper suggests that large area of reforestation would be inevitable in future though persistent and large agricultural demand in coming decades even more. And local reforestation at slope farmland with ecological vulnerability should be imperative at present to avoid severer damage. At the same time, from the perspective of Land Change Science, the results demonstrate that the research on land use change in the agro-forestry ecotone is typical and critical, particularly those dealing with the analysis of spatial and temporal characteristics and the simulation of climate, hydrology, and other environmental effects.  相似文献   

20.
China is entering a critical and accelerating phase of urbanization.As one of the most urbanized regions in China,the Changjiang(Yangtze)River Delta has experienced dramatic urbanization and urban transformation.However,in the recent years,many changes have taken place in this region and there is limited attention to the regional urbanization path evolution,its problems and the way to solve these problems.Therefore,we should revisit the urbanization process in the Changjiang River Delta again.In this paper,we revisited urbanization paths of the Changjiang River Delta by data analysis,influence factors of urbanization by the Gray Relational Analysis,and major challenges to urbanization of the Changjiang River Delta by theoretical considerations.We found that the urbanization of the Changjiang River Delta had experienced several stages of large-scale spatial and urban system restructuring.Within the Changjiang River Delta,Shanghai,Zhejiang and Jiangshu had experienced different urbanization path with local characteristics.But with their development model gradually converging,their urbanization model is also converging.We also found that the major influence factors affecting the Changjiang River Delta urbanization were dynamic change and urbanization was driven by different key factors in different socio-economic development stages.Meanwhile,the Changjiang River Delta urbanization is facing many problems such as existing institutional arrangements,including the hukou(household registration)system and others which can not meet the needs of current socioeconomic development and urbanization.Therefore,it is imperative to promote institutional innovation and adopt a new urbanization development strategy for the sake of the orderly and sustainable urbanization development in the Changjiang River Delta.  相似文献   

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