Based on the long-term meteoro1ogical data at 19 meteorological stations over Liaohe Delta during the period of 1961-2010, the sensitivities of Penman-Monteith ET0 to the mean temperature(Stm), wind speed(Su), relative humidity(Srh) and solar radiation(Srs) were calculated and analyzed in three climate sub-regions over Liaohe Delta. The results show that relative humidity is the most sensitive variable to ET0 in semi-arid sub-region, followed by wind speed, solar radiation and air temperature. While, relative humidity is the most sensitive variable to ET0 in semi-humidity sub-region and coast zone, followed by solar radiation, air temperature and wind speed. Trend analysis and Mann-Kendall significant test in both of seasonal and interannual scale demonstrate that sensitivity coefficients of ET0 to air temperature, wind speed, relative humidity and solar radiation present variation and change trend among semi-arid sub-region, semi-humidity sub-region and coastal zone.
In recent years, more scholars have taken the initiative to review the path dependence from the perspective of institutionalization. Attention has been paid on the possibility of path creation, which is characterized by real-time influence and mindful deviation. However, most of the behavioral researches remain in the level of theoretical discussion and model specification. This article takes Huizhou City, China as an example to empirically analyze the path dependence and path creation in the regional development since the reform and openning-yp which began in 1979. It reveals that there is path creation in Chinese regional development, and politics of scale is an important strategy to realize it. The path creation of Huizhou, which is in the Zhujiang River Delta, is actually a trial of local globalization—the scalar jumping from locality (rimland of the Zhujiang River Delta) to global (core area of the Zhujiang River Delta). In the process of regional politics of scale, the local government, which positively organizes locality to participate in politics of scale, is the active subject dominating the politics of scale, while the central government is the powerful third party in the politics of scale, holding the absolute controlling power of scalar system. With the construction of regional scalar fix, the core area of the Zhujiang River Delta forms stable regional division of labor system by the structural power of self-reinforcing. As a peripheral locality, Huizhou made use of “big project investment promotion” and “state-owned enterprise reform and investment promotion” for several times to mobilize large multinational enterprises, the news media and other outside groups to establish external alliance, so as to scale up and finally enter the core area. The case analysis of Huizhou in this article explains the dynamic operation system of “path creation”, and theorizes the phenomenon of rimland breaking the unbalanced development to the realization of path creation with politics of scale by the locality. At the same time, it provides theoretical reference and advices for the rimland to break the unbalanced development status, indicating that local globalization is the key for the rimland to scale up, and the rimland should position the locality in a global perspective and actively fight for the support from a third party to build the locality-global connection.
Along with the constant improvement of the integrated spatial development pattern in the Changjiang River Delta, the evolution of social and economic spatial pattern has become a hot spot field in the research on the integration of the Changjiang River Delta, but the attention is paid insufficiently to the income spatial pattern which can mostly reflect the living standard of integrated region. Analyzing the income pattern and spatio-temporal evolution characteristics of this region is beneficial for measuring the integration progress of the Changjiang River Delta region scientifically and comprehensively, and can provide a reference for other integrated development regions. Based on the data of urban residents’ per capita disposable income and rural residents’ per capital net income of 74 county-level regional units in the Changjiang River Delta region in 1989-2011, and by means of coefficient variation and Markov chain, etc., this article has analyzed the spatio-temporal evolution characteristics of income pattern in the Changjiang River Delta. The result shows that, since 1989, 1) the overall regional difference of urban income has increased first and then decreased, while the regional difference of rural income has kept decreasing; 2) urban income pattern has transformed from the core-periphery structure with Shanghai as the center to the belt structure with income decreasing progressively from coastal areas to inland, and the club convergence, in terms of growth, has become obvious after integrated development; 3) rural income pattern has tended to be balanced gradually, the polarization of high income has been relieved somewhat, but it is difficult for low-income clubs to move upward; 4) rural income growth has depended on cities, but the growth rate is relatively slow, and this has resulted in the sustained enlarging of the income gap between urban and rural areas.
This article introduces the reaction degree coefficient and the influence coefficient, constructs the industrial contact intensity model, and analyzes the spatial network characteristics of industries in the Changjiang River Delta and Beijing-Tianjin-Hebei (BTH) metropolitan region through the model of industry contact intensity. It focuses on the difference between the two regions and research the formation of metropolis shadow. The results show: 1) the better the industries contacts among the cities in region, the higher the economy level of region; 2) the better the industries between central city and other cities in region, he higher the economy level of region; 3) from the perspective of industries spatial contacts, the weak industry contact between central city and outlying areas is the key reason for the metropolitan shadow’s formation.
The traditional geographic space is undergoing a rapid transformation in the information age. The cyberspace plays a continuing role on the real geographical space, and the space of flow takes as a new spatial form. The residents’ fluidity can reflect the characteristics of the “space of flow” to a large extent in the information age. Based on the comprehesive measures of resident fludity carried out in the city, this article researches on the characteristics of the “space of flow” and the coupling relationship between the resident fludity and physical geographical space, through the correlation analysis of the resident fludity and the activity level of physical geographical space. On the basis of the index of resident fludity in the information age, this article uses survey data of behavioral characteristics of residents during the information age and the method of comentropy to determine the weight to evaluate the resident fluidity in Nanjing. The result indicates that the spatial characteristics of the resident fludity shows the layered structure of center-periphery, and there is a spatial tendency to expand along the axis. In the transitional phase of industrial era to information age, the resident fludity, on the one hand, is constrained and limited by the geographical space, which shows some characteristics of geographical space; on the other hand, due to such reasons as uneven space of residents’ information using and individual differences of information on the behavior, the resident fludity indicates a new characteristics of spatial difference. According to the coupling relationship between the fluidity of residents and physical geographic space, “space of flow” can be divided into four types: high fluidity-strong activity, high fluidity-weak activity, low fluidity-strong activity and low fluidity-weak activity. The various combinations represent the organizational model and structure of the “space of flow”. During the transitional period, we should focus on coordinating development of two types of regions, high fluidity-weak activity and low fluidity-strong activity, of cyberspace and geographical space to enhance the function of “space of flow”. It is a meanfull attempt of quantitive evaluation for the “space of flow”, and the advanced research will be done on the basis of a large number of sample surveys.
The relationship between transportation infrastructure construction and economic growth has become a research hotspot at home and abroad, but there are few studies about the spatial structure of the relationship between comprehensive transportation accessibility and the level of economic growth at county level. Comprehensive transportation system is firstly mentioned in the 1950s, it refers to the comprehensive, dynamic, and complex system which is composed of five transportation modes including railway, highway, waterway, airway and pipeline. At present, foreign transportation industry is well known as the "fourth industry". Under the background of global economic integration, the transportation from the original production conditions evolving into national economic growth point and driving force, and expansion of space force contribution to regional economic development is rapidly increasing. In recent years, China has invested large amounts of funds in transportation infrastructure construction, the rapid development of highway, railway, civil aviation and other transport modes, and high-speed rail and other new traffic tools deeply influenced regional economic spatial pattern, such systemic problems need to have further research. There is need for keeping up with the changes, in order to maintain coordination between transportation and regional economy, but it is rare about three-dimensional, multi-dimensional, and high co-integration research at home and abroad. We need the corresponding research results to guide and support under the rapid development of economy and transportation industry. Based on existing achievements and 91 counties in Shandong Province, based traffic statistics in 2009 and the 2011 economic statistics in Shandong Province, the authors build a model of comprehensive transportation accessibility indexes which include center city location index, county road links degree and opening accessibility, analyze the characteristics of spatial structure of the relationship between comprehensive transportation accessibility and the level of economic growth, and build 16 combination types. Those conclusions are achieved: 1) The regional differences is huge about comprehensive transportation accessibility and the level of economic growth, coefficients of variation are 0.690 and 0.349; 2) Combination types include 12 types which are maily identified as coordination type, advanced type; 3) Coastal economic zone, Jinan metropolitan area, areas along the Jiaozhou-Jinan railway has a good advantage in comprehensive transportation accessibility and the level of economic growth which is at a high level of coordination, but there is existing opposite situation in the western Shandong. The study about to the relationship between comprehensive transportation accessibility and the level of economic growth will help to realize high level of coordination between transportation and regional economic development.
The relationship of regional industrial structure and urbanization is an important part of Urban Geography. By analyzing the evolvement of industrial structure and its urbanization response in Sichuan Province since the reform of China in 1978, the article revealed the characteristics of the urbanization response of the industrial structure evolvement at different industries, and tried to perfect the theory of urban development and to provide a scientific basis for the industrial restructuring of Sichuan Province. This article proposed two concepts, which are Coefficient of Urbanization Response to the Secondary Industry, represented with the symbol R(2), and Coefficient of Urbanization Response to the Tertiary Industry, represented with the symbol R(3). Taking Sichuan Province as an example, the author described their characteristics since The Reform of China in 1978, and analyzed the internal relations of the development of industries and the urbanization. The results show that the urbanization response to the industries in Sichuan Province presents spatio-temporal differences. Both the coefficient of urbanization response to the secondary industry and the coefficient of urbanization response to the tertiary industry increased, and its coefficient of urbanization response to industrial structure increased. The coefficient of urbanization response to the secondary industry decreased and the coefficient of urbanization response to the tertiary industry increased, while the change of coefficient of urbanization response to industrial structure depends on the change amplitude of the former two coefficients. According to the combinations of respective urbanization response strength in different industries, 21 cities and prefectures in Sichuan Province were divided into three categories: consistent response, partial secondary industry response, and partial tertiary industry response. The correlation mechanism between the evolvement of industrial structure and urbanization was analyzed through multiple linear regression, and the main factors were determined by stepwise. It was showed that the major factors to the evolvement of the industrial structure are urban economic density, spatial concentration, population concentration and urban system, which play a role in the different aspects of the evolvement. Because of different strength of urbanization response of regional industrial structure evolvement, different regulation measures should be taken. In the consistent response, urban economy and rural economy should be coordinated to upgrade industrial structure. In the partial secondary industry response which economic development are junior,the development of the secondary industry should be sped up preferentially, and the size of the cities should be controlled. In the partial tertiary industry response, the urban system should be properly adjusted, and the development of the tertiary industry should be accelerated. The regulation should also take the main functional area planning and the trends of urbanization response into account.
In the process of rapid urbanization, the outdoor recreational resources are becoming scarcely. Although the construction of parks can promote recreational welfare and happiness for urban dwellers, few studies have focused on the recreational happiness of park users and its inherent differences, which carried great significance for urban governments to allocate the recreational facilities and services. Thus, this study, taking Hangzhou as a case, carried out a questionnaire survey on the dwellers in urban parks so as to explore the components, spatial disparities and social differences of recreational happiness for urban residents by using the methods of Principal Component Regression and Multivariate Analysis of Variance. The results show that: firstly, the park-based recreational happiness of urban residents exists three dimensions with emotional happiness as the first principal component which can be interpreted by the variables of enjoyment, relaxation and fullness, perceptional happiness as the second component which can be explained by the variables of ‘increasing efficiency at work’, ‘promoting family harmony’ and ‘enhancing personal health’, and social happiness as the third component which can be illustrated by the variables of ‘making new or old friends’, ‘developing interpersonal relationship’ and ‘improving life quality’; secondly, there exist spatial disparities for the recreational happiness of park users,with the large urban parks mainly undertaking the functions of improving the emotional and perceptional happiness and the community parks raising the social happiness for urban residents; thirdly, the four demographic variables, including income, age, education and occupation have significance influences on park-based recreational happiness, which can be further illustrated by the impact of income on the emotional happiness variable, education on social happiness, age on emotional and social happiness, and occupation on the whole components of recreational happiness. Hence the urban governances should allocate the recreational facilities in parks according to the components of recreational happiness and the characteristics of its social and spatial differences.
A scientific spatial structure of regional tourism plays a significant role in the development of regional tourism economy. As one of the basic theories for regional development, Point-Axis Theory is vital to regional tourism spatial exploitation both in theory and practice. After analyzing spatial distrubition of tourism resources in South Anhui international Tourism and Culture Demonstration Zone, its spatial structure of tourism transportation and structure of tourism market, the authors, under the guidance of Point-Axis theory, measured and suggested the important tourist nodes, axes of trouism devlopment, tourism areas in the region and hence built a system of tourism spatial structure which includes “two centers, two development axes, and three tourism areas in the region”.
In late 2009, the Chinese government committed to cut its carbon dioxide emissions per unit of gross domestic product (GDP) by 40%-45% of those in 2005 by 2020, in order to demonstrate its commitment to reducing global emissions. Although the national intensity reduction target is clearly set, how this target should be allocated to the various sectors has not yet been determined. To control the carbon emission in China, one of the most difficult and complex issues is how to allocate the greenhouse gas emission reduction burdens into province level, and forming a set of strict assessment indicators. The regional allocation of carbon emission reduction decides the reduction responsibility of different areas, relates to regional sustainable development and concerns whether China will deliver on its reduction promises. According to China's situation, there are great differences among provinces in economic development, population, standard of living, economic structure and energy use, thus the emission reduction task cannot be simply allocated, and various factors must be taken into account. From the references, the key issues are: 1) allocation object;2) allocation principle;3) considerations in allocation;4) allocation standards;5) allocation methods;6) allocation model;7) reliability and reasonability in the analyzing the former studies. This article reviewed the researches on the carbon permit allocation among countries as well as carbon mitigation targets allocation among different provinces in the context of emission intensity commitment in China, and then analyzed the allocation methods in China from the above seven aspects. Based on literature review, there are large divergences in the allocation object, principles, indicator, methods, model, etc. in China. Related researches are still in the primary stage, and no research results can be directly applied in the implementation process. So these issues must be integrated and clearly considered in the regional allocation of carbon emission reduction in order to be really fair, just, feasible, sustainable, and ultimately fulfill the emission reduction commitments. Finally, this article emphasized that the points which restricts the regional allocation of carbon emission reduction in China is the absence of acceptable grounds, but not the policy instrument. In order to ultimately fulfill emission reduction commitments, and achieve the sustainable development of different regions, researchers should pay much attention to the theory basis study, and emphasis should be paid to improve the allocation models as well as sensitivity analysis of the input parameters.
The existing study of urban thermal environment focuses on the urban morphology for urban scale,which does not take full account of the effect of the thermal environment and especially wind environment of the layout of the buildings form for the small-scale area and non-homogeneous distribution. Numerical simulation was carried out to investigate the wind environmental state around a building group consisting of six rectangular high-rise buildings by using the Reynolds averaged equations and the renormalization group (RNG) κ-ε turbulence model. The six buildings were initially arranged into two rows and three columns. Six types of building group with different layouts were obtained by altering the distance between two adjacent buildings in each column. The wind-velocity ratios and the corresponding velocity vector field around each type of building group at pedestrian height level (1.5 m) were then examined and compared with each other. The average outdoor air flow of X-shape is the weakest among all layouts, which is unfavorable for ventilation. The variation of measure points' wind velocity near windward endpoint of buildings in O-shape is comparatively slow. In addition, this layout has the minimum wind velocity at outlet position. These show that O-shape layout has the least wind tunnel effect on outdoor wind environment. Compared with H-shape and O-shape, Y-shape with windward concave, can improve the wind velocity of outlet position. However, if the concave continues to be widened and changes into V or U-shape, the wind velocity of outlet position will decrease. To go further, the study quantifies the concave shape, trying to seek the link between the concave shape and wind velocity ratio of the outlet. The relationship between the x, which is concave coefficient and the y, which is wind velocity ratio at outlet position can be described as a polynomial function. In the end, the study proposes that, in Y, U and V-shape layouts, when the initial wind direction reverses during summer and winter, there are some measure points having comparative difference on wind velocity in two seasons. When designers plan the outdoor landscape, especially in making choice of the green or pavement, these points need detailed design to enhance ventilation in summer and reduce air flow in winter.
Soil moisture is an important impact factor of agricultural production and regional ecosystem. The No. 2 small watershed in Heshan farm of Heilongjiang Province was selected as the study area, the characteristics of the dynamic of soil moisture and soil water profile in different land use types were analyzed in this article. The results showed that: the soil moisture of embankment was the maximal, and the woodland’s was the least. The variation trends of soil moisture content of different land use types were as same as the variation trend of precipitation in the observation period, and they showed a reduced trend, but there were some differences between the soil moisture variation curves of different land use types, the soil moisture cures could be divided into three types: two peaks and three troughs type (wheat field, soybean field, woodland and field road), two peaks and two troughs type (embankment), two peaks and one trough type (grassland). The soil moisture variation in the observation period was divided into relatively stable period, consumption period, and supply period. The influence of land use type on the water content of soil profile increased with soil depth, and the soil moisture of different land use types showed different variation trends with soil depth. Among them, because of the presence of plow pan, the soil moisture of wheat field and soybean field increased first and then decreased; the soil moisture of woodland decreased gradually with the soil depth; the soil moisture of grassland and field road for the difference soil property reason presented the trend of increased first and then decreased, but the max soil moistures of these two land types appeared in different depth; because of the soil property did not change with soil depth, the soil moisture of embankment increased gradually with the soil depth. In addition, there is also a seasonal diversity in the water content change of soil profile in every land use type. The water content variation of soil profile in wheat field appeared an obvious seasonal diversity, but with the increase of soil depth the diversity decreased; the seasonal change of soil moisture in soybean mainly in the depth of 0-70 cm, and the seasonal change was not obvious under the depth of 70 cm; the seasonal diversity of soil moisture change in each section of soil profile in woodland is the largest; the top layer and the layer in the depth of 70-80 cm which was composed by peat were the layers that seasonal diversity of soil moisture in grassland mainly happened, and the diversities of other layers were small; because of there were not any plants on the field road, and the soil moisture variation subjected only to the influences of rainfall and evaporation, the seasonal diversity of soil moisture in field road mainly appeared in the top layer of soil, but the diversity in deeper layer were not obvious; the seasonal diversity of soil moisture in embankment was as same as field road, but the reasons that leaded this phenomenon were that the soil property were all the same from top to bottom, and the soil moisture of top layer was effected by the plants, precipitation and evaporation. Besides the land use types, slope position and direction, soil texture, topography are all the important influence factors for the dynamic changes of soil moisture, further studies are needed to determine the interaction of these factors above and the main control factors.
Taking Shuangheyu small watershed, the typical small watershed of the Yimeng mountainous area, as the object of study, the optimal allocation of land use structure in the study area was carried out based on the unit of land patches. Taking the control of the output of agricultural non-point source pollution (Nitrogen and Phosphorus, etc) into consideration, the optimal allocation of land use recognized the increase of economical and environmental benefit as the primary goal. The data was obtained using field in-situ observations district and Real-Time Kinematics（RTK）field measurement device. Land suitability evaluation was carried out through combination of the single-factor evaluation and the comprehensive evaluation method. The optimal allocation of land use structure was carried out through the method of effective coupling of linear programming model with dominant optimization analysis capabilities and GIS equipped with powerful spatial configuration function. The results showed that: the very combining of linear programming model and GIS not only provided the optimal allocation of land use with sound constraint effect in terms of area, but also matched the configuration information with specific spatial location at the same time, which enhanced the scientificalness and visuality of the optimal results. As taking account of the output of N, P non-point source pollutant into the factors considered by the optimal allocation of land use, the configuration results realized the goal of unifying the economic and environmental benefits through establishing multi-objective linear programming model of minimizing output of the non-point source pollution and maximizing the economic effectiveness. The optimization scheme of the Shuangheyu small watershed increased the area of orchard and forest land by 52.3% and 820%, respectively; and reduced the proportion of the area of farmland (cultivated land) by 38.3% and wasteland by 89.3%. The total N and P annual output was reduced by 15.3% and the annual economic efficiency was improved by 41%, among which the orchard, with its overwhelmingly superior area, made the most significant contribution to the increase of economic benefits in the optimization scheme. Land suitability evaluation was conducted through combination of the single-factor evaluation and the comprehensive evaluation method, which was applied in meso and micro-scale systems and made up for the deficiency of a linear programming model. It was turned out that the method was easy to operate and had good availability of data, which guaranteed the reliability of the configuration result. The orchard, with high economic effectiveness, comparatively lower N、P output risk and good flexibility in spatial configuration, was main factor influencing the land use optimal allocation, which should be put priority in optimization scheme. This study could provide scientific evidence for the rational utilization of land resources and lay the foundation for ecological construction of the Yimeng mountainous area.
This study analyzed the spatial distribution of the type and thickness of biological soil crust, ground surface compaction and grain-size composition of surface sediments through a cross-section parallel to the prevailing wind direction in Shapotou section of Baotou-Lanzhou railway protective system, and discussed the significance of the biological soil crust to the changes of the aeolian environment in the protective system. Results showed that the biological soil crust was developed gradually from lichen-algae crust to crossly exist of moss crust and lichen-algae crust along the prevailing wind direction in the protective system. The crust distribution was developed from no crust, patch style to continuous crust formation with gradually increasing on surface compaction along the prevailing wind direction in the vegetation area of the protective system. The ground surface compaction was much higher in the vegetation area than the mobile dune area no matter with developed crust or not. The grain size of the surface sediments became fine, and the sorting got worse with the increasing of the protective distance. Suspended components (grain size<0.1 mm) increased along the protective distance. The suspended component was much higher in the vegetation area than in the mobile dune area along the cross-section direction, and much higher in the crust layer than the 5 cm layer under curst in the depth direction. The content of silt and clay in the biological soil crust layer was much higher than its below layers in the vertical direction, and they increased with undulation which caused by the terrain change of the fixed dunes along the cross-section. These results implied that the aeolian environments tended to be stable along the cross-section. It changed gradually from intense erosion and deposition aeolian activity in the upwind mobile dune area to deposition dominated aeolian environment in the downwind vegetation area of the protective system. The upwind area of the vegetation area that without crust developed was a transition area from erosion and deposition to deposition dominated aeolian environments. There was still erosion and deposition activity at this area but the intensity was much less than the mobile sand area. Relative stable aeolian environment produced advantageous conditions for the development of the biological soil crust, which inversely enhanced surface stability and its wind erosion resistance ability remarkably in the vegetation area of the protective system. The better-developed moss crust was distributed in the gentle terrain area of the fixed and semi-fixed dunes while the lichen-algae crust was widely distributed in the vegetation area of the protective system. This spatial distribution variation of difference type crust implied the spatial difference on surface stability of the aeolian environments in the protective system. Spatial distribution of the attributes of the biological soil crust vibrated with the terrain of fixed dunes showed that dune terrain influenced local aeolian environment in the protective system.
Based on the correlation coefficients and scatter points slope methods, the accuracy of TRMM 3B43 data at monthly time scale during 1998-2011 was validated using 24 meteorological stations data, with the method of Kriging under ArcGIS,the error spatial distribution map of TRMM 3B43 data was drawn in order to research the regional difference. There was a strong correlation between TRMM 3B43 data and meteorological stations observation data(R=0.928;p<0.01), but the value of TRMM 3B43 precipitation was greater than meteorological station, the deviations were 32.0%(spring), 38.3%(summer), 36.8%(autumn), 34.9%(winter), respectively. The TRMM 3B43 data was accurate in the south and the northwest, while the northeast and middle area was poor, especially in east Mt. Daxue and three Parallel Rivers area, the deviation is greater than 35% in east Mt. Daxue and three Parallel Rivers area and 25%-35% in other areas. The error spatial distribution of TRMM 3B43 precipitation is quite different, but most distribution follows a basic structure that distributed along the longitude in north of Hengduan Mountains and along latitude in south. The meteorological stations in Hengduan Mountainous Region are spaced widely and distributed unevenly. The terrain is complicated and varied in the study area, the longitudinal range-gorge caused an obvious action that east and west blocked but north and south through, which impacted on the spatial distribution of southwest monsoon obviously, and the southwest monsoon is the crucial factor which influenced the precipitation of Hengduan Mountainous Region. In spring and summer, the precipitation spatial and temporal distribution is discontinuous because of range-gorge terrain. In autumn and winter, the precipitation equivalent area distributed continuously, the influence of terrain is not obvious. The main error sources of the meteorological stations are of scarcity at high elevation and the mountain terrain special surface.
The simulation results of nonhydrostatic mesoscale numerical model WRFv3.1, FNL reanalysis data and observation precipitation data are used to perform the synoptic dynamic analysis of the rainstorm over Meiyu front and the evolution characteristics of rain band in Huaihe River Basin. In this article, we draw on the decomposition technique of empirical orthogonal function (EOF) to reveal the evolution of low level wind field, which has an important influence on the distribution of mesoscale rain band during this precipitation process. The first mode of EOF analysis performed for horizontal wind at 850 hPa reflects that the southwester strength in the later rainstorm process caused the change of rain band distribution. Based on that and by combining with vertical vorticity tendency equation, a preliminary analysis of mesoscale vortex’s evolution mechanism in rain band has been conducted. Results show that: 1) The evolution of rain band is relative to the initiation and development of low level jet, moving and developing east along the newly generated low level jet in the later stage of the precipitation. 2) The evolution of vorticity's horizontal & vertical advection terms indicate the movement of rain group and it develops in the moving direction at middle and low levels. The positive vorticity center is prone to move and develop from the negative vorticity’s horizontal advection area to the positive one. The vertical advection transports term upward the vorticity center caused by the convergence movement at low level. Therefore, the vorticity and its horizontal advection at middle level strengthen, promoting the vortex moving and developing downstream.3) The vertical motion benefits the evolution from horizontal vortex tube to vertical vorticity after wind vertical shear at low level strengthens. Thus, the twisting term in vorticity equation plays an important role in the development of local vorticity.
：The whole life of winter wheat in Huaihe River Basin (HRB) are mostly in winter-spring drought season. Natural precipitation shortage is the main factor which restricts the wheat production, so to study the spatial and temporal distribution regulation of winter wheat are very important for winter wheat planting plans and irrigation management of HRB. Based on data of pressure, vapor pressure, maximum temperature, minimum temperature, average temperature, relative humidity, precipitation, wind speed and sunlight hours of 171 weather stations of HRB in 1971-2010, this article calculates the water surplus and deficit rate (WSDR) of the whole growth period (before winter growth period, wintering period, reviving and heading period, grain-filling and ripening period) of four winter wheat areas of HRB, and also analyze the spatial and temporal variation characteristics of WSDR. The results show that the spatial distribution of WSDR in HRB in recent 39 years is affected by climatic and geographic factors, and it has obvious geographical characteristics: WSDR decreases from north to south, and it is the zonal mode structure. In different growing stage of winter wheat, WSDR in grain-filling and ripening period is most serious, reviving and heading period takes second place. Although the annual tendency of WSDR is not obvious, the growth period of winter wheat which have the best and the worst water conditions are in the same age. In 1980s , the water supply of before winter growth period is the most adequate time, meanwhile is the most serious water shortage time from wintering period to grain-filling and ripening period inⅠ,Ⅱand Ⅲ areas. It is also the same as that in Ⅳ areas in 2001-2010. Moreover, WSDR during mid-later growing period in north plain and northeast hilly winter wheat area are serious in four areas, especially during grain-filling and ripening period. Which effect yield greatly, it need take message to combat drought, and decrease the damage of drought.
Climate change and regional development under the background of water resource decreased over the Huanghe River basin, which is under the monsoon climate control. The runoffs during flood season in the Huanghe River are about 60%-70%. Based on the water level records and Yu-Fen-Cun records in Qing dynasty documents and modern hydrological records, we reconstructed the annual flood-season runoff of middle reaches of the Huanghe River (Sanmenxia station) and the upper reaches (Tangnaihai) is based on the tree-ring width. The average of runoff is 19.94×109 m3 (Tangnaihai) and 50.78×109 m3(Sanmenxia). In this article, the extreme flood/dry years are reconstructed based on a new method. Based on the two runoff series, the synchronization of the Huanghe River and the Yongding River is stagabl, and during 1840-1860s, 1890-1910s, the synchronization disappear, the inverse correlation is very obvious. The wavelet shows that there is 4a-6a cycle in both of the 2 stationgs, In MWP, the trend of the Huanghe River inverse correlationship is more obvious. Rain-fed agriculture is the most important economy part of China during the past thousands of years, while rainy summer and autumn leads to rivers flood, so in history Chinese government must predominate the flood to avoid the agricultural loss. Wavelet shows that there is a 50 year cycle in the runoff series. The results show that: the runoff in the middle reaches of the Huanghe River has interannual and interdecadal oscillations like 6-8 years, quasi-22 years and 50 years. The determination of the quasi-22 years is linked to the changing of Wolf Sunspot Numbers. The solar activity is significant during the 1830s. ENSO event is negative with the changing of natural runoff at the inter-annual scale. There is a low-flow period in the last 4 eras of LIA, and it has been the longest low-flow period since 1766. The summer is the key reason for the changing of flood season beginning time for the unstable rainband moving from the middle and lower reaches of the Changjiang River to the middle reaches of the Huanghe River.
Flood disasters information in Northern Song Dynasty in 960-1127 and Yuan Dynasty in 1264 -1367 in Kaifeng area was extracted based on historical records. By comparative study, characters of flood disasters and climate changes reflected by them during these two periods were discussed. The results showed that frequent occurrence of flood disasters during both periods in Kaifeng area, and flood disasters occurred once every 2.75 to 2.89 years in average. Precipitation pattern at grade Ⅱ was the main type in Northern Song Dynasty. The crevasse of rivers and overflow at grade Ⅲ and Ⅳ, however, turned out to be the prominent performance during Yuan Dynasty. Flood disasters occurred frequently in early 70 years of Northern Song Dynasty. Instead, they exhibited a low-incidence in earlier and later of Yuan Dynasty, but occurred high-frequently during the middle 60 years. Flood disasters during both dynasties concentrated in summer and autumn, and the precipitation increasing or concentration of summer monsoon occupied the main driving force. The spatial differences were small in Northern Song Dynasty, but had remarkable differences dependent on distances with the diversion of the Huanghe River in Yuan Dynasty. The climate during about 40 years of the earlier Northern Song Dynasty was a little dry, then, entered physic wet-dry changes. The climate in Yuan Dynasty kept wet and continued till late Yuan Dynasty. Furthermore, flood disasters during both periods had common inter-annual cycles like quasi-3 and 7 years.
