With the acceleration of industrialization and urbanization, there is a phenomenon of hollowing villages resulting from the vacancy and idleness of rural housing in the core of villages in the vast rural areas of China. In this paper, typical transect along No.106 State Road with obivious gradients both in the condition of physical environment and in the level of socioeconomic development is taken as a study. Its total area mounts to 0.155 million km2. The rural land consolidation potential in transect along No.106 State Road is estimated as follows: Firstly, the comprehensive index of rural hollowing was evaluated by using the analytic hierarchy process (AHP) method and standardized method, based on typical survey-based data and socioeconomic statistics. Secondly, considering natural conditions, characteristics of land resources and the relevant legal provisions for rural residential land, a realistic transformation potential evaluation index system was established by the 10 indexes relating to natural, social and economic factors to calculate the realistic transformation potential index of rural land consolidation. Finally, by multiplying rural hollowing index and realistic transformation potential index as comprehensive correction coefficient to make the correction of the theoretical potential, the status quo potential and long-term potential of rural land consolidation were achieved based on potential calculation model. The stragety to consolidate rural land for various rural land consolidation potential areas in transect along No.106 State Road is also given. The results showed that the correction coefficient of rural hollowing in typical transect area along No.106 State Road was 0.18-0.82 and the correction coefficient of realistic transformation potential was 0.07-0.32. The comprehensive potential of rural land consolidation was 93219.4 hm2 in 2009 and 145430.0 hm2 in 2020, and the coefficient of increasing arable land was 6.8% in 2009 and 11.4% in 2020, respectively. This study will provide a scientific basis for hollow village renovation and new rural area construction planning decisions.
Location choice for cultivated land protection in the post-disaster reconstruction area is an important issue for maintaining rural development and protecting the environment. Based on the cost-benefit theory, the paper combined direct input costs, opportunity costs and policy costs into cultivated land input costs, then contrasted it with the potential benefits. The paper comprehensively developed an analytical framework of location choice in post-disaster reconstruction area and constructed a 12-item index system of location choice for cultivated land protection. Taking the severely-afflicted Pengzhou city in Sichuan Province as a case, the paper identified the most suitable location for cultivated land protection during post-disaster period under the framework, using village as an evaluation unit with the help of GIS spatial analysis technique. The results indicate that preferred locations in Pengzhou city are mainly distributed in Tongji Town, Xinxing Town, Cifeng Town, Guihua Town, Longfeng Town, Junle Town, Shengping Town, Sanjie Town, Aoping Town, most parts of Lichun Town and Gexianshan Town, with a total area of 73.5 km2. The research provides scientific basis for land replenishment and reallocation during the reconstruction work in Pengzhou city.
Based on the decoupling method, this article has did some work on the following: re-defined the non-agriculture GDP by taking construction land occupation of cultivated land quantity and the non-agriculture GDP value as the main index, as well as improved the decoupled research methods; did empirical research in Kangle County on the relationship between economic growth and cultivated land occupation by using relevant statistical data from 1997 to 2009. The results show that: 1) There’re four main types in the relationship between cultivated land occupied for construction purpose and non-agriculture GDP in Kangle County: negative decoupling, weak decoupling, recession decoupling and strong decoupling. 2) The decoupling curve showed "M" type in general, the cyclical change vary from "non ideal state", "deformity state" to "ideal state". 3) According to the decoupling elastic curve, the research period can be divided into three stages, that is, 1999-2002, 2003-2006 and 2007-2009. In each stage, the decoupling curve variation has its own reason. 4) Both results and factors in the charge of decoupling are consistent with the actual situation in Kangle County, so it has strong practical significance.
Water footprint intensity is an index that can comprehensively reflect the water use efficiency, this paper firstly estimated the water footprint of 31 provinces, municipalities and autonomous regions in China (excluding Hong Kong, Macao and Taiwan due to no data) from 1995 to 2009, and the water footprint intensity was then calculated, the ESDA (Exploratory Spatial Data Analysis) model was applied to study the spatial correlation pattern and changing tendency of water footprint intensity, the results show that: 1) the water footprint intensity has a decreasing tendency in general which means that the water use efficience are increasing in the 15 years, but the decreasing amounts of water footprint intensity are imbalance among the 31 provinces (regions), the regions located in the west China have a larger decreasing amount than the regions located in the east China in general. 2)From the aspect of global spatial difference, the water footprint intensity has a positive correlation characteristics, which means that there exists a spatial cluster feature, in other words, the regions with high water footprint intensity are apt to be adjacent to the regions with high water footprint intensity, and the regions with low water footprint intensity are apt to be adjacent to the regions with low water footprint intensity. 3) From the aspect of local spatial difference, the regions with LL (low-low) or HH (high-high) correlation pattern have a large percentage in the 31 provinces (regions), and the number of this kind of regions are steadily increasing in the 15 years, which reflects the fact that the special cluster becomes more and more obvious, and a spillover effect of water footprint intensity may exist. Among these regions, the regions with LL (low-low) correlation pattern are mainly located in the eastern coast regions of China, and water footprint intensity in these regions has an obvious diffusing tendency. The regions with HH (high-high) correlation pattern are mainly located in the west China, which are steady in spatial distribution in these years.
Land use and land cover change have been greatly affecting the function and structure of wetlands landscape ecosystem. It can make so many changes on wetlands from multiple aspects, such as to initiate the wetlands fragmentation process. Wetlands within the Zhangye Heihe National Wetland Nature Reserve is of a great significance to keep the eco-environment safety of northwestern China. Besides that, it also plays a key role in preventing the Tengger Desert and Badain Jaran Desert to be a whole. However, its landscape begins to be fragmented with the change of land use and land cover in recent years. Based on multi-temporal remotely sensed TM and ETM images from1975, 1987, 1992 and 2010, changes of land use and land cover in the nature reserve during 1975-2010 were quantitatively analyzed using transition matrix in this paper.At the same time, the landscape fragmentation indices contained patch density, aggregation index, mean patch size, mean shape fragmengted index and area-wegihted mean shape fragmengted index were calculated to study the effects of land use and land cover change on landscape fragmentation process of the wetlands in the nature reserve and its surrounding areas. The results show that the land use structure in the nature reserve and its surrounding areas has undergone great changes and its wetland landscape fragmentation became more and more serious from 1975 to 2010. The proportions of farmlands in the nature reserve and its surrounding areas have increased 7.67% and 5.5% respectively. On the contrary, the wetlands declined 6.91% and 0.4%. In terms of wetland landscape, the wetland patches tend to be fragmented, especially for the river and bottomland wetlands. The mean shape fragmengted indices and area-wegihted mean shape fragmengted indices have raised from 0.48 and 0.88 to 0.52 and 0.91 in 1992-2010. However, its aggregation index decreased 9.19%. All of those indicated that the wetlands in the nature reserve has been fragmented under the effects of land use and land cover change. As for how land use and land cover change functioned on the wetland fragmentation, it can be expressed with the effect of land use and land cover change on the mean patch size, aggregation indices, shape fragmentation indices and so on. Because land use and land cover change play a key role in shifting material cycle and energy transportation mode of wetland at basin scale, it can alter the ecological processes of landscape elements and influence the wetlands landscape pattern and function in the nature reserve. Therefore, it is strongly suggested land use and land cover can affect the fragmentation process of the wetlands.
Organic carbon storage and sequestration potential in agricultural soils is suggested to be an important issue in the study of terrestrial carbon cycling and global climatic change.In this study, soil organic carbon storage and cropland surface soil carbon pool saturation levels in different counties as well as soil carbon sequestration potential and difference between upland and paddy field in carbon sequestration potential in Songnen Plain maize belt were investigated by using the data from the Second State Soil Survey carried out during 1979-1982 and from cropland investigation and quality evaluation project in Jilin Province during 2003-2006. Results showed that soil organic carbon storage increased 7.20 TgC from 1980 to 2005. In terms of soil carbon pool saturation levels, Dehui County showed the highest value of 4.11 kgC·m-2 among the four counties, and Jiutai County followed with the lowest in Gongzhuling County. Assuming the land use, tillage, fertilization and climatic conditions of the cropland remain the same as they were in 1980, the soil carbon sequestration potential of the cropland of Songnen Plain maize belt would be 8.17 TgC. In terms of per unit area soil carbon sequestration potential, Jiutai County showed the highest value of 0.77 kgC·m-2, followed by Nong’an County, and Dehui and Gongzhuling counties were lower than the study area of 0.63 kgC·m-2. Soil carbon pool saturation levels of upland and paddy field were nearly equal.
Eco-sensitivity evaluation is the basis for land development, which has important practical significance for the establishment of environment-friendly economic and social development model. Compared with the single geomorphic region, the complex geomorphic region is limited by more eco-sensitivity factors in land exploitation. More serious is that these factors have very complicated spatial characteristics and they affect each other. Based on the existing research results, the paper takes Qinzhou city as a case study, invents an eco-sensitivity assessment system which includes land-ecology, water-ecology and plant-ecology; then it makes a systematic comprehensive assessment for all watersheds by using qualitative classification and spatial quantitative model in the support of remote sensing and GIS technology, and groups Qinzhou city’s 273 watersheds into three types: high-sensitivity-area, medium-sensitivity-area and low-sensitivity-area; finally, it suggests to limit land exploitation activities in the high-sensitivity-area and construct a ecological security network to protect the city’s ecological security. The results show that this method can help us find the eco-sensitivity characteristics of complex geomorphic region and the government can work out more scientific policy to protect this region’s ecological security.
As an important province of the less developed regions, the urbanization process of Gansu Province continues to accelerate, the urbanization rate continuously improves, however, the urban efficiency did not attract enough attention. It’s significant to improve the urban competitiveness and sustainable development of less developed regions by increasing the urban efficiency. The data envelopment analysis (DEA) is the effective tool to measure urban efficiency, but the traditional DEA can not distinguish the difference among the effective units and define the urban efficiency growth potential. The aggressive cross-evaluation mechanism is introduced along with virtual decision making units (DMU) to overcome the shortcoming of the traditional DEA. In this paper, with land, capital, labor, technology, information, water and electricity consumption being the input indicators, and GDP the output indicator, the DEA-Cross Model is employed to analyze the urban efficiency of 12 prefecture-level cities in Gansu Province based on the panel dataset of urban socioeconomy from 2005 to 2009. The result of the traditional DEA showed that six cities of Gansu Province maintain DEA effective during the study period, such as Lanzhou, Jinchang, Wuwei, Pingliang, Qingyang and Longnan, accounting for 50% of the total cities. The results of the DEA-Cross Model showed that the urban efficiency in Gansu Province is low (between 0.053 and 0.067) from 2005 to 2009, less than 7% of the ideal DMU. And the standard differential obtained an upward trend from 2005 (0.0476) to 2009 (0.0494), the gap among cities became widened. From the perspective of spatial distribution, cities in the central part of Gansu and in Hexi Region have higher urban efficiency than those in the east and south of Gansu, the gap between different regions became narrow (the standard differential decreased from 0.024 in 2005 to 0.021 in 2009). From the perspective of city type, urban efficiency of industrial cities is higher than that of non-mining cities. From the perspective of city scale, urban efficiency of big cities is higher than that of small and medium-sized cities, and the gap between different scales also became narrow (from 0.051 in 2005 to 0.016 in 2009). The clustering results showed that Lanzhou, Jinchang and Jiayuguan belong to the "high input and high output"type, Dingxi and Longnan belong to the "high input and low output"type, and the remaining cities belong to the" low input and low output" type. On the basis of the present study, some suggestions regarding improving urban efficiency were given in the current situation of urban construction and management, including strengthening land intensive productivity capacity, optimizing the industrial structure, promoting the rational division between different regions, accelerating the process of infrastructure construction, innovative management systems and mechanisms, application of the advanced technologies and optimizing the development environment.
This paper investigated the area variation of Duoqing and Gala lakes in the southwestern part of Xigaze region in Tibet based on the topographic map in 1975 and seven periods of MSS/TM satellite dataset during the 1970s to 2009. Results show that the area of the above two lakes has the same variation trend. Namely, the area of Duoqing and Gala lakes was lager than 80 km2 and 10 km2 respectively in other years except in 1976 which has smaller areas before the year 2002. Furthermore, the areas reached the maximum value in 2000 and they obviously narrowed the range after 2002. Considering the variation of the glaciers, the supply function of their melt water to the lakes is not evident though the variation of glaciers in the above basin exhibited degrading status as glaciers in other regions of the Tibetan Plateau. The climatic variation trend over the above region has the characteristics of increasing temperature, decreasing evaporation and fluctuation precipitation. The precipitation was positively related to the expansion and shrinkage of lake areas, but negatively related to the air temperature. Comprehensive analysis shows that the variation of lake areas has no close relation with the shrinkage of glaciers and the precipitation was the main reason for the lake area variation.
To analyze the risk of chilling injury to maize further, this article focuses on the construction of an evaluation model, which includes the temperature which represents the hazard factor, exposure degree and sensitivity level, and is used to judge the risk of chilling injury to maize in Heilongjiang Province. The data in this research includes daily average temperature data from 1961 to 2009, date of different growing status from 1980 to 2009 of the 24 meteorological stations in Heilongjiang Province, and the spatial resolution of GIS data is 1 km×1 km. Method of research is mainly AHP. Initially, the risk of hazard factor from 1961 to 1979 is calculated by adopting the criterion which is "Anomaly of Sum of Monthly Average Temperature from May to September" and that from 1980 to 2009 is calculated by adopting the criterion of "Comprehensive Decision System of Chilling Injury for Maize in Heilongjiang Province", respectively. Then, comparing the planting area of maize of 75 stations as the exposure degree index, risk zones of exposure degree are concluded. After that, risk zones of the sensitivity of chilling injury are outlined based on per unit area yield of maize. At last, this article sets down a comprehensive evaluation model of chilling injury to maize based on the hazard factor, exposure degree and sensitivity level in Heilongjiang Province. According to this model, Heilongjiang is divided into five zones, which are high risk zone, sub-high risk zone, medium risk zone, sub-low risk zone and low risk zone. Specifically, Daxinganling mountain, Xiaoxinganling mountain and southern mountain areas are high or sub-high risk zones mainly because of lack of enough heat for crop growing. Despite the risk of hazard factor being medium, the northern part of Songnen Plain is sub-high risk zone considering its high exposure degree and sensitivity level. Because the risk of hazard factor, exposure degree and sensitivity level are all low or sub-low, the risk of chilling injury to maize in the eastern part of Sanjiang Plain is low. In all, the model can not only help to promote the capability of quantitative assessment of chilling injury to maize in Heilongjiang Province, but can be used for reference to construct the damage evaluation models of other agricultural & meteorological disasters as well.
Drought is a major natural disaster that heavily affects the crop yield in China. In this paper, the temporal and spatial variation characteristics of drought in Henan Province, China, are analyzed by using standardized precipitation index (SPI) and remotely sensed vegetation condition index (VCI) respectively. In addition, by correlative analysis, we analyzed the relationship between meteorological drought and agricultural drought in Henan Province. The results show that the meteorological drought frequency appeared a slight rising trend in Henan Province during the last 60 years. The meteorological drought frequency was higher in summer and autumn, while the agricultural drought frequency was higher in autumn and winter in Henan Province. The spatial pattern of drought frequency varied from one season to another. On the whole, agricultural drought lags behind meteorological drought, with a lag of about two months in winter, almost one month in spring and less than one month in summer. Additionally, there is a strong correlation between SPI and VCI in winter and spring, while the correlation becomes worse in summer and the worst in autumn. Considering from the spatial characteristic, the positive correlation between SPI and VCI of winter wheat/summer maize planting region is better than that of the non-cultivated land, while the positive correlation is the worst for rice planting area in the south of Xinyang City.
Poyang Lake wetland is an important district of ecological function zoning in China, which has the functions of flood controlling and biodiversity conservation for ecological services. There are nine national and provincial nature reserves in Poyang Lake area. In recent years, the regional drought meteorological disasters frequently occurred caused by global warming, which made Poyang Lake area water body and water level of wetlands decline, even dry up. This resulted in the breeding of a large number of moss grassland in the region. Moorburn occurred frequently consequently. This is a big threat to Poyang Lake wetland nature reserve and regional ecological environment. In early 2012, the events of moorburn appeared in many places in Poyang Lake area. Facing to this urgent situation, this study, using the remote sensing quickly monitoring technology and vegetation ground investigation method, acquires the first-hand moorburn distribution area, location and vegetation growth state data. Serial knowledge are obtained based on the vegetation growth situation contrast analysis between moorburn area and non-moorburn area, and GIS buffer and overlay analysis. 1) The total patches of the moorburn region are 95, the total area of the burned is 10278.6196 ha, and the largest patch area is 1293 ha. Moorburn region mainly distributed in the Poyang Lake National Nature Reserve in Wucheng town, Yongxiu county, and the Nanjishan provincial wetland nature reserve in Xinjian county. 2) Moss grassland number was increased obviously in moorburn area, and its surface biomass and vegetation coverage are higher than that in non-moorburn area, but lower in the late period of growth. The vegetation height is lower in moorburn area than that in non-moorburn area in all the progress of bourgeon and growth stage. The moss grassland community species richness and biodiversity in moorburn area is lower than that in non-moorburn area obviously in the late period of growth. 3) GIS analysis indicates that the land cover types which were mostly influenced by the moorburn are still the dry lakebed and adjacent farmland. With the expansion of the buffer zone, the proportion of affected forests and rural settlement types increased, and more attention should be paid to this consequence. Related suggestions on wetland resources protection and moorburn management are proposed finally.
Based on the technology of RS and GIS, vegetation coverage changes were analyzed quantitatively every two years with spatial models after water delivery in lower reaches of the Tarim River. The result indicates that low coverage vegetation, bare land and sandy land were the key land categories in the study area. The area of vegetation coverage (Ⅰ-Ⅳ) increased 986.76, 681.84, 1091.88 and 8641.89 hm2 in 2010 compared with that in 2000, while the bare land and sandy land (Ⅴ) decreased 11420.37 hm2, indicating that the water delivery was effective. The conversion between Ⅲ and Ⅳ as well as between Ⅳ and Ⅴ was the major transformation type of vegetation coverage throughout the study period in the study area. The development of vegetation coverage turned to be an equilibrium state characterized by steady increase with increasing frequency and volume accumulation of water supply, while it turned to be a non-equilibrium state characterized by frequent changes with decrease of water supply. Changes in vegetation cover can reflect the water situation objectively, and the continuous and stable water supply was the premise of steady growth of vegetation coverage.
The glaciers on Yulong Mountain (5596 m a.s.l.) are located in the southernmost in mainland Eurasia. The largest is Baishui Glacier No.1. The snow that accumulates on Baishui Glacier No.1 includes marine aerosols associated with the summer monsoon, and dust brought in winter is from Central/West Asia, Africa or the Thar Desert area. In order to further understand the influence of natural and human factors on the regional atmosphere and precipitation chemical characteristics, fresh snow samples at Baishui Glacier No.1 were collected from April 2006 to October 2006 for chemical data analysis.The characteristics of ion and the changes of surface snow in rainy season in Baishui Glacier No.1, Yulong Snow Mountain had been analyzed and discussed. Contrast analyses with wet deposition at high altitudes of other mountains and plateaus were also carried out. The results showed that the surface snow can be seen as the background value for summer precipitation chemical composition in the Yulong Mountain area. The main acidity ion is NO3- in rainy season. pH is higher because of the neutralization of Ca2+. Sea salt tracer analysis showed that sea originated aerosol was the dominant source of dissolved ions in surface snow. The ions concentration was low during the mid June to September and was negatively correlated with precipitation. The ions of NO3-, SO42- and Ca2+ in the study area, as the main contributor to inorganic ions, were higher than most precipitation at other high altitudes areas. Moreover, high concentration of Ca2+ showed significant influence of local lithology on high-level wet deposition.
For solving the two difficult problems about Bayesian factor computation (i.e., determination of parameters prior distribution and numerical integration of hydrologic frequency model) in the process of hydrologic frequency model selections and averages, this paper firstly combined the Bayesian sampling method with POME (principle of maximum entropy) to determine the expression of parameters posterior distribution, and then the method of approximate sums after interval segmentation was used instead of the numerical integration of hydrologic frequency model, finally a new method of Bayesian factor computation was proposed. The accuracy and effectiveness of the new method have been verified by both observed hydrologic series analyses and Monte-Carlo tests. The results show that series length and parameters values have great influences on the computation results of Bayesian factor and models posterior probability. The essence of Bayesian information criterion (BIC) is to compute the Bayesian factor by using a group of best parameters estimation results; whenever unfavorable factors are encountered, the analyses results of BIC would become bad due to the inaccurate parameters estimation results. Compared with the BIC criterion, the new method is more effective and reliable, since it can overcome the influence of those unfavorable factors by analyzing and describing the uncertainties of model parameters.
China invested a large number of funds in building water conservancy projects in order to alleviate the contradiction of water supply and demand. However, how to evaluate the effect and impact of investment on national economy has become one of the hot spots urgently to be solved for reasonally identifying investment direction and investment decision making. A static CGE model of Heilongjiang Province is built, designing the three investment programs to make quantitative estimate about potential impact of water conservancy investment policies on the total economic output, the total output of different sectors, other sectors investment and the quantity of water supply in Heilongjiang Province. The results show that: 1) the water investment can stimulate the development of the national economy, when the scale of investment growth is 40% to 50%, GDP growth is the fastest; 2) the water sector investment growth will boost investment rise in high water consumption sectors of industry and agriculture, while investment decline in general water industry, construction, general-water services and high-water service; 3) the order of the total output growth rate of the various departments is high-water industry, high-water services, general-water services, agriculture and construction, while the output of general-water industry reduced, the fastest growth rate of water consumption is high-water industry, followed by the high-water services, general-water service and construction; and 4) the water sector investment growth is larger than 43% in order to meet the demand for water, and suitable water investment growth is 43% to 50%.
It is necessary to establish agricultural water-saving compensation mechanism to realize water conversation. With the typical EDM method, the impact on the consumer, producer and social surpluses of agricultural water-saving technology input are analyzed. The result indicates that from the study, the input of agricultural water conservation led to the overall increase in social welfare including both of consumer and producer surpluses; the change of the social welfare caused by the policy implementation allocates between consumers and producers, the more impact will be born by the less elasticity side; according to the compensation principle of "who benefits and who compensates" and input-output, the welfare distribution of total surplus from agricultural water conversation input between producers and consumers determines the cost share of agricultural water conversation projects between different subjects, and the basic compensation standard; the building of perfect water market is particularly important for farmers to trade their saved water and increase income, also arouse their enthusiasm to develop agricultural water conversation.
