The rapid socio-economic development of China is pushing the transfer of land productive element from agricultural sector to non-agricultural sector, which has a profound impact on China's resources and environment and the pattern of urban and rural development. It is an important breakthrough to regulate and control land non-agriculturalization scientifically and allocate the limited land resource between rural and urban area reasonably in order to ease the contradiction of land use. Based on the coupling relationship between land non-agriculturalization and economic development stage, this article evaluates the suitability of land non-agriculturalization in counties around Bohai Rim in 2008 by carrying capacity model, and defines the threshold of moderate land non-agriculturalization. The results show: because of regional land resource endowment and the requirement of socio-economic development, the demand and the supply curves of construction land represent forward and reverse Sigmoid curve respectively, the intersection of which shows the ideal state of land non-agriculturalization decided by the supply and demand condition of construction land; the calculation of the panel county data around Bohai Rim shows that the proportion of land non-agriculturalization ranges from 2% to 30%, and has a positive correlation with per capita GDP, particularly at finished stage of industrialization; the type of supply and demand condition of land non-agriculturalization transiting from surplus to overload with the economic development evolution from primary stage to advanced stage; while about 75% of the amount of counties are on surplus condition at the early industrialization, about 65% and 45% of the amount of counties are on loadable condition at the middle and later industrialization, respectively; the trend of land non-agriculturalization shows a slow growth from the early to later industrialization, and the threshold of land non-agriculturalization is between 10.0% and 17.5%; the differences of driving effect of industrialization and urbanization determine the regional differences of the non-agriculturalizated land scale; the amount of counties, with the moderate scale of land non-agriculturalization, accounting for 53.3% of the samples. According to local conditions, different types of strategies and construction land planning for land non-agriculturalization should be adopted to achieve regional sustainable development.
Rural tourism has become one of the important driving forces to the rural energy consumption patterns transition in China. Studies on the rural energy consumption transition and benefit evaluation induced by tourism provide a basis for design policy on energy strategies for rural tourism and sustainable development of rural tourism. Taking Liupan Mountain Pro-poor Tourism Experimental Region as the case study, using various investigation methods including participant observation, participatory rural appraisal, interviews, and questionnaires, this paper examines the energy consumption of rural tourism households and traditional households, and assesses the overall efficiency of the energy consumption patterns of rural tourism. Results show that the poverty reduction project has played a significant role in promoting the socio-economic development and eco-environment improvement. The total energy consumption per household of rural tourism households is 3409.43 kgce, and it is 42.67% higher than traditional households. In energy consumption structure, commercial energy is dominant in the rural tourism households, new energy (solar energy) is widely used, the proportion of traditional energy is decreased. The three ratio of rural tourism households is 93:5:2, and that of traditional households is 46.30:0.48:53.22. It also has changed the traditional energy consumption patterns and the existing pattern of "poverty life-energy shortages-environmental degradation". Compared to traditional households, the economic benefit of rural tourism households is 4.53 yuan/kgce and increases by 2.86 times, while the ecological benefit of 0.11 yuan/kgce and social benefit of 1.09 yuan/kgce have significantly improved. The study also found that in view of the extensive demonstrativeness of the rural tourism energy consumption in the poor areas, this kind of energy consumption patterns based on the large-scale input of the external traditional commercial energy should not be advocated by rural energy consumption and tourism development, and is contrary to the national rural energy policy orientation. Therefore, in rural tourism development process, based on making full use of local energy, combined with the tourism development features of humanity excrement increasing greatly, we should tap further the utilization potential of solar energy and biomass energy (biogas), and establish new energy consumption pattern predominated by new energy and supplemented by traditional biomass and commercial energy.
To examine long-run relationships and short-run dynamics of prices among the four energy resources, including coal, natural gas, uranium and crude oil in the international market, the paper uses the monthly data of IMF from 1985 through to 2011, separately constructs a VAR and a VEC model. The results include: 1) there is a permanent relationship among four energy resources in the long run: so far the price of uranium changes by 1%, it will lead to price of coal and natural gas negatively change 2.11% and 7.01% respectively, and price of oil positively change 7.97%. 2) The result of impulse response analysis on the energy resources indicates that they all react immediately to innovations of themselves to a large extent. However, the durations are different at all: to uranium, a little bit fade only till the 15 months end, while coal and oil goes down after 6 and 2 months later, respectively, and natural gas plummets in no time. 3) Except that the variance of natural gas can be decomposed into variance of natural gas and oil with the ratio of nearly 70:30 at the end of 15 month, the variance of uranium, coal and oil price almost comes from themselves. 4) The coefficient of natural gas is big and negative, with significant statistics. It means that the deviation of natural gas price would be corrected in the short run. However, the coefficients of coal, oil and uranium are very small, and the ones of oil and uranium are not significant. So, oil and uranium price doesn't have any ability of dynamic adjustment.
Water conservancy plays a greater role in China's sustainable development. A thorough analysis of China's evolvement of national condition and water regime, together with a reasonable division of water conservancy development stages keeps us well informed about the reference value to the strategic choice of water conservancy development. The theory and methodology of the division of water conservancy development stages is a relatively new subject in academic research. This paper puts forward a set of theoretical framework based on a comprehensive understanding of interactive relationship between the water conservancy development and eco-environment-socio-economic system, analyzes its supply-demand's evolution tendency, and then evaluates the stage features of water conservancy development. Based on this, it puts forward the methodology of stage division of water conservancy development: investigate the supply and demand of water conservancy development evolution, integrating with the ecological environment changing trend and selecting some representative years as the node, to get the division of water conservancy development stages judged by quantitative index analysis and empirical analysis. According to the above theory and method, this paper divides China's centennial water conservancy development (1949-2050) into seven main phases.
Taihu Lake Basin is China's traditional food producing area with high grain yield and the forefront of China's economic development. With the gradual population increase and rapid urbanization development, the demand for food is increasing rapidly while cropland resources are fast dwindling. Therefore, the supply and demand conflict of food keeps intensifying. From a macro perspective, this paper discusses the temporal and spatial patterns of grain production changes and food security level of 27 county seats in Taihu Lake Basin from 1985 to 2010. The results are as follows: Firstly, the grain production showed instability and a tendency to decline, and it can be divided into three stages which are fluctuant development-sharp drop-stead growth. Secondly, it also showed significant regional differences. The analysis of different regions reveals the reality that all county seats have different degrees of decline other than the four counties in the northwest, especially Suzhou, Wuxi, Changzhou and Hangzhou. Then, the gravity centers of grain production appear the tendency moving from central area to northwest area and relative advantages of food production gradually blurred. On the whole, it presented a decline in the grain production. Finally, based on food security assessment, the fluctuations coefficient of more than 70% of the years and the total grain yield variation are above the national average level, so there will be a high-risk of food security. It is illustrated that the food insecurity counties expand from 4 to 16 and 59% has been a serious food deficit. In the future, the study area is still threatened by the decrease in the quantity and the degradation of the quality of cultivated land. In view of the analysis results, countermeasures for reducing cropland pressure and guaranteeing the balance of food supply were proposed, and it is of great significance to perfect the protection policy of cultivated land and grain production and bring forward some research measures for ensuring food security according to the actual situation of different regions.
To reveal the impact of ecological risk of land use change in the small watershed of the Three Gorges Reservoir Area, Caotang River watershed is chosen as the study area. Land use information was obtained from satellite remote sensing TM images of 1990, 2000, 2004 and CBERS data of 2010. The grid by 500 m×500 m was created as the auxiliary evaluation unit, and the GIS technology was employed as the data integration analysis platform. In order to generate the map of land ecological risk in 1990, 2000, 2004 and 2010, the system sampling method and block Kriging were used to make the index a spatial variable. The results indicated that land use reasonable index in the study area increased from 0.78 to 0.81, a rise of 0.03 from 1990 to 2010, appearing first a deteriorating trend and then improved trend, land use structure is reasonable along with contiguous distribution of five ecological risk levels of the study area. Edge of the study area is at low risk, the closer the distance, the higher the level of risk of the center of the study area. Regional ecological risk distribution patterns have obvious space correlation with arable land and water distribution area. Five types of ecological risk are mainly concentrated on the slopes of 15°-25° and >25° and at elevations of 500-1000 m and 1000-1500 m. Ecological risk appears first a deteriorating trend and then improved trend. The largest area of ecological risk is at lower level risk in 1990 and 2010 of the study area, accounting for 28.23% and 37.41% of the total area; in 2000 and 2004, the largest area of ecological risk is at high level risk, accounting for 26.29% and 35.54% respectively. The study revealed the main reason for the temporal and spatial variation of the Caotang River Small Watershed Ecological Risk is the constraint of natural conditions and control of human factors. The natural conditions are the incentives and human factors control is the main reason. Type of land use changes is the most important impact of changes on ecological risk factors. Finally we put forward some countermeasures for temporal and spatial variation of regional ecological risk. Specific measures include to find out the optimal combination of land-use types with improved unreasonable land-use types, to improve the stand structure, vigorously transformation of coniferous forest and shrub replanting made mixed coniferous forest; we should undertake unitive reasonable planning and management for land use which was closed with Hydro-Fluctuation Belt area while considering the water environmental pollution and soil erosion problems as a whole.
Henan Province is located in the north-south climatic transitional zone with frequent flood and drought disasters. The risk probability of flood and drought disasters in Henan Province were researched with comprehensive utilization of disaster data and information diffusion model from two aspects of disaster-produced and disaster-consequence, so as to provide a theoretical basis for strengthening flood and drought risk assessment and management. The results showed that: 1) during the period of 1988－2007, the flood years are mainly 2003, 2000, 1998, 1996 and 2005, and the drought years are 1997, 2001, 1999, 1992 and 1988. 2) When the rainfall anomaly percentage were at 20%, 30% and 40%, the floods probabilities were 0.10, 0.06 and 0.04; when the rainfall anomaly percentage were at-20%,-30% and-40%, the droughts probabilities were 0.13, 0.07 and 0.03. 3) When the disaster occurrence rates of floods were 5%,10%,15%, the risk probabilities were 0.81, 0.54, 0.35 respectively, that was 1-3 a encounter, and when disaster rate was greater than 20%, approximately 4.5 a encounter; while the disaster rates of droughts were at 5%, 10%, 15%, 20%, 25%, the risk probabilities were respectively 0.87, 0.72, 0.58, 0.47, 0.38, and that were 1.2 a, 1.4 a, 1.7 a, 2.1 a, 2.6 a encounter. 4) The droughts occurred more frequently than the floods in Henan Province. There was a larger regional difference in space, both flood and drought high risk zones were mainly in Zhumadian, Nanyang, Pingdingshan, the regions with higher drought risk than floods were mainly in Sanmenxia, Luoyang, Zhengzhou, Jiaozuo, Anyang, Xuchang, and the regions with higher flood risk than drought were mainly in Xinyang, Luohe, Kaifeng, Shangqiu, Zhoukou, Puyang, in addition, the regions with both small flood and drought disasters risk were in Jiyuan and Hebi.
Road plays an important role in the development of economy and society, but it also imposes a threat to environment and ecosystems. Research on such an effect is urgent for environmental protection and ecosystem conservation. This paper quantified the intensity of road network's disturbance in the Lancang River Valley with a road disturbance index, which was established based on the characteristics of a road and its surrounding environment, and then analyzed the spatial pattern of this disturbance and its impact on landscape. The results showed that there was obvious spatial difference of road disturbance intensity throughout the whole Lancang River Valley, the intensity in the middle and lower reaches was far more serious than that of the upper reaches. The road effect-zones were irregular polygons with intricate boundary and taking the spatially scattered severe effect-zones as centers, the disturbance intensity decreased gradually outwards. Comparing landscape patterns and their transformation characteristics among different road effect-zones, it was found out that cropland and built-up area were mainly distributed in severe effect-zones, and the transformation in severe effect-zones was far more violent than that in a weaker one. The above results suggested that road development was an important driving force for landscape change, so sensitive areas should be avoided in the decision-making for new development in the Lancang River Valley.
Straw return and other farming management measures can effectively increase soil organic carbon (SOC) storage, thus contributing to mitigate the increase in the atmospheric CO2 concentration. Based on the EPIC model, which was validated using the database of long-term observation in Qianyanzhou and Yingtan experimental stations in Jiangxi Province. EPIC model was based on the meteorological information from 1990 to 2010 and soil database in Jiangxi Province, to simulate the paddy soil carbon sequestration potential from 2010 to 2030 under alternative crop residue return scenarios in Jiangxi Province. The results indicated that the top soil organic carbon stocks showed a decreasing trend under the straw removal(CR 0%) and straw incorporation 25% (CR 25%) scenarios, the ratio of loss is 21.3% and 6.5%, and an increasing trend in the case of straw incorporation 50%(CR 50%)and straw incorporation 100% (CR 100%)scenarios, the ratio of increasing is 5.4% and 11.9%;compare to the CR 0% scenario, the carbon sequestration potential of crop straw return scenarios of CR 25%, CR 50% and CR 100% are 6.43, 14.92 and 25.26 Tg C (1 Tg= 106 t) in paddy soils of Jiangxi Province. The simulating results demonstrated that conservation tillage (straw return) is an effective way to improve the paddy soil carbon sequestration.
Research on the impact of land use/land cover change on carbon budget is one of the key issues in the field of global change, as well as a possible way to answer the question of "Missing carbon sink". However, this issue in northwest arid area of China is weak, which limits comprehensive understanding of the mechanism of the interaction between land use change and carbon cycle. In this paper, Manas River Watershed was chosen as the study area due to its representativeness of water and land exploitation in this area. By adopting empirical statistical model—Bookkeeping model, research on effects of two main types of land use/cover change (desert change into farmland and farmland abandonment) on the carbon budget were carried out in Manas River Watershed over the past 50 years. Land cover map, published vegetation/soil carbon density data as well as field survey data are utilized for this research. Results showed that the reclamation activity of Manas River Watershed increases carbon stocks. From 1962 to 2008, vegetation and soil carbon storage of the watershed increased by 6.34×105 and 3.14×106 t, respectively, which result in the total carbon stock increase by 3.77×106 t. The impacts of different land use/land cover change on carbon budget are significantly different because of the variation in area and carbon density between conversion types: Vegetation and soil carbon storage are significantly increased with reclamation of arable land from desert grassland and bare land; the vegetation and total carbon storage reduced while soil carbon storage increased with the conversion of woodland to arable land; carbon storage in Manas River Watershed reduced because of farmland abandonment.
In contingent valuation surveys, data is often complicated by zero willingness to pay (WTP) responses in the sample. Without properly dealing with, zero responses would deeply reduce the reliability and validity of welfare valuation. Based on a case study on the WTP for ecological compensation of the Yangtze River Basin in Nanjing city, 1403 individual questionnaires in closed-ended double bounded dichotomous choice format were collected. Given conventional methods dealing with zero responses will result in estimation bias in terms of WTP, special attention was paid to the issue of zero response in the survey, and a Spike model that allows for a non-zero probability of zero response was applied. Because different types of zero responses have different economic implications, without distinguishing between true zero response and protest responses will result in non-neglecting measure bias. The conventional methods to deal with zero response have been known as dropping it from the analysis, or substituting it with either zero or a near zero positive number. When dropping zero responses, it yielded a WTP between 359 and 396 yuan per household per year. While replacing zero responses with a near zero positive number, it yielded a WTP between 154 and 208 yuan per household per year. However, dropping zero responses will run the risk of sample selection bias, while replacing it with near zero number seems somewhat too subjective. Thus, a Spike model that allows for a non-zero probability of zero WTP in referendum-style was brought into practice. It includes many of the often used models as special cases and allows various analyses that are not possible in standard applications. Under the Spike model, the zero response samples were further divided into protest response and true zero response according to their behind motivations. Then the value of WTP was estimated between 259 and 288 yuan per household per year, which is significantly smaller than the dropping method but larger than the replacing method. The total compensation value paid by Nanjing households was at least 24.4×108 yuan in the following five years. It was also found that there were obvious differences in the determinations of decision-making between the willing to join step and willing to pay steps. Environmental services are luxury, and only when people's income reaches a certain level will they buy them. Thus at the practical level, considering the heterogeneous acceptability and burden of expenditure, special attention needs to be paid to the low-income families.
All land use types in the city are affected by human, but the impact on each type varied enormously, hence vertically forming a certain distribution model. In a flat country, distance is the most important factor that interferences the distribution of land use; and basing on this assumption, Von Thünen and Burgess introduced their famous concentric models. However, the absolute flat country is inexistent, so how does the elevation affect the distribution of urban land use? Would it establish its own unique land use model of distribution in vertical orientation? In this paper, a case study was conducted in Guangzhou City by comparing land use vertical distribution pattern in 1990, 1995, 2000, 2005 and 2009 using remote sensing image interpretation and DEM data. The results showed that: 1) Various types of land use showed different characteristics of distribution changing with elevation. Some types of land use are mainly concentrated in a range of elevation, while other types of land use are relatively scattered. 2) From low elevation to high, the most dominant types of land use vary from farmland, water, urban land, orchard, to woodland in 2009. With the raise of elevation, the advantage of the most dominant type decreases first and then increases quickly. 3)From 1990 to 2009, the overall trend of the magnitude of land use change in vertical orientation are similar: the intensity of land use change decreases with the raise of elevation; and in the progress of land use change, the primary changes of land use are the spread of urban land and orchard and the retreat of farmland and woodland between 1 m to 90 m. 4) Based on the definite landforms and stage of economic development, the corresponding vertical land use hierarchical models of land use will form. From low elevation to high, the vertical land use hierarchical model in Guangzhou is composed of the layers of vertical land use, i.e., mixed layer of farmland, fishpond and shoaly land; mixed layer of water and farmland; mixed layer of urban and farmland; mixed layer of orchard, farmland and agricultural settlements; mixed layer of orchard, woodland and farmland; mixed layer of orchard and woodland; and woodland layer. 5) We discussed the vertical hierarchical model of land use in natural landscape period, agriculture landscape period, rapid-urbanization period, post-urbanization period and complete-urbanization period. And the theory of succession of community in ecology can well explain the evolvement of vertical hierarchical model of urban land use.
With Xingping County in Shaanxi Province as the research site, geostatistics and Geographical Information System (GIS) were employed to establish the best semi-variance theory model and to study the spatial distribution, sufficiency and deficiency pattern, and content changes of soil alkali-hydrolyzable nitrogen (AN) at county scale based on the 1651 topsoil samples taken by "S-shaped" methods in 2009, so as to provide theoretic guidance for soil fertilization management and agricultural industry in Guanzhong Basin. The result showed that soil AN content in the study area ranged from 7.70 mg·kg-1 to 82.60 mg·kg-1, concentrated at the level of 30-40 mg·kg-1 with an average of 37.76 mg·kg-1 which decreased by 28.62% compared to that recorded in the 1980s. AN content satisfied the normal distribution after Box-Cox transformation (p=0.35) with Kolmogorov-Smironov (K-S) test. Under about 300-m sampling scale, soil AN demonstrated weak spatial dependence was mainly affected by human factors including fertilization, cropping systems and so on. There is obvious spatial difference in AN content distribution, which is shown as high in the center, while low in the surrounding areas. In the year of 2009, according to the abundant degree of soil AN content in Xingping County, 27.33% of farmland has proper AN content (40-60 mg·kg-1), but as high as 72.67% (below 40 mg·kg-1) is lack of AN. According to the Second Soil Alkali-hydrolyzable Nitrogen Classification Standard of Xingping, during the past 3 decades, the AN content in previous 1-3 grades farmland decreased sharply, but increased in the previous 5th and 6th grades farmland, and finally concentrated at the 4th grade. A total of 26.17% of the farmland AN content grade changed, of which 22.68% of the farmland decreased significantly. The decreasing trend of soil AN content might be attributed to the reducing of nitrogen fertilizer and incorrect agronomic measures. It is necessary to conduct further field survey to collect the key limiting factors where soil AN content was low or reduced sharply and take measures timely to increase soil AN content.
We carry out research to the temperature, depth, meta and ecological situation of the sedimentary marine water of the silicalite, phosphorite, barite rock, metal rich bed of the upper and lower rock bed of the profiles in Hunan and Guizhou provinces. The paleo-marine water temperature of the sedimentary stage of the silicalite is averaged as 84.81℃ or 87.27℃, that of the phosphorite is averaged as 42.17℃, and the rock-forming temperature of phosphorite is similar to the silicalite, smaller than 100℃, being respectively 37-47℃ and 79-98℃. The water depths vary within 100-300 m. Silicalite, sulfide-rich black shale(metal rich bed) and barite formed within the weak-alkaline meta environment. But the phosphorite formed within the weak-acidic and weak-alkaline meta environment. The rock-formation and mineralization model research thoroughly indicated the existence of the basic-phile elements Ni, Mo, V, Cr and PGE have genetic connections with the basaltic rock and super basic rock. The area belongs to the east Tetheyan sea during the early Cambrian, and the south China plate and the Australian plate formed the deep fault zone during the early Cambrian separation stage, which might be the corridor of the sea water carrying out deep cycle, absorbing the magnesium-iron lower-crust PGE, forming the rich-metal hot brine water and depositing in the sea bottom.
By literature reviewing, which is about the key variables in the user cost approach, this paper proposes to eliminate the arbitrariness in the chosen of discount rate in user cost approach. Based on the estimation of U.S. social discount rate, this paper measures the user cost of U.S. oil and gas resources, then finds out that, during 2000 to 2008, the user cost of U.S. oil and gas resources increased obviously from 18.508 billion USD to 226.428 billion USD, and the fluctuation of user cost of U.S. oil and gas resources was affected deeply by the social discount rate. Comparing the data of U.S. mineral royalties of oil and gas resources with user cost, we have the conclusion that the growth of U.S. mineral royalties of oil and gas resources was slower than the growth of user cost of U.S. oil and gas resources, and the compensation of royalties to user cost was declining, and during 2002 to 2008, the proportion of the compensation of royalties to user cost dropped dramatically from 42.68% to 10.83%.
Since operation and management mode for rural drinking water engineering projects are diverse and complicated, it is necessary to select a new dynamic extension evaluation model by taking Zhejiang Province as an example. Three typical operation and management modes are chosen, for comparative evaluation, including village collective management mode, contract management mode and water user association management mode. The evaluation aims to identify their suitable conditions, advantages and disadvantages for convenient extension and application. In the evaluation process, the extension evaluation model was innovatively combined with deviation analysis method and matter-element model, process element model and material element model for extension evaluation are established, and through a series of steps such as to determine measured conditions, determine weight coefficient via deviation analysis method, and established associated function and calculation qualified degrees, and calculation specification qualified degrees, and calculation excellent degrees. Fifteen different run management modes of rural drinking water engineering projects in Liandu District of Lishui city in Zhejiang Province were selected for evaluation, and evaluation results were obtained. The evaluation results are basically consistent with the actual conditions, verifying the viability of the model and method. This provides basis for the model application and informationization, but also provides technical support for the operation and management of rural drinking water project decision-making sector mode application in the future.
The drought and the flood, which are strongly affected by artificial activities, have become one of the hottest issues worldwide. In this study, we analyzed the advances in the mechanisms of the drought and the flood events affected by the artificial activities, and the results showed that the increasing flux of greenhouse gases and concentration of aerosol in the atmosphere due to artificial activities have accelerated the global-climate change process. Furthermore, the spatio-temporal patterns of the extreme hydrological processes have also been changed. In addition, the land degradation has altered the spatio-temporal distribution of water resource and the hydrological cycle, which has further weakened the ability of flood control and drought relief. Although the hydrological projects can re-allocate the water storage in the basin, to cope with the drought and flood events, however, it could also exacerbate the drought and flood in the meantime. Based on the results mentioned above, we further discussed the quantitative analytical methods of the influence from human activities upon the drought and the flood.
