Archive

  • Select all
    |
    Resource Economics
  • Resource Economics
    HE Ling-yun, CHENG Yi, JIN Li-cheng, ZHONG Zhang-qi
    Download PDF ( ) HTML ( )   Knowledge map   Save

    Based on the energy prices of China and foreign countries, industry development and energy consumption of China in the period of 1978-2012, this paper analyzes the influen-cing paths, the static and dynamic effect of domestic and foreign energy prices on energy consumption of China through Granger Causality test, regulatory effect model and state space model. Firstly, it is found that there’s no direct causality between China’s energy price and energy consumption, but the former can impact on the latter through influencing output and energy structure. Meanwhile, there’s no significant causality between foreign energy price and the related variables except energy efficiency with a time lag effect. Besides, foreign energy price is the Granger reason of the change of domestic energy price when the time lag is 1. However, increasing the time lag weakens the guiding effect. Secondly, when a single path is taken into consideration, neither of the two prices has effectively influence on China’s energy consumption. However, when considering comprehensive paths, both prices have significant effect on China’s energy consumption. Rising energy price has obvious pulling effect on energy consumption through output and industrial structure on one hand; and has depressing effect on energy consumption through energy efficiency improvement on the other hand. Combining the output, structure, and efficiency paths, we find that the comprehensive energy saving effect of the two energy prices are -0.161 8 and -0.009 1, respectively. It shows that reasonable rising of energy price can reduce energy consumption to some extent. In the sample period, effect of domestic energy price is more significant than that of foreign energy price. The effect of foreign energy price on energy consumption through price transmission is -0.250 9, which indicates that the linkage between the domestic and foreign prices is weak and the price transmission is blocked. Thirdly, the effect of foreign energy price on energy consumption through price transmission is only -0.004 0 in short-term while -1.308 3 in long-term, which indicates a certain depressing effect on energy consumption. Fourthly, the effects of the two energy prices on China’s energy consumption are dynamic. Removing the results contradicted with the theory, the comprehensive effect of the domestic energy price fluctuates between -0.016 and -0.356. Besides, foreign energy price has positive effect on China’s energy consumption in most sample periods, which is inconsistent with the theory. However, through “price-price” path, we find the foreign energy price has energy saving effect to certain extent. The effect fluctuates between -0.065 and -0.038 9 and becomes stable after 2000. Overall, the narrower the spread of domestic and foreign energy prices, the bigger the depressing effect of a rising energy price on energy consumption. Effectively rising energy price is beneficial to energy saving. Our research is important for policy makers to establish effective energy-pricing policies. These policies can improve the linkage between foreign and domestic energy prices and then promote energy conservation.

  • Resource Economics
    WEI Long, PAN An
    Download PDF ( ) HTML ( )   Knowledge map   Save
    In line with rapid economic growth in China, intensive attentions were paid to the correlations between sustainable development and environment. According to the data from World Mining Congress, the mineral production of China in 28 categories ranked first in the world in 2012, in which 12 kinds of minerals shared more than 50% in the world��s total production. As strategic bases for energy resource, resources-based cities play supportive roles in the China��s economic development. However, the environmental pollution problems resulting from resource exploitation and processing are very prominent at present. Following the classical EKC analytical framework and the existing researches on resources-based cities, this paper introduces the endogenous elements and additional variables of export, FDI, R&D and pollution abatement level, and further uses the Fixed Effect Model and IV-GMM method to make an empirical investigation into the influences of export and FDI on the environmental pollution in China��s resources-based cities by using the panel data of 285 prefecture cities (115 resources-based cities and 170 others) from 2005 to 2012. It demonstrates the heterogeneity of influences among different types of cities. The results show that export business significantly aggravates environmental pollution in China��s resources-based cities, and FDI aggravates environmental pollution to some extent; the income level and environmental pollution have inverted U-shaped relationship in major prefecture cities; and influences on the environmental pollution are heterogeneous in different types of resources-based cities because the degrees that they depend on the resources and their technologies are different. China has made relevant policies and plans about mineral resources exploitation and sustainable development in resources-based cities at present. However, the conclusions of this empirical research still reflect some deficiencies related to the implementation and effects of the policies, which meanwhile provide enlightenments for improving the policies and their implementation. The deficiencies involved include disorderly market competition, failures of foreign investment policy, and neglecting the development of basic energies. Accordingly, the enlightenments mainly consist of improving the order of competition through market mechanisms, encouraging technology import, restricting the FDI and export in resources, making targeted policies at different development stages, and achieving the sustainable development and utilization of basic energies.
  • Resource Ecology
  • Resource Ecology
    WEI Hui-lan, ZONG Xin
    Download PDF ( ) HTML ( )   Knowledge map   Save
    In order to explore how the effective of implementing ecological compensation in grassland can excite herdsmen to voluntarily change the grassland utilization patterns for a desired goal of ecosystem services, the subsidy policy for grassland ecological protection in Maqu County, an important water conservation and recharge area in Yellow River, is taken as a case study. Based on the minimum-data method, the ecosystem services are measured by water conservation of grassland. The supply curve of water conservation in graze-prohibited grassland in Maqu County is derived from the spatial distribution of the opportunity cost per unit area of graze-prohibited grassland. And the compensation standard is linked to the desired goal of water conservation in the graze-prohibited grassland. The results show that: 1) The implementation of ecological compensation can motivate herdsmen to stop grazing in grassland, but the proportion of prohibited area changes with the standard of ecological compensation, and the desired goal of water conservation provided by the graze-prohibited grassland changes with the proportion of prohibited area. 2) The desired goal of water conservation in Maqu County is 77 383.998 0×104 m3 which is obtained from the existing 17.67×104 hm2 of graze-prohibited grassland. To achieve this goal the compensation standard for herdsmen is 1 751.76 yuan/hm2 which leads to a total amount of 30 950.503 8×104 yuan. In addition, the implementation cost of 2 650.235 0×104 yuan and the transaction cost of 1 768.459 9×104 yuan are needed. However the current ecological compensation standard is 300 yuan/hm2, that only 0.64% of the grassland can be protected under this standard, and only 495.26×104 m3 of the desired goal of water conservation can be achieved in theory.
  • Resource Ecology
    WU Shan-shan, YAO Zhi-jun, JIANG Li-guang, WANG Rui, LIU Zhao-fei
    Download PDF ( ) HTML ( )   Knowledge map   Save
    Vegatation NPP is considered to be a key factor of ecological responses to climate change. The objective of this study was to analyze the spatial-temporal variations and hydrological effects in the source region of the Yangtze River. Trend analysis, correlation analysis and runoff process indexes were applied based on MODIS NPP products over the period of 2000-2010, as well as annual runoff, temperature and precipitation data in the same period. The results indicated that during the period 2000-2010, the annual NPP (aNPP) of vegetation tended to increase at a rate of 48.22 gC/m2. Influenced by water and heat resources, vegetation aNPP increased from northwest to southeast, which showed an obvious spatial heterogeneity. Moreover, the increase rate of different vegetation types varied across the study region. The aNPP of coniferous forest increased fastest among all vegetation types with a rate of 3.03 gC/(m2·a), followed by shrub, alpine meadow and alpine grass, the rates of which were 2.68, 1.43 and 0.85 gC/(m2·a), respectively. The increase of vegetation NPP was distinctively related to temperature from June to September and precipitation from May to August, which showed a significant positive correlation. The increases of runoff coefficient and water conservation index during the period 2000-2010 were also shown in the increase of vegetation aNPP, which was advantageous to water resources in the source region of the Yangtze River.
  • Resource Ecology
    HAO Hai-guang, LI Xiu-bin, ZHANG Hui-yuan, ZHANG Ji-ping
    Download PDF ( ) HTML ( )   Knowledge map   Save
    The impact of human production and consumption on ecosystem is always at the center of academic attention, and an understanding of their linkages is important for effective environmental policy and decision-making. Based on rural household survey data in Taipusiqi County, Duolun County, and Zhengxiangbaiqi County in the Inner Mongolia Autonomous Region, China, we calculated ecological footprint of rural households to identify the impacts of production and consumption on ecosystems in agro-pastoral interlaced region, and further investigated its determinants including household characters, income, income structure, labors, and land endowment. Considering the nature of goods consumed and produced by farm households, we defined and calculated six kinds of ecological footprint (EF): total production footprint (PEF), arable land production footprint (APEF), grassland production footprint (GPEF), total consumption footprint (CEF), arable land consumption footprint (ACEF), and grassland consumption footprint (GCEF). The calculation and analysis results showed that: 1) the CEF was 0.559 ghm2 per capita, and the PEF was 2.045 ghm2 per capita in 2011. The PEF was three times more than the CEF. The farm households can be divided into three groups according to the size of their ecological footprint: high EF group, medium EF group and low EF group. Most of the rural households belong to the low EF group, and the size of GCEF and GPEF determines which group they belong. 2) The ecological footprint, especially the GCEF and GPEF had a significant positive correlation with income, which indicated that increasing of income more depend on livestock production and the household with more income consume more livestock products. Part-time farming or non-farming employment reduces the occupancy of local natural resources to some extent. 3) The ethnic minority households, the households with higher proportion of income obtained from livestock rearing, and the households with more grassland per capita had bigger ecological footprint and bigger GCEF and GPEF, while their ACEF and APEF were smaller. Considering the vulnerable ecosystem in agro-pastoral interlaced regions, ecosystem conservation policy makers should fully understand the differences of EF among farm households and the determinants, and take measures to reduce the ecological footprint and improve the welfare of farm households such as establishing and improving the ecological compensation mechanism, transforming livestock-rearing patterns from an extensive style to an effective style, encouraging non-farming employers to move out of rural area, and improving the diversification of livelihoods of farm households, so as to mitigate the environmental pressure caused by rural households.
  • Resource Evaluation
  • Resource Evaluation
    YANG Zi-sheng
    Download PDF ( ) HTML ( )   Knowledge map   Save
    Constructing mountainous cities is one of the ten models of urban construction in the 21st century. In order to expand the urban development space and protect high quality farmland in plains or flatland areas, the Ministry of Land and Resources of China determines to develop the slopes and build urban and industrial projects on mountainland as one of the countermeasures. Carrying out the evaluation of land suitability for urban construction in mountainous areas will provide a foundation and support for constructing mountainous cities. For the research of land suitability evaluation for urban construction in mountainous areas is still weak, the evaluation index system, evaluation standard, techniques, method and other key problems need in-depth and extensive discussion and empirical research. Given this, this study built constructive land suitability evaluation index system which contains seven special factors and ten general factors, five of which are special factors at the same time, according to the particularity of urban construction in mountainous areas. And then, by using an approach combining the “Extreme Conditions Method” and “Suitability Index Method”, with the help of GIS technology, this study determined each single index of evaluation factors and the comprehensive suitability index, and analyzed and assessed the constructive land suitability of each evaluation unit and its suitability grade in mountainous areas of Dehong Dai-Jingpo Autonomous Prefecture in Yunnan Province by using basic pattern spots on 1:10 000 land-use map in the Second National Land Survey as the evaluation unit. The results show that, in the mountainous areas of 985 787.40 hm2 in the prefecture, the area of land suitable for construc-tion and non-suitable for construction respectively account for 14.37% and 85.63%. And the composition of first grade, second grade and third grade of land suitable for construction are 12:33:55. The evaluation results have been applied in the revision and compilation of “General Land Use Planning (2010-2020) in Dehong Dai-Jingpo Autonomous Prefecture”, which achieved obvious effects. Based on the strategy of “Constructing Mountainous Cities”, Dehong Prefecture eventually successfully implemented its strategy of “Protecting Flat Farmland and Constructing Mountainous Cities”, by which more than 84% of qualified farmlands in flat areas throughout the prefecture were under effective permanent protection and the occupation of farmlands reduced substantially. The suitability evaluation index system and the method developed in this study are applied for evaluating the construction land suitability in mountainous areas in Yunnan, however it will provide a technical support for high quality farmland protection in flatland areas and a reasonable pattern of urban construction in mountainous areas in not only Yunnan Province, but also domestic and foreign similar mountainous areas.
  • Resource Evaluation
    WANG Cheng-jin, CHENG Jia-jia, ZHANG Meng-tian
    Download PDF ( ) HTML ( )   Knowledge map   Save
    The temporal-spatial relationship between coal resources reserves and production capacity directly determine the development stages and evolving path of coal base. How to scientifically identify the development stage of coal base and depletion level of coal resources has important significance on regional development. We designed the model for identifying development stage of coal base. The model takes proportion of surplus resources as a key indicator, and product capacity and service time as auxiliary indicators. It describes the main features in each phase; especially it can identify the time point of resources depletion. Furthermore, we analyzed the interior spatial differentiation of coal base from the perspectives of amount, production capacity, output, and depletion level of coal mines. Finally, we integrated the spatial and temporal views to probe the regularities of coal base’s lifecycle. The result shows that Jining coal base displays a classic lifecycle with four phases, including starting phase (1958-1995), growing phase (1996-2010), mature phase (2011-2020) and depleting phase (2021-2089). It has significant feature of long infancy, short middle and long old ages. The distribution of coal mines and their capacities and depletion levels resulted in the interior spatial differentiation in Jining coal base. During the lifecycle, the resources exploitation firstly expanded outward from two core regions (Yanzhou Coal Field and Tengnan Coal Field), subsequently will be followed by continuously shrinking and depletion. This research details the lifecycle regularity of resources base. The integrated analysis in temporal and spatial views of evolution and developing phase enriched the studies on resources base and resources-based city.
  • Resource Evaluation
    WANG Xin-ge, XI Jian-chao, KONG Qin-qin
    Download PDF ( ) HTML ( )   Knowledge map   Save
    The land-use perspective has attracted wide attention in both domestic and abroad rural development study. Combining participatory rural appraisal methods (PRA), GIS spatial analysis and remote sensing technology, this paper focuses on tourist villages’ spatial evolution during the last 30 years from land-use perspective, taking two close villages in Yesanpo tourism area as examples. The research found that, since 1986, the commencement of tourism industry in Yesanpo area, these two villages with similar foundation had been heading in different directions, showing accelerated polarization trend. Gouge Village was gradually evolving into new-type tourist town, becoming more and more flourishing and solid; while Jiaojiekou Village, on the contrary, was becoming increasingly dilapidated and hollow. This differentiation was manifested in three aspects: 1) From the perspective of settlements’ spatial morphology, Jiaojiekou Village had experienced a spatial evolution process characterized by extensive sprawl on the periphery and decline in the interior space; while Gouge Village, in contrast, had conducted not only external expansion but also interior reconstruction, becoming gradually intensive. 2) From the perspective of settlements’ space function, Jiaojiekou Village had kept relative homogenous land use pattern, with increasingly simplified land function structure; while the land function of Gouge Village had become more and more heterogeneous, changing from residential land to varieties of lands satisfying tourists’ demands for accommodation, shopping, catering and entertainment, and showing spatial differentiation as well. 3) From the perspective of population distribution, in Jiaojiekou Village, the migration of villages from central to peripheral area and the outflow of population represented by going out to work had led to the “centre-periphery” style of population distribution and the decrease of population density; by contrast, Gouge Village had experienced population gathering from surrounding villages to the main village, and seasonal population influx dominated by tourists resulted in considerable different population structures and spatial distribution between tourism off and peak season. The research also indicates that, the polarization of tourist villages, in essence, is physical response to different non-agricultural path during rapid industrialization and urbanization procedure in China, tourism induced endogenous non-agricultural process in Gouge Village, and external driven non-agricultural process resulted from accelerating industrialization and urbanization in Jiaojiekou Village. We hold the view that this polarization process implies the gradually dilapidation of traditional villages and prosperity of new-type tourist towns in the future, and the spatial overflow of tourism effects is able to provide a possible scenario for traditional villages’ transformation in rural tourism destination. Furthermore, solving the problem of spatial polarization of rural settlements in tourism destination requires different land use policies during rural transformation, and integrated spatial plan on tourist destination scale.
  • Resource Evaluation
    HE Wei-feng, YAN Jian-zhong, ZHOU Hong, LI Xiu-bin
    Download PDF ( ) HTML ( )   Knowledge map   Save
    Since the 1980s, China has entered a forest transition phase, which has brought us more ecological environment services. However, it still lacks a systematic understanding of the micro-mechanisms of the forest transition on household scale, which has restricted making targeted measures for restoration of forest vegetation. Based on a field survey of 1 015 households in the “two wings” region of Chongqing Municipality, using tools of participatory rural appraisal (PRA), this paper systematically analyzes the micro-mechanisms of forest transition and their influencing factors. The results show that: 1) The micro-mechanisms of forest transition include firewood substitution, cultivated land abandonment, decrease in numbers of livestock breeding and fruit planting. In terms of firewood substitution, firewood consumption per capita and the proportion of firewood consumption decreased by 354.31 kgce and 3.46% from 2003 to 2011, respectively. For cultivated land abandonment, the area of cultivated land abandonment tended to increase since the 1980s and reached the peak between 2008 and 2011. For livestock breeding, nearly 80% of investigated rural households reduced the number of livestock by 2011. As to fruit planting, although it was ever an important factor of forest transition in other regions of the world, the total area of fruit planted by the investigated households is only 9.85 hm2. 2) As the underlying cause, off-farm employment is not only in favor of firewood substitution and fruit planting, but also the reason of cultivated land abandonment and decrease in numbers of livestock breeding. In addition, the four micro-mechanisms of forest transition are also affected by other factors. For firewood, improving the availability of alternative energy (e.g. coal, liquefied gas), and speeding up the implementation of biogas policy can speed up firewood substitution. For abandonment, property of cultivated land (e.g. radius of farming, land quality), and invasion of wild boar can result in cultivated land abandonment. Meanwhile, disaster risk, lack of irrigation, and abandonment behavior of other farmers also have a litter impact on cultivated land abandonment. For fruit industry, the government encouraging policies can accelerate the development of fruit industry. The results perfectly reveal the development of four micro-mechanisms of forest transition in mountainous areas of Chongqing city and their influencing factors, which provides a scientific basis for policy-making to coordinate the contradiction between forest restoration and food safety.
  • Resource Evaluation
    XIANG Xiao-zhi, JIA Shao-feng
    Download PDF ( ) HTML ( )   Knowledge map   Save
    This paper tries to estimate and predict the water demand of China’s energy industry in 2012,2020 and 2030 by studying the current water usage of the energy industry and the development trend. The results showed that: in 2020 and 2030, the water demand of China’s energy industry will reach 655×108 m3 and 677×108 m3 respectively,which is a minute increase, less than 20% compared to that in 2012 (about 573×108 m3). This meant the water requirement of energy industry development in China can be guaranteed. Thermal power generation will remain the largest consumer, taking over 75% of the water consumption of energy industry. While developing rapidly,wind power generation,nuclear power generation and solar power generation will not consume a large amount of water. Shale gas has become a new bright spot in the development of China’s oil and gas resources exploration, and the water demand in this sector is negligible compared to the total water demand for energy, though water usage concentrated in a short term of its early exploitation may affect other sectors around the mining regions. The water demand of energy crops,which will increase by 30×108 m3 from 2012 to 2020 and 18×108 m3 from 2020 to 2030, would be a major factor of the increasing water demand of energy industry in the future.
  • Resource Evaluation
    PAN Jing-hu, ZHANG Jian-hui, HU Yan-xing
    Download PDF ( ) HTML ( )   Knowledge map   Save
    The food security is related to the national economic development and the social stabilization. The study on regional difference of per capita grain possession and its driving mechanism at the county level is significant to regional food security in the situation of limited arable land and rapid urbanization, especially in underdeveloped areas. Agricultural statistics of Gansu Province at county level for the period of 1991-2011 is collected and the GIS spatial analysis technique as well as other tools such as Moran��s I, Getis-Ord and gravity model are introduced to describe the spatial variation of per capita grain possession at county level. Geographically weighted regression (GWR) model was used to explore the driving factors of per capita grain possession, and the aim is to illuminate the current situation of per capita grain possession, provide the scientific basis for sustainable development of agriculture in Gansu Province, and guarantee national grain security. The conclusions are as the follows. Firstly, per capita grain possession showed an overall trend of rise but fluctuated occasionally over the period of 1991-2011. The gravity center of per capita grain possession transferred from the northwest to southeast. Secondly, per capita grain possession at county level in Gansu showed a strong positive spatial autocorrelation that the similar areas clustered in space. The regional per capita grain possession had a significant spatial-temporal variation, and the trend of speciali-zation and regionalization was enhanced. The county-level per capita grain possession had been gradually depolarized. LISA cluster map demonstrated that counties with higher per capita grain possession gathered in the middle part of Hexi Corridor, while counties with lower per capita grain possession gathered in the area of Longzhong Loess Plateau and Gannan Plateau. Spatial pattern of hot spots and cold spots changed significantly during the past 20 years. Thirdly, the driving forces of the evolvement of per capita grain possession can be identified through the following aspects: the basis of natural conditions, the policies on regional development, the interaction among economy, science and technology, and the productive factor. Effective regulation and favorable policies can promote per capita grain possession and guarantee regional grain safety. The driving factors of different regions show localization characteristic of non-stationary intercourse. The effect of population change on variation of per capita grain possession is the largest, whose coefficient estimation is negative. The secondary factor is the economic development level. The urbanization rate is the third influencing factor, and it is negatively correlated with per capita grain possession. The majority of factors that influence the per capita grain possession of Gansu at county level showed obvious latitudinal zonality or longitudinal zonality.
  • Resource Evaluation
    GUO Zheng, LI Jun, ZHANG Yu-jiao, CAO Yu, ZHANG Li-na, FAN Peng
    Download PDF ( ) HTML ( )   Knowledge map   Save
    In order to investigate long-term effects of deep soil desiccation on yields of dryland apple orchards, and to determine suitable age limit of apple orchards on Loess Plateau, WinEPIC model was used to simulate water productivity and deep soil desiccation of dryland apple orchards during 1965-2009 at four sites on the Loess Plateau, which included Luochuan County of Shaanxi Province in semi-humid region, Baishui County of Shaanxi Province in semi-humid and prone-to-drought region, Yan��an City of Shaanxi Province in semi-arid region, and Jingning County of Gansu Province in semi-arid and prone-to-drought region. The simu-lated results showed as follows: in Luochuan, Baishui, Yan��an and Jingning, simulated yield of 1-45 years old apple orchards averaged 26.05, 23.89, 22.29 and 20.51 t/hm2, respectively, and annual yield increased to a maximum at the earlier stage of growth, then followed by the tendency of decrease fluctuating with the local rainfall. In 1-20-year-old apple orchards,average annual water consumptions are higher than annual rainfalls, which resulted in desiccation in deep soil layers. In 1-22-year-old orchards of Luochuan, 1-21-year-old orchards of Baishui, 1-18-year-old orchards of Yan��an and 1-16-year-old orchards of Jingning, simu-lated monthly available soil water amounts in 0-15 m soil profile decreased rapidly with strong fluctuation. Soil desiccation rates in Luochuan, Baishui, Yan��an and Jingning were 59.6, 56.9, 63.9 and 64.9 mm per year, respectively, but they kept at a relatively low level and fluctuated with annual and seasonal rainfall changes at the later stage. The soil moisture in profiles varied sharply, the humidity declining annually. Dry soil layers occurred in the 13th, 11th, 7th and 6th year in Luochuan, Baishui, Yan��an and Jingning respectively, and the thickness of desiccated soil layer increased annually. In the 20-year-old orchards of the four sites, dry soil layers all have already exceeded 11 m in thick, and the soil moistures in 3-15 m layers remain steady after that. There were significant differences in water productivities and soil desiccation effects among the apple orchards at the four sites, and the soil water could be sustainably used by the apple orchards at the four sites for about 20-25 years.
  • Resource Evaluation
    LU Jie, ZHANG Shuo-xin, FANG Jiang-ping, ZHENG Wei-lie
    Download PDF ( ) HTML ( )   Knowledge map   Save
    Pinus densata is a tree unique to China. P. densata natural forest is an important water conservation forest in the middle reaches of Yarlung Zangbo River in Tibetan Plateau. It plays an important role in maintaining water balance and soil and water conservation. Precipitation, throughfall and stemflow were monitored in natural forest of P. densata distributed in Gongbu Nature Reserve of Southeast Tibet from April to October of 2013. Meanwhile, nutrient elements (N, P, K, Na, Ca, S, Mg, Si, Mn, Fe, Cu, and Zn) contents in the water were determined. According to allotment of water amount, input of each element in the forest was calculated. The variation characteristics of nutrient elements through the hydrological processes of the forest were analyzed. The results showed that: Since the precipitation in Tibetan Plateau was divided into the obvious dry and wet season, temporal and spatial dynamics of nutrient elements contents from throughfall and stemflow changed remarkably when precipitation pass through canopy layer and after rainfall and surface of P. densata’s interaction (needles, branches, and stem). The biggest variation coefficient of concentration value in the precipitation was 1.485 for Zn, and the smallest was 0.255 for S. The biggest in the throughfall was 0.844 for Na, and the smallest was 0.304 for S, while those in the stemflow were 0.809 for P and 0.318 for Si, respectively. There were no significant relations among the trace elements (Mn, Fe, Cu, Zn), and between the trace elements and the others, respectively. There were significant relations between the others. The average contents of Cu annually in the precipitation, throughfall and stemflow were the lowest, which were 0.023, 0.047 and 0.066 mg/L, respectively. That of N was the highest in the precipitation, which was 1.604 mg/L, and those of Na were highest in throughfall and stemflow, which were 3.401 and 4.307 mg/L, respectively. The differences of each element contents in the samples collected from the precipitation, throughfall and stemflow were significant, and the order were: stemflow>throughfall>precipitation. The monthly patterns of nutrient concentration were “∩”, “N” or “∪” types. The leaching coefficients of the throughfall and stemflow were both more than one, and the stemflow leaching coefficients were greater than the corresponding throughfall leaching coefficient. The nutrients input of precipitation, throughfall and stemflow were 64.172, 79.949 and 15.623 kg/hm2, respectively. The Na, K and Ca input of throughfall and stemflow accounted for more than 50%. The total input of throughfall was 5.12 times that of stemflow. The input of precipitation was main N element. The net leaching input was 34.057 kg/hm2 (except for N), and ranked in the order of Na>Ca>K>Mg>Si>S>P>Mn>Fe>Zn>Cu, and the input of N was -2.658 kg/hm2. The research results not only provided a theoretical basis for economic evaluation of P. densata forest ecosystem service function, but also enriched the assessment content of the national ecological security barrier in Tibet Plateau.
  • Resource Evaluation
    LONG Xi-ting, YUAN Rui-qiang, PI Jian-gao, SUN Xi-liang, LIU Chang-ming
    Download PDF ( ) HTML ( )   Knowledge map   Save
    Shallow geothermal energy is a kind of clean energy. Development of the energy is still in beginning stage. Based on a number of field surveys and tests in Changsha, the adaptive partition of developing of shallow geothermal resource was evaluated, and the total shallow geothermal capacity, available resource, and potential were studied. Furthermore, environmental and economic benefits from the development were discussed. Changsha is located in a low geothermal gradient area of South China. The average shallow geothermal gradient is 2.41 ℃/100 m in South China. While our results show that the shallow geothermal gradient varies between 0.69 ℃/100 m-1.98 ℃/100 m with an average of 1.40 ℃/100 m in Changsha. The total shallow geothermal capacity and available resource are 3.34×1014 kJ/℃ and 3.55×1014 kJ/a respectively. The thin Quaternary sediments (20 m in average) present almost no impacts on the shallow geothermal energy. Besides, sandstone, mudstone, slate, granite and carbonatite distri-bute widely within 200 m underground. Those bedrocks are of high thermal conductivity and bad water yield property. Therefore, it is considered that the ground-source heat pump system of pipe heat exchanger is the appropriate choice to develop shallow geothermal energy in Changsha. The area that best suits for the ground-source heat pump system accounts for 62.6% and the area that better suits accounts for 33.9% for the ground-source heat pump system. The Yuelu Mountain area and the central city are not suitable for the ground-source heat pump system for the bad geological settings. Only the ambient areas of rivers are suitable for ground-source heat pump system of groundwater heat exchanger. Heat exchange power of the heat pump system of pipe heat exchanger is 1.25×107 kW in winter and 1.66×107 kW in summer. At the same time, the geothermal developing potential is (4.22±0.31)×105 m2/km2 and (3.82±0.17)×105 m2/km2 in winter and summer respectively. The temperature differences used by the ground-source heat pump system are higher in summer than in winter, which is induced the higher heat exchange power and developing potential of shallow geothermal energy in summer. Exploring shallow geothermal energy in Changsha will bring great benefit in economy and environment due to the high available temperature difference and long running term of air conditioner. About 1.21×107 t/a standard coal will be saved by exploring and utilizing the shallow geothermal energy in Changsha. Besides, emission of CO2 (about 2.89×107 t/a) and air pollutants will also be reduced. Development of shallow geothermal energy is beneficial to achieve the energy conservation and emission reduction target and to succeed in sustainable development of Changsha.
  • Resource Research Method
  • Resource Research Method
    QIAN Long-xia, ZHANG Ren, WANG Hong-rui, WANG Yang-jun
    Download PDF ( ) HTML ( )   Knowledge map   Save
    In the studies of water resources supply and demand, supply and demand balance has received much attention, but the risk of supply and demand is little addressed. In this paper, the index system of risk of water supply and demand is established from the viewpoint of threat, vulnerability and loss. Functions of threat and consequent lost are constructed which take into consideration of random effects. The probability distributions of water supply and water demand are simulated by Logistic regression. Based on DEA, a evaluation model for water supply and demand risk is developed and the risk of 2020 in Beijing is evaluated. The results show that, if the inflow condition is as that in 1956-2012, the monthly risk has evident seasonal variation features. The risk coefficients of spring and summer are relative low, which are around 0.4. Those of autumn are relative high, basically ranging from 0.4 to 0.6. Those of winter are the highest, which range from 0.6 to 1. If no measures are taken for risk control, the risk from January to October will increase continuously. After using reclaimed water and South-to-North Transferred water, risks from January to December are reduced greatly, however, the risk of each month still has the tendency of increase except for November.