Table of Content

    15 January 2017, Volume 32 Issue 1 Previous Issue    Next Issue
    Discussion on Water Resources Liabilities
    JIA Ling, GAN Hong, WANG Lin, QIN Chang-hai
    2017, 32 (1):  1-11.  doi: 10.11849/zrzyxb.20160142
    Abstract ( )   HTML ( )   PDF (1244KB) ( )   Save
    With the rapid development of economy, more and more natural resources have been depleted. It results in more and more severe problems of environment pollution and ecosystem deterioration. It is no doubt that human society has the liability to protect the environment. However, how to define and quantify this liability and how to fit it into the evaluation system of economic development is an issue to study. This paper, aiming at renewable, random and flowing water resources, discusses whether water resources liabilities exist in the balance sheet of assets and liabilities and how to define and account water resources assets and liabilities based on the principles of economics, accounting and statistics. After summing-up the experiences from relevant researches in natural resources liabilities and water resources liabilities and clarifying the concepts of water assets, water resources assets, liabilities, financial liabilities, environmental liabilities etc., the study draws the conclusions: 1) Generalized water resources liabilities can be defined as the negative impact on water resources volume, environmental quality and ecosystem function due to excessive improper economic activities. It could be further stated as the over-use of water resources leading to the damage on water cycling process and renewability of water, the over-discharge of wastewater and pollutant to natural water bodies leading to the reduction of environmental capacity, and the over-occupation of ecological water use leading to the decrease of ecosystem service. 2) Special water resources liabilities can be explained as the relations of obligatory right and debt on water resources between environment (creditor) and economic entity (debtor), which is defined as the debtor’s present obligation of compensation, restoration or reparation of the damage of water cycling process and renewability of water resources occurred in water-related activities. 3) Water liabilities can be accounted by introducing environment into balance sheet for water resources as a virtual sector to account water resources as non-financial and non-productive assets in economic account system. The occurrence of water resources liabilities can be confirmed by comparing the water resources used by the economic entities in an administrative region with the total volume of water right and interests for the economic entities in the region. The methodology of water resources liabilities proposed by authors can make it possible to format the balance sheet for water resources. It can also be referred to other natural resources in similar studies.
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    Theoretical Discussion
    Arable Land Requirements Related Food Consumption Pattern—A Case Study in Lhasa, Xigaze and Shannan Region of Rural Tibet
    GAO Li-wei, XU Zeng-rang, CHENG Sheng-kui, XU Shi-wei, ZHANG Xian-zhou, YU Cheng-qun, SUN Wei, WU Jun-xi, QU Yun-he, MA Jie
    2017, 32 (1):  12-14.  doi: 10.11849/zrzyxb.20160134
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    The development of planting forage grass is one of the important ways to alleviate the grass-livestock conflict and entironment problem in rural Tibet. The diversity of food consumption pattern and the increase of food imported from inland areas reliefed Tibet from the pressure of food production, and provided advantage for local planting forage grass. Based on household survey data, market research data and statistical data, with the improved conceptual model of the relationship between food consumption and arable land requirement from Gerbens-Leenes et al. (2002), the potentials of sparing arable land for planting forage grass were analyzed systematically in Lhasa, Xigaze and Shannan respectively (the YLN region in rural Tibet). The analysis results of food consumption structure related to arable land requirement showed that there was a low arable land requirement of farmer diet structure in rural Tibet, which indicated the huge potential for sparing land for forage. The arable land requirement per household of Lhasa, Xigaze and Shannan was 5 542.3, 7 400.1 and 5 521.7 m2 in 2010, respectively, and the potential for forage was 4 777.5, 2 977.3 and 2 054.4 m2, respectively, which accounted for 46.3%, 28.7% and 27.1% of arable land possessed per household in Lhasa, Xigaze and Shannan, respectively. However, considering the rapid growth of population and the adverse factors of fragile ecological environment to the agricultural production in rural Tibet, the government should differentially carry out structural adjustment of agriculture and animal husbandry step by step based on the situation of agricultural production and the development level of animal husbandry of different regions in the YLN region of Tibet (Lhasa, Xigaze and Shannan), increase the enthusiasm of farmers for planting forage grass with subsidies and other incentives, establish and improve the forage grass market for forage resources allocation, alleviate local contradiction between grass and livestock, and raise income of forage grass planting in rural Tibetan.

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    Resource Utilization and Management
    An Analysis on Crop Choice and Its Driving Factors in Hani Rice Terraces
    YANG Lun, LIU Mou-cheng, MIN Qing-wen, TIAN Mi, ZHANG Yong-xun
    2017, 32 (1):  26-39.  doi: 10.11849/zrzyxb.20160123
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    Honghe Hani Rice Terraces System is one of the Globally Important Agricultural Heritage Systems (GIAHS) sites approved by Food and Agriculture Organization (FAO) in 2010. The system of forest-village-paddy-river in Hani terrace, which has formed over 1 300 years in history, has multiple values, including ecological value, economic value and cultural value. However, in recent years, with the development of modern agriculture and tourism, the cultivation practices for high yield and uniform variety cropping bring in serious problems there, such as ecological problems and food security problems. From the viewpoint of farming behavior, we conducted our surveys to learn about the local crop economic input-output, cultivated land resource, rural household information and local natural resources. Participatory Rural Appraisal (PRA) was used to gain the information in Yuanyang County, Yunnan Province. And Seemingly Unrelated Regression (SUR) was used to test the theoretical result on the individual peasant household level. Then, this paper summarized the status quo of crop cultivation structures and analyzed their driving factors in Hani terraces fields. The results showed as follows: 1) In the 41.23 hm2 available cultivated land referred in survey, the plants ordered by their total cultivated area are hybrid rice, maize and fruit, which rank top three in all corps. As the regional traditional crop, the cultivated area of the terrace red rice takes only 12.04% of total available cultivated land referred in survey. 2) The local rural farmer prefer hybrid rice to the terrace red rice due to its much higher economic benefits. Thus, there were more cultivate areas for hybrid rice compared to the terrace red rice. In addition, the terrace red rice is mainly cultivated in the land with poor situation, such as low quality and high altitude. Furthermore, maize is also widely cultivated there for both food and feed. 3)The economic benefit of crop, the quality and altitude of arable land have great influence on the choice of alternative crops, such as hybrid rice and red rice. As for individual peasant household, their characteristics and resource endowment have influence on choosing different corps. The family population and the altitude of cultivated land are positively correlated with the behavior of planting the terrace red rice at the 1% significance level, while the number of cooperatives is negatively correlated with the behavior of planting the terrace red rice at the 1% significance level. The conclusions of this paper is that the decrease of the traditional crop is becoming a trend in Hani terrace fields, especially for individual peasant household. If things continue in this way, it would threaten the stability and sustainability of Honghe Hani Rice Terraces System.

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    Changes of Planting Structure and Quantitative Evaluation of Influencing Factors in Traditional Soybean Producing Areas: Taking Nenjiang County in Heilongjiang Province as an Example
    DONG Fei-fei, LIU Ai-min, FENG Zhi-ming, XUE Li, YANG Xiao
    2017, 32 (1):  40-49.  doi: 10.11849/zrzyxb.20160177
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    Northeast China, especially Heilongjiang Province, is a traditional soybean producing areas, where planting structure changes have resulted in decline in domestic soybean production. However, imports of soybean continued to rise in China, and China has become the world’s first soybean importer. To explore the planting structure changes and the main influencing factors in traditional soybean producing areas, this paper selected Nenjiang County as the study area. Firstly, interpreting TM/OLI images gave the changes of planting structure in this area; secondly, quantitative evaluation on the influence factors was made by taking soybean farmers’ willingness as dependent variable. The results show that: 1) The planting structure in the study area has greatly changed since 2000. Soybean acreage increased dramatically in the fourth accumulated temperature zone during 2000-2007. Maize planting area increased in the fourth and fifth accumulated temperature zones during 2000-2014, and has a tendency to continuously expand northward. Although soybean planting area expanded northward and eastward, its areal proportion in the total grain sown area decreased by 27% in 2014 compared to 2000. 2) The target price policy has the maximum influence on the willingness of farmers’ planting soybeans, accounting for 18.86%, followed by soybean price and crop rotation, which take 18.52%, and the impact of total investment of soybean accounts for 13.81%. The influences of other factors all count for less than 10%. The competitive advantages of domestic soybeans are “non-GMO” and “edible protein”. In addition to the policies for supporting soybean production, the country should take more important strategies to encourage the relevant enterprises to diversify the non-GMO soybean products, and strictly control the transgenic soybean in the field of food. These strategies enable reasonable premium for processing enterprises and soybean farmers and improve farmers’ production enthusiasm in traditional soybean producing area through market mechanism.

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    Resource Ecology
    Spatial-temporal Variation of Growing-season NDVI and Its Responses to Hydrothermal Condition in theTarim River Basin from 2000 to 2013
    LUO Min, Guli JIAPAER, GUO Hao, GUO Hui, ZHANG Peng-fei, MENG Fan-hao, LIU Tie
    2017, 32 (1):  50-63.  doi: 10.11849/zrzyxb.20160141
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    The spatial and temporal distribution of vegetation cover has undergone certain changes in the Tarim River Basin due to the impacts of comprehensive treatment project and recent climate change. Clarifying the relationship between the vegetation cover and the climate change as well as human activities can provide a scientific reference for ecological maintenance and management of Tarim River Basin. Hence, by using trend analysis, R/S analysis, partial correlation analysis and residual analysis, this study analyzed the spatial-temporal changes of NDVI in the growing season and distinguished the range and extent of the impacts of precipitation and temperature changes and human activities on vegetation cover change in the Tarim River Basin from 2000 to 2013. The results showed that: 1) The NDVI in the study area has been increasing with an average rate of 0.8%/10 a from 2000 to 2013. The changing rate in plains was significantly higher than that in mountains. The NDVI in growing season in the mountainous areas of Kaidu-Kongque River Basin and parts of the upstream and midstream of the Tarim River Basin presented obvious degradation trend. Meanwhile, NDVI in the downstream of the Tarim River Basin continued going up. 2) The vegetation cover change was mainly affected by climate change in mountain area and the temperature is the main determining factor. The increase of temperature promoted the growth of vegetation. The changes of the vegetation cover in middle-low mountains and the plain area of the mountain pass were the results of the combination of precipitation and temperature, and mainly affected by precipitation. The NDVI showed a positive correlation with precipitation and a negative correlation with temperature. 3) The increasing oasis irrigation area and the comprehensive treatment project for vegetation restoration led to the NDVI increase in the oasis. Human activities are the main driving force for vegetation growth in this area. 4) The ecological brake in the midstream of the Tarim River Basin restored the vegetation in the downstream, but it affected the water usage of the upstream and midstream to some extent. Especially for the midstream, the ecological brake led to the degradation of the vegetation with the rate of 0.1%/10 a. The relevant departments should further strengthen the reasonable allocation of the water resources and give full play to the role of the ecological brake for water resources regulation.

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    The Spatio-temporal Variation of Ecological Property Value and Eco-Economic Harmony in Gansu Province
    LI Zhen, PAN Jing-hu, HU Yan-xing
    2017, 32 (1):  64-75.  doi: 10.11849/zrzyxb.20160181
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    With the fast development of socio-economic, more attention has been focused on the property value of natural resources and environmental benefit. In this regard, Ecological Property Value (EPV), which is considered as one of the most significant resource and wealth in a country, has being concerned more and more in recent years. EPV is one of the bases of social development. Understanding the EPV in a region is very useful in taking effective management to improve the sustainable development. So, it is very important to assess the EPV. Massive vector and raster spatial data are analyzed in the environment of GIS software. Remote sensing data sets, as well as meteorological data, NDVI and GDP, are resampled at a spatial resolution of 1 km. The EPV and its spatial-temporal variation in Gansu Province from 2000 to 2010 are evaluated and the spatial distribution maps of EPV are drawn. This paper develops spatial model of Ecological Economic Harmony (EEH). The EEH is developed to reflect the coordination degree of the EPV and GDP. The results show: 1) The overall amount of EPV in Gansu Province are 2 430.84 billion and 2 487.40 billion in 2000 and 2010 respectively. 2) The forest ecosystem offers the most of EPV. About half of the total EPV in Gansu Province is contributed by Longnan and Gannan. 3) The spatial distribution of EPV in Gansu Province exhibits a declining trend from southeast to northwest, and the EPV in the Hexi Corridor and Longnan area increased rapidly from 2000 to 2010. 4) The ratios of the EPV to GDP in most of cities decreased in different degrees, which shows unmatching of the development of the EPV and the growth of GDP and the tremendous pressure of protection of ecological environment. 5) The present pattern of the coordination of ecological and economic systems expresses that the potential crisis zone occupies the central location and has a broad coverage, followed by low-grade conflict zone and initial degradation zone. There are some uncertainties for evaluating EPV based on quantitative remote sensing retrieval and economic evaluation methods. The uncertainties are mainly from two aspects: the EPV and the criteria for evaluation, and the spatial resolution of remote sensing data and the precision of applied ecological model.
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    Resource Evaluation
    Regional Comparison of Water Footprint in China Based on the Multi-regional Input-output Analysis: In the Analytical Framework of “Amount-Relative Index-Structure”
    WU Zhao-dan, ZHAO Min, TIAN Ze, MA Chao
    2017, 32 (1):  76-87.  doi: 10.11849/zrzyxb.20160117
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    In the analytical framework of “amount-relative index-structure”, applying multi-regional input-output analysis as well as the Pseudo Gini Coefficient Difference Causes Decomposition method in 42 economic sectors of 30 provinces (not including Xizang, Hong Kong, Macao and Taiwan due to no data), the provincial water footprint is evaluated and the reason causing the difference is analyzed; the urgency of water footprint reduction in each province (i.e. water footprint amount reduction) is evaluated and the key point should be adjusted is found; suggestions for specific adjustment are put forward. It is found that the variance coefficient of water footprint in 30 provinces is 51.79%, the water footprint amounts in Xinjiang and Heilongjiang being the largest in 30 provinces, while those in Tianjin and Beijing being the smallest. Comparing the relevant indexes in different regions, there are greatest necessities for Ningxia, Heilongjiang and Shanghai to reduce their water footprints, for Tianjin, Shanxi and some other provinces to improve their household direct water use efficiencies. According to the regional comparison of sector structure, the agriculture, forestry, animal husbandry, fishery, food manufacturing and tobacco processing industry are sectors should be paid key attention in reducing water footprint in all the 30 provinces. As for the water footprint sources, the water footprints of Qinghai, Ningxia and Xinjiang mainly come from local source, while those of the remaining provinces are all from external sources. The main sources of water footprints of the key sectors in each province can be concluded, for example, the water footprints of agriculture, forestry, animal husbandry and fishery in Heilongjiang, Tianjin, Hainan are from local sources. Considering the above analysis results of urgency, each province should strengthen the water use adjustment on key sectors and main sources.
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    Estimation of Mass Balance of Shiyi Glacier in the Heihe River Basin, Qilian Mountains during 2000-2012 Based on LiDAR and SRTM
    XU Chun-hai, LI Zhong-qin, WANG Fei-teng, WANG Lin
    2017, 32 (1):  88-100.  doi: 10.11849/zrzyxb.20160108
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    Glacier mass balance is the most direct reflection of climate, and its dynamic fluctuation can cause the changes of glacier morphological characteristics and melt water runoff. Usually, glacier mass balance is measured with glaciological and geodetic methods. In this study, geodetic method is used to measure the mass balance of Shiyi Glacier in the Heihe River Basin. Based on Airborne Laser Scanning (Light Detection and Ranging, LiDAR) point cloud data and SRTM (Shuttle Radar Topography Mission) DEM, we establish the process for glacier mass balance calculation. Firstly, LiDAR point cloud data are preprocessed, including filtering (classification) and interpolation. Triangulated irregular network (TIN) filtering algorithm can easily realize the point cloud data filtering to obtain precise ground point cloud data. Based on TIN filtering algorithm, we obtain the ground point cloud. And the DEM is generated from LiDAR data based on natural neighborhood interpolation method, and is resampled to the resolution of 1 m. Then, taking LiDAR DEM as the reference data, multi-source DEM data are matched with cosine curve fitting. The maximum terrain curvature of LiDAR DEM is extracted, and the spatial resolution error is corrected. After those processes, based on error analysis and accuracy assessment, we acquire ice surface change of Shiyi Glacier. Result shows the ice elevation of Shiyi Glacier changed -7.47±0.92 m from 2000 to 2012, with a glacier thinning rate of 0.62±0.08 m·a-1. According to other related studies, the volume-mass conversion parameter is assumed to be 850±60 kg·m-3. It is estimated that the average mass balance of Shiyi Glacier is -0.53±0.07 m w.e. ·a-1, and the cumulative mass change of the glacier is -6.35±0.78 m w.e., which is about (330.4±40.8) ×104 m3 water equivalents. Compared to other typical monitors on glacier mass balance, the results is reliable. The summer temperature rise in the study area caused serious mass loss of Shiyi Glacier in recent years. LiDAR point cloud data have high precision and spatial resolution, however it is less used in glacier volume research at present. In this paper, it is applied in measuring glacier mass balance changes, showing the promising prospects and practicability of both the data and the method.

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    A Comparative Analysis of the Two Dynamic Snow-melting Process and Their Relationship with Air Temperature during 2013-2015 in the Area of Maduo, Tibetan Plateau
    ZHOU Yang, XU Wei-xin, ZHANG Juan, BAI Ai-juan, LIU Xiao-jing, XU Guo-yuan
    2017, 32 (1):  101-113.  doi: 10.11849/zrzyxb.20160121
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    The recognition and research of high-frequency dynamic snow-melting process in hinterlands of Tibet Plateau are insufficient due to the restriction of natural conditions and observation data. In this paper, every 30-minute snow depth and synchronous air temperature observation data of Maduo area in the winter of 2013-2015 are used to investigate the dynamic snow-melting processes in December, 2013 and November, 2014 and their relationship with air temperature. The results indicate that the snow melted slowly at first and then quickly during the whole snowmelt process in the winter of 2013-2014, and the snow melting process mainly occurred during 13:00-18:00. The snow melted in an uniform process during the winter of 2014-2015, and the snow melting process mainly occurred during 7:00-16:00. There is a close relationship between snow depth and air temperature. The daily maximum temperature during two winter snowmelt process were both lower than 0 ℃. The temperature three hours before the snow melting significantly affected the snow depth change. The snowmelt magnitude is mainly determined by the temperature in half an hour before the melting. There is close linear relationship between snow depth and air temperature. The two snow melting processes were close related to the variation of temperature above 0 ℃, which inferred temperature-rise process can promote snow melting.

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    Impact Analysis of Climate Change on Water Quantity andQuality in the Huaihe River Basin
    ZHANG Yong-yong, HUA Rui-xiang, XIA Rui
    2017, 32 (1):  114-126.  doi: 10.11849/zrzyxb.20160184
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    The impact of climate change on watershed water quantity and quality is one of the hot and difficult issues in the research field of climate change and water, especially the impact on water quality. In this study, the well-calibrated distributed water quantity and quality model was used to assess the impact of climate change in the Huaihe River Basin based on the daily precipitation and temperature data in climate scenarios generated through climate models. The spatial and temporal variations of water quantity and quality were simulated in the reference period (1990s) and future periods (2020s and 2030s). The impact of climate change on monthly water quantity and quality processes at the outlet of middle and upper stream of Huaihe River Basin, and the spatial distribution of runoff and pollution coefficients were analyzed. In addition, based on the spatial and temporal distribution characteristics of extreme precipitation during the specified paroxysmal water pollution incidents, the frequency and time of possible paroxysmal water pollution incidents in the future were deduced. Results showed that: 1) The precipitation of the whole basin decreased in the A1B scenario of MPI model, while the temperature increased obviously with an extent of nearly 2 oC, leading to increasing evapotranspiration inevitably. Thus, the runoff magnitude at the outlet would decrease remarkably. The increasing of temperatures would increase the degradation of water pollution loads, and the decreasing of precipitation would also lead to a reduction of non-point source loads into the river, so the pollution load at the outlet would decrease. 2) In the perspective of spatial distribution, the average runoff coefficient would decrease in the future. The upstream regions of Shaying River and Guohe River would be highly affected by climate change. Due to the reduction of runoff coefficient, not only the frequency of water pollution in the basin would rise, but also the distribution of the contaminated areas would change. The most affected regions locate in the upstream regions of Hongru River, Shaying River and Jialu River. 3) If the pollutant emission level and operation rules of dams and sluices keep changed, the specified paroxysmal water pollution incident would happen in July 2035 during the periods of 2020s and 2030s, and its occurrence frequency would be about 20 years, which is much lower than the occurrence frequency of 3-4 years in the reference period. In conclusion, the impact of future climate change on water quantity and quality in the Middle and Upper Huaihe River Basin would be moderate. The study is expected to provide scientific and technical supports for adapting water pollution prevention to climate change in the Huaihe River Basin, as well as provide a certain reference for the impact assessment of climate change on water quantity and quality at the basin scale.
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    Study on the Sensitivity and Vulnerability of Winter Wheat Yield to Climate Change in Sichuan Province
    CHEN Chao, PANG Yan-mei, ZHANG Yu-fang, CHEN Dong-dong
    2017, 32 (1):  127-136.  doi: 10.11849/zrzyxb.20160145
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    Based on the meteorological observation and winter wheat production data during 1981-2012 from 88 counties well spreading over the winter wheat growing regions of Sichuan Province, the sensitivity and vulnerability of winter wheat production to climatic factors and climate change were estimated by using the regression method. The results showed that the air temperature and diurnal temperature range increased in the entire growth period of winter wheat during 1981-2012, but the precipitation and solar radiation showed decreasing trends in some counties while showed increasing trends in others. With a 1 ℃ increase of air temperature in growing-season, 1 ℃ increase of diurnal temperature range, 100 mm decrease of precipitation and a 100 MJ·m-2 decrease of radiation, the yield of winter wheat in some of these regions was sensitive to the changes. From sowing to maturity, the area of winter wheat that was sensitive to decreasing precipitation is the largest, which took 6.5% of the total sown area. As for vulnerability, the area vulnerable to decreasing radiation was the largest, which was 2.4%. As for different growth stages of winter wheat, the area of winter wheat that were sensitive and vulnerable to the decrease of radiation during sowing to jointing period were the largest, which were 9.4% and 7.9% respectively. Taking the four climatic variables together into consideration, the area of winter wheat that had significant change in yield was roughly 40.0%, and the yield changed -23.0%-9.5%, but the area showed vulnerability took about 14.0%. The region with yield vulnerability mainly located in the northwest plateau of Sichuan, and part of western basin, southern basin and southwest Sichuan.
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    The Spatial and Temporal Distribution of Drought in Shaanxi Province
    REN Yi, WANG Yi-min, CHANG Jian-xia, HUANG Qiang
    2017, 32 (1):  137-151.  doi: 10.11849/zrzyxb.20160166
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    At present, most of the drought researches are based on a single meteorological or hydrologic drought index which can not reflect the drought situation or social contradiction of supply and demand of water comprehensively. This paper studied the spatial and temporal distribution of drought in Shaanxi Province based on the method taking the social economic factors of drought into account. The natural meteorological factors are also taking into consideration. We established comprehensive drought evaluation index of Shaanxi Province with fuzzy comprehensive decision process on basis of meteorological data from 19 meteorological stations in Shaanxi from 1960 to 2013. The results showed that the spatial distribution of drought in Shaanxi Province is heterogeneous, the drought in the central Shaanxi (DI value is about 3) is more serious than in northern Shaanxi, and there is no drought in south Shaanxi at the same time where water resources are abundant. Drought occurrence frequency in Shaanxi Province is very high. The medium drought phenomenon mostly existed in the north and south (frequency approached to 80%-99.99%). The severe droughts occurred in the central Shaanxi more often (frequency approached to 79%). The method of water supply and demand evaluation considered the influence of social economy and the actual supply and demand contradiction. And the comprehensive meteorological drought index considered the effects of meteorological factors. The results of the two methods are basically identical, but only one type of drought index can not reflect the overall actual situation when there exists great difference of water quantity in different areas. In water shortage regions, the results of fuzzy comprehensive drought index are closer to the fact. In regions where water resource is extremely rich and water supply ability is strong, the results of water supply and demand method are closer to the fact. And in economic developed areas, social economy drought index is suggested. When doing researches of drought, it shall give full consideration to the natural meteorological factors and actual water supply ability.
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    Comparison of PhytOC Sink for Three Different Ecotypes of Bamboos
    FENG Sheng-fei, HUANG Zhang-ting, YANG Jie, WU Jia-sen, JIANG Pei-kun, ZHENG Rong
    2017, 32 (1):  152-162.  doi: 10.11849/zrzyxb.20160098
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    In order to study the distribution and accumulation characteristics of PhytOC in the different ecotypes of bamboo species, in this study, we selected three bamboo ecosystems which developed in the same type of soil in Zhejiang Province. The samples were collected from the above ground part of bamboo at different ages (leaves, branches, stems), existing litters and soils at different depths, and the content of phytolith, PhytOC and silicon in each sample were analyzed. The results showed that: 1) The accumulation and distribution of contents of phytolith and PhytOC in organs of the three kinds of bamboos are in the same order that is leaf > branch > stalk. The maximum contents of phytolith and PhytOC are in the soil, and the content of PhytOC goes up with the increase of soil depth. 2) As for the stocks of PhytOC in the three kinds of bamboos, the stock of PhytOC in Phyllostachys prominens ecosystem is the maximum, while the stocks of PhytOC in Dendrocalamopsis oldhami and Pseudosasa amabilis ecosystem are almost equal. 3) According to the estimated areas of the three bamboo species, the total carbon sequestration capacity of Pseudosasa amabilis ecosystem is slightly larger than that of Dendrocalamopsis oldhami, and is much larger than that of Phyllostachys prominens.
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    Comprehensive Discussion
    Evolution of Ecological Footprint Models forNatural Resources Accounting
    JIN Xiang-mu, LIU Qian-kun
    2017, 32 (1):  163-176.  doi: 10.11849/zrzyxb.20160125
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    As a tool of natural resources accounting in light of ecology, the ecological footprint model developed from one-dimension to three-dimension. The evolution of ecological footprint model was presented in 4 aspects, including scientific problem, model conception, utilization orientation, and explanatory ability. The result revealed that: 1) The ecological footprint model was a biological and physical tool of natural resources accounting, and it made up the shortage of natural resources accounting in SNA. 2) The one-dimension model firstly introduced the concept of biologically productive land to the natural resources accounting, and measured the appropriation of ecology by biologically productive land area; the two-dimension model introduced the concept of ecological carrying capacity, opening up a new vision of land carrying capacity evaluation; the three-dimension model divided natural resources into flows and stocks, depicting the ecological pressure lively. 3) Even though the two-dimension and the three-dimension models were based on the one-dimension model, three models solved different problems respectively, and they were adapted to different scales. 4) The ecological footprint model was a static model, so it couldn’t demonstrate changes in the ecological system and economic system; limit of closure model made the result reflect regional ecology hardly. Further improvement was demonstrated as well.
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