To study the water-heat characteristics of soil in the active layer in high altitude permafrost regions and to examine the interaction between soil and moisture under freeze-thaw cycles, a physical process by the CoupModel was used to simulate the soil temperature and moisture in the active layer, using the meteorological, the soil thermal and the moisture data on different depths in the active layer at the Tanggula test site. Comparisons between simulated and monitored data in situ showed that: 1) for soil temperature in the active layer, the simulated results fit well with the monitored, and the determination coefficient (R²) is more than 0.94 with the mean value of 0.98 while mean square deviation is relatively small, implying the CoupModel could successfully simulate the soil temperatures. 2) For soil moisture, results generally reflect water content variation in the active layer with R² ranging from 0.88 to 0.93, the mean is 0.90 and the mean square deviation is 4.24, indicating a bit poor accuracy compared to soil temperature. 3) As to the heat flux of soil within the depth of 0-20 cm, results simulated is consistent with the monitored. The simulation accuracy is improved with depths, which may be related to the depth from the natural ground surface. The frozen depth is about 3.0 m, which is close to the observed data. It is concluded that the CoupModel can be well applied to study soil water-heat characteristics of the active layer in permafrost regions with higher elevations in Qinghai-Tibet Plateau.

Desertification process as a great problem affects most of the countries in the world. This process has a high rate in arid and semiarid areas. Today, human societies are encountering the desertification phenomenon as a serious problem which causes various irreparable damages to economic and social sectors. In order to assess desertification results in production of different regional models for their application in another region the indices should be re-investigated and adjusted to local conditions. Several models have been developed for desertification evaluation. The present study, attempts to assess quantitatively the desertification process has in an area located at Sistan plain of Iran (Niatak region as a case study) by using Modified MEDALUS method. The obtained results indicated that of the whole studied region (comprising 4819.6 acres), 2651.56 acres (55%) are located in medium desertification intensity class, 1269.48 acres (26.34%) are positioned in severe desertification intensity class, and 898.54 acres (18.64%) are placed in vary severe desertification intensity class.

Heatwave has become an extreme meteorological disaster which occurred frequently during the summer. Moreover, heatwave could evidently affect the healthy conditions of residents. Thus, study the spatial pattern of heatwave health risk would be helpful for us to prevent from and respond to the impacts of heatwaves. Using the historically meteorological datum of Xiamen, this study built a database of heatwave cases and analyzed the basic characteristics of heatwaves in Xiamen. Taking a heatwave event occurred in 2010 as a case, we analyzed the spatial pattern of heatwave health risk by using both the remote sensing data and the demographic data. It is concluded as the following statements. (1) The intensity of heatwaves in Xiamen is quite low, but its frequency is rather high. An intensive heatwave occurred occasionally. (2) The regions with high health risk are located in Xiamen Island, lying from the northeast toward the southwest. The regions with the highest healthy risk are located in the northern and southeastern Jiangtou sub-district, Huli district, and the most area of Xiagang sub-district and Siming district. (3) The human health risk pattern of Heatwave is associated with the spatial distribution of environmental and demographic factors. Generally, this study promotes and extends the scientific knowledge on the health risk of heatwaves.

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This paper discusses by using two examples the calculating question of professor Fu Baopu's experimental formula for Mountain precipitation and points out that the improvement of the calculating method for this formula suggested by yan Yuhua and Lai Hongnian which was published on Geographical research 6(1) has a lot of questions. Between the calculating result of Fu's formula and the practical material of the two examples, there appear more differentiations.

Decomposition of litter plays an important role in carbon turnover and nutrients cycling in wetland ecosystem. Tide is the key feature for the estuarine tidal wetland. The wetlands of the Minjiang River estuary region are one of the major estuarine tidal wetlands in the southeast of China, and the Shanyutan is the largest wetland in the Minjiang River estuary region. Litter decomposition, nutrient dynamics and influencing factors of two native species (Phragmites australis and Cyperus malaccensis) and one exotic invasive species (Phragmites australis) were studied using mesh bag method in two sites under different tidal water submergence conditions. One site was near the tide ditch, and the other is far from the tide ditch in central Shanyutan wetland. The results indicated that: (1) Frequent tidal water submergence had no significant effects on the litter decomposition rates of three plants. (2) Frequent tidal water submergence accelerated the N and P loss of Cyperus malaccensis and Spartina alterniflora, however, it had little effect on Phragmites australis. (3) The order of litter decomposition rate was Cyperus malaccensis＞Spartina alterniflora＞Phragmites australis, with rates of 0.003166-0.005280 d 1, and the time of 95% dry mass of litter loss ranged from 1.56 to 2.61a. (4) C concentrations had only a little change, and the major pathway of C release was mineralization during the 280 days; there was an upward trend in N concentrations, at the end of the experiment, N content had a net loss and the major pathway of loss was mineralization; there was an obvious fluctuating downward trend in P concentrations at the end of the experiment, P content had also a net loss and leaching losses were responsible for much of P loss. (5) Litter quality was a main factor influencing the litter decomposition rates of the three plants. Litter decomposition rate of Cyperus malaccensis with the lowest C/P was the greatest.

The transformation and development of urban waterfront space is the key way to promote the optimization of urban space and the adjustment of industrial structure, which has become the main part of the current international urban renewal and redevelopment efforts, and a large number of relevant studies have emerged. Therefore, it is necessary to summarize the existing studies. Taking the relevant publications in the Web of Science and Science Direct databases from 1988 to 2020 as the analysis object, this study systematically examined the research results of the transformation and development of urban waterfront space abroad, summarized and analyzed the research contents and main conclusions from the aspects of the transformation process, mode, motivation and mechanism, and effect. The results show that international studies on the transformation and development of waterfront space mostly used qualitative methods to carry out descriptive analysis of cases, the research themes have shifted from paying attention to practical needs to exploring underlying academic issues and gradually diversified, and the research perspective increasingly emphasizes humanism and the concept of equality. Finally, considering the international research experience and domestic reality, this study proposed that in the future, China should change the research perspective and research object, pay attention to the comparative study of multiple cases in different regions, reveal the transformation process of urban waterfront space, simulate the transformation mechanism of urban waterfront space, and comprehensively evaluate the transformation effect of urban waterfront space, so as to optimize and improve the research system of urban waterfront space in China.

目前水温预报的降水资料严重不足，特别是无资料地区将很大可能利用卫星遥感反演获取降水信息，丹遥感资料提供的降水时间尺度往往较长，难以满足水文预报需求。论文提出了一种基于统计，针对独立降水事件，将长时段降水聚解为短时间尺度降水的方法。研究将此方法应用于史灌河七邻雨量站，分别聚解了七邻6h、3h、2h、1h降水为10min降水。研究表明，该方法计算简单，能保证模拟的总量同实际的完全一致，雨强同实际的基本一致，具有较好的区域适应性。图6表6参8

An artificial Masson pinus forest has been chosen to measure the precipitation inside and outside of the forest, as well as stemflow.

The characteristics of wetland landscape structure in watershed in the Naoli River the Sanjiang Plain are exhibited in three aspects. The first one is wetland landscape gradient characteristic in the longitudinal landscape structure of the watershed from the sources area of rivers to the lower reaches, which shows that wetland landscape types were differently distributed according to the topographic gradient and hydrological gradient and formed a wide riparian landscape corridor in the watershed; the second is wetland landscape gradient characteristic in the transverse structure of watershed with perpendicularity rivers in the watershed, which also shows that wetland landscape types are differently distributed in a topographic gradient and hydrological gradient and formed an extensively distributed wetland area in watershed's flood plain; the third is wetland landscape internal structure, which shows that many small mosaics or patches were distributed in the microscopic geomorphic units in the extensive wetland landscapes. The driving forces leading to substantial changes of wetland landscape structure in the watershed were identified as: 1) land reclamation has led to more than 75% of wetlands loss in historical periods and 98% of the lost wetlands direct conversion to agricultural lands in the watershed, which is the major reason for watershed wetland landscape structure changes; 2) drainage ditches construction for agricultural development and dikes construction for flooding prevention after the 1980s has led to wetland loss and fragmentation and landscape structure changes in the watershed; 3) changes in wetland hydrological condition due to agricultural development have led to wetland ecosystem degradation, as a result, almost all the remaining marsh wetlands in the plain were degraded to meadow wetland at present state.

Land ecosystems have been suffering increasingly serious degradation and destruction resulting from irrational development modes and intensifying human activities, which even threatens human’s survival. Early warning is generally considered one of the most effective ways to maintain land ecological security, which can eliminate land ecological crises at the early stage. Dynamic characteristics of early warning for land ecological security require an immediate review and foreseeing on land ecological crises. Aiming at overcoming the drawbacks of the model with constant weights that is not able to well reveal dangerous factors, the authors introduced the variable weight theory to early warning of land ecological security in the present paper. First, a warning index system of land ecological security can be established and the warning limit for each index can be determined. Second, Forecasting values of the warning indices can be estimated for further warning. Third, the ‘basic weight’ can be determined by certain methods, such as analytic hierarchy process (AHP). Fourth, the basic weight of each warning index in corresponding periods can be appropriately adjusted to a higher level in that actual values of the index were relatively lower than that at the denial level. At the last, a comprehensive evaluation value can be calculated using the specified index value and variable weight in conjunction with the punishing variable weight model. A lower comprehensive evaluation value would result in a lower actual value and a higher variable weight, which is the principle of the ‘punishing variable weight’. The authors applied the punishing variable weight model to Huai’an City, Jiangsu Province. Variation trends in land ecological security for the city during the period 1996-2010 were systematically evaluated and analyzed using the punishing variable weight model. Results showed that the variable weight value of the warning index was higher than its basic weight; however, its corresponding comprehensive evaluation value was found to be lower than that from the basic weight evaluation. Furthermore, the changing range of the weight was different in terms of basic weights. The general level of land ecological security of Huai’an City during 1996-2005 was shown to be relatively steady on the interval of high warning, which was caused by combined effects of natural factors, social factors and economic factors. However, some values with regard to human activity factors lay in the interval of moderate warning primarily owing to the increasing occupation of cultivated land through construction activities and to decreases in pollutant disposal levels as well. If relevant departments could take more positive and effective measures in protecting cultivated land, reducing emissions of pollutants, promoting social equality and balancing regional development, the land ecological security conditions would be continued and even increase during the period 2006-2010.

本文从地貌和气候两方面分析了四川大巴山区的自然环境特点，指出了山区的自然资源和开发利用中存在的问题。认为该地区资源丰富、潜力巨大，因该走综合开发、全面发展的道路。开发中要从生态经济的观点出发，明确以林为主的方向；要根据自然条件的垂直差异，发展“立体农业”；要利用山区的优势，寻找开发的突破口，迅速振兴山区经济。

Danxia geomorphology originates from China. This paper studies the spatial distribution and differences in characteristics of Danxia landforms. Based on relevant research and investigations, three congregated areas of Danxia landform in China are discussed in this paper. They are the southeast area (including Jiangxi, Fujian, Zhejiang, Hunan and Guangxi provinces), the southwest area (the transitional zone of Yunnan-Guizhou Plateau and Sichuan Basin) and the northwest area (including Longshan mountain and along the banks of the Huanghe River and its anabranches). Not only the conditions of geology and geography of the three areas but also the differences of Danxia landforms of the three areas are analyzed. The Danxia landscape, characterized by upright-shaped peaks, Danxia mesa, stone wall, cave and vertical cave, "Danxia natural bridge", "a narrow strip of sky" and so on, often presents in the southeast area. The landscape of southwest area is characterized by Danxia escarpment faces and waterfalls. In the northwest area, the Danxia landscape has the traits of arid areas simultaneously, for example, mud-coating type, columniation type, board type, moreover, it is greatly different between these environmental factors such as the microclimate, water, wind, and the loess cover. Finally it explores the causes which lead differences in landform and also explains the landform formation process and its mechanism with reference to the rates of crustal uplift, the tectonic red-basin, and the external processes including working of running water, weathering, biogenic, gravity in each area of Danxia Landforms in China.

A milestone in the Year of Biodiversity is that the Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization to the Convention on Biological Diversity(CBD)was adopted in the 10th Conference of Parties(COP 10)held in Nagoya,Japan,Oct 18- 29,2010.Traditional knowledge(TK)is a key issue in the Protocol’s text and its negotiating period.This paper aimed to protect TK by defining its concepts and categories and promoting benefit-sharing with TK’s holders.Based on the analysis for the TK concepts of relevant international organizations and conventions, in particularly on the author’s current years’research work on TK in the ethnic areas of China,this paper proposes the categories and the classification system for the TK associated with biological resources,i.e. (i)the knowledge for traditional use of agricultural bio-species and genetic resources;(ii)the knowledge for traditional use of medicinal bio-species；(iii)traditional technical innovations for bio-resource use and traditional practices for farming and living styles;(iv)traditional cultures such as customary laws and community protocols that are related to conservation and sustainable use of bio-resources;and(v) traditional geographically biological indicators.Furthermore,this paper introduced the provisions for access and benefit-sharing of TK and proposed to share fairly and equitably the benefits produced from use of TK with indigenous people,local communities and other kinds of holders such as a country for the ancient documented TK.In addition,aimed to the existing problems for traditional knowledge protection,the national strategy for TK protection was introduced and measures for TK inheritance,development,utilization and protection measures were put forward,which are significant for TK’s popularization and beneficial to local communities of the ethnic groups in China.

With Pukou District of Nanjing as an example, the article introduces SLEUTH cellular automaton model and adopts the Landsat TM/ETM+ remote sensing data in five study periods(the years of 1988, 1995, 2000, 2004 and 2008)to simulate the general situation of urban expansion of the study area with or without the planned cross-river channels.And the influence of the planned cross-river channels on the urban growth of riverside city is analyzed from the perspective of quantity increase of construction land as well as spatial growth.The research shows that:1) SLEUTH model, after adjusted and tested, could well simulate the quantity growth of construction land as well as its characteristics of spatial distribution in the study area, therefore, it could be fairly applicable to the research of urban expansion of the study area; 2) the construction of planning cross-river channel has a significant impact on accelerating the growth of riverside city, but its driving effect will gradually decline year by year.The newly increased construction land in the study area will rise by 48.05% and 62.33% in 2020 and 2030, and the contribution rate of planned cross-river channel is 20.67% and 17.50%, with a decreasing driven effect year by year, which is particularly significant in the street of Jiangpu, Dingshan and Yanjiang in "Pukou New Town".

Generally, in southern China with complex growing system, fragmentized and dispersed paddy field, and long-term overcast and rainy weather, the performance of using vegetation index (VI) time-series datasets derived from remote sensing imageries to extract multiple-cropping index was seriously constrained by the lower spatial resolution. Currently, the application of higher spatial resolution images can be the exclusive and effective way to extract the spatial pattern of different rice cropping systems annually in these regions. In this paper, firstly, the spatial distribution of paddy field in Poyang Lake Region (PLR) was obtained through one TM imagery interpretation. Secondly, the annual phenological calendar of various systems of paddy rice was defined with the agro-meteorological data. According to the significant characteristics that Normalized Difference Vegetation Index (NDVI) fluctuates sharply along with the growth process of paddy rice, map of NDVI for paddy field was derived from another TM image within the applicable time window. Then, different cropping systems of paddy rice were classified by means of Unsupervised Classification in Erdas Imagine 9.2. Finally, yield of each raster (100 m) was calculated with unit yield from local statistical department. The results showed that, late April to late June can be the time window to differentiate early rice and single-season rice, while early July till early August and middle September to early October could be the time window for the differentiation between single-season rice and late rice. Specifically, the planting areas of single-season and early/late rice are 3081.58 km² and 3602.97 km² in 2005, respectively, indicating that the multiple-cropping index is 153.9%. Single-season rice is generally distributed around the periphery of the built-up area, while double-season rice expanded along the delta. The total yield of paddy rice reached to nearly 16.5 million tons with a proportion of single-season to double-season approximating to 3 ∶7. The two seasons rice both had a higher yield in the lower reaches and delta area of the Ganjiang River.

South Africa is China's largest trading partner and investment destination in Africa, especially in infrastructure construction. Study of the spatial distribution of South Africa's population is of great significance to the cooperation of the two countries. Based on the census data from 1996 to 2011, this paper describes the spatial pattern and evolving trend of the diverse population of South Africa with time series and cross section data between 1996 and 2011 at county level, based on population density analysis, spatial autocorrelation analysis, population gravity center model, shift-share analysis, and unbalanced index. Using the software platform of ArcGIS and OpenGeoDa, conclusions are made as follows. (1) Population density of South Africa has "high on east and low on west" features, and also has multicore clustering characteristics in metropolitan areas and port cities. (2) Population density varies significantly in different regions. Metropolitan areas and coastal port cities have high population densities, while central and western regions have low population densities. (3) In terms of trend in population change, population distribution in South Africa became more and more imbalanced from 1996 to 2011. The gravity center of population moves to the northwest of South Africa since 1996. (4) Shift-share analysis shows population growth rate have undergone "high-low-high" stages for the last 15 years. At provincial level, Gauteng andWestern Cape have been always the places with dense populations.

石油供应与需求是当今世界关注的问题。西欧的石油资源十分贫乏。本世纪五十年代到六十年代,随着中东石油的开发,西欧大量增加原油进口。结果,石油在共能源消费结构中所占的比重迅速提高,西欧也成为世界上最大的原油净进口地区。在西欧各个地区的能源消费结构中石油所占的比重是不相同的。这一差异首先是由当地能源(特别是煤炭)的地理分布特点所决定的。煤炭资源比较丰富的英国、比利时、西德等国,能源消费结构中石油所占的比重较低。而当地能源十分贫乏的国家如意大利、葡萄牙、希腊等就主要依靠进口原油。西欧的原油供应主要来自西亚与非洲。在西欧各原油进口国与世界各主要原油出口地区间有着不同的组合关系。如北非原油主要到地中海沿岸各国,西非原油则多去北海沿岸国家,苏联原油则供应地中海沿岸及与东欧相邻的几国。这一组合关系主要与它们之间的相对位置有关。在“石油危机”后,西欧的石油消费量略有减少,而能源消费结构中石油所占的比重下降较多。未来的趋势是:由于其他能源利用的扩大,石油的消费量将继续下降。但在本世纪末以前,石油仍将是西欧最主要的能源。在西欧各国之间,由于能源资源与石油消费水平的差异,将表现出不同的变化趋势。

河岸(溪旁)的植被有助于调控沉积物及化学元素向江河的流失。滨海平原农田水域的研究表明,河岸林生态系统是良好的营养库,并能减少周围农田生态系统的养分流失。河岸林生态系统土壤和植被的吸收与运转,截获了农田流向河道的养分,如果定期采伐树木,那末河岸生态系统就能有效地起到短期和长期截获与贮存养分的作用,从而确保了养分的净吸收。

工业旅游是一类特殊的综合型旅游产品,近年在我国发展很快,表现出都市综合型、特色工业城市、名胜旅游区三大类型.发展工业旅游具有宣传广告、科普教育、带动第三产业、兼备学术交流、优化企业环境、推进城市旅游发展和精神文明建设等显著的综合效益.广州具有发展都市型工业旅游的资源、设施、区位、市场和旅游发展基础等良好的软硬条件,应当抓住当前广州工业旅游发展的大好形势,着重从工业旅游的景观特色营建和旅游产品优化两个方面入手,从战略发展的高度加以理论探讨和实践引导,让这一新生事物长盛不衰,魅力永存.

The purpose of this paper is to systematically analyze the alert values of cultivated land in 31 provinces, autonomous regions and municipalities of mainland China, based on the national warning values of cultivated land, with the aim to provide reference for national land management decision-making. The warning values of arable land at provincial levels vary greatly. On the basis of differences in the pressure index, cultivated land pressures in major provinces in China were analyzed in detail in order to build the interest-driven mechanism for arable land protection with incentives-constraint. The major regional coefficients were designed accordingly. An algorithm for quantifying the alert values of per capita arable land and examining regional differences in farmland alert values in 31 provinces, autonomous regions and municipalities was used in this analysis. The pressure index of cultivated land, and the farmland surplus or deficit were calculated to understand the Red Line of arable land protection given by government. Results showed that there were marked differences in the warning values of the arable land without taking into account differences in food consumption expenditure in each province. In terms of the warning values of the arable land, Hunan Province was the smallest and Gansu Province was the largest. As for the pressure index of the cultivated land, Heilongjiang was the smallest and Beijing was the largest. Without accounting for differences in consumption, the warning value of the arable land in Gansu was found to be 7.78 times more than that in Hunan. The pressure index of the cultivated land in Beijing was estimated to be 15.04 times more than that in Heilongjiang. But the warning value of the arable land under the condition of taking differences in consumption into consideration in Gansu was 5.31 times more than that in Hunan. The pressure index of the cultivated land in Beijing was 37.77 times more than that in Heilongjiang. It can be drawn that the pressures from the cultivated land in light of the warning values of the arable land at the provincial level vary greatly. In terms of the pressure differences, a land incentives-constraint management at different levels was pointed out. Beijing, Shanghai, Tianjin and Guangdong were the strong constraint level province and municipalities in farmland management. Shanxi, Zhejiang, Fujian, Tibet, Shaanxi, Qinghai, and Liaoning were under a general constraint level. The others were taken as policy-encouraging provinces in arable management. In terms of the arable land demand for food production, farmland deficit provinces, autonomous regions, and municipalities involve Beijing, Tianjin, Shanghai, Zhejiang, Fujian, Guangdong, Shanxi, Shaanxi, Tibet, Qinghai, and Liaoning, showing varying magnitudes of deficits. The others were farmland surplus provinces. Based on the surplus or deficit of arable land, where farmland was utilized to produce food, national Food - Ecological Security payments paid by provinces and autonomous regions and the transfer-payment system regulated by governments should be built to prevent the arable land from consistently decreasing in these deficit provinces and to stimulate protection of cultivated land in those surplus provinces.

Crop growth in Hedong rain fed agricultural region of Gansu Province mainly rely on the natural rain. Spring and summer drought is the main factor affecting the growth of maize. The monthly meteorological data of 13 meteorological stations in Hedong region from 1957 to 2012 were acquired. To investigate the temporal and spatial distribution of spring and summer drought in Hedong maize planting areas, we used SPEI index to reveal the trend, cycle, spatial change of drought and its relation with circulation in recent 56 years. The results show that: Both the spring and summer season in Hedong maize planting areas become dryer in recent 56 years, and the situation was aggravating since the mid 1990s. The variation of drought underwent three phases. Both the spring and summer season were slightly arid before the 1980s. Summer droughts were more severe than spring drought from 1980s to 1990s. After 2000s, spring droughts were more severe than summer drought. The drought cycles of spring and summer are 20 years and 14 years respectively. The periodicities of drought were mainly affected by the sunspot. There was a significant difference in the spatial distribution of drought frequencies before and after SPEI mutation. Low drought frequency area transformed into high frequency area after the abrupt change of SPEI, and the draught prone areas expanded. The main circulation factor influencing spring and summer drought in this area was ENSO events, especially on summer drought. The significant increase of ENSO events were the main reason of more serious drought in Hedong region in recent 20 years. When ENSO warm events occur, it tends to be drought in spring and summer in this area; when ENSO cold events occur, it turns from dry to wet in spring and summer in this area.

It is of significance to study the effect of land use change on ec osystem service values.This paper aimed to provide decision support for sustain able use of resources and protection of eco-environment by assessing land use change and its consequent changes in ecosystem service values of Jilin Province .We obtained land use data by interpreting remote sensing images.Based on dyna mic data of land use in Jinlin,this paper analyzed changes in land use and ecos ystem service values using the ecosystem service value coefficients put forward by Costanza et al.In addition,coefficients of sensitivity were introduced to test the rationality of ecological value coefficients.Results show that from1 980to2000,area of rangeland,water bodies and wetlands decreased and oth er categories of land use increased.Due to comparatively small valuation coeffi cients(VC)of cultivated land and comparatively big VC of wetland and water bod ies,the increment in cultivated land could not offset the total decrement in regional ecosystem service values because of decrease in area of wetlands and wa ter bodies.Meanwhile,city sprawl has also led to loss of ecological values.T he total ecosystem service values of the study area reduced dramatically,from U SD12365.14×10 6 to USD10700.38×10 6 in period1980-2000.There was a13.46%net decline in annual va lue of ecosystem services in study area(i.e.USD1664.76×10 6 net decline in total ecosystem service values)and a0.72%decline per ye ar.In recent five years,the degradation of woodland,wetland and rangeland sl owed down because of enhancement of eco-environment protection.There was an 0.54%decline per year in ecosystem service values from1995to2000,w hile there was an0.78decline per year from1980to1995,which shows t hat the decline in ecosystem service values has been lessened in recent five ye ars.

This study has investigated the influence of Arctic Oscillation (AO) on dust storm frequency in North China in spring seasons during 1961?2007. There is a significant linkage between dust storm frequency and AO; a negative (positive) AO phase is related to an increased (decreased) dust storm frequency in North China. This relationship is closely related to changes in the cold air activity in Mongolia. The cold air activity exerts large impacts on the dust storm frequency; the frequency of cold air activity over Mongolia not only positively correlates with the dust storm frequency in North China, but also shows a long-term decreasing trend that is an important reason for the long-term decreasing of dust storm frequency in North China. The AO has large influence on the frequency of cold air activity over Mongolia; a negative (positive) AO phase is highly related to an increased (decreased) frequency of cold air activity over Mongolia, which results in an increased (decreased) dust storm frequency in North China.

Based on dynastic period division and AMS¹⁴C dating performed on the sedimen-tary layers at Zhongba and Yuxi sites, and also the analysis of Na, Ca and Mg of 201 sedi-mentary samples from Zhongba site and that of Ca and Na in 47 sedimentary samples from Yuxi by using an inductively coupled plasma–mass spectrometry (ICP), we found that there were 35 time periods when the contents of Ca and Na were reversely correlated, i.e. when-ever the content of Ca was the highest, the content of Na was the lowest, and vice versa. Among them, there were 21 time periods when the content of Ca was the highest, and Na was the lowest, indicating that there were about 21 prosperous periods of ancient salt pro-duction at Zhongba site since 3000BC. Other 14 time periods with the peak values of Na while the low values of Ca indicate 14 declined periods of salt production at Zhongba site since 3000BC. The conclusion obtained from the reverse relationship between Ca and Na contents in this paper is consistent with that “the salt production at Zhongba site started in the new stone age, developed in the Xia and Shang dynasties, reached at the heyday in periods from the Western Zhou to the Han Dynasties, maintained stable to develop in the Tang and the Song dynasties, and gradually declined after the Song Dynasty because the sea salt were conveyed into Sichuan region, however, still had production in the 1970s–1980s”, educed from archeological exploration. All the above mentioned results indicate that there is a re-verse relationship obviously between the contents of Na and Ca in sediments at Zhongba site for ancient salt production, which can

China has been experiencing unprecedented urbanization process. In 2011, China's urban population reached 691 million with an urbanization rate of 51.27%. Urbanization level is expected to increase to 70% in China in 2030, reflecting the projection that nearly 300 million people would migrate from rural areas to urban areas over this period. At the same time, the natural growth rate of China's population is declining due to the combined effect of economic growth, improvement in education quality, and modern social consciousness. As a result, Chinese government has loosened its "one-child policy" gradually by allowing childbearing couples to have a second child if either of them is from a one-child family. An accurate prediction of the future spatial pattern of population and its evolution is critical for a variety of key policy-making processes in China, such as industrial development, ecological conservation, industrial upgrading and transfer, and environmental protection. In this paper, a top-down method was developed to project the spatial distribution of China's future population with considerations of both natural population growth at provincial level and the population migration between provinces from 2010 to 2050. The results suggested that the overall spatial pattern of Chinese population is unlikely to change significantly over the next four decades. Shanghai, Beijing, Tianjin and Jiangsu will remain the top 4 provinces in terms of population density in China, and Xinjiang, Qinghai and Tibet continue to have the lowest density of population. China's population is projected to continue to concentrate in eastern coastal provinces. Population densities of Shanghai, Beijing, Zhejiang will peak in 2030, while that of Guangdong will keep increasing until 2035. Due to the large amount of moving-out labors and gradually declining fertility rates, population densities for Central and Northeast China will decrease from 292 persons per km² in 2010 to 253 persons per km² in 2050, exhibiting a downward trend. The majority of the western provinces, including Shaanxi, Chongqing, Guizhou, Yunnan, Sichuan, Gansu, Ningxia, Qinghai, Xinjiang, Tibet, Guangxi and Inner Mongolia are likely to remain sparsely populated, with an averaged population density no more than 100 persons per km².

After the adoption of the policy of reform and opening-up to the outside world,many changes in politics,society and economy have taken place in the Yangtze River Delta region and have resulted in rapid expansion of urban area.Using multi-temporal remote sensing images,we analysed the spatial and temporal urban dynamic change pattern of the Yangtze River Delta region in the past two decades.The results showed that from the end of the 1980s to the year 2000,the main land use change pattern is the rapid decrease of cultivable land and forest area and the fast expansion of urban area.Urban land use in the Yangtze River Delta presents a concentrated expansion,typically from vegetation landscape to a mixed urban and rural landscape,i.e.,95% from farmland 1.8% from forest land and 1.5% from grassland.Using remote sensing image to categorize land use,monitor land use change,and calculate land use change transfer matrix is a promising method to show distributed spatial pattern of land use and land use dynamic change.There exist different constitutional proportions relating to land use dynamic changes between the first decade and the second decade.The urban sprawl speed is lower in the second decade than the first one.The land use dynamic change affects the eco-environmental change in this region.For example,the urban expansion pattern directly affects the local climate change and the air quality of this region.Analyzing the correlation between the spatial pattern of urbanization and eco-environment in this region,we found that the urban sprawl pattern is one of the direct factors affecting the spatial distribution of regional urban heat islands and spatial pervasion of urban air pollution.By comparing the relationship between the land use change pattern and eco-environment,we can provide sustained decision-making strategy for improving eco-environment,developing local economy,and promoting the social progress.

Water stress is one of the main factors that affect the crop growth. Water stress can induce agricultural drought, and decrease the yield. Analysis on the water stress under rain-fed condition can reflect the influence of local climate and soil on the crop growth. It is very helpful for the agricultural drought management and improving the water use efficiency (WUE). This study simulated the growth of winter wheat under rain-fed condition using EPIC (Environmental Policy Integrated Climate Model) crop growth model. The temporal and spatial pattern of water stress was analyzed. It was found that the rainfall in this area could not afford the demand of the crop growth. The water stress in the later period of winter wheat growth season was very serious, especially in the third 10 days of May when the frequency of the severe water stress was up to 48.2%. Through the contrast between regions, the Hebei-Shandong-Henan low-lying plain and the agro-forestry hilly region in Shandong were worse than the other two regions in the study period.