Starting from the three constituents of tourism system—destination system, tourist source system and travel traffic system—this thesis analyzes the constitution of an evaluation index system for the suitability of wetland tourism development, comes up with this system which is composed of 19 indexes in 4 aspects, namely, resources endowment, urban dependence, traffic accessibility and population & economic base, and determines the weighing of indexes through analytic hierarchy process(AHP), with the aim of quantitatively evaluating the suitability of tourism development for the wetland resources in Jiangsu Province.Next, this thesis sorts out 126 wetland nature reserves within Jiangsu Province from the regional planning for important ecological functional area in Jiangsu Province released by Environmental Protection Department of Jiangsu Province, collects or calculates 19 index to figure for these wetland nature reserves. The values of 4 sub-items among the evaluation index system for the suitability of wetland tourism development as well as the total value were calculated by weighted score. It is shown by the calculation results that the total value of suitability of tourism development for 126 wetland nature reserves falls in between 36.64 and 72.98.According to sub-item evaluation result, Jiangsu wetland resources are clustering into four tourism development types by K-means cluster analysis, namely the highest suitability wetland resources,higher real suitability wetland resources,higher potential suitability wetland resources and low suitability wetland resources, including 38, 19, 36 and 33 wetland nature reserves respectively.Subsequently,it is suggested that the highest suitability wetland resources should be actively develop and the higher real suitability wetland resources should be moderately developed, the higher potential suitability wetland resources should be developed accompanying economic growth and the development of low suitability wetland resources should be temporarily restricted. Simultaneously, public welfare development ideas have been proposed.Finally,some topics currently without conclusion have also been discussed,including principle of tourism development of wetland resources, inconsistency between tourism development suitability of wetland resources and environmental bearing capacity, and relation of tourism development of wetland resources and environmental destruction.

The spatial variations of soil moisture and biodiversity have become central issues in ecohydrology which contribute to the understanding of the response of terrestrial ecosystem to precipitation change in water-limited areas. Based a precipitation gradient (250-550 mm) in the Loess Plateau, vertical soil moisture (0-3 m) and species diversity at 47 grassland sites across a southeast-northwest transect were surveyed. The spatial variations of soil moisture and species diversity were evaluated, and the tradeoff between them along the precipitation gradient was quantified. Results showed great variation of soil moisture in the vertical profiles along the precipitation gradient. Significant linear correlation existed between the average soil moisture of the profile and the mean annual precipitation, and the soil moisture in the shallow layer (0-1 m) was affected more greatly by mean annual precipitation. The Patrick index and Shannon-Wiener diversity index also showed positive linear correlation with precipitation, however, Pielou evenness index did not (P>0.05). The linear piece-wise quantile regression was applied to determine the inflection points of the response of tradeoff between species diversity and soil moisture to the precipitation gradient. It revealed obvious trend of the tradeoff along the precipitation gradient. The inflection point of the tradeoff was detected at the mean annual precipitation of 370 mm. Under the 370 mm annual mean precipitation, soil moisture constrains species diversity in the relatively arid regions, while the synergy between soil moisture and species diversity exists in the relatively humid regions in this study. This suggests species maintaining in the relatively arid regions is at the cost of soil water. The results demonstrate that the precipitation gradient determined the tradeoff between soil moisture and species diversity in the grasslands of the Loess Plateau. Consequently, this tradeoff could be an ecological indicator and tool for restoration management in the Loess Plateau.

From the angles of the response of ecosystem and tourist perceptions,the response of Liupan mountain ecological tourism attraction trails to human being tourism trampling disturbance was studied.This study was conducted to investigate the patterns and extent of trampling impacts along the main tourism trails.In addition to vegetation change represented by cover reduction (CR) and floristic dissimilarity (FD),leftover reduction(LD),increase of soil hardness (SHI) and Index of Land Cover Impact (ILCI),the Limits of Acceptable Change(LAC) was also added as indicator for tourist impact.The results show that trampling disturbance mainly were limited in 1 to 3 miles along the trail;the composite ecosystem in Xiao Nanchuan with arbor,bosk and grass got most serious disturbance.Using ILCI and LAC Index the responses of the three typical ecosystems were assessed.The ILCI values of the investigating sections along the 1-meter trail impact is seriousy disturbed,then 2-3 meters, and beyond 3 meters,it is seldomly disturbed.Based on Limits of Acceptable Change (LAC) questionnaires filled out by visitors,the standard of acceptable change in ground coverage was found to be 55.7 % of the coverage reduction from the trail.from this standard,the investigating areas along the 1-meter trail far exceed the LAC.The impac variables are correlated to the gradient,border area gradient and width of the trail.The Index of Land Cover Impact (ILCI) could be an useful index to evaluate the tourism disturbance.The results also indicate that the current tourism disturbance has had some negative effect on the tourist experience and ecosystem.Some suggestions for management were offered to minimize the trampling impacts of this trail.Improving the development environment,strengthening the planning of tourism attraction,and establishing the forest system and tourism information system would offer important guidance to the promotion of sustainable development of Liupan Mountain.

The impact of hydropower development on river ecosystems cannot be ignored, and scientific evaluation of its impact will contribute to the establishment of a more sustainable hydropower development patterns. In this paper, we analyzed the benefits and losses of the cascade hydropower development in the mainstream of the Wujiang River on the riparian terrestrial ecosystems and river ecosystems by using both equivalent factor and functional value evaluation methods. Based on the benefits and losses, we made a comprehensive evaluation of the cascade hydropower development on the river ecosystem services. The results show that the hydropower development in the mainstream of the Wujiang River increased the values of the riparian terrestrial ecosystem and river ecosystem services, particularly in the hydrological regulating and water supply functions. In addition, positive effects of the development were found on the power generation, hydrological and air regulating functions, while negative effects were observed on biodiversity maintaining and soil conservation. And the positive effects on river ecosystem service are greater than the negative effects. It was difficult to compare directly the ecological losses of unit electrical energy with other basins as different hydropower stations had their own emphasis regarding the positive and negative effects. Based on the long-term survey data of fish resources in the Wujiang River, the trend of fish biological loss index was analyzed to understand temporal cumulative ecological effects of hydropower development. The differences in the spatial pattern of hydropower generation were discussed by using InVEST model. The impact of ecosystem services such as biodiversity was hard to evaluate directly in terms of currency, and the service value per unit area of the water body was considerably higher than that of any other land-use types, which resulted in a conservative, e.g. a low value of negative effects of the hydropower development in the mainstream of the Wujiang River, and a high ratio of positive to negative values.

This study aims to evaluate the impact of land use/cover change (LUCC), especially rapid urbanization, on annual runoff change in Taihu Basin, where monsoonal flood is prone to happen. Xitiaoxi River Basin, one of the main sub-basins of Taihu Lake Basin, was chosen as study area to study the spatial variation of runoff under different land use conditions. A new spatial analysis method called geographically weighted regression model (GWR) was employed to quantitatively evaluate the impact of LUCC on runoff variation. The monthly runoff process was generated by SWAT model (Soil and Water Assessment Tool). The results showed that: 1) All R² and Nash-Sutcliffe efficiency E_NS were above 0.85, and the relative errors |Re| were all less than 15% in the calibration and validation period, suggesting SWAT model perform well. 2) The runoff change was spatially nonstationary, and was significantly correlated with the mostly changed type of land use in the sub-basin, among which the influence of urban land-use had the greatest influence, followed by the forest-grass land and cultivated land. Urban land-use expansion could increase local regional runoff depth by 37.6%-45.2%, while the forest-grass land and cultivated land shrinking could increase local regional runoff depth by 16%-26.2% and 9.2%-15.4% respectively. 3) Spatially, the influence of urban land-use change on runoff depth increased gradually from upstream to downstream in the basin. On the contrary, the impacts of the forest-grass land and cultivated land on runoff process presented decline trend from upstream to downstream. 4) Compared with single-factor GWR model, the multifactorial GWR model had better prediction accuracy and was more suitable to analyze the spatial relationship between runoff and LUCC.

Eco-compensation is an important policy of ecological construction and environmental protection in China. Targeted poverty alleviation is also a significant measure to promote regional coordinated development and ensure that impoverished people can get rid of poverty on schedule. There are some coupling points between the two, such as objects, subjects, carriers, standards, ways and means. China has put forward "a set of poverty alleviation through eco-compensation". Many regions, in light of their actual situations, have also carried out relevant works by combining eco-compensation with targeted poverty alleviation. At present, there are some connections and coupling developments between targeted poverty alleviation and eco-compensation in China. The five typical coupling developments are shown in the following. (1) Coupling development between poor population and eco-compensation object. For the poor people with labor capacity, the government will employ them as forest rangers. As for the targets of poverty alleviation, they will be directly included in the scope of preferential policies of eco-compensation funds and receive subsidies under eco-compensation policies. (2) Coupling development between poverty alleviation region and eco-compensation area. In China, most of the poverty-stricken areas, such as concentrated areas with special difficulties, key counties for poverty alleviation and development, and poverty stricken villages, are distributed in ecologically fragile areas whose ecosystems are sensitive and need to be protected. (3) Coupling development between poverty alleviation industry and eco-compensation measure. The local governments guide the poor to realize green transfer of production, help the impoverished villages to adjust and optimize their industrial structure and transform the mode of economic development, train the impoverished households in planting and raising, and help them to develop special industries such as rural forest tourism, famous and special cash crops, farm recreation, and under-forest economy. (4) Coupling development between poverty intensity and eco-compensation standard. In China, we have implemented regional differential compensation policies, such as appropriately raising eco-compensation standards for poverty stricken villages and poor households, raising subsidies for ecological public welfare forests, and increasing the salaries of forest rangers, etc. In some regions, when determining the key poverty alleviation targets, we, in addition to considering poverty factors such as economic income, should also figure out whether these poverty alleviation targets undertake ecological construction tasks, such as ecological public welfare forest protection, and finally determine the corresponding compensation standards based on their ecological contribution. (5) Coupling development between poverty alleviation policy and eco-compensation requirement. In defining the object of poverty alleviation, priority should be given to the impoverished population who bear the task of public forest protection. In the arrangement of poverty alleviation funds and development funds, such as subsidies for returning farmland to forests and subsidies for under-forest economy arranged by various sectors, are preferentially inclined to the poorer households under the same conditions. In the key areas of poverty alleviation, priorities should be given to the fields of ecological environment construction and protection, the ecological industry development, and some other aspects which are closely related to eco-compensation policies. Each has its own connotation and characteristics. In order to further promote the coupling development between targeted poverty alleviation and eco-compensation in China, we can take measures in many aspects, such as strengthening theoretical researches, clearing the direction and focus of coupling, consolidating the public foundation, and innovating the development model.

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.

影响复杂地形下气温分布与变化的因素很多, 其中尤以海拔高度和地形的影响最显著。论文在前人研究的基础上，对以前的模型进行了一些改进，考虑了坡度、坡向和地形相互遮蔽作用对复杂地形下天文辐射的影响，基于数字高程模型(DEM)数据，研制了以复杂地形下天文辐射为起始数据的复杂地形下平均气温的分布式模型，在模型中还考虑了海拔高度、山区太阳总辐射、日照百分率。以地形复杂的贵州高原为例，应用100 m×100 m分辨率的DEM数据及气象站常规观测气象资料，计算了贵州高原复杂地形下各月及年的平均气温精细空间分布。结果表明：①坡度、坡向、地形遮蔽对平均气温的影响较大，由于局地地形因子的影响，复杂地形下平均气温的空间分布具有明显的地域分布特征，地形对平均气温的影响在计算时是不容忽视的；②季节不同，局地地形因子对复杂地形下平均气温空间分布的影响不同，冬半年大于夏半年。平均气温随海拔高度的增加而降低。南坡随坡度的增大而升高；北坡随坡度的增大而降低。在坡向影响上，1—5月、10—12月偏北坡月平均气温偏低，偏南坡月平均气温偏高；7—8月因太阳高度较高，因此出现相反的情况，北坡高于南坡。

Based on the daily data from108 meteorological stations in Southwest China during 1960 to 2011, as well as use of the monthly potential evapotranspiration and monthly precipitation data, the surface humidity index was calculated. The temporal and spatial variation characteristics of surface humidity index were analysized by using the methods of Inverse Distance Weighted interpolation in ArcGIS 9.3, moving t-test technique, climate tendency rate and Morlet wavelet. The results show that: in recent 52 years, the surface humidity index in Southwest China is decreasing in fluctuation and the decreasing rate is -0.005/10 a, which showed the slightly trend to drought. The 1990s have the greatest increase in change to wet and the anomaly value is 0.106. The 21st century witnesses the most significant increase in desiccation and the anomaly value is -0.052. Especially after 2002, surface humidity index drops significantly, the minimum value appears in 2009 and the anomaly value is 1.41. Annual humidity index exists obvious differences in space. The surface humidity index not only decreases from southeast to northwest, but also from south to north. Western Sichuan Plateau and the Yunnan-Guizhou Plateau are the low center value while the high value center is in the western Sichuan Basin. The area turning to be dry is larger than to be wet in the study area, correspondingly, the process of turning to be dry is more obvious than that of wet. Abrupt change analysis and Morlet wavelet power spectrum analysis indicated that surface dry and wet conditions in Southwest China have abrupt change events in 1990 and 2003 with a period 10.638 years.

Public security events are the results of the interaction of 'Human-Space-Time' in a specific context. Public security spatial planning and the corresponding administration system are important approaches to deal with the public security events in the long term. Based on the framework of 'Human-Space-Time' interaction in the public security planning, this paper reviews the relevant research about 'prevention, early warning, emergency dispatching, and post-disaster recovery'. On this basis, the framework of content, technical methods and support system of public security spatial planning is constructed. First, the content system should be consistent to the multi-level spatial planning system and the national emergency response mechanism. It is necessary to implement special planning and comprehensive planning, focusing on the problems of the planning and management of space, facilities and emergence response in terms of natural disasters, accident disasters, public health events and social security events. In terms of the technical method system, it is necessary to build and improve the methodological and technical support system of space-time elements identification and analysis, space-time process simulation and early warning of public security events. Last, for the support system, it is necessary to improve the space-time accessibility of the public security facilities system and strengthen the public security oriented social governance, based on the new infrastructure construction such as the space-time big data management system.

It is of great significance in the implementation of rural revitalization strategy and the realization of its multiple goals to scientifically evaluate the level of the sustainable development ability and determine targeted development types of villages and towns. Based on sorting out the implication of the sustainable development ability implication of villages and towns from the perspectives of potential, support and resilience, this study establishes the evaluation framework and evaluation models. Meanwhile the study takes 25 towns in Jiangjin district of Chongqing as research units to quantitatively measure the sustainable development ability of villages and towns in 2017. And then it reveals the spatio-temporal differentiation and accordingly identifies the vulnerabilities types, and proposes targeted regulation strategies. The results shows that: (1) The sustainable development ability of villages and towns is the result of the interaction of potential, support and resilience. (2) On the whole, the potential of villages and towns shows a spatial pattern of " high in the north and low in the south" in Jiangjin; the support of villages and towns shows a spatial pattern of "high in the north and low in the south" in Jiangjin; the resilience of villages and towns shows a spatial pattern of "high in the south and low in the north" in Jiangjin; the sustainable development ability of villages and towns shows a spatial pattern of "high in the southwest, low in the northeast, cluster distribution". (3) We divide the sustainable development ability of villages and towns in Jiangjin into four types, including potential enhancement type, urban-rural integration promotion type, ecological security improvement type and potential-support-resilience ability comprehensive development type. Based on the principle of "ecological priority-classified control-highlight emphasis-local adaptation", the study proposes differentiated sustainable development ability improvement strategies for different types, to guide the sustainable development of villages and towns.

Artificial neural networks(ANNs)whose elements are inspired by biological nervous systems are composed of simple elements operating in parallel.Commonly neural networks are adjusted,or trained,so that a particular input leads to a specific target output.Neural networks have been trained to perform complex functions in various fields of application including predic-tion,pattern recognition,system identification,classification and optimization.Conventional statistical models fail to deal with non-linear relations among the physical factors.However,as an alternative approach,ANNs can map complex temporal and spatial pat-terns by using non-linear transfer functions.In this paper,regionalization of ecological assets is conducted by unsupervised artificial neural network,namely Self-Organizing Feature Mapping(SOFM).The field data employed as input for training represent spatial ecological features such as longitude,latitude,annual mean temperature,annual mean precipitation,aridity,biological tempera ture,assets demand index,assets scarcity,NPP of unit area and ecological value of unit area collected at84sites on Qinghai-Tibet Plateau.After the iterative learning phase in the SOFM analysis,each of the84sites is associated with an output unit.Each output unit contains some of the sites and there is obvious discrete grouping of cases.The SOFM,therefore,appears to have organized the sites such that the various output units are associated with different eco-logical assets classes.In order to assess the performance of SOFM,the comparison with cluster analysis is carried out.The result indicates that the overall performance of the neural network algorithm was better than that of cluster analysis for ecological regionalization.Finally,using SCS paradigm,conver-sion from SOFM classification to ecological assets regionalization is conducted.ternsbyusingnon linearconductedbyunsupervisedSOFM.Thefielddata

Domestic tourists'flow to Jiuzhaigou is expressed as the linear and sea sonal flow between several nodes.Based on case studies,this paper identifies some regularities:(a)Tourism image of the destination and tourists' preference are essential to their perception, cognition and decision; (b)Tourists' attributes (age, educational background,occupation and income,etc.) have effect on their preference and destination's decision; (c)The tourists' decisions are correlated with their economic ana lysis following their perception,preference,and motive; (d)The domestic tourists to Jiuzhaigou mainly select summer holiday and some festivals,which was the result of some causes.Then the peper emphasizes the importance of the image's decision of tourism destination.

Wetland is one of the three major ecosystems of the Earth, which plays an important role in climate regulation, water supply and environmental purification. Based on the land ecological remote sensing interpretation data and socio-economic data from 1990 to 2015, this research quantitatively studied the change of ecosystem service value of different wetland types and different functions in the Beijing-Tianjin-Hebei (Jing-Jin-Ji) Urban Agglomeration and each city by modifying the ecosystem service equivalent value, and the wetland function was orientated by calculating the internal and external contribution rates of the wetland value. The results showed that: (1) The ecosystem service value of wetland in Jing-Jin-Ji Urban Agglomeration showed a trend of rising first and then wavily descending. The wetland value in 2015 increased by 2.93×10⁹ yuan compared with 1990, mainly due to the increase of the value of river canals, reservoirs and ponds, as well as the increase of hydrological regulation value and water supply value. (2) Among the 13 cities in the Jing-Jin-Ji Urban Agglomeration, Tianjin had the highest ecosystem services value, and wetland value in the eastern coastal regions had increased. Inland cities in the south not only had a small wetland area, but their value had also declined year by year. (3) Hydrological regulation, water supply and environmental purification were the dominant functions of most urban wetlands in the urban agglomeration, while river canals, reservoirs and flood land were the main types of wetlands that provided service functions. The reduction and increase of ecosystem services value were closely related to human activities. Therefore, understanding the changing trend of wetland value and clarifying the functional orientation of wetland can not only enhance people's awareness of wetland ecological protection, but also provide scientific basis for the protection, restoration and sustainable use of wetland in the Jing-Jin-Ji Urban Agglomeration in the future.

At present, China is promoting the modernization of territorial space governance, and the territorial space planning system is also being reconstructed. As a response, the spatial planning of metropolitan area is facing the transformation of political logic oriented by ecological civilization and development logic constrained by resources and environment. Based on the transformation of planning logics, the paper clarifies that the spatial planning of metropolitan area is a special planning with the focus on coordinated development of space as the core in the system of territorial space planning, and puts forward the technical framework of the spatial planning of metropolitan area from the two perspectives, namely, corresponding demand objectives and coordination of local conditions. Based on the above new requirements, the paper considers that the planning should focus on the formulation of conduction and coordination-oriented index system, the optimal allocation and regulation of liquidity factor resources, the planning of spatial pattern of coordinated control and utilization, and the spatial cooperation of cross-border groups. In view of the lack of a unified implementation subject, this paper puts forward the organizational mode of spatial planning compilation in different types of metropolitan areas. Regional cooperation mechanism, dynamic monitoring of the plan, and co-construction of information platform for management, are also proposed. Through the systematic discussion on the spatial planning of metropolitan area, this paper will provide theoretical basis and methodological guidance for the compilation of the forthcoming spatial planning and the modernization of the spatial governance of metropolitan area.

Food waste has become a global problem, which causes widespread concern from the public. The consumption segment is an important part of food waste, and it is increasingly serious. Food waste at the consumer segment is mainly divided into household food waste and food waste outside home. Food waste at the consumer segment has different impacts on national food security, resources and environment, and social and economic development. Food waste at the consumption segment is affected by factors such as economic and social development, cultural background, demographic characteristics, and consumer behavior and awareness. At present, the study of food waste at the consumer segment mostly uses methods such as weighing (or estimating) and measurement model. It still needs to be further explored by developing reasonable quantitative methods, establishing complete theoretical models and proposing concrete research methods. In addition, to reduce food waste at the consumer segment, we should encourage multi-stakeholders to make a joint effort to deal with food waste at the consumer segment from the perspectives of government, society, individuals and other angles.

Based on the calculation of the ecosystem service supply, demand and coordination degree in the Yellow River Basin, we comprehensively analyzed the co-variation trend of land spatial pattern and coordination degree of supply-demand in this basin. Then, correlation analysis and quantile regression were used to analyze the influence of various land spaces on the coordination degree of supply-demand, and its regional heterogeneity. The results showed that: (1) Land spatial pattern, and supply and demand of ecosystem services showed significant spatio-temporal differentiation. The upper and middle reaches of the river and the lower reach are areas with densely distributed and significantly increased productive land and living land from 2000 to 2015. The increase in supply of ecosystem service was consistent with the distribution of cultivated land and forest land, and that in demand of ecosystem service was consistent with the distribution of population density and construction land. (2) The spatio-temporal change of the coordination degree was affected by the evolution of land spatial pattern. The influence of the land spaces on the coordination degree of supply and demand was different under different coordination levels, and there was significant regional heterogeneity in different regions. (3) According to different land spaces that had an impact on the coordination degree, different areas should rationally lay out land space and formulate development policies to promote effective ecosystem management.

Using the daily precipitation data of 34 meteorological stations in Beijing and its surrounding areas, this paper attempts to describe the variation trends of drought-flood in Beijing in different seasons during 1960-2013. Based on Standardized Precipitation Index (SPI), correlation analysis, Morlet wavelet analysis and other climate diagnosis method, we analyzed the influence factors of drought-flood variations. It is found that the number of minor drought-flood events decreased, while that of the severe drought- flood events increased during that period, which indicates that drought and flood events were becoming more extreme. At short- time scales, SPI fluctuated greatly, which means that drought and flood alternated frequently. At long-time scales, droughts and floods alternated frequently before the 1980s; after the middle of 1980s, SPI was going down, so that the number of flood disasters decreased, while the number of drought disasters increased gradually. Since there was little precipitation during 1999- 2008, the continuous drought occurred during the past decade. The urbanization process had obvious effect on the intensity of droughts and floods, but it did not affect the interdecadal variation. The relationship between drought-flood and El Niño-Southern oscillation (ENSO) is unstable. During the El Niño before 1980s, precipitations in summer showed a decreasing trend, leading to a severe drought in Beijing. With the emergence of the anomalous convection over the western North Pacific after the 1980s, the relationship became weak. The western Pacific subtropical high and East Asian summer monsoon showed relatively stable relationship with the variation of droughts and floods in Beijing: when the East Asian summer monsoon was stronger than normal and the western Pacific subtropical high went more northward, continuous droughts occurred in Beijing, whereas the reverse would cause flood.

Rural tourism is an important part for implementing the strategy of rural revitalization. Based on the data survey of 375 tourist villages in the city of Luoyang, combined with geographical data and traffic data, this paper uses Bootstrap DEA method, traffic network accessibility algorithm and geographic detector to study the spatial differentiation and formation mechanism of village scale tourism efficiency in Luoyang. Result shows that the correlation between comprehensive efficiency and scale efficiency is significantly higher than that between comprehensive efficiency and pure technical efficiency. This suggests that the comprehensive efficiency of rural tourism development is mainly based on the scale efficiency, and the agglomeration of business units has not improved the pure technical efficiency. The high value areas are distributed around Luoyang and Luanchuan and extended along the Zhengzhou-Lushi Expressway and Luoyang-Luanchuan Expressway. The main factors of spatial differentiation of comprehensive technical efficiency are the tourism carrying capacity of the village and poverty-related factors. In the future, the development of village tourism should follow the path of intensive development, give full play to the combined effects of traffic accessibility, natural part of human settlements environment and agglomeration so as to promote the advanced production factors and innovation of business forms, and guide rural tourism from extensive to intensive development. In rural areas, especially in the mountainous areas of western Henan, the market of tourism elements such as land, labor force, science and technology, finance and information has not really been formed, which restricts the allocation of tourism development elements in the most effective way. Furthermore, the agglomeration effect of tourism elements is not significant and the total factor productivity of tourism is relatively low. Therefore, in order to improve the comprehensive technical efficiency of rural tourism development, it is necessary to strengthen the innovation of land system, tourism statistics and information system, financial market, social organization, and the cultivation of new farmers and management subjects, so as to give full play to the activation effect of the high-level tourism production factors on the rural tourism resources and elements.

s:Global change stands for the trend of modern world science.The interactions between global change and terrestrial ecosystems,which include water cycle,carbon cycle,food and fiber,serve as the core.Global temperature will rise and the precipitation pattern will be changed as a result of global change.Doubled CO 2 will cause global temperature increase by about 4℃,that will bring on change of water resource(±10%).After50years from2000on ward,the temperature in western China will rise by1.7℃～2.3℃,and the precipitation will in crease by5%～23%under condition of continual increase in CO 2 concentration.There will be a negative effect on grain yield based on global comprehensive factors,which includes overall climatic change,socio-eco-nomic change,and population increase etc.,despite grain yield in crease due to eleva tion of CO 2 .Global change will aggravate fresh water crisis of the world.Ac cording to pre dic tion,fresh water will be insufficient for the essential need of the one sixth population in the world by2050.Agri-culture is the largest consumer of fresh water,accounting for about 75%of current water use.How to increase agriculture water use efficiency(WUE)has become a key task of saving fresh wa ter resource,promoting sustainable use of fresh water re source and en hancing socio-economic development in arid or semiarid areas at present.The concepts and formulas of agriculture water use efficiency are different with various scales and application objectives.They mainly include physiological concept based on leaf level,general concept based on field level and comprehen-sive concept based on regional level.Elevated CO 2 can enhance crop WUE,but has a little ef-fect on crop colony after long growing period.Moderate high temperature can promote crop WUE,but over high temperature is impossible for such an enhancement,and the soil moisture has the same situation.Run-off can be mitigated by building terraces,inter-tilling etc.There are sig nifi-cant effects of different planting patterns on crop WUE,for example,the capacity of soil evapo-ration will decrease from59%to41%by prac ticing intercropping of field crops with forest.There are also some effects of different soil fertili ties,different fertiliza tion methods,cov ers on field,dif-ferent species and/or varieties etc.on crop WUE.The main principles for in creasing WUE in-clude decreasing run-off and evaporation,and promoting tran spiration of crops.This re view de-scribed model for increasing WUE based on three major paths,including engineering of water saving,agronomic management and methods of controlling physiological proce dures,breed ing and gene engineering etc.Several key researching directions are also put forward at the end of this paper.

Water resources are the biggest rigid constraint facing the Yellow River Basin, and the proposed virtual water concept provides an effective way to optimize the regional allocation of water resources based on value flow. To implement the major national strategy of ecological protection and high-quality development in the Yellow River Basin, it is important to scientifically assess the basin virtual water flow pattern and its impact. Based on the 2017 input-output table and sectoral water use data of each province in China, this study applied the environmentally extended multiregional input-output model and structural path analysis to portray the virtual water flow pattern at the regional and sectoral levels in the Yellow River Basin from a local-distant perspective, and further examined the water risk transfer due to virtual water flow in conjunction with the water risk transfer model. The results indicated that: (1) At the regional level, the risk transfer value of virtual water flows from outside the basin to inside the basin was relatively high. Therefore, the Yellow River Basin significantly reduced its own water shortage risk by net transferring virtual water from the outside. (2) At the provincial level, the proportion of local virtual water was the highest and the proportion of sub-local virtual water was the lowest in each province. Inner Mongolia and Henan were more supportive of virtual water flows within and outside the basin. The proximal virtual water flow path mitigated the risk of localized water shortage. The sub-local and sub-distant virtual water flow paths with Sichuan and Inner Mongolia as sources had high risk-transfer values. (3) At the sectoral level, the key sectors for important virtual water flow paths were agriculture and construction. Among them, agriculture usually served as the source sector of the pathway, while construction mostly served as the terminal sector of the pathway. Virtual water flows from agriculture to industry and services tended to result in higher risk-transfer values. Virtual water flow pathways with construction as the terminal sector in the watershed also had a high risk-transfer value. Therefore, effective ways to promote water conservation and reduce the risk of water shortage in the Yellow River Basin through cross-regional and cross-sectoral coordination and optimal allocation of water resources should be actively explored.

As two key variables to represent vegetation activities, the Net Ecosystem Production(NEP) and the Net Primary Productivity(NPP)played important roles in the study of global change and regional ecological environment evaluation. Biome-BGC was a biogeochemical cycles model, which could simulate the storage and fluxes of water, carbon and nitrogen within the vegetation and soil components of a terrestrial ecosystem. In this paper, in use of the series of MODIS LAI product and the meteorological data in 2004, we simulated the NEP and NPP in the Huang-Huai-Hai Region. Since there was no crop eco-physiological parameters in the Biome-BGC model, we simulated the crop by modifying the grass eco-physiological parameters, and adding the code of fertilizers, irrigation and harvest.The simulated results showed that the NEP and NPP were greater in the southern part of the region.The respective order of average NEP and NPP of different vegetation types was as follows: mixed forest, deciduous broadleaf forest, evergreen needleleaf forest, crop, shrub and grassland; and mixed forest, crop,deciduous broadleaf forest, evergreen needleleaf forest, shrub and grassland.Compared to the observation data, MODIS NPP product and the statistical data, we found that Biome-BGC model successfully simulated the regional vegetation productivity, and the coefficient of determination between the simulated NPP of crop and the statistical data had reached 0.6123. In addition, the simulated result of crop NPP in the Huang-Huai-Hai Region was closer to the statistical data than the MODIS NPP product.

Water resources sustainable development is an important part of sustainable development.As an important region of land programming and comprehensive exploiting,many serious eco environmental problems have occurred in Songnen Basin because of uneven distribution and long period unreasonable development of water resources.Now problems of water resources have become the bottleneck factor of economy and construction in Songnen Basin.In order to achieve sustainable development of water resources in Songnen Basin,this paper takes groundwater system theory as principle,and water resources sustainable utilization as goal,the distribution characteristics of water resources were demonstrated first,and then the developing potential of water resources was analyzed on the basis of water resources statistic information and prediction of water resources demand,and finally some countermeasures for water resources sustainable development in the 21st century was presented.

China is feeding roughly 20% of the world's population with less than 9% of the world's cultivated land. The food security at national and regional scales has been a major concern. In this study, we took the province-level area as the research unit and utilized GIS spatial analysis and statistical tools to examine the overall characteristics of grain production changes, the evolution characteristics of regional patterns and the impact of these changes on regional grain supply and demand pattern in China during 1999-2018. The results showed that the total national grain output significantly increased with an annual rate of 1.1 million tons. The total grain output of Northern China showed a significant growth trend, while that of Southern China remained stable. The increment of maize yield played a leading role in these changes. The spatio-temporal yield variations of five major food crops (rice, wheat, maize, beans and tubers) were quite different in the past 20 years at provincial-level scale. The change of grain yield had great influence on regional grain supply and demand pattern. Particularly, Guangdong, Zhejiang and Fujian provinces located in the southeast coastal region had changed from supply-oriented provinces of major grains with rice and wheat into demand-oriented provinces. However, the per capita share of grain was 368.0 kg/person in Y 1999-2003 period(the five-year average during 1999-2003) and 461.5 kg/person in Y 2014-2018 period (the five-year average during 2014-2018) at national-level scale, respectively; and the per capita share of the two major grains was 220.3 kg/person and 247.6 kg/person in Y 1999-2003 and Y 2014-2018 periods, respectively. The change of sown area was the direct reason for the change of grain crop yield at national and regional scales. Nevertheless, the fundamental reason was more attributed to the change of attribution, function and quality, which is driven by land use value. Our study classified the reasons for the decrement of cultivated land into "non-agriculture" "non-grain" "wastage" and "ecology" types. Considering the formation causes of each type, the corresponding countermeasures and suggestions for the sustainable use of regional cultivated land were put forward in order to provide reference for the adjustment of regional grain planting pattern and the transformation of demand-oriented provinces of two major types of grain to self-sufficient provinces.

The impact of landscape changes on the quality and connectivity of habitats for multiple wildlife species is a global conservation concern. Zhalong Wetland is not only the priority areas of biodiversity conservation in China, but also the largest haibitat in the world with a large number of red-crowned cranes (Grus japonensis) breeding. The red-crowned crane was listed as a globally endangered species by the IUCN Red List of threatened species (IUCN, 2012), which is the umbrella species and the most sensitive biological indicator species of ecological changes in Zhalong Wetland. The selection of breeding habitat and the dispersal between suitable habitats in the study area are of great significance to the protection of wild red-crowned cranes. Firstly five variables (distance to water, soil wetness, NDVI, distance to roads and distance to buildings) were derived, which was hypothesized to influence the quality of habitat for red-crowned cranes according to the actual investigation within an area encompassing the entire Zhalong Nature Reserve. The MAXENT model was used to predict the suitable habitat distribution of red-crowned crane and analyze the response curve of each factor. The results showed that the red-crowned cranes were more likely to inhabit far away from roads and residents, and the breeding habitat might be close to water with more vegetation in a higher soil moisture condition. Finally, 38 suitable habitat patches were extracted from MAXENT model to simulate the multipath dispersal of red-crowned cranes when they lost flight ability based on circuit theory in landscape connectivity. Our map of maximum current flow between patches highlighted the possible pinch points, which can be used for red-crowned cranes moving directly between patch pairs. Current flow summed across all pairs of patches highlighted areas important for keeping the entire network connected. The results show that based on the suitable habitat patches predicted by MaxEnt model, considering the migration and diffusion behavior of the red-crowned crane in the breeding period, the comprehensive importance of the suitable habitat patches is evaluated by using the area weighting of the cumulative current density, and the suitability level is more consistent with the real nest distribution of the red-crowned cranes. Map results can be used to support the planning efforts concerned with the maintenance of red-crowned cranes metapopulation structure, as well as to protect the landscape features that facilitate the dispersal process.

Based on the runoff and precipitation data at Heyuan, Lingxia and Boluo sations during 1956-2005, the Mann-Kendall, Rescaled Range analysis and wavelet transform analysis methods are used to find out the variation law of runoff and its impacting factors in the Dongjiang River Basin. The results show that there are no significant changing trend and abruptly jumping point for runoff series in the Dongjiang River Basin. The results of continuous wavelet transform indicate that there are obvious periodic variations with scales 4 a, 7-9 a, 11-13 a and 16-22 a for the annual runoff series, and scale 7-9 a is the first period. The computed Hurst exponents indicate that a long-term memory characteristic exists in the annual runoff series. Annual runoff amount is related to the occurrence of El nio event. And sunspot number(SSN) is significantly correlated to annual runoff amount. The results of linear correlation indicate that the more SSN is, the less annual runoff amount is. The results of statistical analysis show that trends and abrupt change of runoff are in accordance with that of precipitation, evaporation respectively, especially with the precipitation. Among the climate factors,precipitation and evaporation are the most important factors to the changes of runoff. NDVI(Normalized Difference Vegetation Index) series in the Dongjiang River Basin show a significantly decreasing trend during 1982-2005, but NDVI series presents insignificant effect on runoff directly, which may indirectly affect runoff by impacting evaporation. Runoff variations in the Dongjiang River Basin are affected by synthetic effect of regional climatic elements and vegetation deterioration.

Several problems in the study of the population supporting capacity of land resources are discussed in this paper. The problems are the understanding of definition, the calculating of land productivity and crop yield, the evaluating of land resources, and the adjusting of land use structure.How to define and understand the population supporting capacity of land resources is the key in the study. A specified land evaluation for the study is the necessary foundation for the land productivity calculating and the land use structure adjusting. The predicted crop yield based on economic statistics can not represent land productivity. There are also some problems in crop yield calculated by the method of AEZ.

Environmental regulation is an essential policy instrument for achieving coordinated development of the economy-resources-environment (ERE) system. Taking 53 coastal cities in China where the ERE system has more distinct properties and more obvious contradictions between subsystems as the research object, this paper systematically calculates the ERE coupling coordination from 2003 to 2020 by using entropy weight method. Then, this paper aims to explore the impact and mechanism of different environmental regulation tools on the coupling coordination degree of ERE system of coastal cities by utilizing the fixed effect model and mediation effect model. The results indicate that: (1) The coupling coordination degree of ERE system increased from 2003 to 2020, but its overall level is still at a medium to low level. And the regional imbalance of the coupling coordination degree of the ERE system shows a weakening trend, and the gap between cities was gradually narrowed over time. (2) The coupling coordination degree of ERE system is impacted in an inverted "U-shape" by command-oriented environmental regulation, whereas market-oriented environmental regulation has a "U-shaped" impact on the coupling coordination degree of ERE system. It is found that that the coupling coordination degree of the ERE system in most cities is promoted by command-oriented environmental regulation and inhibited by market-oriented environmental regulation according to the inflection point position. (3) Technological innovation contributes to the partial mediation effect in the influence of environmental regulation tools on the coordinated development of ERE system. Different from technological innovation, the upgrading of industrial structure has partial mediation effect in the influence of command-oriented environmental regulation on the coordinated development of ERE, while it has masking effect in the impact of market-oriented environmental regulation on the coordinated development of ERE system.