Extensions of GAP‐tree and its implementation based on a non‐topological data model

This paper discusses extensions of GAP‐trees from three aspects and its implementation based on non‐topological structure in order to enhance access to large vector data sets. First of all, we apply cartographic generalization rules to build a generalization procedure of the GAP‐tree, which makes coarse representations more consistent with human cognition. Second, we replace the three‐dimensional (pseudo‐) Reactive‐tree index with a 2D R‐tree index and a B‐tree index to improve the system efficiency. Finally, we compress a binary GAP‐tree into multi‐way GAP‐trees in order to reduce data redundancy. The shallower multi‐way GAP‐trees not only eliminate redundant data but also accelerate the system's response time. The extensions have been successfully implemented in PostgreSQL. A test of Beijing's land‐use data at the 1:10 000 scale demonstrates that the extended GAP‐trees are efficient, compact, and easy to implement.     

Geographical Detectors‐Based Health Risk Assessment and its Application in the Neural Tube Defects Study of the Heshun Region,China

Physical environment, man‐made pollution, nutrition and their mutual interactions can be major causes of human diseases. These disease determinants have distinct spatial distributions across geographical units, so that their adequate study involves the investigation of the associated geographical strata. We propose four geographical detectors based on spatial variation analysis of the geographical strata to assess the environmental risks of health: the risk detector indicates where the risk areas are; the factor detector identifies factors that are responsible for the risk; the ecological detector discloses relative importance between the factors; and the interaction detector reveals whether the risk factors interact or lead to disease independently. In a real‐world study, the primary physical environment (watershed, lithozone and soil) was found to strongly control the neural tube defects (NTD) occurrences in the Heshun region (China). Basic nutrition (food) was found to be more important than man‐made pollution (chemical fertilizer) in the control of the spatial NTD pattern. Ancient materials released from geological faults and subsequently spread along slopes dramatically increase the NTD risk. These findings constitute valuable input to disease intervention strategies in the region of interest.     

Croundwater Evolution and its Influence on the Fragile Ecology …

塔里木盆地南缘第四系松散沉积物以第三系弱透水层为隔水底板构成良好的储水场所含水层厚２００～９００ｍ,主要由冲洪积卵砾石、砂砾石和细砂组成。地下水位埋深由山前倾斜平原的５０～１００ｍ逐渐过渡为细土平原的１～３ｍ,矿化度相应地由１～３ｇ．Ｌ＾－１变化到３～５ｇ．Ｌ＾－１。大部分地下水由地表径流和渠系、田间灌溉水入渗转化而成,约占地下水补给总量的９４％以上。人类历史时期,气候地下水演变中依旧起着主导作用     

GIS,multi‐criteria and multi‐factor spatial analysis for the probability assessment of the existence of illegal landfills

This work deals with the identification of potentially contaminated areas using remote sensing, geographic information systems (GIS) and multi‐criteria spatial analysis. The identification of unknown illegal landfills is a crucial environmental problem in all developed and developing countries, where a large number of illegal waste deposits exist as a result of fast, and relatively unregulated, industrial growth over the past century. The criteria used to perform the spatial analysis are here selected by considering the characteristics which are ‘desirable’ for an illegal waste disposal site, chiefly related to the existence of roads for easy access and to a low population density which facilitates unnoticed dumping of illegal waste materials. A large dataset describing known legal and illegal landfills and the context of their location (population, road network, etc.) was used to perform a spatial statistical analysis to select factors and criteria allowing for the identification of the known waste deposits. The final result is a map describing the likelihood of an illegal waste deposit to be located at any arbitrary location. Such a probability map is then used together with remote sensing techniques to narrow down the set of possibly contaminated sites (Silvestri and Omri, 2008 Silvestri, S. and Omri, M. 2008. A method for the remote sensing identification of uncontrolled landfills: formulation and validation.. International Journal of Remote Sensing, 29(4): 975–989. [Taylor & Francis Online] , [Google Scholar]), which are candidates for further analyses and field investigations. The importance of the integration of GIS and remote sensing is highlighted and represents a key instrument for environmental management and for the spatially‐distributed characterization of possible uncontrolled landfill sites.     

“Greatest lake period” and its palaeo-environment on the Tibetan Plateau

The Tibetan Plateau is the biggest lake distribution area in China, in which lake evolution is one of the important compositions for plateau environmental changes. It is also very significant in the study of regional environmental evolution. To answer the questions that how and when the paleo lakes evolved, the indicators and their dating data of the important events must be identified. As the key items for detecting the past environment, they are also the most concerned problems in geo-scien…     

Modelling the impacts of cropland displacement on potential cereal production with four levels of China’s administrative boundaries

Cropland displacement, as an important characteristic of cropland change, places more emphasis on changes in spatial location than on quantity. The effects of cropland displacement on global and regional food production are of general concern in the context of urban expansion. Few studies have explored scale-effects, however, where cropland is displaced not only within, but also outside, the administrative boundary of a certain region. This study used a spatially explicit model (LANDSCAPE) to simulate the potential cropland displacement caused by urban land expansion from 2020 to 2040 at four scales of the Chinese administration system (national, provincial, municipal, and county levels). The corresponding changes in potential cereal production were then assessed by combining cereal productivity data. The results show that 4700 km² of cropland will be occupied by urban expansion by 2040, and the same amount of cropland will be supplemented by forest, grassland, wetland, and unused land. The potential loss of cropland will result in the loss of 3.838×10⁶ tons of cereal production, and the additional cropland will bring 3.546×10⁶ tons, 3.831×10⁶ tons, 3.836×10⁶ tons, and 3.528×10⁶ tons of potential cereal production in SN (national scale), SP (provincial scale), SM (municipal scale), and SC (county scale), respectively. Both SN and SC are observed to make a huge difference in cereal productivity between the lost and the supplemented cropland. We suggest that China should focus on the spatial allocation of cropland during large-scale displacement, especially at the national level.     

Playing Lotto with Rotto? Tourism,the environment and gambling with the ethos of a Western Australian island

Rottnest Island is a popular holiday destination offshore from Perth, the capital city of Western Australia. Rottnest (or Rotto) attracts approximately 500 000 visitors annually. The island is managed by a statutory government authority, the Rottnest Island Authority (RIA), for the purposes of providing recreation and holiday facilities and services, and protecting its natural and cultural values. While there are advantages in management by one body, there appears to be a conflict in managing both the tourism business and the environment, largely as a result of funding issues. While further tourism development would boost the RIA's self-funded operating budget, increased pressures may compromise the island environment and the Rottnest ethos, which revolves around a relaxed and casual social ambiance. The RIA aims to develop Rottnest as a model for sustainability, but are dilemmas surrounding economic sustainability potentially risking the island's environmental and social sustainability? This paper concludes that in the pursuit of economic returns from tourism, Rottnest Island's environmental and social values face an uncertain future.     

Paleomagnetism of Early Tertiary volcanics in the South Shetland Islands and its tectonic implications

ＰａｌｅｏｍａｇｎｅｔｉｓｍｏｆＥａｒｌｙＴｅｒｔｉａｒｙｖｏｌｃａｎｉｃｓｉｎｔｈｅＳｏｕｔｈＳｈｅｔｌａｎｄＩｓｌａｎｄｓａｎｄｉｔｓｔｅｃｔｏｎｉｃｉｍｐｌｉｃａｔｉｏｎｓＬｉｕＪｉａｎ（刘坚）；ＧｅＴｏｎｇｍｉｎｇ（葛同明）；ＤｕａｎＷｅｉｗ...     

Species composition and quantitative variation of zooplankton in the Great Wall Bay and its adjacent waters，Antarctica

ＳｐｅｃｉｅｓｃｏｍｐｏｓｉｔｉｏｎａｎｄｑｕａｎｔｉｔａｔｉｖｅｖａｒｉａｔｉｏｎｏｆｚｏｏｐｌａｎｋｔｏｎｉｎｔｈｅＧｒｅａｔＷａｌｌＢａｙａｎｄｉｔｓ　ａｄｊａｃｅｎｔｗａｔｅｒｓ，ＡｎｔａｒｃｔｉｃａＨｕａｎｇＦｅｎｇｐｅｎｇ（黄凤鹏）ａｎｄ...     

Grassland coverage inter-annual variation and its coupling relation with hydrothermal factors in China during 1982–2010

GIMMS (Global Inventory Modeling and Mapping Studies) NDVI (Normalised Difference Vegetation Index) from 1982 to 2006 and MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI from 2001 to 2010 were blended to extract the grass coverage and analyze its spatial pattern. The response of grass coverage to climatic variations at annual and monthly time scales was analyzed. Grass coverage distribution had increased from northwest to southeast across China. During 1982–2010, the mean nationwide grass coverage was 34% but exhibited apparent spatial heterogeneity, being the highest (61.4%) in slope grasslands and the lowest (17.1%) in desert grasslands. There was a slight increase of the grass coverage with a rate of 0.17% per year. Increase in slope grasslands coverage was as high as 0.27% per year, while in the plain grasslands and meadows the grass coverage increase was the lowest (being 0.11% per year and 0.1% per year, respectively). Across China, the grass coverage with extremely significant increase (P<0.01) and significant increase (P<0.05) accounted for 46.03% and 11% of the total grassland area, respectively, while those with extremely significant and significant decrease accounted for only 4.1% and 3.24%, respectively. At the annual time scale, there are no significant correlations between grass coverage and annual mean temperature and precipitation. However, the grass coverage was somewhat affected by temperature in alpine and sub-alpine grassland, alpine and sub-alpine meadow, slope grassland and meadow, while grass coverage in desert grassland and plain grassland was more affected by precipitation. At the monthly time-scale, there are significant correlations between grass coverage with both temperature and precipitation, indicating that the grass coverage is more affected by seasonal fluctuations of hydrothermal conditions. Additionally, there is one-month time lag-effect between grass coverage and climate factors for each grassland types.     

Construction of the homogenized temperature series during 1910–2014 and its changes in Hunan Province

Based on the statistical method and the historical evolution of meteorological stations, the temperature time series for each station in Hunan Province during 1910–2014 are tested for their homogeneity and then corrected. The missing data caused by war and other reasons at the 8 meteorological stations which had records before 1950 is filled by interpolation using adjacent observations, and complete temperature time series since the establishment of stations are constructed. After that, according to the representative analysis of each station in different time periods, the temperature series of Hunan Province during 1910–2014 are built and their changes are analyzed. The results indicate that the annual mean temperature has a significant warming trend during 1910–2014 and the seasonal mean temperature has the largest rising amplitude in winter and spring, followed by autumn, but no significant change in summer. Temperature variation over Hunan Province has several significant warm-cold alternations and more frequent than that in whole China. Annual and seasonal mean temperatures except summer and autumn have abrupt warming changes in the recent 100 years. The wavelet analysis suggests that the annual and four seasonal mean temperatures in recent 100 years have experienced two climatic shifts from cold to warm.     

Change in summer daily precipitation and its relation with air temperature in Northwest China during 1957–2016

On the basis of the summer daily-precipitation meteorological data collected from weather stations across Northwest China from 1957 to 2016, this study evaluated the trends in 12-daily precipitation indices in the summer season and their relations with air temperature. Precipitation-event intensity, which was averaged over the total study area, increased in recent decades although the total precipitation continuously decreased. In particular, intensity generally decreased in the northern and eastern parts and increased in the southern and western parts of the study area. None of the 12 precipitation indices was significantly correlated with temperature in Xinjiang; R95 N(number of events with precipitation greater than the long-term95 th percentile), RX1 day(greatest 1-day total precipitation), PI(simple daily intensity), and R10(number of heavy-precipitation days) were significantly and positively correlated with temperature in Qinghai–Gansu. However, low correlation coefficients were observed. In the Loess Plateau, P(total precipitation), WS(maximum number of consecutive wet days),R95 N, and WD(number of wet days) were significantly and negatively correlated with temperature, whereas Gini(gini concentration index) and DS(maximum number of consecutive dry days) were significantly and positively correlated with temperature. Results of the study suggested that climate shift was evident in terms of daily precipitation, and the study area faced new challenges involving precipitation-event intensity increasing in the southwestern part and unevenly dispersing in the northwest.     

The role of sub‐national government and the private sector in future spatial data infrastructures

A Spatial Data Infrastructure (SDI) facilitates and coordinates the exchange and sharing of spatial data between stakeholders in the spatial data community. With this objective in mind, countries throughout the world are developing SDIs to manage and utilize their spatial data assets more effectively. These countries are developing SDIs to assist in various kinds of decision‐making at different levels of government jurisdictions that have an important impact within their national boundaries. However, current research shows that SDI is understood and described differently by stakeholders from different disciplines and different jurisdictional levels. Therefore, in many cases, SDI initiatives remain very much an innovation, even among practitioners. There are still uncertainties regarding the benefits and identities of SDIs, particularly in connection with how they evolve over time to meet user needs. This paper reviews and assesses the development of SDIs throughout the world over the past 15 years and the leadership role of national governments in SDI creation. This assessment is based on the SDI activities of various jurisdictions including Asia‐Pacific, Australia, North America, and Europe, and research into the worldwide effects of spatial information clearing houses. This assessment includes a discussion on emerging trends in SDI development, with particular reference to the increasingly important role played by sub‐national governments and the private sector within the framework of SDI development. The paper concludes with a discussion of the implications for future SDI development, including the delivery of a virtual world that has a particular focus on facilitating decision‐making at a community level within a national context.     

The potential for the use of Open Source Software and Open Specifications in creating Web‐based cross‐border health spatial information systems

Globalization is contributing to the blurring of borders making irrelevant the distinctions between domestic and international health problems. Cross‐border and global health spatial information systems (CBHSIS) are required to address the new global health challenges. There is a need to build and document alternatives for addressing the technological, economic, and sociocultural–political challenges encountered in the creation and deployment of these systems. This paper documents the building of a prototype Web‐based multimedia GIS system for use in a public health context using Open Source Software and Open Specifications and its deployment across the US–Mexico border. These technologies offer advantages in addressing several of the challenges previously mentioned. We highlight the technological and sociocultural–political issues important in successful collaboration across borders and cultures and in the creation of interoperable CBHSIS.     

Sustainable Agriculture in the “Belt and Road” Region in Conjunction with the Sustainable Development Goals

The countries along the “Belt and Road” (B&R) should devote their efforts to top-level planning in the field of agriculture, so as to ensure the sustainable development of agriculture in the region. This will require a precise assessment of the sustainability of agriculture along the B&R. With a view to understanding the concept of sustainable agriculture along the B&R, combined with the interpretation of the agricultural objectives contained in the United Nation’s Sustainable Development Goals (SDGs), this study uses statistical regression analysis and trend prediction to predict the social and economic development trends in terms of economic growth and urbanization in the countries along the B&R up until 2030, and the corresponding impacts on agricultural resources and the environment. The results show that the future prospects for agricultural resources and the environment along the B&R are not promising, and meeting the future food security needs of the region will be difficult. Only by adopting innovative policies and implementing strategic planning can the goals of sustainable agricultural development and food security by 2030 be achieved in this region. Therefore, countries along the B&R should formulate agricultural development strategies from three aspects: building an agricultural cooperation platform, setting up special funds, and innovating the agricultural cooperation mode, so as to achieve the sustainable development of agriculture in the region.     

Crop cover reconstruction and its effects on sediment retention in the Tibetan Plateau for 1900–2000

Geographically explicit historical land use and land cover datasets are increasingly required in studies of climatic and ecological effects of human activities. In this study, using historical population data as a proxy, the provincial cropland areas of Qinghai province and the Tibet Autonomous Region (TAR) for 1900, 1930, and 1950 were estimated. The cropland areas of Qinghai and the TAR for 1980 and 2000 were obtained from published statistical data with revisions. Using a land suitability for cultivation model, the provincial cropland areas for the 20th century were converted into crop cover datasets with a resolution of 1 × 1 km. Finally, changes of sediment retention due to crop cover change were assessed using the sediment delivery ratio module of the Integrated Valuation of Ecosystem Services and Trade-offs (In- VEST) model (version 3.3.1). There were two main results. (1) For 1950–1980 the fractional cropland area increased from 0.32% to 0.48% and land use clearly intensified in the Tibetan Plateau (TP), especially in the Yellow River–Huangshui River Valley (YHRV) and the midstream of the Yarlung Zangbo River and its two tributaries valley (YRTT). For other periods of the 20th century, stability was the main trend. (2) For 1950–1980, sediment export increased rapidly in the Minhe autonomous county of the YHRV, and in the Nianchu River and Lhasa River basins of the YRTT, which means that sediment retention clearly decreased in these regions over this period. The results of this assessment provide scientific support for conservation planning, development planning, or restoration activities.     

Do Siberian marmots influence toad-headed agama occupancy? Examining the influence of marmot colonies and three steppe habitats in Mongolia

The Siberian marmot is a large, endangered rodent and often considered a keystone species because of its perceived effects on steppe ecosystems. However, few studies have examined the effects of marmots on other species. We examined the influence of marmots on toad-headed agama occupancy probability in an arid steppe region of Mongolia. We modeled the influence of marmot colonies and three habitats, including rocky outcrops, open plains, and shrubland using an occupancy modeling framework based on three surveys of 122 sites from June to August 2010. We detected agamas during 64% of surveys and at 85% of sites. Marmot colonies and their interactions with other habitats had little influence on occupancy probability at a given site. The amount of surrounding open plains and shrubland also showed little influence. Our results indicated toad-headed agama occupancy was inversely related to the amount of surrounding rocky outcrop. Rocky outcrop may be less suitable to agamas because of its sparse vegetation, lack of burrows, and heat-absorbing qualities. Although marmots affect the distribution of other species, our results suggest they exert little influence on toad-headed agamas. We also suggest that the creation of rocky habitat by mineral mining will negatively impact toad-headed agamas.