Temporal and spatial variability response of groundwater level to land use/land cover change in oases of arid areas

This paper conducts a case study on the impacts of land use/cover change （LUCC） on the temporal and spatial variability of the groundwater level in an arid oasis in the Sangong River Watershed by using the geographical information system （GIS）, remote sensing （RS） and geostatistical methods. The temporal and spatial variability of the groundwater level in the watershed in 1978, 1987 and 1998 is regressed by using the＇semivariogram model and Kriging interpolation. The LUCC classification maps derived from the aerial images in 1978, Landsat TM image in 1987 and Landsat ETM image in 1998 are used to superpose and analyze the conversion relationship of LUCC types in the regions with different isograms of the groundwater depth. The results show that the change of groundwater recharge was not so significant in the whole oasis, but the temporal and spatial LUCC was significant either in the normal flow periods or in the high flow periods during the 20-year period from 1978 to 1998, and there was a close correlation between them. There is generally a moderate spatial correlation of groundwater level （33.4%） and the spatial autocorrelation distance is 17.78 km. The regions where the groundwater level is sharply changed are also the regions where the land resources are increasingly exploited, which include mainly the exploitation of farmlands, woodlands, and building, industrial and mining lands. The study reveals that the LUCC affects strongly the temporal and spatial variability of the groundwater level in the arid oasis. The study results are of direct and practical significance for rationally utilizing shallow groundwater resources and maintaining the stability of the arid oasis.     

Quantitative assessment and analysis on the dynamic change of ecological capital in arid areas

Ecological capital is the summation of the direct value of biological resources and the ecological service function value of ecosystems. Under the support of RS, GPS and GIS, in this paper the RS-based quantitative measurement model of assessing ecological capital is developed based on the traditional ecology theory and the research on the value of ecological capital per unit area by using the ecological parameters including Landsat TM data, CBERS satellite data, meteorological data, MODIS satellite data, land cover data and field-measured data. A case study on the spatiotemporal distribution of ecological capital in Changji Hui Autonomous Prefecture in 1990, 1995 and 2003 is carried out, and the dynamic change of ecological capital in the prefecture is measured and compared with GDP. The maps of the spatial distribution of ecological capital in the study area are charted, and the characteristics of spatial distribution of ecological capital are analyzed. The results show that the values of ecological capital in the prefecture in 1990, 1995 and 2003 were 1.47368×10^11, 1.66160×10^11 and 1.77895×10^11 yuan RMB （hereafter referred to as yuan） respectively, and that in spatial distribution, the ecological capital decreases from the alpine zones to the plains and from the oases to the deserts, which accords with the zonal distribution of vegetation in arid areas. The measured results can more objectively reflect the ecological capital and its spatial distribution in arid areas, provide an ideal foundation for further study in the future, and can also be combined with the study on service functions of ecosystems and the regiona planning as an important basis of regional planning.     

Vapor corridor phenomenon and response of vegetation NPP in Longitudinal Range-Gorge Region

To study the causation and ecological effect of ＂Corridor＂ phenomena in the Longitudinal Range-Gorge Region （LRGR） in South China and South-East Asian. Supported by the geographic information system （GIS）, vegetation, climate and topography database of the LRGR are founded, The northernmost limit of the tropical rain forest is 28ο-22, which has been promoted 3 or 4 latitude by Vapor ＂Corridor Phenomenon＂. Through ANN analysis, landform proves to be a very important factor affecting NPP distribution. Affected by longitudinal valley landform and monsoon, moisture and quantity of heat has a longitudinal belt distribution, and NPP distribution has seemly distribution. Take Lyonia ovalifolia, Myrica nana scrub as an example, high NPP valuescrub distributes on a wet-tongue area in the valleys. The minimum temperature sensitive value to NPP is 1.588, and altitude is 1.053, precipitation is 1.006, aspect is 1.003. Corridor phenomenon in the LRGR formed special moisture and heat patterns and brings about a series of ecological effects, such as influencing space distribution of vegetation form and NPP spatial patterns of both vegetations and plants.     

Present-day crustal movement in China continent and its southeast coast region

Based on the observations of global positioning system (GPS) , a movement model for quantitatively describing the seven continent blocks in China, Tibet, Sichuan-Yunnan, Gansu-Qinghai, Xingjiang, the South China, the North China and Heilongjiang is established, and the derived velocity field (1994—1996) is consistent with the focal mechanism " P" stress axis field and the geological model on the whole. China continent moves toward east (including N\E, NE, E, EES and ES) . Furthermore, the intrablock deformation model for Fujian and its neighboring sea region is also established. The derived velocity field and strain rate field (1995—1997) show that along with the southeast coastal region, the whole China moves toward southeast. There are compression from sea to continent in the northwest direction and extension in the northeast direction. The direction of principal stress axis at present is NW (NWW) SE (SEE) . The collision of India plate with Eurasian plate plays a major role in the crustal movement of China continent, while the collision and pushing of Philippine plate play the direct and important role in the crustal movement and strong earthquake gestation in the southeast eoastal region of China continent.     

Study on RS-and GIS-based ecological capital assessment in arid areas

Ecological capital assessment is currently one of the important research contents in the interdisciplinary field of ecology, resources economics, environmental economics and ecological economics. To scientifically assess ecological capital redounds to decision-makers to consider the ecological cost in economic development, and is also necessary for sustainable economic development in arid areas. Based on the theory of landscape ecology, in this paper the per unit area ecological capital values in arid areas are researched by using the Land-sat TM data, CBERS satellite data, meteorological data, MODIS satellite data and other ecological data, and the RS- and GIS-based models of assessing ecological capital values in arid areas are developed. Moreover, based on the field-measured data, a case study on ecological capital assessment in the Manas River basin, Xinjiang in 2003 is carried out. The basin is divided into 4 ecological capital areas so as to quantitatively calculate the ecological capital values of the ecosystems, analyze the spatial distribution of ecological capital, and chart the maps of spatial distribution of ecological capital. The results show that the total ecological capital value of the ecosystems in the Manas River basin in 2003 was 1.494 54×1011 yuan RMB. In spatial distribution, the ecological capital decreases from the alpine zones to the plains and from the oases to the deserts, which accords with the distribution of vegetation zonality in this arid area. The assessed results can objectively reflect the ecological capital and its spatial distribution in the arid basin, and can also provide reference for roundly carrying out the assessment of ecological capital in arid areas.     

Study on RS- and GIS-based ecological capital assessment in arid areas

Ecological capital assessment is currently one of the important research contents in the interdisciplinary field of ecology, resources economics, environmental economics and ecological economics. To scientifically assess ecological capital redounds to decision-makers to consider the ecological cost in economic development, and is also necessary for sustainable economic development in arid areas. Based on the theory of landscape ecology in this paper the per unit area ecological capital values in arid areas are researched by using the Landsat TM data, CBERS satellite data, meteorological data, MODIS satellite data and other ecological data, and the RS- and GIS-based models of assessing ecological capital values in arid areas are developed. Moreover, based on the field-measured data, a case study on ecological capital assessment in the Manas River basin, Xinjiang in 2003 is carried out. The basin is divided into 4 ecological capital areas so as to quantitatively calculate the ecological capital values of the ecosystems, analyze the spatial distribution of ecological capital, and chart the maps of spatial distribution of ecological capital. The results show that the total ecological capital value of the ecosystems in the Manas River basin in 2003 was 1.49454×10^11 yuan RMB. In spatial distribution, the ecological capital decreases from the alpine zones to the plains and from the oases to the deserts, which accords with the distribution of vegetation zonality in this arid area. The assessed results can objectively reflect the ecological capital and its spatial distribution in the aridbasin, and can also provide reference for roundly carrying out the assessment of ecological capital in arid areas.     

Theoretical critical value curve and driving force formation of ecological migration in the arid land

The features of the fragile eco-environment of the arid land decide that its capacity of disturbance-resistance is lower. The natural desert oases in the arid land are in mosaic patches distributed in a wide Gobi desert. The population distribution is greatly dependent on water resources. The population is characterized with dispersed distribution, simple production and living style, and poverty and remoteness. The reason why the ecological migrations are carried out lies in the ecological problems. ＂Ecological degradation＂ is the main driving force of the ecological migration. Then, the strength of the driving force depends on the degree of ecological degradation. Hence, whether to carry out ecological migration depends on the extent of ecological degradation. Theoretically, the critical value curve for calculating ecological migration in the arid land is put forward through comprehensive research of relative problems of ecology, economics etc., combined with the ecological migration experience in the arid land, and based on the features of the arid environment. In this article, with this curve, the theoretical research and some practice of the ecological migration have been done from the perspective of natural behavior and governmental behavior of the driving force formation of ecological migration. It analyses the active driving force （factors） and negative forces （factors）, and points out the timing and steps of implementing the ecological migration in the arid land. The theoretical curve embodies certain originality and applicability, which provides a quantitative method for evaluating the degree of ecological degradation and the theoretical base for implementing ecological migration projects.     

Estimation of crop water requirement based on principal component analysis and geographically weighted regression

In this study the principal component analysis (PCA) and geographically weighted regression (GWR) are combined to estimate the spatial distribution of water requirement of the winter wheat in North China while the effect of the macroand micro-topographic as well as the meteorological factors on the crop water requirement is taking into account. The spatial distribution characteristic of the water requirement of the winter wheat in North China and its formation are analyzed based on the spatial variation of the main affecting factors and the regression coefficients. The findings reveal that the collinearity can be effectively removed when PCA is applied to process all of the affecting factors. The regression coefficients of GWR displayed a strong variability in space, which can better explain the spatial differences of the effect of the affecting factors on the crop water requirement. The evaluation index of the proposed method in this study is more efficient than the widely used Kriging method. Besides, it could clearly show the effect of those affecting factors in different spatial locations on the crop water requirement and provide more detailed information on the region where those factors suddenly change. To sum up, it is of great reference significance for the estimation of the regional crop water requirement.     

Research on barrier function and spatio-temporal heterogeneity of vegetation in southern LRGR

This article, taking MODIS-EVI as an index, analyzes the spatio-temporal distribution pattern of vegetation in the southern Longitudinal Range-Gorge Region （LRGR） and explains its cause by ARCGIS and SPSS. The result shows that the regional difference of Enhanced Vegetation Index （EVI） is remarkable with apparent topographical effect, especially for longitudinal ranges. As to temporal heterogeneity, because of the existence of certain time difference of the monsoon air affecting the study area, in addition to the obvious regional difference in spatial distribution of EVI, this kind of regional difference is significantly correlated in location with macro-landforms, especially the case of Ailao Mountain and Wuliang Mountain. As to spatial heterogeneity, by taking Ailao Moutain as a rough divide, because of the alternation of high mountains and gorges in the northwest of the study area, precipitation variance almost follows a sine curve from west to east with the mountain and gorge terrain, and hence EVI changes rapidly; while EVI changes insignificantly in the east of the study area because its terrain becomes rather gentle. The effect of longitudinal mountains on the reallocating of heat and moisture factors is the main cause for EVI regional difference. Especially, the effect of Ailao and Wuliang mountains on rainfall interception in rainy seasons and cold wave block in dry seasons is even more obvious. By counting statistical data of points at altitudes between 1400 and 1500 m in a cross-section, the annual mean precipitations in five sub-areas are 1244.67, 1081.44, 1111.41, 1033, and 807.11 mm respectively in rainy seasons, while the annual mean minimum temperatures are 7.93, 7.46, 7.28, 8.44, and 9.16℃ respectively in dry seasons.     

Influence of Spatial Features on Land and Housing Prices

The analysis of hidden spatial features is crucial for the improvement of hedonic regression models for analyzing the structure of land and housing prices. If critical variables representing the influence of spatial features are omitted in the models, the residuals and the coefficients estimated usually exhibit some kind of spatial pattern. Hence, exploration of the relationship between the spatial patterns and the spatial features essentially leads to the discovery of omitted variables. The analyses in this paper were based on two exploratory approaches: one on the residual of a global regression model and the other on the geographically weighted regression (GWR) technique. In the GWR model, the regression coefficients are allowed to differ by location so more spatial patterns can be revealed. Comparison of the two approaches shows that they play supplementary roles for the detection of lot-associated variables and area-associated variables.     

企业空间数据仓库的构建方法

在现有企业数据仓库多维模型的基础上，结合空间数据的特性和不同决策处理需求，提出了3种构建企业空间数据仓库的方法. 通过原型系统的验证，说明这些方法是有效可行的.     

基于空间数据库的数据挖掘技术

探讨扩展传统数据挖掘方法如分类、关联规则、聚类等到空间数据库的方法，着重对空间数据库系统实现技术及空间数据挖掘系统等进行比较分析，提出了一种空间数据挖掘系统的实现模式。     

空间数据集成研究--以空间数据仓库的构建为例

随着空间数据复杂性的增加，现有的空间数据库和空间分析工具已经不能提供足够的决策支持，迫切需要建立大量具有历史数据，以及不同尺度的空间数据仓库．在建设空间数据仓库的过程中，数据集成是一个重要的环节，专门针对空问数据的集成更是一项艰巨的工作，本文在研究了现有的空间数据库，空间数据仓库以及空间数据集成的基础上，首先探讨了空间数据仓库模型的建立过程，然后系统提出了面向空间数据仓库数据模型的数据集成的两个主要的方面：不同数据源的空间数据的集成；不同尺度维上的空间数据的集成.     

空间分析基本问题与主要内容的探讨

空间分析是地理信息系统的核心之一,是当前研究的热点.在回顾空间分析起源的基础上,从几个角度给出空间分析内涵的理解;指出空间分析涉及的几个基本问题,包括地理空间性、空间自相关、空间尺度与空间抽样.在此基础上,论述了空间分析的主要研究内容,即空间位置分析、空间自相关、空间插值、空间回归分析及空间分析中的模型与模拟研究.最后展望了空间分析下一步发展,认为空间分析不仅需要在强化基础理论研究,亦当在地理信息服务的过程中,充分结合地理信息系统技术、数据挖掘技术及空间决策支持系统研究,为人口、资源、环境及公共健康等重大问题的决策提供科技支撑.     

Spatial aggregations for spatial based decision 

For spatial based decision making such as choice of best place to construct a new department store, spatial data warehousing system is required more and more previous spatial data warehousing systems; however, provided decision making of nonspatial data on a map and so those cannot support enough spatial based decision making. The spatial aggregations are proposed for spatial based decision making in spatial data warehouses. The meaning of aggregation operators for applying spatial data was modified and new spatial aggregations were defined. These aggregations can support hierarchical concept of spatial measure. Using these aggregations, the spatial analysis classified by nonspatial data is provided. In case study, how to use these aggregations and how to support spatial based decision making are shown.     

Spatial aggregations for spatial based decision making in spatial data warehouses

For spatial based decision making such as choice of best place to construct a new department store, spatial data warehousing system is required more and more previous spatial data warehousing systems; however, provided decision making of non-spatial data on a map and so those cannot support enough spatial based decision making. The spatial aggregations are proposed for spatial based decision making in spatial data warehouses. The meaning of aggregation operators for applying spatial data was modified and new spatial aggregations were defined. These aggregations can support hierarchical concept of spatial measure. Using these aggregations, the spatial analysis classified by non-spatial data is provided. In case study, how to use these aggregations and how to support spatial based decision making are shown.     

空间统计学及其在公共卫生领域中的应用

经典统计学处理公共卫生数据空间属性数据的能力不足,空间统计学具有优势,由此得到广泛应用.目前空间统计学在公共卫生领域主要应用有:疾病制图、分布格局探测、空间相互关系分析、病因分析以及时空预警等方面.     

一种新的空间分类挖掘方法

空间分类是空间数据挖掘的一个重要的研究分支 ,空间分类挖掘在对空间对象进行分类时 ,要考虑空间对象的非空间属性及其邻接对象对它分类的影响。本文提出一种新的空间分类挖掘方法 ,该方法将空间对象的非空间属性及空间属性分开来进行考虑。该分类方法具有良好的应用前景。     

地理加权回归分析空间数据的空间非平稳性

空间数据一般具有空间非平稳性的特征,用一般线性回归模型来拟合空间数据,其分析结果不能全面反映空间数据的真实特征．地理加权回归模型是一种相对简单而又有效的探测空间非平稳性的新方法,属于局域空间分析模型．它允许不同的地理空间存在不同的空间关系,其结果是局域而不是全域的参数估计,因此能够探测到空间数据的空间非平稳性．以银行不良贷款原因分析为实例来验证空间数据的空间非平稳性．     

空间数据仓库综述

叙述了空间数据仓库的概念及其功能特征,根据其与GIS、空间数据库的关系概括出其结构框架,分析了空间数据仓库的发展现状,并根据现状提出存在的问题及解决方法.