Table of Content

25 May 2004, Volume 23 Issue 3 Previous Issue    Next Issue

Original Articles

An Object-oriented Spatio-temporal Data Model for Spatial Information in Regional Planning WANG Liming, WANG Ying, WEN Hui, ZENG Lan, LI Jun 2004, 23 (3):  1-8.  doi: 10.11820/dlkxjz.2004.03.001 Abstract ( )   PDF (878KB) ( )   Save National Development and Reform Commission declared that the eleventh five-year planning would put emphasis upon the spatial information integration. In regional planning, the spatial information is dynamic and complicated， so it is very essential that we should find an effective way to organize and manage all kinds of spatial information. Object-oriented method is a promising technology to help us with creating spatio-temporal data model， which gives us an idea to integrate the spatial information in regional planning． This paper suggests an object-oriented spatio-temporal data model for the spatial information in regional planning based on object-oriented theory and method; furthermore, it brings forward the definition and description of geographical feature classes structure. Object-oriented technology has comprehensive meaning in language, and it can express every spatial entity around us vividly and exactly. This spatio-temporal data model can inspect and record the changing of spatial information, so we can prosecute spatio-temporal analysis, forecast the development trend of regional economy, and establish reasonable implementary blue print in regional planning. Therefore, spatio-temporal data model is perfect in contrast with others. References | Related Articles | Metrics

Landscape Multi-Scale Image Analysis Based on the Region Growing Segmentation HUANG Huiping, WU Bingfang 2004, 23 (3):  9-15.  doi: 10.11820/dlkxjz.2004.03.002 Abstract ( )   PDF (806KB) ( )   Save Segmentation is the basis of object-oriented image analysis. For many years, due to the increasing require for object-oriented image analysis, procedures for image segmentation have been a main research focus in this area. The aim of segmentation is to extract the interesting region from remote sensing image, so the region-based approach is the best way for image segmentation. The region growing method generates many meaningful objects through merging the spectral-similar neighboring pixels. Meanwhile landscape spatial heterogeneity requires multi-scale analysis with remote sensing information extraction. Each pattern or process has its inherent feature in different scales. To ensure high precision surface information, the remote sensing application model building on one scale image need to be modified if it is used on the other scale. The combination of image segmentation and multi-scale analysis becomes a new trend in remote sensing application. Based on the scale affect and minimum-heterogeneity rule, this paper presents the necessity and possibility of multi-scale affects analysis as well as the principle and practice of the region growing image segmentation. There are two sites to test the multi-scale image segmentation process. The results show the image objects richness of geometry and semantic information. Therefore this approach offers an optical solution for the object-oriented and multi-scale image analysis. References | Related Articles | Metrics

Researches on New Spatial Forms in Information Era ZHEN Feng 2004, 23 (3):  16-26.  doi: 10.11820/dlkxjz.2004.03.003 Abstract ( )   PDF (1528KB) ( )   Save Space is a key theme for geographical research. With wide application of information technology in social economic system, traditional geographical space is undergoing rapid transformation. Based on the western explanation on new spatial forms, the paper tries to research new spatial forms produced by information technology. Physical space, virtual space and gray space are put forward. Then, the paper analyzes the concepts, components and types of physical space, virtual space and gray space. Gray space is the way from physical space to virtual space and also the interaction space between physical space and virtual space. Comparing to the other two types of space, gray space manifests the fused characteristics of physical space and virtual space. Finally, the paper compares similarities and differences of these three types of space, and argues that the co-existed spatial process is a continual phenomenon. References | Related Articles | Metrics

To Reduce MCSs Spatial Data Database Using Correlation Analytical Method FANG Zhaobao, LIN Hui, WU Lixin, JIANG Jixi 2004, 23 (3):  27-33.  doi: 10.11820/dlkxjz.2004.03.004 Abstract ( )   PDF (844KB) ( )   Save Several heavy rainfalls in Changjiang River Basin are considered to be highly related to the moving out of the mesoscale convective systems (MCSs) from the Tibetan Plateau to the east. To discover the rules of MCSs moving and promulgating, the relationship is established between moving trace of MCSs and its surrounded environmental physical field. And the database of spatial data mining is designed to the MCSs moving out to east from Tibetan Plateau. In the database of spatial data mining, there are not only 18 attribute terms brought by 9 environmental physical variables, but also some spatial character terms of MCSs, such as area, position, shape, and intension of MCSs. By analyzing the cloud-top’s temperature of black body (TBB) from the hourly GMS infrared images and the data of the High Resolution Limited Area Forecast System (HLAFS) of the Tibetan Plateau from June to August in 1998, the database of spatial data mining is built. It is studied that the database is reduced using correlation analytical method. The study reveals that the height(H), the vortex (VOR), the divergent(DIV), the water vapor flux divergent（IFVQ）, the wind aplomb speed（W） and the K-index are relatively independent parameters among the nine environment physical variables around the MCSs, while the temperature（T）, the fake correspond potential temperature (θse) and the relative humidity(RH) are highly related to each other，as well as to the Height. Hence, we suggest that the temperature(T), the fake correspond potential temperature(θse) and the relative humidity(RH) be not considered for the construction of the data base of MCSs spatial data mining, so as to increase the efficiency of the MCSs spatial data mining and to reduce the data redundancy. References | Related Articles | Metrics

Experimental Simulation of Anastomosing Multiple Channel Formation WANG Suiji, BO Junli 2004, 23 (3):  34-42.  doi: 10.11820/dlkxjz.2004.03.005 Abstract ( )   PDF (1543KB) ( )   Save Anastomosing river is a new fluvial river pattern that gets more attention from researchers. The hydrological, geomorphological and sedimentological characteristics of some anastomosing rivers have been revealed. But the experiment simulation of anastomosing river is vacant hitherto. The flume simulation experiments are the reappearance of natural rivers under the condition of decreasing time and space. This work reports a formation and evolution of anastomosing river simulated in a flume. The experimental beginning condition is: an artificial meandering channel in the assistant area of flume; a rectangle floodplain (4.5 m ×16.5 m) with concave cross sections is in the objective area and its stratum has a structure of double layers. The upper layer with a thickness of 1.5 cm consisted of Gaolin whose median grain size is 0.0132 mm；below layer with a thickness of 0.5 m consisted of fine sands whose median grain size is 0.188 mm. The mean longitudinal gradient of the floodplain is 0.0058 from 5.5 m to 17 m and 0.0077 from 17 m to 22 m along the ordinate. Adoptive constant discharge is 3 cm3/s. Suspended sediment load is 4.5 g/min in the first 3 hours and 1.2 g/s thereafter. The total time span of flume experiment is 50 hours. In the initial stage of simulation the sedimentation mainly occurred in the upper reach, the random erosion occurred at the middle reach and the backward erosion mainly occurred in the lower reach of the objective area. A rudimental anastomosing river with multiple channels connected each other basically appears about 13.5 hours. Hereafter up to 25.5 hours the evolution fashion of the anastomosing river changed from downcutting erosion to lateral erosion, but the fall back of channel banks is not evident. It indicates that the anastomosing channels change into their autumn. From 25.5 hours to 50 hours the abandonment or avulsion of individual channel is the new evolution characteristics of the simulated anastomosing river. The whole flume experiment simulates successfully the formation and evolution of natural anastomosing rivers and proves that the anastomosing river is a new river pattern which is different from anabranched river. This is a useful attempt to reveal the formation of anastomosing river via flume simulation and helpful to understand the characteristics of anastomosing river. References | Related Articles | Metrics

High Mountain Glaciers&rsquo|ELA0 and Climate JU Yuanjiang, LIU Gengnian, ZHANG Xiaoyong, FU Hairong, WEI Xia, CUI Zhijiu 2004, 23 (3):  43-49.  doi: 10.11820/dlkxjz.2004.03.006 Abstract ( )   PDF (3509KB) ( )   Save The authors of present paper deal with the implication of the equilibrium line altitude (ELA0) of glacier for environment and review the methods of its identification so far within China and abroad. Finally the authors identified the ELA0 for the present No.1 glacier in the Urumqi glacier valley, Tianshan Mts, China, by determining its maximum elevation of lateral moraines (MELM), based on their field observations in recent years and a study of great amount of the related data surveyed since 1960. As a result, the authors revised the formula for the relationship between the present ELA0 and climate. This formula is then applied to characterize the glacier in the stage of second glacier advance during the Little Ice Age and hence the results of semi-quantified presumption of climate prior to about 250a B.P. are obtained. References | Related Articles | Metrics

The Driving Forces of Land Use in Intensive Agricultural Region Based on the Behavior of Household ——A Case Study in Quzhou County in Hebei Province KONG Xiangbin, ZHANG Fengrong, QI Wei 2004, 23 (3):  50-57.  doi: 10.11820/dlkxjz.2004.03.007 Abstract ( )   PDF (975KB) ( )   Save The corn yield has much more relationship with the economic development， which will experience the period from low to high; and after the peak， it will become low. Households have different land use aims in different phases, showing the food first， the optimum of food and profit and profit ultimately. The food value of the land is super to any other land value to meet the food requirements of the family at the first phase. Household have no other means of production but the labour force. Household will introduce such extensive methods as increasing the sown area， reclaiming the margin arable land and decreasing the substance input. The main types of conversion is the land from the margin land to arable land; household will abandon the arable land to reclaim other margin land when they think the output of land is below the labor input. Households will keep the balance of food demand and the money pursuit at the second phase, in which they demand not only the food security but the money profit. Households will arrange the means of production such as labour forces， money and different proportion of land.And that leads to the increase of output ， the substitution of input and the increase of the economic cropping area . With the development of economic level， the cost of labor forces will increase. Households will make good use of the means of production. According to the return of different land use types, different land use types will keep balance under the conditions of equilibration of margin input and margin output; if not， transformation will occur. The arable land is maybe transformed into construction land. If the scale of food land is small， household will decrease the input or abandon the land to some extent. According to our analysis， households are experiencing the second phase in which they have enough food and work hard to make more money. References | Related Articles | Metrics

Progress in Monitoring and Simulation of Soil Moisture SHAO Xiaomei, YAN Changrong, XU Zhenjian 2004, 23 (3):  58-66.  doi: 10.11820/dlkxjz.2004.03.008 Abstract ( )   PDF (1248KB) ( )   Save As known to all, variance of soil water not only has great impact on regional hydro, but also influences climate greatly through vegetation and soil. Monitoring and simulation of soil moisture are important basis of land sustainable use， planning and management of water resources and water-saving technique in agriculture. Therefore, soil water has been up to the agenda in the Global Soil Wetness Project, and become one of the focuses in the study of Global Climate Change. A critical review on soil moisture monitoring， spatial variability and simulation was carried out in this paper．As a result, it can be concluded that "3S"techniques including Geographical Information System(GIS)， Remote Sensing(RS)， and Global Position System(GPS) have played an important role in the monitoring soil moisture．The pre-processing， communicating and mining for soil moisture data have been timely dealt with by computer networks in some developed countries．However， many developing countries include China failed to do that．The Geo-statistics theory has already been extensively employed to analyze the spatial pattern and variability of soil moisture， but most existed researches have been done in the fine and small scales， and few researches in coarse scales．After analyzing advantages and disadvantages of the established models for simulating soil moisture， we proposed that integrated non-parameter models should be established to simulate soil moisture by combining "3S" techniques and Geo-statistics theory．This paper is attempts to probe into the study of monitoring and simulating soil moisture and summarize the methods and approaches used in the soil water research, which may be helpful for improving the relevant study in China. References | Related Articles | Metrics

Numerical Simulation of Environmental Influence Under Different Irrigation Volume in Arid Regions of NW China GAO Yanhong, CHEN Yuchun, LU Shihua GAO Yanhong, CHEN Yuchun, LU Shihua 2004, 23 (3):  67-73.  doi: 10.11820/dlkxjz.2004.03.009 Abstract ( )   PDF (1242KB) ( )   Save The environmental variations under different volume irrigation from 20 July to 30 July, 2002, were studied in the arid region of NW China based on the non-hydrostatic atmos-pheric mesoscale model MM5, in which the land surface process parameterization (OSU LSM) involving soil layers, vegetable layer and hydrological process was included. The horizontal resolution was selected as 1km. The influence on energy and water exchanges between land surface and atmosphere, atmospheric temperature and humidity at 2m height, soil moisture at four layers (10cm, 30cm, 60cm, 100cm depth ) and surface/underground runoff under different volume irrigation was analyzed. The proper volume maintaining the micro-climate of oasis was found out through analyzing. The following results were obtained: 1)Accounting soil moisture conservation and the micro climate maintenance over oasis, 500m3 /hm2 drop irrigation for later dekad of July, 2002, is a proper volume in the middle reaches of HEIHE river basin if the land used is agriculture land. 2)The 500m3/hm2 /10d is just half of the minimum norm and one-third of maximum norm of flood irrigation. This conclusion proved indirectly that drop irrigation is a water saving and high quality irrigation method, which could hold the limited water resources massively in arid region of North -West China. References | Related Articles | Metrics

Review about the Carbon Cycle Researches in Grassland Ecosystem GENG Yuanbo, QI Yuchun, DONG Yunshe 2004, 23 (3):  74-81.  doi: 10.11820/dlkxjz.2004.03.010 Abstract ( )   PDF (867KB) ( )   Save The some major research field of the carbon cycle in grassland ecosystem are reviewed that, and some problems are put forward about these researches. These reviews are focused on as follows: 1. The carbon storage in grassland ecosystem, which include the carbon storage in plant carbon pool and soil carbon pool；the distribution and measure on NPP and biomass in grassland. 2. The soil respiration in grassland, it was considered the most important process in the carbon cycle in grassland. 3. The effect of the climate and human activity such as reclamation，graze and fire, upon the carbon cycle in grassland. 4. The potential effect of increasing carbon dioxide in atmosphere on the carbon cycle in grassland. Some major problems are as follows: 1. The measure method and the origin of the data of carbon storage and flux for contrast and statistical analysis in worldwide grasslands are different; 2. It is very difficult distinguishing the four process of soil respiration, namely, three biological process, including soil microbial respiration, root respiration and soil animal respiration, and one abiological process, thus the effect of each process on carbon flux is not very clear; 3. The research on the effect of human activity on carbon cycle in grassland should be intensified. References | Related Articles | Metrics

Some Advances in Evidences of Quaternary Aeolian Environment LU Ruijie, HA Si, YUE Xingling, CHEN Yuan 2004, 23 (3):  82-90.  doi: 10.11820/dlkxjz.2004.03.011 Abstract ( )   PDF (1215KB) ( )   Save The research of Quaternary Aeolian environment has great significance to understand the momentous climatic changes. As the time series of instrumental observation data is too short to reconstruct the past environmental variables, the reliable proxies have been widely applied to the Quaternary Aeolian environment research. Based on the analysis of the proxies and extracting the valuable information and evidences about the climatic variables, the long time series of past environmental changes can be reconstructed. This paper formulates the evidences (morphological evidences, sedimentological evidences and biogeomorphical evidences) used in the Quaternary Aeolian environment research, presents the problems existed in using the evidences, analyzes the tendency of the future research, and points out that the synthetic using of proxies and improving the precision of dating are still the emphases. References | Related Articles | Metrics

SVI and VCI Based on NDVI Time-Series Dataset Used to Monitor Vegetation Growth Status and Its Response to Climate Variables QI Shuhua, WANG Changyao, NIU Zheng, LIU Zhengjun 2004, 23 (3):  91-99.  doi: 10.11820/dlkxjz.2004.03.012 Abstract ( )   PDF (1038KB) ( )   Save In this paper, the 20-year NDVI time-series dataset composed every ten days was used to induce SVI (Standard Vegetation Index) and VCI (Vegetation Condition Index). The vegetation growth status spatial pattern for China, at the first ten days of March and May in 2000 , was studied with SVI. Results showed that the winter maize was eugonic in March, but in May winter maize was not in good status; and the area where vegetation was not in good status compared with the past years was enlarged from March to May. Considering the validity of VCI in monitoring vegetation growth status has been approved by some studies and the maganificent correlation between SVI and VCI, we reached the conclusion safely that SVI is valid in monitoring vegetation growth condition. A 20-year rain and average air temperature dataset collected at 10 meterological stations located at differrent vegetation cover type was used to study the VCI and SVI’s response sensitivity to climate variables. Results showed that: (1) The dominant factor on vegetation growth is spatio-temporal and land cover type specified; (2) For forestory cover type, SVI and VCI exhibit some relation with the total precipitation before due time at the first ten days of March, while in May irrelevance between SVI or VCI and climate variables was found that can be explained by NDVI saturation phenomena always happening on forest cover area; (3) For meadow/grassland and shrub, air temperature exhibits a little more remarkable relativity than precipitation especially for VCI; (4) For crop area, according VCI, vegetation growth status has more remarkable relativity with air temperature in March, while precipitation has become the preponderant factor on growth status at May especially for winter wheat area; (5) The drought indice based on time-domain spectral vegetation index were not always valid because their response to precipitation was spatialy and temporaly specified; (6) VCI is more excellent at indicating climatic changes. References | Related Articles | Metrics

Temporal - Spatial Analysis of Temperature and Its Effect on Climate and Water in Qinghai Gonghe Basin SUN Jianguang, LI Baoguo, LU Qi 2004, 23 (3):  100-106.  doi: 10.11820/dlkxjz.2004.03.013 Abstract ( )   PDF (759KB) ( )   Save In the northeastern part of Qinghai-Tibetan plateau lies Gong-he basin. The paper discusses the temporal-spatial characteristic of temperature and its effect on climate and water according to the meteorological data (1953~2001) from three weather stations and soil water material (1980~2002) in Qiabuqia weather station by time series method, DEM and Penman-Monteith equation. The results show that annual temperature time series are not stationary, but with linear upward trend; and annual average temperature in Chaka and Qiabuqia and Guinan is increasing by 0.0247、0.0422 and 0.0272℃ respectively per year according to the linear model in Gong-he basin; furthermore, the spatial distribution of annual average temperature can be simulated by using multivariable linear model based on digital elevation model (DEM 100×100m2) and by using the data at three permanent weather stations and more than ten temporary weather stations. The two big sand bands(Shazuyu-Tala and Mugetan) is in the higher scope of temperature(1.0~4.0℃ and 1.0~2.9℃) according to the simulated result, and there is a direct correlation between annual temperature and potential evapotranspiration in space; with temperature rising, the saturated difference of water pressure and potential evapotranspiration increases gradually, and soil water decreases in topsoil; so it makes the climate drier, and desertification become more serious gradually in the future in Gong-he basin in Qinghai province. But in short-term, especially in the period of research, the change of climate is very slight, so the cause of desertification needs to be analyzed further in Gong-he basin. References | Related Articles | Metrics