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Non-Algorithmically Integrating Land Use Type with Spatial Interpolation of Surface Soil Nutrients in an Urbanizing Watershed

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Pedosphere 2017年第1期27卷 147-154页

作者： WU Qian LI Qingliang GAO Jinbo LIN Qiaoying XU Qiufang Peter M.GROFFMAN YU Shen Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021 China Zhejiang A&F University Lin'an 311300 China University of Chinese Academy of Sciences Beijing 100049 China Cary Institute of Ecosystem Studies Millbrook NY 12545(USA)

Integrating land use type and other geographic information within spatial interpolation has been proposed as a solution to improve the performance and accuracy of soil nutrient mapping at the regional scale. This study developed a non-algorithm approach, i.e., applying inverse distance weighting （IDW） and ordinary kriging （OK）, to individual land use types rather than to the whole watershed, to determine if this improved the performance in mapping soil total C （TC）, total N （TN）, and total P （TP） in a 200-km2 urbanizing watershed in Southeast China. Four land use types were identified by visual interpretation as forest land, agricultural land, green land, and urban land. One hundred and fifty soil samples （0-10 cm） were taken according to land use type and patch size. Results showed that the non-algorithm approach, interpolation based on individual land use types, substantially improved the performance of IDW and OK for mapping TC, TN, and TP in the watershed. Root mean square errors were reduced by 3.9% for TC, 10.770 for TN, and 25.9% for TP by the application of IDW, while the improvements by OK were slightly lower as 0.9% for TC, 7.7% for TN, and 18.1% for TP. Interpolations based on individual land use types visually improved depiction of spatial patterns for TC, TN, and TP in the watershed relative to interpolations by the whole watershed. Substantial improvements might be expected with denser sampling points. We suggest that this non-algorithm approach might provide an alternative to algorithm-based approaches to depict watershed-scale nutrient patterns.

关键词： geographic information system inverse distance weighting non-algorithm approach ordinary kriging spatial pattern

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Soil property mapping by combining spatial distance information into the Soil Land Inference Model(SoLIM)

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Pedosphere 2021年第4期31卷 638-644页

作者： Chengzhi QIN Yiming AN Peng LIANG Axing ZHU Lin YANG State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101(China) College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049(China) Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application and School of Geography Nanjing Normal UniversityNanjing 210097(China) Department of Geography University of Wisconsin-MadisonMadison WI 53706(USA) Key Laboratory of Virtual Geographic Environment Ministry of EducationNanjing Normal UniversityNanjing 210023(China) School of Geographic and Oceanographic Sciences Nanjing UniversityNanjing 210093(China)

The Soil Land Inference Model(SoLIM) was primarily proposed by Zhu et al.(Zhu A X, Band L, Vertessy R, Dutton B. 1997. Derivation of soil properties using a soil land inference model(SoLIM). Soil Sci Soc Am J. 61: 523–533.) and was based on the Third Law of Geography. Based on the assumption that the soil property value at a location of interest will be more similar to that of a given soil sample when the environmental condition at the location of interest is more similar to that at the location from which the sample was taken, SoLIM estimates the soil property value of the location of interest using the soil property values of known samples weighted by the similarity between those samples and the location of interest in terms of an attribute domain of environmental conditions. However, the current SoLIM method ignores information about the spatial distances between the location of interest and those of the sample. In this study, we proposed a new method of soil property mapping, So LIM-IDW, which incorporates spatial distance information into the SoLIM method by means of inverse distance weighting(IDW). The proposed method is based on the assumption that the soil property value at a location of interest will be more similar to that of a known sample both when the environmental conditions are more similar and when the distance between the location of interest and the sample location is shorter. Our evaluation experiments on A-horizon soil organic matter mapping in two study areas with independent evaluation samples showed that the proposed SoLIM-IDW method can obtain lower prediction errors than the original SoLIM method, multiple linear regression, geographically weighted regression, and regression-kriging with the same modeling points. Future work mainly includes the determination of optimal power parameter values and the appropriate setting of the parameter under different application contexts.

关键词： digital soil mapping location of soil sample inverse distance weighting soil organic matter Third Law of Geography

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Monitoring and early warning system of porcine pasteurellosis based on WebGIS

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Information Processing in Agriculture 2021年第1期8卷 148-158页

作者： Zihan Zhu Haoran Wang Li Gao Xiang Gao Xinghua Meng Yao Xu Jianhua Xiao Department of Veterinary Surgery Northeast Agricultural UniversityHarbin 150030China

The incidence of porcine pasteurellosis in China is so widespread that it is difficult to clearly understand the prevalence and maintain continuous *** order to reduce immense negative economic impact on the livestock industry;monitoring,early warning,and visual management systems are highly *** this study,a monitoring and early warning systemfor porcine pasteurellosis was established based onWeb Geographical Information System(WebGIS)*** establishing a path analysis function,buffer analysis function,and hot spot analysis function,it can provide a method of support and control of infectious *** early warning of disease,four common interpolation methods were tested,all of which showed that the affected area of porcine pasteurellosis in China was mainly concentrated in the south of the mainland.A cross-validation method was used to compare the four interpolation *** cross-validation showed that the inverse distance weighting(IDW)method was suitable for forecasting the occurrence of porcine pasteurellosis in ***,using C sharp(C#)as the development language and WebGIS technology,a monitoring and early warning system based on Browser/Server structure was *** is the first monitoring and early warning system of porcine pasteurellosis based *** performance of theWebGIS technology indicated a great potential for animal infectious disease applications and provided a foundation for future work.

关键词： Porcine pasteurellosis Monitoring and early warning Web geographical information system inverse distance weighting

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GIS Mapping, Biomonitoring and Distribution of Heavy Metal Concentrations Using Neem (Azadirachta indica) Bark in Makurdi Town, Benue State, Nigeria

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Journal of Geoscience and Environment Protection 2023年第7期11卷 213-226页

作者： Ada Florence Ogli Mohammed Ahmed Adams Udoji Itodo Raymond Ahulle Wuana Rufus Sha’Ato Department of Chemistry Akawe Torkula Polytechnic Makurdi Nigeria Department of Geography Bayero University Kano Nigeria Department of Chemistry/Centre for Agrochemical Technology Joseph Sarwuan Tarka University Makurdi Nigeria

The present work determined the concentration and spatial distribution of heavy metals (As, Hg, Cr, Cd and Pb) in soil samples from Makurdi and its environs using geographic information system (GIS). The specific objective is to produce the spatial distribution maps showing the spatial distribution of toxic heavy metals in the study area. inverse distance weighting (IDW), a GIS technique was used to produce dotted maps showing the spatial distribution of heavy metals in neem bark for better visualization of contamination zones and non-contamination zones. The map reveals few hotspot areas showing areas of high concentrations of the heavy metals investigated which were identified in red colours, the following concentration ranges were obtained;As (4.71 - 6.43 mg/kg), Cd (13.9 - 16.84 mg/kg), Cr (46.3 - 60.84 mg/kg), Hg (3.70 - 5.05 mg/kg) and Pb (24.02 - 31.34 mg/kg). These hotspot areas were found close to business outlets, fuel filling and service stations, farm sites where the application of fertilizers and pesticides were persistent coupled with heavy traffic of vehicles and other machinery which was associated with As, Hg, Cd, Pb and Cr been released into the environment thus, suggesting anthropogenic activities controlling the concentration of these heavy metals in the study areas. The cumulative effect of these heavy metals into the barks of neem could pose as danger, because this plant is used as herbs in folk medicine.

关键词： Heavy Metal Contamination Spatial Distribution inverse distance weighting Folk Medicine Makurdi

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Trends and Geostatistical Interpolation of Spatio-Temporal Variability of Precipitation in Northern Cameroon

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American Journal of Climate Change 2016年第2期5卷 229-244页

作者： Elisabeth Fita Dassou Auguste Ombolo Steven Chouto Guillaume Ewodo Mboudou Jean Marcel Abate Essi Etienne Bineli Department of Climatology Hydrology and Pedology Higher Institute of Sahel University of Maroua Maroua Cameroon Department of Hydraulics and Water Management Higher Institute of Sahel University of Maroua Maroua Cameroon Department of Environmental Sciences Higher Institute of Sahel University of Maroua Maroua Cameroon Institute for Geological and Mining Research (IRGM) Center for Geological and Mining Research Garoua Cameroon

This paper examines the spatial and temporal variability of the mean annual precipitation in the Northern Cameroon on the context of climate change during the time period 1950-2013. The study used homogeneous monthly and annual precipitations database of twenty-five stations located in the Northern Cameroon and Southern Chad Republic. Geostatisticals interpolation methods (Kriging and inverse distance weighting method) associated with Digital Elevation Model were used to establish the spatial distribution of annuals precipitations. The non-parametric Mann- Kendall test and Sen’s slope method were performed to determine respectively trend and magnitude. The result indicates a spatial distribution of precipitation mainly determined by the topography and the geography of the study area. The trend analysis shows a decrease of annual average precipitation across the Northern Cameroon at a rate of ?0.568 mm/year over the time period 1950-2013. The magnitude of decreasing trends ranged between 0.11 and 3.92 mm/year. Statistically significant decreasing trends at the 95% level of confidence were noted at 10% while 5% of stations showed statistically significant increasing. However, 60% of stations indicate a decreasing trend. Monthly analysis of rainfall shows a decreasing trend during June and September while July and August present an increasing trend.

关键词： Precipitation Kriging inverse distance weighting Mann-Kendall Test Trends Northern Cameroon

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Mapping of Precipitation, Temperature and Evaporation Distributions in the Porsuk Basin Using Distant Forecasting Methods

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Computational Water, Energy, and Environmental Engineering 2017年第4期6卷 321-350页

作者： Recep Bakis Yildirim Bayazit Hakan Uygucgil Cengiz Koc Department of Civil Engineering Anadolu UniversityEskisehirTurkey Department of Civil Engineering Bilecik Seyh Edebali UniversityBilecikTurkey Department of City and Regional Planning Faculty of ArchitectureMugla Sitki Ko&ccedil man University MuglaTurkey

Geographical data are of great importance in meteorology and climate science. These data can create the areal distribution models analyzed by spatial interpolation methods. The values of the areas without measurement data are estimated with these distribution models. In this study, distribution of meteorological parameters such as precipitation, temperature and evaporation in Porsuk basin, which is determined as research area, was investigated by inverse distance weighting (IDW) and Ordinary Kriging methods. Actual meteorological data analyzed of the basin do not show a normal distribution statistically. Therefore, the data were firstly subjected to normalization and then analyzed according to the IDW and Ordinary Kriging methods to create distribution maps of precipitation, temperature and evaporation data. Quadratic mean error values were compared to investigate the reliability of analyzes. In this study, the analysis results of precipitation, temperature and evaporation data have been calculated by two different methods. Ordinary Kriging method has been determined as the method making the most accurate estimation.

关键词： Geographical Information Systems inverse distance weighting Ordinary Kriging Meteorology Porsuk Basin Turkey

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Ionospheric Grid Modeling of Regional Satellite Navigation System with Spherical Harmonics

Ionospheric Grid Modeling of Regional Satellite Navigation S...

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第四届中国卫星导航学术年会

作者： Jiachen Fan Xiaoli Wu Enqiang Dong He Zhao Haibo Kan Jinshi Xie Beijing Satellite Navigation Center

As an important component of differential navigation service, ionospheric grid can greatly improve the accuracy of single frequency users. Wide-Area Augmentation System （WAAS） broadcasts a set of ionospheric grids data for authorized single frequency GPS users every 300s. WAAS uses inverse distance weighting （IDW） algorithm to calculate the vertical total electron content （VTEC） at those ionosphere grid points （IGP）. IDW algorithm has good correction accuracy, but has low availability in the area with few ionosphere pierce points （IPP）. The availability and accuracy of ionospheric grid by IDW algorithm depend on the distribution of monitoring stations and the constellation of navigation system. As the constellation of regional satellite navigation system consists mainly of geostationary earth orbits （GEO） satellites and inclined geosynchronous orbits （IGSO） satellites, the IPPs have a concentrating distribution. Considering that the distribution of monitoring stations are all in China, using IDW algorithm to calculate ionospheric grid will not have good availability. This paper proposes a practical algorithm to calculate the regional ionospheric grid based on spherical harmonics （SH） model and International Reference Ionosphere （IRI-2012） model. Compared with IDW algorithm, the simulation data analysis indicates that the SH algorithm can greatly improve the availability from 82.62% to 99.83% for China’s mainland and from 34.66% to 94.25% for all grids, but the average correction RMS of ionospheric grid increases from 2.60TECU to 3.33TECU.

关键词： regional satellite navigation system ionospheric grid spherical harmonics inverse distance weighting

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