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Spatio-Temporal Assessment of Water Quality in Douala IV Municipality, Cameroon

Journal of Water Resource and Protection 2019年第12期11卷 1441-1461页

作者： Mary Lum Fonteh Niba Theophile Fonkou Cornelius Mbifung Lambi department of geography Higher Teacher Training College The University of Bamenda Bambili Cameroon department of Plant Biology Faculty of Science University of Dschang Dschang Cameroon department of geography Faculty of Social and Management Sciences University of Buea Buea Cameroon

The study analysed the spatial and temporal contamination levels of fresh water resources by saline intrusion in the Douala coastal area. Water samples were collected from 19 stations. 3 stations were selected from the mangrove area and 16 stations were selected from the rest of the area partitioned into four transects (coastal transect, inner transect 1, inner transect 2 and inner transect 3). Sampling was done repeatedly during the wet and dry seasons. They were analyzed for physico-chemical parameters according to the American Public Health Association methods. Geostatistical analysis was used in mapping the water properties. Considerable levels of actual electrical conductivity values (208.91 to 660.63 and 45 to 7540 μS/cm for the wet and dry seasons, respectively);calcium (0.06 to 85 and 4 to 256 mg/L for the wet and dry seasons, respectively);sulphate (0 to 103 and 0 to 99 mg/L for the wet and dry seasons) and total dissolved solids (15.79 to 1467 and 20 to 3750 mg/L for the wet and dry seasons, respectively) were observed for ground water in the study area based on spatio-temporal assessment. From the output grid, it could be deduced that the south eastern region had a hint of salt water intrusion (SWI) contamination of fresh water resources with actual value highs of electrical conductivity (1790 and 820 μS/cm) for the dry and wet seasons, respectively. Calcium highs (140 and 16 mg/L) for the dry and wet seasons were obtained at the central part of the study area. The spatial distribution of calcium highs extends from the central zone of the study area in the dry season and the south eastern zone in the wet season. The southern region is more vulnerable to contamination by calcium ions during this season. An up to date scope for surveillance monitoring and forecasting regarding the deterioration of coastal aquifers is recommended. Modelling of aquifers shifts for the coastal zone should be instituted as a means of ensuring efficient fresh water resources eva

关键词： Spatio-Temporal Assessment Fresh Water Resources Water Quality Geostatistics Douala IV Municipality Cameroon

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The Dynamics of Domestic Water Vending in Enugu North L.G.A of Enugu State, Nigeria

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Journal of Water Resource and Protection 2012年第4期4卷 224-230页

作者： Emmanuella C. Onyenechere Ebere I. Eleazu Okechi D. Azuwike Sabina Osuji Chimezie F. Igwe department of geography & Environmental Management University of Port Harcourt Port Harcourt Nigeria department of geography& Environmental Management Imo State University Owerri Nigeria department of Urban & Regional Planning Imo State University Owerri Nigeria

The present investigation provides a case study of water vending in Enugu North Local Government Area, Enugu State of South Eastern Nigeria. Questionnaire copies were randomly distributed in the study area to 200 households. Data obtained from the field were analyzed using descriptive statistics and chi-square test. The analysis revealed that almost all the residents of Enugu North L.G.A. obtain their water from independent water vending systems which are operated by the private sector. Tanker truck, distributing and small retail water vendors all operate in the study area. There are an estimated number of 250 tanker truck drivers serving Enugu North L.G.A. Approximately 35 tanker trucks serve Hill- top/Udi siding ward, while there are a total of 52 retail vendors in Onuasata ward. Majority of the respondents are low income earners who spend within the ranges of NGN500 ($3.33) and NGN1500 ($10) a month on water on the average. 50.0 percent of these respondents opined that vended water was expensive. Of the respondents, 49.4 percent consumed 91 - 100 litres per capita per day, which is less than the 120 litres per capita per day recommended by the Federal Re- public of Nigeria’s National water supply and sanitation policy document of 2000. This deficit can be attributed to the cost of vended water. From the chi-square test, there is significant difference in the unit cost of water sold by vendors in the various wards in Enugu North L.G.A. In the absence of regular water provision through pipe-connections from the public utility, water vending should be supported but regulated. Meeting the water and sanitation target and optimizing water resources for the Millennium Development Goals (MDGs) by 2015 will require a dramatic scaling up of joint efforts by the state government and the people in ensuring that vendors provide safe water at a low cost.

关键词： Households Enugu State Tanker Trucks Water Policy Cost Water Vending

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Classifications of Satellite Imagery for Identifying Urban Area Structures

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Advances in Remote Sensing 2020年第1期9卷 12-32页

作者： Abdlhamed Jamil Abdulmohsen Al-Shareef Amer Al-Thubaiti department of geography & GIS Faculty of Arts & Humanities King Abdulaziz University Jeddah KSA

This study compares three types of classifications of satellite data to identify the most suitable for making city maps in a semi-arid region. The source of our data was GeoEye 1 satellite. To classify this data, two pro-grammes were used: an Object-Based Classification and a Pixel-Based Classification. The second classification programme was further subdi-vided into two groups. The first group included classes (buildings, streets, vacant land, vegetations) which were treated simultaneously and on a single image basis. The second, however, was where each class was identified individually, and the results of each class produced a single image and were later enhanced. The classification results were then as-sessed and compared before and after enhancement using visual then automatic assessment. The results of the evaluation showed that the pix-el-based individual classification of each class was rated the highest after enhancement, increasing the Overall Classification Accuracy by 2%, from 89% to 91.00%. The results of this classification type were adopted for mapping Jeddah’s buildings, roads, and vegetations.

关键词： Remote Sensing Satellite Imagery Image Processing Classification Assessment Urban

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Analysis of Hydro-Climatical Variability in the Mo Basin in Togo

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Journal of Water Resource and Protection 2021年第12期13卷 1043-1060页

作者： Koko Zébéto Houédakor Dametoti Yamoula department of geography Faculty of Human and Social Sciences Université de Lomé Lomé Togo

Climate changes are affecting water resources around the world and the Mo Basin (MB) in Togo is no exception to this observation. This study aims at analyzing the influence of hydro-climatical data in the Mo Basin. To achieve this, Pettit’s stationarity break tests, Hubert’s segmentation, Nicholson’s [1] reduced centered index, Lamb [2] and flow coefficients have been applied. In addition, temperature, precipitation, evapotranspiration, relative humidity and discharge data from 1961 to 2018 have been used for this purpose. While rainfall is decreasing despite an increase of 22.8% at the Fazao station and 2.8% at Sotouboua station, the flow coefficients evolve synchronously with the precipitation data and show a strong link between both parameters. The climatic balance sheet is positive six months in the year (May to October), throughout the period of observation (1961-2018). Only 1962 and 1963 recorded an annual rainfall greater than the annual evapotranspiration. The other years undergo a climatic drought, increasingly pronounced, which strongly impacts the hydrology of rivers. This has a strong impact on water resources and food security and resources of the Fazao-Malfakassa reserve in the region.

关键词： Climate Variability Hydro-Climatic Balance Mo Basin Togo

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Applications of Thermal Imaging in Agriculture—A Review

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Advances in Remote Sensing 2014年第3期3卷 128-140页

作者： Roselyne Ishimwe K. Abutaleb F. Ahmed department of geography Environmental Management and Energy Studies University of Johannesburg Johannesburg South Africa School of geography Archaeology and Environmental Studies University of Witwatersrand Johannesburg South Africa

In thermal remote sensing the invisible radiation patterns of objects are converted into visible images and these images are called thermograms or thermal images. Thermal images can be acquired using portable, hand-held or thermal sensors that are coupled with optical systems mounted on an airplane or satellite. This technology is a non-invasive, non-contact and non-destructive technique used to determine thermal properties and features of any object of interest and therefore it can be used in many fields, where heat is generated or lost in space and time. Potential use of thermal remote sensing in agriculture includes nursery and greenhouse monitoring, irrigation scheduling, plants disease detection, estimating fruit yield, evaluating maturity of fruits and bruise detection in fruits and vegetables. This paper reviews the application of thermal imaging in agriculture and its potential use in various agricultural practices.

关键词： Infrared Radiation Infrared Thermography Thermal Imaging Crop Agriculture

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地球地质历史中非生物成因的自组织耗散结构(英文)

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地学前缘 2009年第6期16卷 257-275页

作者： S.L.Shvartsev Tomsk department Trofimuk Institute of Petroleum Geology and Geophysics of Siberian Branch of the RAS

自从地球上有水出现,就持续存在水-岩体系的平衡-不平衡。这一体系内部是不协调的,这就决定了它在地质历史的长河中自发地连续发展的可能性,并导致完全新的矿物相和水的不同地球化学类型的生成。在地壳中这一体系持续在一个热力学分支... 详细信息

自从地球上有水出现,就持续存在水-岩体系的平衡-不平衡。这一体系内部是不协调的,这就决定了它在地质历史的长河中自发地连续发展的可能性,并导致完全新的矿物相和水的不同地球化学类型的生成。在地壳中这一体系持续在一个热力学分支的线性域中,远离平衡而发育。它积聚太阳能,形成非生物成因耗散结构。它在连续发育惯性中起特殊作用,然后发育为一种生命物质。前进自组织将向该体系倾斜的趋向,定义为无机物质发育的基础之一。还有其他的一组体系都从这个体系中继承了它大多数的性质。水-岩体系的演化导致了次生矿物相和水的地球化学新类型的形成。随着演化程度加深,体系在成分上、结构上逐渐变得复杂,形成新的地球化学介质,它们又反过来控制新矿物相的生成从而对自身的性质产生影响。这一过程在地质历史上是永恒的。这便是矿物界自组织的要点,即包括发生、生长及新结构形体的时-空弥散以及矿物、地球化学介质的形成,最后是新的有机物质和生命的起源。

关键词：耗散结构前进自组织平衡水-岩体系矿物生成的能量次生矿物生成的地球化学类型

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Retrieving crop leaf area index by assimilation of MODIS data into a crop growth model

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Science China Earth Sciences 2010年第5期53卷 721-730页

作者： WANG DongWei1,2,3, WANG JinDi1,2 & LIANG ShunLin4 1 State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing Applications, CAS, Beijing 100875, China 2 School of geography, Beijing Key Laboratory of Environmental Remote Sensing and Digital City, Beijing Normal University, Beijing 100875, China 3 Haihe River Water Conservancy Commission, Tianjin 300170, China 4 department of geography, University of Maryland, College Park, MD 20742, USA 1. State Key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing Applications CAS Beijing 100875 China2. School of Geography Beijing Key Laboratory of Environmental Remote Sensing and Digital City Beijing Normal University Beijing 100875 China3. Haihe River Water Conservancy Commission Tianjin 300170 China4. Department of Geography University of Maryland College Park MD 20742 USA

Leaf area index (LAI) is an important parameter in monitoring crop growth. One of the methods for retrieving LAI from remotely sensed observations is through inversion of canopy reflectance models. Many model inversion methods fail to account for variable LAI values at different crop growth stages. In this research, we use the crop growth model to describe the LAI changes with crop growth, and consider a priori LAI values at different crop growth stages as constraint information. The key approach of this research is to assimilate multiple canopy reflectance values observed at different growth stages and a priori LAI values into a coupled crop growth and radiative transfer model sequentially using a variational data assimilation algorithm. Adjoint method is used to minimize the cost function. Any other information source can be easily incorporated into the inversion cost function. The validation results show that the time series of MODIS canopy reflectance can greatly reduce the uncertainty of the inverted LAI values. Compared with MODIS LAI product at Changping and Shunyi Counties of Beijing, this method has significantly improved the estimated LAI temporal profile.

关键词： inversion leaf area index crop growth model time series MODIS

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Post-industrial Economic Restructuring and Wage Inequality in Urban China, 2003-2015: A Sectoral Perspective

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Chinese Geographical Science 2020年第3期30卷 516-531页

作者： YANG Fiona Fan HU Fox Zhiyong WANG Yuhua School of geography and Planning Sun Yat-sen UniversityGuangzhou 510275China department of Asian and Policy Studies The Education University of Hong KongHong Kong 999077China College of Water Conservancy and Civil Engineering China Agricultural UniversityBeijing 100083China

Income inequality in urban China has attracted growing attention from China’s urban researchers and policy makers. Whereas many studies have interrogated the pattern and process of the income gap in Chinese cities undergoing the institutional transformation from plan to market, relatively little is known about how such unequal distribution of income is related to China’s ongoing structural transformation toward a post-industrial economy. Drawing on a decomposition methodology based on the Theil index, this study aimed to address this lacuna through an empirical investigation of China’s urban wage inequality from a sectoral perspective. Our empirical study identified the low-wage manufacturing sector and the high-wage producer services sector as the two biggest contributors to urban wage inequality in China. Urban wage inequality within the producer services was found to be caused by the spatial concentration of a disproportionate number of high-paying jobs in a few developed, high-tier city-regions on the eastern coast. Our empirical findings have important implications for the formulation of policies to address the income inequality that plagues China’s continuing urbanization.

关键词： wage inequality post-industrial economy economic restructuring producer service urban China

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The Influence of Large-Scale Circulation on the Summer Hydrological Cycle in the Haihe River Basin of China

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Acta meteorologica Sinica 2011年第4期25卷 517-526页

作者： OU Tinghai LIU Yanxiang CHEN Deliang David RAYNER ZHANG Qiang GAO Ge XIANG Weiguo School of geology Beijing Normal University Beijing 100875 China department of Earth Sciences University of Gothenburg GSteborg 40530 Sweden National Climate Center China Meteorological Administration Beijing 100081 China College of Atmospheric Sciences Chengdu University of Information Science ~ Technology Chengdu 610225 China

In this study, we focus on changes in three important components of the hydrological-cycle in the Haihe River basin （HRB） during 1957-2005： precipitation （Prep）, actual evaportranspiration （ETa）, and pan evaporation （PE）-a measure of potential evaporation. The changes in these components have been evaluated in relation to changes in the East Asian summer monsoon. Summer Prep for the whole basin has decreased significantly during 1957-2005. Recent weakening of the convergence of the integrated water vapor flux, in combination with a change from cyclonic-like large-scale circulation conditions to anti-cyclonic-like conditions, led to the decrease in the summer Prep in the HRB. ETa is positively correlated with Prep on the interannual timescale. On longer timescales, however, ETa is less dependent on Prep or the large-scale circulation. We found negative trends in ETa when the ERA40 reanalysis data were used, but positive trends in ETa when the NCEP/NCAR reanalysis data were used. PE declined during the period 1957-2001. The declining of PE could be explained by a combination of declining solar radiation and declining surface wind. However, the declining solar radiation may itself be related to the weakening winds, due to weaker dispersion of pollution. If so, the downward trend of PE may be mainly caused by weakening winds.

关键词： hydrological cycle runoff Lamb-Jenkinson classification circulation Haihe River basin (HRB)

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Smartphone based precise monitoring method for farm operation

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International Journal of Agricultural and Biological Engineering 2016年第3期9卷 111-121页

作者： Wu Caicong Zhou Lin Wang Jie Cai Yaping College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China department of Soil&Crop Sciences Texas A&M UniversityCollege StationTX 77843USA department of geography and Geographic Information Science University of Illinois at Urbana-ChampaignUrbana-Champaign 61820USA

Although Global Navigation Satellite System(GNSS)terminal has been widely used for fleet management,it cannot satisfy the need of managing changes of laborer and implement during farm operation,which are important for social service cooperatives comparing to family farms in *** objective of this study was to explore a precise,low cost and easy-to-use method for vehicle fleet management of large scale farm machinery cooperatives.A smartphone based application software(APP)named Precise Monitoring System(PMS)was developed to record the farm operation information including tractor,implement and laborer by scanning their Quick Response codes(QR codes),and obtain real time GNSS positions by using built-in GNSS chip of *** the convenience usage for farmers,only two buttons,“start/pause/continue”and“stop”were designed to record farm operation ***,IDs,positions and operation status were combined and transferred to the server through GPRS/3G/*** kinds of experiments were designed and conducted to verify the *** results showed that PMS can realize the basic functions such as precise and real-time monitoring,operation quality tracing,operation mileage and operation area calculating,and U-turn *** method and APP could record complex combination of production factors precisely and accurately,which is suitable for the management of vehicle fleet,and can replace GNSS terminal to some extent.

关键词： smartphone agricultural machinery farm operation monitor method system

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