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GIS Application for Monitoring Groundwater Arsenic Contamination in Bangladesh Md. Rowshon Kamal 1 , Md. Masud Karim 2 and Kwok Chee Yan 1 1 Department of Biological and Agricultural Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor DE, Malaysia. 2 Dainichi Consultant Inc., 3-1-21 Yabuta Minami, Gifu 500-8384, Japan. ABSTRACT. Bangladesh is a nation of over 125 million population with a geographical area of 1,48,393 km 2 and located on the Ganges, Brahmaputra, and Meghna Delta. The major part of the country is now severely affected by mass poisoning from arsenic in groundwater. The latest statistics on the arsenic contamination in groundwater indicates that 59 out of 64 districts, about 80% of the total area of Bangladesh and about 40 million people are at risk. Presently about 116 million people depend on water from tube-wells for drinking, cooking, washing and bathing and about 60 million people are drinking and using arsenic contaminated groundwater. Arsenic level now ranges from 0 ppm to 0.98 ppm and the maximum permissible level of arsenic in Bangladesh drinking water is 0.05 ppm. Average values of different tubewells data on thana census blocks have been used in this study. A spatial and temporal distribution of Groundwater Arsenic Contamination Intensity (GACI) has been developed using Geographical Information System (GIS) in order to assist decision making process in some critical areas, particularly to protect human health. The digitized thana boundary maps with longitude-latitude coordinates storing information in the form of metadata has also been developed to visualize GACI information in thana census blocks of Bangladesh. The MapBasic Professional 4.5 has used for developing user-interface design and MapInfo Professional 4.5 for the visualization of spatial information. The user-interface GIS approach can help policy makers deciding proper groundwater utilization and taking necessary steps to supplying safe drinking water to the domestic and industrial areas. KEY WORDS: groundwater, arsenic contamination, monitoring, Bangladesh and GIS. INTRODUCTION Natural resources are not only the basis for economic activities and human welfare, but also make up essential components of our natural environment. They are subject to ever increasing demands and exploitation by growing populations and per-capita requirements. Government regulations and international agreements, market mechanisms, cultural traditions and individual preferences affect and control these resources, but rarely do these mechanisms suffice to ensure a sustainable management of resources, and in particular, the commons [1] . Groundwater provides safe drinking water to over 86 percent of the rural population in Bangladesh [2] . This extensive coverage is indicative of the country’s successful attempt to provide safe drinking water to its general people. This respectable public health effort was overshadowed when in 1993 an alarming discovery confirmed of arsenic contamination in groundwater. The arsenic contamination discovery was first made in the northeastern part of the country. Groundwater contamination of arsenic has already affected 59 out of 64 districts of Bangladesh. It is estimated that around 1.12 million tubewells are contaminated by arsenic of the whole country [3] . Now a days, advanced technology has become emerging management tool to various environmental agencies to provide spatial and temporal updated information in their environmental problems. The powerful GIS software tools in problem oriented systems provides direct and easy access to large volumes of data. It supports their interactive analysis and helps to display and interpret results in a format directly understandable and useful for decision-making processes. An organized collection of computer hardware, software, geographic data, and
Transcript

GIS Application for Monitoring Groundwater ArsenicContamination in Bangladesh

Md. Rowshon Kamal1, Md. Masud Karim2 and Kwok Chee Yan1

1Department of Biological and Agricultural Engineering, Faculty of Engineering, UniversitiPutra Malaysia, 43400 UPM Serdang, Selangor DE, Malaysia.2Dainichi Consultant Inc., 3-1-21 Yabuta Minami, Gifu 500-8384, Japan.

ABSTRACT. Bangladesh is a nation of over 125 million population with a geographicalarea of 1,48,393 km2 and located on the Ganges, Brahmaputra, and Meghna Delta. The majorpart of the country is now severely affected by mass poisoning from arsenic in groundwater. Thelatest statistics on the arsenic contamination in groundwater indicates that 59 out of 64 districts,about 80% of the total area of Bangladesh and about 40 million people are at risk. Presentlyabout 116 million people depend on water from tube-wells for drinking, cooking, washing andbathing and about 60 million people are drinking and using arsenic contaminated groundwater.Arsenic level now ranges from 0 ppm to 0.98 ppm and the maximum permissible level of arsenicin Bangladesh drinking water is 0.05 ppm. Average values of different tubewells data on thanacensus blocks have been used in this study. A spatial and temporal distribution of GroundwaterArsenic Contamination Intensity (GACI) has been developed using Geographical InformationSystem (GIS) in order to assist decision making process in some critical areas, particularly toprotect human health. The digitized thana boundary maps with longitude-latitude coordinatesstoring information in the form of metadata has also been developed to visualize GACIinformation in thana census blocks of Bangladesh. The MapBasic Professional 4.5 has used fordeveloping user-interface design and MapInfo Professional 4.5 for the visualization of spatialinformation. The user-interface GIS approach can help policy makers deciding propergroundwater utilization and taking necessary steps to supplying safe drinking water to thedomestic and industrial areas.KEY WORDS: groundwater, arsenic contamination, monitoring, Bangladesh and GIS.

INTRODUCTION

Natural resources are not only the basis for economic activities and human welfare, but alsomake up essential components of our natural environment. They are subject to ever increasingdemands and exploitation by growing populations and per-capita requirements. Governmentregulations and international agreements, market mechanisms, cultural traditions and individualpreferences affect and control these resources, but rarely do these mechanisms suffice to ensure asustainable management of resources, and in particular, the commons [1]. Groundwater providessafe drinking water to over 86 percent of the rural population in Bangladesh [2]. This extensivecoverage is indicative of the country’s successful attempt to provide safe drinking water to itsgeneral people. This respectable public health effort was overshadowed when in 1993 analarming discovery confirmed of arsenic contamination in groundwater. The arseniccontamination discovery was first made in the northeastern part of the country. Groundwatercontamination of arsenic has already affected 59 out of 64 districts of Bangladesh. It is estimatedthat around 1.12 million tubewells are contaminated by arsenic of the whole country [3].

Now a days, advanced technology has become emerging management tool to variousenvironmental agencies to provide spatial and temporal updated information in theirenvironmental problems. The powerful GIS software tools in problem oriented systems providesdirect and easy access to large volumes of data. It supports their interactive analysis and helps todisplay and interpret results in a format directly understandable and useful for decision-makingprocesses. An organized collection of computer hardware, software, geographic data, and

personnel designed to efficiently capture, store, update, manipulate, analyze, and display allforms of geographically referenced information. GIS provides a valuable tool for informationanalysis, automated mapping and data integration. Mark et al. [4] gives a useful definition thatencompasses its functionality. It is defined as a computerized system for the storage, retrieval,manipulation, analysis and display of geographically referenced data, where include physical,biological, cultural, demographic or economic information and provide valuable tools in thenatural resources, social, medical and engineering sciences, as well as in business and planning.

Information technology in particular, GIS provide powerful tool for effective decision support innatural resources management. A GIS can automate existing as well as provide enhancedcapability to analyze geographic information for decision-making purposes. This study has beenconducted on the arsenic databases of all thanas in Bangladesh. These basic databases areutilized for visualizing geographically located arsenic contamination level by User-interface GISTool. It will help to provide temporal and spatial GACI information to policy personnel aboutcurrent situation and take necessary steps for supplying safe drinking water to the domestic andindustrial areas and to mitigate the groundwater arsenic contamination.

DATA REQUIREMENTS AND SOURCES

Various information are stored in the GIS in the form of geographic data sets or layers. Thedigitized thana census blocks map provided the geographical framework. In studies using GISthe first requirement is the availability of a map which is the backbone of the system. MapInfoProfessional 4.5 used for digitizing the study area. The accuracy of manual digitizing merelydepends on how accurate the hardcopy map is duplicated on a computer by hand. Geographicallyreferenced arsenic data were collected on a number of tubewells in the different locations for theindividual thana census block and after then average values were taken in this study. Data onsome thanas was not available. To perform the monitoring of GACI, geographically referenceddata were typically obtained from the Dainichi Consultant, Incorporated, in Japan working withthe Arsenic Mitigation Project in Bangladesh. The lack of information is the major bottleneck forthe study.

DATA STRUCTURES

The database is a core of GIS. The MapInfo Professional software used to generate inputs ofGroundwater Arsenic Contamination Intensity in the Thana census block (3rd largest area). GISsoftware provides flexibility in developing and tailoring output formats to meet individualrequirements. Its database allows storage, retrieval, and analysis of data in formats that areinterchangeable between different computer based application packages and helps to develop theuser-interfaces. Database is facilitated by structured format defining fields (Columns) andrecords (Rows) data repository. The completeness and accuracy of database give the quality ofanalysis and final products of the system. This database helps to portray geographical locationsand monitor changes of the GACI in both spatial and temporal dimensions. Secondary data maybe generated from that in the database. MapBasic provides powerful Database-access tools. Thestructure of the database is customized to the needs of the user. Linking database with the User-interface helps to understand about the overall pictures of country's GACI for the policy makers.

DESIGN AND OPERATIONS OF USER-INTERFACE GIS TOOL

Description of Main Menu

The MapBasic programming language has used to develop user-interface tool for monitoringGroundwater Arsenic Contamination Intensity. The main menu of Arsenic Monitoring appears

directly in the Menu bar of MapInfo. It comprises eight menu items and its sub menu itemsnamed by district, as detailed in Figures 2 and 3. This tool is devoted to the monitoring of thepresent situation of GACI for the thana census blocks of whole of the country, individualdivisions and districts, respectively. The dialog window is activated in the MapInfo windowwhen user clicks on Sub-menu item Arsenic Intensity shows in the Figure 4. It proposes thedisplay of maps, browses and charts to visualize the GACI level when user clicks on a particularCheckBox dialog and/or any number of dialogs. These CheckBox dialogs are directly linkedwith programming modules and instantly display output within the MapInfo window whendialog window is terminated. OKButton and CancelButton dialogs control the dialog window.By clicking on the Menu item Exit, then instant message appears to inform the user that theapplication is terminated. It gives dialog message during operation period and user will be ableto know how to get information for specific query from dialog window.

Run MapBasic Program“Arsenic Monitoring”

Select Menu“Arsenic Monitoring”

SelectSub menu

Click on Sub Menu ItemArsenic Intensity

Visualizationof Dialog

Choose QueryFrom CheckBox

Exit Program

If No

ChooseAgain

ChooseAgain

DisplayOutputs

If No

Fig. 1. Flowchart Showing Operational Systems to Arsenic Monitoring Program

Fig. 2. Main Menu and Menu Items of Customized Window for Arsenic Monitoring.

Fig. 2. Main Menu and Menu Items of Customized Window for Arsenic Monitoring.

Fig. 3. Showing Customized Window for Monitoring of Individual District

Fig. 4. Showing Dialog Window and Queries by CheckBox Dialogs for Arsenic Monitoring.

RESULTS AND DISCUSSIONS

At present several groups of the government (British and Swiss) with financial and technicalassistance from international donor agencies (World Bank), NGOs and Universities are workingon the arsenic problems and exchange of information among themselves. Groundwaterconcentration below 0.01 mg/l is considered safe according to World Health Organization(WHO) Drinking Water Guidelines. However, in Bangladesh, the maximum permissible limit ofarsenic in drinking water is 0.05 mg/l. In many different ways (i.e. map, graphs and tabularform), the user-interface GIS could provide rapid information on the present status of arseniccontaminated groundwater of the thana census blocks. Figures 5 and 6 explain the presentarsenic concentration by graph and color-coded map of the whole country. The first two lightcolors show arsenic concentration under permissible limit for drinking and rests are above thelimit in the Figure 5. Arsenic concentration of 163 thanas has exceeded the permissible level0.05-ppm out of 460 shows in Figure 5. The arsenic concentration of some thanas is severaltimes higher than of permissible limit of 0.05, shows in Figures 7 and 8. The user can get also

affected thana name by using label button or by keeping the cursor on the particular thana.Figure 9 shows spatial distribution of arsenic concentration > 0.05 ppm with labeling of thanas inKhulna division. Table 1 also presents average and maximum arsenic concentrations of affectedthanas in Khulna.

Fig. 5. Thematic Map of Arsenic Concentration onThana Census Blocks of the Country.

Fig. 6. Arsenic Concentration of ThanaCensus Blocks of the Country.

Fig. 7. Thematic map on affected Thana CensusBlocks of arsenic concentration > 0.05 ppm.

Fig. 8. Arsenic Concentration > 0.05 ppm ofThana Census Blocks of the Country.

Fig. 9. Thematic Map of Khulna Division whereArsenic Concentration > 0.05 ppm.

Table 1. Arsenic Concentration of ThanaCensus Blocks of Khulna Division.

Fig. 10. Comparison of Average and Maximum Values of Arsenic Concentration onThana Census Blocks along with WHO and Bangladesh Standard of the Khulna Division.

Average and maximum arsenic concentration of all thana census blocks have also presentedalong with the values of WHO and Bangladesh standard in Figure 10. The two straight linesrepresent arsenic safe level by WHO and Bangladesh Standard 0.01 and 0.05, respectively. Dotline shows maximum values of all thana census blocks in Khulna division and other straight linefor the average values. Dialog window would be able to give information by clicking theCheckBox dialogs for different queries for all divisions and districts accordingly.

CONCLUSISON

The discovery of arsenic in groundwater in several areas of Bangladesh has aroused widespreadconcerns. We need to conduct the assessment rapidly, compiling existing information andintegrating these data with GIS. The user-interface GIS can be used successfully for monitoringgroundwater arsenic contamination intensity on the basis of thana census data. The informationcan be explored to enable monitoring arsenic contamination evolve towards decision makingusing GIS user-interface tool. This program can be used for monitoring of GACI in differentscales after updating of database in the future. This study would be helpful for building upmonitoring technique for different depths with geographically referenced tubewell locations forindividual thana census block. This comprehensive study will give detail picture of GACIthroughout the country and can be helpful to coordinating among the different working groupson arsenic mitigation projects in Bangladesh.

REFERENCES1. Hardin, G. (1968) The tragedy of the commons. Science 162:1243-1248.2. BBS, Statistical Year Book of Bangladesh, Bangladesh Bureau of Statistics, 1997.3. Karim M. M. and Z. R. Begum (1999) Groundwater Arsenic Contamination Inventories and

Risk Assessment using GIS: Case Studies Kishoreganj and Netrokona Districts ofBangladesh. 92nd Annual Meeting of A & WMA, San Diego, St. Louis, USA.

4. Mark. D M. Et al (1996) The GIS History Project. www.spatial.edu/ucgis/mark/chgis.html


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