Abstracts of PG.Dip. (WRD) Project Reports

 

 

 

Project title:

Assessment of Local Views on Water Logging in a Polder Project and its Solutions

 

Name of the student:

Maqsud Hashem

 

Name of the Supervisor:

Dr. Sujit Kumar Bala

 

Date of award of diploma:

30 August 2006

 

Abstract:

Polders projects implemented in the coastal area of Bangladesh for Flood Control and Drainage (FCD) are suffering from water management problems. The Polder 43/2D, a FCD project, located at Patuakhali Upazila, is one of them. The gross project area is about 8,800 ha. After implementation in 1995, the project had a better agricultural production for a few years. Within ten years of implementation of the project, most of the drainage canals were silted up except the Marichbunia, which serves the two third area of the polder. The 4-vent regulator over Marichbunia canal failed and the canal was closed by a cross dam. As a result, the whole project faced water logging, drainage congestion and degraded water quality. This study has been carried out at Polder 43/2D to assess local views on water logging by applying Participatory Rural Appraisal (PRA) and its solutions considering people’s views and suggestions to make the polder management sustainable.

 

At first, a reconnaissance study was carried out in the study area through Transect Walk and a Social Mapping was done for identifying stakeholders directly or indirectly involved in the polder management. Four PRA groups were formed for conducting Focussed Group Discussions (FGD), through which problem identification and its ranking were performed. Historical Time Lines in Water Management of Marichbunia Canal and Seasonal Variation, the well known tools of PRA, were applied through discussions with local farmers, fishermen, key informants, local leaders and professionals. Finally, Problem Tree regarding water management was generated by summarising the local views of different stakeholders.

 

It has been found from the PRA that priority of problems varies according to occupation of people (farmers and fishermen), location of area (medium highland and low land) and gender (male and female). People of all groups confirm common opinion about maintaining sustainable FCD project. The local people showed their willingness to participate in operation and maintenance of water control structures. Water control structures should be constructed considering land elevation at micro level for better use and management. Local influential groups play vital role in decision making in rural water management. Common people are usually guided by decisions from local influential groups. Women possess their own views on water management. Their participation, role and ideas vary to some extent from men. Water professionals need to take a closer look at local views and ideas. Local views should be studied and taken into consideration by officials involved in water development project planning and implementation.

 

 

 

 

 

 

Project title:

Determination of Location of Shared Stand Posts for Vulnerable People at Duptara Village Piped Water Supply System using GIS

 

Name of the student:

Marina Rahman

 

Name of the Supervisor:

Prof Rezaur Rahman

 

Date of award of diploma:

11 November 2006

 

Abstract:

In Bangladesh, a large number of people are suffering from the lack of arsenic safe water. The government, NGOs, external agencies and many other institutions are undertaking different programs to provide arsenic safe water to the populations especially in rural areas. Among the various options available, piped water supply system for rural villages and growth centers is one of the feasible options to provide arsenic safe water in rural areas. Piped water supply is different from other alternative options (hand tube well, dug well, pond sand filter, chemical based treatment household units etc). Piped water supply schemes can provide solution to the arsenic problem and can also deliver water of the appropriate quality and in adequate quantity.

 

The Government and the World Bank have agreed to support the implementation of an initial group of pilot village piped water supply systems. Within these, Duptara village piped water supply system is one of the pilot water supply systems where the study is conducted to find the location of shared stand posts for vulnerable people using GIS. The study included analysis of vulnerable people of the community who are not able to pay even the lowest tariff for a shared stand post. A limited number of stand posts with free access to water limited to drinking and cooking purposes is to be provided for these vulnerable people.

 

The study has been conducted in three paras at Duptara village of Araihazar upazila in Narayangonj district through detailed household survey for vulnerability assessment. Twenty criteria have been used to assess vulnerability of a household. The criteria include age, sex, education, marital status, religion, no. of household members, income, housing type, physical disability, current water source, distance of water source, water source of drinking purpose, security issues of women and girls for water collection, quality of existing water, problem for water collection, arsenic effected patients and suffering from water borne disease. Feasible locations of shared stand posts have been identified based on focused group discussion with vulnerables and consultation with local elites and knowledgable persons. GIS tools have been used to fix the location of shared stand post on the basis of average, maximum and minimum distances. Developed GIS methodology will be useful for generating such data for feasibility study of piped water supply system.

 

 

 

 

 

 

Project title:

Environmental Impacts of Drainage Congestion inside the Dhaka Town Protection Embankment at Rayerbazar Area

 

Name of the student:

Nahid Rezwana

 

Name of the Supervisor:

Dr. Sujit Kumar Bala

 

Date of award of diploma:

29 March, 2007

 

Abstract:

 

Drainage congestion inside Dhaka Town Protection Embankment (DTPE) has created serious environmental changes in the western part of the Dhaka City. In a study carried out in the inner side of the DTPE at Rayerbazar, Environmental Impact Assessment (EIA) was obtained by applying a suitable expert system, taking consideration of both primary and secondary data. The study result shows that drainage congestion has a severe impact (Environmental Impact Value, EIV is -319) on the hydrology, agriculture, fisheries, health and socio-economic condition of the study area. The main causes of drainage congestion at Rayerbazar are unplanned and rapid urbanization along with the inadequate drainage system, encroachment and filling up of the drainage channels, discharge of waste from the tanneries and households. The result suggests that Government should take proper steps to mitigate the problem and local people should be more aware about the situation.                

 

 

 

 

 

 

 

Project title:

Impact of Groundwater Irrigation on Dry Season Flow of the Tangan River   

 

Name of the student:

Mousumi Datta

 

Name of the Supervisor:

Dr. M. Shahjahan Mondal

 

Date of award of diploma:

30 August 2006

 

Abstract:

In Bangladesh groundwater irrigation is a common practice for agricultural production. Increased use of groundwater irrigation for agricultural uses may have resulted in declines of dry season streamflow and baseflow. In this study, an attempt was made to investigate the relation of the Tangan River dry season flow and baseflow with the abstraction of groundwater in its catchment through the systematic use of statistical and baseflow separation techniques. Data analyzed include streamflow, baseflow, and groundwater levels. The baseflow separation was done using the software BFLOW.

 

Boro season (January to early May) was considered for the study since groundwater is the only source of irrigation during these four months. Average decadal (10- day) streamflow and baseflow were calculated for these four months over a period from 1973 to 1993. Time series of average decadal srtreamflow and baseflow showed a declining trend of river flow. The study estimated the percentage of average streamflow and baseflow reduction in the Tangan River during these four months period over the study time of 1973 to 1993 and these were found to be 41 % and 35 % respectively. Trend line fitted to the lowest groundwater table was also found to be downward and this indicates the lowering of groundwater table through the time period of 1973 to 1993. An increased amount of groundwater was withdrawn from the study area over the study time, which was estimated from drawdown and specific yield data. A correlation coefficient of -0.66 between the streamflow and groundwater abstraction was obtained for the period from 1973 to 1993. For baseflow and groundwater abstraction, the correlation coefficient was found to be -0.67. Furthermore, for baseflow, the correlation coefficient increases to        -0.91 if data from 1978 are considered due to their better reliability. Groundwater abstraction correlates well with baseflow (-0.91) than streamflow (-0.66). With 1 unit increase of groundwater abstraction, baseflow of the river would decrease by about 0.2 unit. The statistical analysis indicates that the primary factor causing the streamflow and baseflow declines is lowered groundwater level caused by increased abstraction mainly from dry season irrigation.

 

 

 

 

 

 

 

Project title:

Application of Remote Sensing in Identifying Pollutant Spread in the Buriganga River

 

Name of the student:

            Mohammad Ruhul Amin

 

Name of the Supervisor:

            Dr. G.M. Tarekul Islam

 

Date of award of diploma:

February 19, 2006

 

Abstract:

An experimental method was applied to interpret relationship among highly turbid water from Buriganga River and reflectance of Remote Sensing Image, Landsat TM of the year 2003 and SPOT-4 of the year 2001 for estimating sediment concentration in the river. The satellite data should become an independent measurement tool for water management authorities. Water of Buriganga River is characterized by high concentration of suspended and dissolved organic and inorganic particulate matter derived from Dhaka City sewage and industrial waste disposal added with transported sediment from upstream. The study synchronized field based water quality data i.e. sediment concentration in different places of the river with remotely sensed imagery (SPOT and Landsat) to derive inference for predicting sediment concentration of the Buriganga river based on only satellite images. Again Total Solids (TS) were measured at 12 water samples of different locations along the Buriganga River. Supervised and unsupervised classification techniques were applied to the satellite images for mapping the sediment concentration distribution. On the other hand correlation coefficient and coefficient of determination were calculated among sediment concentration values and DN values of corresponding places of the images. The Landsat band ratio band3/band4 (Red: 0.63-0.69µm / NIR: 0.76-0.90µm) had highest correlation coefficient of -0.53 among reflectance of all Landsat bands and band ratios.  The result showed that higher level of turbidity will give lower value of reflectance in those Landsat bands. SPOT band XS3 (correlation coefficient of 0.49), band ratios XS3/XS1 (correlation coefficient of 0.55) and XS3/XS2 (correlation coefficient of 0.573) were highly correlated with sediment concentration. The use of remotely sensed reflectance  ratios reduced skylight reflection and was therefore used instead of a single band. As a result sediment concentrations quantified to a high precision (±33%) in band ratio XS3/XS2. The SPOT-HRV and Landsat TM data provided reasonable sediment concentration distribution in the Buriganga River. The results of the sediment detection process were mapped for effective visualization of pollutants spread throughout the Buriganga River channel.

 

 

 

 

 

 

 

Project title:

            Sediment Transport Predictor in the Ganges River

 

Name of the student:

            Shahana Akhter

 

Name of the Supervisor:

            Dr. G.M. Tarekul Islam

 

Date of award of diploma:

            2004

 

Abstract:

           

The sediment transport characteristics of the Ganges river have been studied. The peak discharge does not necessarily always coincide with the peak sediment load. There is a phase lag between the peak discharge and the peak sediment load. The peak sediment load occurs first and then the peak discharge with only exception where the peak sediment load is followed by the peak discharge. In some cases, the peak discharge and peak sediment load occur at the same instances. The maximum discharge and maximum fine sediment discharge are free from trend but the maximum sand discharge and maximum total sediment discharge show an upward trend beginning from 1992. The percent of fine sediment discharge is about 50 which means that the Ganges river at Hardinge bridge gauge station contains a substantial amount of wash loads.

 

The unit stream power formula and modified unit stream power formula have been applied for the estimation and prediction of sediment transports in the Ganges river. The comparison between computed and measured sediment discharge based on Yang’s unit stream power formula and modified Yang’s formula for high concentration of fine sediments show that Yang’s formula over predicts the sediment transport than the modified formula. The discrepancy ratio and standard deviation have been used to indicate the accuracy of the sediment transport predictors.  The modified Yang’s formula is better in the sediment laden Ganges river. Comparisons between computed and measured sediment concentrations based on the average logarithm ratio indicate that the goodness of fit of different equations may be affected by selecting statistical parameters.

 

The sediment rating curve of the Ganges river at Hardinge bridge gauge station have been developed by considering discharge, shear stress, stream power and unit stream power as independent variables. The discharge and unit stream power when used as independent variables give better curve as compared to shear stress and stream power.

 

 

 

 

 

  

Project title:

Environmental Impact of Drainage Congestion in the DND Project Area and Its Mitigation Approach

 

Name of the student:

            Quazi  Md. Fazlul Haque

 

Name of the Supervisor:

            Dr. Md. Zahurul Islam

 

Date of award of diploma:

            2005

 

Abstract:

Most of the DND Project area has now become part of the suburban areas of Dhaka City due to land use transformation in its periphery in the last three decades. With the increase in residential houses, commercial enterprises and industrial concerns, there has emerged a necessity of additional roads, water bodies etc. But adequate drainage facilities is yet to be developed to cope with the changing situation of additional surface runoff caused as a result of urbanization with the increasing trend of population within the project area. In recent years the DND project area is facing acute problems of drainage congestion during resulting in severe sufferings to the inhabitants living within the area. The present study is aimed at identifying the causes of drainage congestion, existing drainage facilities, assess environmental impacts of drainage congestion in the DND Project area and suggest remedial measures for mitigating the problems concerned. For collection of data and information Participatory Rapid Appraisal (PRA) was conducted. Focus Group Discussions (FGDs) were made at different locations to identify the causes and consequences of drainage congestion including remedial measures. Environmental Evaluation System (EES) developed by Battle Columbus Laboratories in the United States was applied to determine the Environmental Impact Value (EIV).

 

The study revealed that the main causes of drainage congestion are: inadequacy of drainage canals, filling up of drainage canals by solid waste, land use transformation through unplanned and rapid urbanization, limitation of the pumps, not starting the pump timely by the operators, accumulation of polythene in the drainage canals, filling up and reduction of drainage canals, encroachment of drainage canals by unauthorised establishments, elevating the road towards plinth level, household waste obstructing drainage channel, construction of roads by earth filling in the canals, absence of proper drainage systems and discharge of different industries particularly by dying industries. The negative impacts in hydrology sector as identified were: water logging, water pollution and hideous smell, while the same as identified in the agricultural sector were: decrease in agricultural lands, yields and land fertility, decrease in pasture lands and fodder, problems in preparation of seed beds. The negative impacts in fisheries sector as identified were: increase in fish diseases and overtopping of fishponds, while the same as identified in health sector were: deficiency in pure drinking water, malnutrition and health hazards of the people especially the children; increase of water borne diseases, mosquitoes and venomous animals and insects. The negative impacts as identified in the socio-economic sector were: decrease in employment opportunity and income of the farmers, change in occupation, damages of homesteads, educational & other institutions and difficulties in schooling of the children, change in land ownership and as a whole decrease in quality of living of the people. Environmental Impact Assessment (EIA) on the hydrological, agricultural, fisheries, health and socio-economic sectors of the DND Project area revealed that the total Environmental Impact Value (EIV) was negative by -200.

 

Based on the findings of the analyses mitigation measures for reducing the potential negative impacts of drainage congestion suggested include re-excavation and improvement of the khals and canals, preservation of the retention ponds and storage reservoirs, and eviction of unauthorised possessions in the retention ponds, Removal of the unauthorised bunds constructed for fish culture, adoption of effective zoning, land use control and regulation to prevent unplanned and haphazard land use transformation.

 

 

 

 

 

 

 

 

Project title:

DEVELOPING GIS TOOL TO IDENTIFY CRITICAL AREAS FOR DRINKING WATER SUPPLY DURING DRY SEASON IN DINAJPUR DISTRICT

 

Name of the student:

S. M. TANVIR HASSAN

 

Name of the Supervisor:

            Dr. A.K.M. Saiful Islam

 

Date of award of diploma:

2005

 

Abstract:

Huge drawdown of the groundwater table is one of the environmental hazards due to large scale groundwater withdrawal during dry period. Hand tube wells (HTWs) and shallow tube wells (STWs) operated under gravitational force, are the main supplier of drinking water in rural areas may be dry out due to excessive drawdown. This worst condition of drinking water supply in rural areas has been found in the north-west part of Bangladesh, namely in Dinajpur district. Therefore, this study was conducted to identify the areas within Dinajpur district where groundwater goes under a certain level of safe yield from which water cannot be withdrawn with hand tube wells. A maximum of 6m depth to groundwater table from ground surface has been considered as the safe yield limit to ensure the drinking water supply in the study area through HTWs and STWs with full operational efficiency.

 

The existing groundwater table of the study area has been analyzed from different groundwater observation wells of BWDB for the last available nine years’ data. Three interpolation methods available in GIS namely, inverse distance weighted (IDW), Thin-plate Spline and Kriging have been tested to construct groundwater level surface from the observation well data. Among this three interpolation methods, Kriging with ordinary linear semi-variance model has given the most accurate result when a few number of groundwater observation well data available. This study showed that the most of the critical areas lie in Biral, Dinajpur Sadar, Kaharole and Khansama upazilas of Dinajpur district where annual groundwater level fluctuation is in the range of 4.0m to 11.0m. Bochagonj, Birganj and Chirirbandar upazilas of Dinajpur district have been found as negligible critical areas where annual groundwater level fluctuation varies from 1.5m to 6.5m. This study also developed some customized tools using Avenue scripts (built in object-oriented programming language) in ESRI’s ArcView GIS 3.2 software with Spatial Analyst 2.0 extension to make the delineation of water scarce areas easy for different time on the basis of available data.

 

 

 

 

 

  

Project title:

An Experimental Study on Sediment Deposition over the Floodplain due to Different Sediment Concentrations in the River Channel

 

Name of the student:

            Syed Mahabubul Haque

 

Name of the Supervisor:

            Dr. Anisul Haque

 

Date of award of diploma:

            2006

 

Abstract:

            The sediment concentrations in the rivers not only vary with time but also vary with different locations of rivers. Even this sedimentation concentration may vary with hours in a day due to the change in velocity, water flow etc. It also varies with various seasons in a year. When a specific length of an earthen embankment fails, floodwater with high velocity enters into the floodplain through the embankment breach, piping, overtopping etc. Thus floodwater spreads over a large area of the floodplain causing sediment deposition due to the reduction of water velocity. Also when there is no embankment in between the floodplain and river channel, in rainy season devastating floodwater also enters in to the floodplain through out the length of the river. This overland flow (without any embankment in-between the floodplain and the river channel also) spreads over a large area of the floodplain causing sediment deposition due to the reduction of water velocity. The present study has been carried out to find out the patterns, thickness, areas and volumes of sediment deposition over the floodplain due to embankment breach and overland flow.

 

This study was carried out in a physical model. The sediment concentration was kept in between 500-3000 mg/l. In all experiments 20 cm embankment breach length and 6 cm height was considered. Each experiment was carried out for the elapsed time of 30 minutes. The measurements of sediment thickness for all the experiments were made (after the elapsed time 30 minutes) both laterally and longitudinally at 2 cm interval over the floodplain.

 

The results of the study give useful information to understand the mechanism of sediment deposition over the floodplain due to embankment breach and overland flow for different sediment concentrations in the river channel. In general the depth, area and volume of sediment deposition in the floodplain increases significantly with increased sediment concentrations in the river channel. The sediment deposition in the floodplain due to fixed embankment breach takes the form of a loop having the center at the breach location. Sediment deposition due to overland flow does not take the form of a loop, sediment deposition follows the path of the river flow, e.g. parallel to the river. The adjacent area at the location of the embankment breach is more vulnerable than the area far from the breach location.

 

A statistical analysis was carried out to find out the relation of maximum, mean, area and volume of sediment deposition over the floodplain due to embankment breach and overland flow with various sediment concentrations in the river channel. As a whole polynomial relation is the best to describe the relation between maximum, mean, area and volume of sediment deposition over the floodplain for various sediment concentrations in the river channel.