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Hydrological and hydrogeological consequences of rapid and large-scale urbanization

Ema Akhilesh, Archana LU (2018) VTGM01 20172
Civil Engineering (M.Sc.Eng.)
Engineering Geology
Abstract
Urbanization is a process where rural population move to urban places for better job opportunities and facilities. This is a natural process and more or less unavoidable. But when this process takes place rapidly and at large -scale, the urban cities will undergo various changes that will impact the environment. Rapid and large-scale urbanization is mainly observed in developing countries of Asia and Africa.
These changes affect the hydrological and hydrogeological processes of the cities, which in turn affects the local people. In order to meet the demands of the growing cities, the land use is changed, for example the lakes are encroached, and the impervious area is increased.
This thesis aims to study the hydrological and... (More)
Urbanization is a process where rural population move to urban places for better job opportunities and facilities. This is a natural process and more or less unavoidable. But when this process takes place rapidly and at large -scale, the urban cities will undergo various changes that will impact the environment. Rapid and large-scale urbanization is mainly observed in developing countries of Asia and Africa.
These changes affect the hydrological and hydrogeological processes of the cities, which in turn affects the local people. In order to meet the demands of the growing cities, the land use is changed, for example the lakes are encroached, and the impervious area is increased.
This thesis aims to study the hydrological and hydrogeological consequences due to rapid and large-scale urbanization through a literature review of three cities. The catchment area of one of the three cities is further studied by computing surface runoff and amount of infiltration through the ground surface for two different years, using software such as extension tools of ArcGIS and HEC-HMS.
Shanghai, Hanoi and Bengaluru cities were chosen for the literature review. These cities were chosen because they face different consequences due to rapid and large-scale urbanization. One of the catchment areas of Bengaluru city, namely Vrishabhavathi valley, was used to estimate the surface runoff and amount of infiltration through the ground surface by numerical simulations.
In the case of Shanghai, the city mainly faces land subsidence due to over exploitation of groundwater. In the case of Hanoi, the city faces water quality degradation. Even though groundwater is exploited there is hardly any changes in the groundwater levels as the city´s aquifer is laterally recharged by the Red river that flows adjacent to the city. Flooding during monsoon, was one of the major effects faced by the Bengaluru city, as the city´s lake areas have been encroached. The lakes once acted as flood controllers.
The estimation of surface runoff and amount of infiltration through the ground surface was carried out on Vrishabhavathi catchment area in Bengaluru city. The years 1975 and 2017 were selected for past and present scenarios respectively. According to the computed simulation, the surface runoff was more important for the year 2017 whereas the amount of infiltration through the ground surface was large for the year 1975. This is due to the adverse change in the land use of Bengaluru city. Before the large-scale urbanization the lakes of this city were connected to each other and these lakes reduced the peak discharge and hence controlled the floods.
Generally, rapid and large – scale urbanization does have effects on the hydrological and hydrogeological processes. As urbanization is more or less unavoidable, care should be taken before the city is expanded. For example, measures such as artificial recharge, rainwater harvesting and flood management should be taken in order to save the city from further negative hydrological and hydrogeological effects. (Less)
Popular Abstract
Water issue is one of the major problems faced in many cities around the world. Urbanization is one of the reasons for this issue. Urbanization is a process where rural population move to urban areas for better opportunities and facilities. When urbanization takes place rapidly and at a larger-scale the cities undergo various changes that will affect the environment.
Rapid and large-scale urbanization leads to change in land use and this in turn will have an effect on groundwater. Hence it is a study in this thesis to investigate if rapid and large-scale urbanization have its effects on the groundwater. The investigation of the effects is carried out through literature study and estimation using softwares.
Rapid and large-scale... (More)
Water issue is one of the major problems faced in many cities around the world. Urbanization is one of the reasons for this issue. Urbanization is a process where rural population move to urban areas for better opportunities and facilities. When urbanization takes place rapidly and at a larger-scale the cities undergo various changes that will affect the environment.
Rapid and large-scale urbanization leads to change in land use and this in turn will have an effect on groundwater. Hence it is a study in this thesis to investigate if rapid and large-scale urbanization have its effects on the groundwater. The investigation of the effects is carried out through literature study and estimation using softwares.
Rapid and large-scale urbanization is mainly observed in Asian and African countries, hence three cities from Asia namely Shanghai- China, Hanoi- Vietnam and Bengaluru- India are selected to study the consequences. These three cities have faced similar consequences in terms of reduction in groundwater levels and water quality degradation. Reduction in groundwater levels is because of increased surface runoff and reduced amount of infiltration due to the change in land use over the years. Apart from this, Shanghai faces land subsidence and Bengaluru faces floods in the low-lying areas during monsoon.
Urbanization changes the land use patterns which in turn affects surface runoff and amount of infiltration from the surface. As part of this thesis estimations are done using ArcGIS and HECHMS softwares. Simulations were carried out for past scenario before urbanization (year 1974) and present scenario (year 2017). The obtained results were then compared to check the effects of urbanization on groundwater
The results from the simulation shows that the present scenario (year 2017) has increased surface run off and reduced amount of infiltration through the ground surface when compared to the past scenario (year 1974). The obtained results confirm that urbanization does have effects on the groundwater. The simulation results are in line with the effects found in the literature study done as part of this thesis.
The results from the simulation can be further used to study other factors related to the amount of surface infiltration and surface runoff such as the change in the soil properties, etc. (Less)
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author
Ema Akhilesh, Archana LU
supervisor
organization
alternative title
Hydrologiska och hydrogeologiska följder av snabb och storskalig urbanisering
course
VTGM01 20172
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
Rapid and large-scale urbanization, ArcGIS, HEC-HMS, surface runoff, surface infiltration.
report number
ISRN: LUTVDG/(TVTG - 5158 )/1 - 57/ (2018 )
other publication id
ISRN: LUTVDG/(TVTG - 5158 )/1 - 57/ (2018 )
language
English
additional info
Examiner: Jan-Erik Rosberg
id
8957789
date added to LUP
2018-09-10 13:47:07
date last changed
2018-09-10 13:47:07
@misc{8957789,
  abstract     = {Urbanization is a process where rural population move to urban places for better job opportunities and facilities. This is a natural process and more or less unavoidable. But when this process takes place rapidly and at large -scale, the urban cities will undergo various changes that will impact the environment. Rapid and large-scale urbanization is mainly observed in developing countries of Asia and Africa. 
These changes affect the hydrological and hydrogeological processes of the cities, which in turn affects the local people. In order to meet the demands of the growing cities, the land use is changed, for example the lakes are encroached, and the impervious area is increased. 
This thesis aims to study the hydrological and hydrogeological consequences due to rapid and large-scale urbanization through a literature review of three cities. The catchment area of one of the three cities is further studied by computing surface runoff and amount of infiltration through the ground surface for two different years, using software such as extension tools of ArcGIS and HEC-HMS. 
Shanghai, Hanoi and Bengaluru cities were chosen for the literature review. These cities were chosen because they face different consequences due to rapid and large-scale urbanization. One of the catchment areas of Bengaluru city, namely Vrishabhavathi valley, was used to estimate the surface runoff and amount of infiltration through the ground surface by numerical simulations. 
In the case of Shanghai, the city mainly faces land subsidence due to over exploitation of groundwater. In the case of Hanoi, the city faces water quality degradation. Even though groundwater is exploited there is hardly any changes in the groundwater levels as the city´s aquifer is laterally recharged by the Red river that flows adjacent to the city. Flooding during monsoon, was one of the major effects faced by the Bengaluru city, as the city´s lake areas have been encroached. The lakes once acted as flood controllers. 
The estimation of surface runoff and amount of infiltration through the ground surface was carried out on Vrishabhavathi catchment area in Bengaluru city. The years 1975 and 2017 were selected for past and present scenarios respectively. According to the computed simulation, the surface runoff was more important for the year 2017 whereas the amount of infiltration through the ground surface was large for the year 1975. This is due to the adverse change in the land use of Bengaluru city. Before the large-scale urbanization the lakes of this city were connected to each other and these lakes reduced the peak discharge and hence controlled the floods. 
Generally, rapid and large – scale urbanization does have effects on the hydrological and hydrogeological processes. As urbanization is more or less unavoidable, care should be taken before the city is expanded. For example, measures such as artificial recharge, rainwater harvesting and flood management should be taken in order to save the city from further negative hydrological and hydrogeological effects.},
  author       = {Ema Akhilesh, Archana},
  keyword      = {Rapid and large-scale urbanization,ArcGIS,HEC-HMS,surface runoff,surface infiltration.},
  language     = {eng},
  note         = {Student Paper},
  title        = {Hydrological and hydrogeological consequences of rapid and large-scale urbanization},
  year         = {2018},
}