Bharath H. Aithal

Insights to urban dynamics through landscape spatial pattern analysis

Urbanisation is a dynamic complex phenomenon involving large scale changes in the land uses at local levels. Analyses of changes in land uses in urban environments provide a historical perspective of land use and give an opportunity to assess the spatial patterns, correlation, trends, rate and impacts of the change, which would help in better regional planning and good governance of the region. Main objective of this research is to quantify the urban dynamics using temporal remote sensing data with the help of well-established landscape metrics. Bangalore being one of the rapidly urbanising landscapes in India has been chosen for this investigation. Complex process of urban sprawl was modelled using spatio temporal analysis. Land use analyses show 584% growth in built-up area during the last four decades with the decline of vegetation by 66% and water bodies by 74%. Analyses of the temporal data reveals an increase in urban built up area of 342.83% (during 1973-1992), 129.56% (during 1992-1999), 106.7% (1999-2002), 114.51% (2002-2006) and 126.19% from 2006 to 2010. The Study area was divided into four zones and each zone is further divided into 17 concentric circles of 1 km incrementing radius to understand the patterns and extent of the urbanisation at local levels. The urban density gradient illustrates radial pattern of urbanisation for the period 1973-2010. Bangalore grew radially from 1973 to 2010 indicating that the urbanisation is intensifying from the central core and has reached the periphery of the Greater Bangalore. Shannons entropy, alpha and beta population densities were computed to understand the level of urbanisation at local levels. Shannons entropy values of recent time confirms dispersed haphazard urban growth in the city, particularly in the outskirts of the city. This also illustrates the extent of influence of drivers of urbanisation in various directions. Landscape metrics provided in depth knowledge about the sprawl. Principal component analysis helped in prioritizing the metrics for detailed analyses. The results clearly indicates that whole landscape is aggregating to a large patch in 2010 as compared to earlier years which was dominated by several small patches. The large scale conversion of small patches to large single patch can be seen from 2006 to 2010. In the year 2010 patches are maximally aggregated indicating that the city is becoming more compact and more urbanised in recent years. Bangalore was the most sought after destination for its climatic condition and the availability of various facilities (land availability, economy, political factors) compared to other cities. The growth into a single urban patch can be attributed to rapid urbanisation coupled with the industrialisation. Monitoring of growth through landscape metrics helps to maintain and manage the natural resources

Visualization of Urban Growth Pattern in Chennai Using Geoinformatics and Spatial Metrics

Urban growth is the spatial pattern of land development to accommodate anthropogenic demand that influences other land uses (e.g.: open spaces, water bodies, etc.). Driven by population increase, urban growth alters the community’s social, political and economic institutions with changing land use and also affects the local ecology and environment. India’s urban population has increased by 91 million between 2001 and 2011, with migration, the inclusion of new/adjoining areas within urban limits, etc. Evidently, the percentage of urban population in India has increased tremendously: from 1901 (10.8 %) to 2011 (31.16 %). Chennai has an intensely developed urban core, which is surrounded by rural or peri-urban areas that lack basic amenities. Studying the growth pattern in the urban areas and its impact on the core and periphery are important for effective management of natural resources and provision of basic amenities to the population. Spatial metrics and the gradient approach were used to study the growth patterns and status of urban sprawl in Chennai city’s administrative boundary and areas within a 10 km buffer, for the past forty years. It is found that though Chennai experiences high sprawl at peri-urban regions, it also has the tendency to form a single patch, clumped and simple shaped growth at the core. During this transition, substantial agricultural and forest areas have vanished. Visualization of urban growth of Chennai for 2026 using cellular automata indicates about 36 % of the total area being converted to urban with rapid fragmented urban growth in the periphery and outskirts of the city. Such periodic land-use change analysis monitoring, visualization of growth pattern would help the urban planner to plan future developmental activities more sustainably and judiciously.

LANDSCAPE DYNAMICS MODELING THROUGH INTEGRATED MARKOV, FUZZY-AHP AND CELLULAR AUTOMATA

Multi temporal land use information were derived using two decades remote sensing data and simulated for 2012 and 2020 with Cellular Automata (CA) considering scenarios, change probabilities (through Markov chain) and Multi Criteria Evaluation (MCE). Agents and constraints were considered for modeling the urbanization process. Agents were normalized through fuzzyfication and priority weights were assigned through Analytical Hierarchical Process (AHP) pairwise comparison for each factor (in MCE) to derive behavior-oriented rules of transition for each land use class. Simulation shows a good agreement with the classified data. Fuzzy and AHP helped in analyzing the effects of agents of growth clearly and CA-Markov proved as a powerful tool in modelling and helped in capturing and visualizing the spatiotemporal patterns of urbanization. This provided rapid land evaluation framework with the essential insights of the urban trajectory for effective sustainable city planning.

Urbanisation Pattern of Incipient Mega Region in India

The focus of the current study is to analyse the spatial patterns of urbanisation and sprawl in Pune city using temporal remote sensing data

Conservation of wetlands to mitigate urban floods

Floods in an urbanized landscape refer to the partial or complete inundation from the rapid accumulation or run-off resulting in the damage to property and loss of biotic elements (including humans). Urban flooding is a consequence of increased impermeable catchments resulting in higher catchment Study area yield in a shorter duration and flood peaks sometimes reach up to three times. Thus, flooding occurs quickly due to faster flow times (in a matter of minutes). Causal factors include combinations of loss of pervious area in urbanising landscapes, inadequate drainage systems, blockade due to indiscriminate disposal of solid waste and building debris, encroachment of storm water drains, housing in floodplains and natural drainage and loss of natural flood-storages sites. Flood mitigation in urban landscape entails integrated ecological approaches combining the watershed land-use planning with the regional development planning. This includes engineering measures and flood preparedness with the understanding of ecological and hydrological functions of the landscape.

Prediction of spatial patterns of urban dynamics in Pune, India

The potential of Markov chain and cellular automata model with help of agents that play a vital role in a cities urbanisation through fuzziness in the data and hierarchal weights (for principal agents) have been used to understand and predict the urban growth for the Pune city, India. The model utilizes temporal land use changes with probable growth agents such as roads drainage networks, railway connectivity, slope, bus network, industrial establishments, educational network etc., to simulate the growth of Pune for 2025 using two scenarios of development - implementation of City Development Plan (CDP) and without CDP. In the study, multi temporal land use datasets, derived from remotely-sensed images of 1992, 2000, 2010 and 2013, were used for simulation and validation. Prediction reveals that future urban expansion would be in northwest and southeast regions with intensification near the central business district. This approach provides insights to urban growth dynamics required for city planning and management.

Modelling hydrologic regime of Lakshmanatirtha watershed, Cauvery river

Basic amenities such as clean water, air and food are essential not only for human livelihood but also for the surrounding biotic habitats in the environment for sustainable development. Due to the human habitation, and the anthropogenic activities, large scale change in land use has affected the hydrologic regime across watersheds. The water resource availability in a catchment depends upon the integrity of the land use, terrain and meteorological parameters such as rainfall, temperature, etc. The land use of the catchment plays an important role in maintaining the water flow in the rivers or streams as either surface or subsurface runoff (Pipeflow and Baseflow), holding water in the sub stratas, recharging the aquifers and hence catering the water demands as per the human and environmental needs. The study was conducted in order to understand the dynamics of land use and its implication on the catchment capabilities in catering the demands of environment (forests), agriculture, domestic and livestock needs on Lakshmanatirtha catchment of the Cauvery river basin which has an area of 3969 km2. The land use assessment using remote sensing and GIS showed the catchment is dominated (61.94%) by agriculture and horticulture, followed by forests with as area of 14.3% followed by other land uses. The Ghats (uplands) of the catchment is dominated by forests where as the plains are with agriculture and horticulture activities. Hydrologic assessment is done using the land use and the meteorological data was carried out at watershed level. The assessment showed that out of five watersheds, four of the watersheds had very high deficiency of water for over 3 months, and one of the watersheds had no deficit. The deficiency of water indicated that the watersheds were not able cater the both the human and environmental needs but also the streams were devoid of water flow which explains the deficiency in maintaining ecological flow.

Measuring urban sprawl in Tier II cities of Karnataka, India

Rapid irreversible urbanisation has haphazard and unplanned growth of towns and cities. Urbanisation process is driven by burgeoning population has resulted in the mismanagement of natural resources. Human-induced land use changes are the prime drivers of the global environmental changes. Urbanisation and associated sub growth patterns are characteristic of spatial temporal changes that take place at regional levels. Rapid urbanization subsequent to opening up of Indian markets in early ninetys show dominant changes in land use during the last two decades. Urban regions in India are experiencing the faster rates of urban dominance, while peri-urban areas are experiencing sprawl. Tier II cities in India are undergoing rapid changes in recent times and need to be planned to minimize the impacts of unplanned urbanisation. This communication focuses on seven tier II cities, chosen based on population. Mysore, Shimoga, Hubli, Dharwad, Raichur, Belgaum, Gulbarga and Bellary are the rapidly urbanizing regions of Karnataka, India. In this study, an integrated approach of remote sensing and spatial metrics with gradient analysis was used to identify the trends of urban land changes with a minimum buffer of 3 km buffer from the city boundary has been studied (based on availability of data), which help in the implementation of location specific mitigation measures. Results indicated a significant increase of urban built-up area during the last four decades. Landscape metrics indicates the coalescence of urban areas has occurred in almost all these regions. Urban growth has been clumped at the center with simple shapes and dispersed growth in the boundary region and the peri-urban regions with convoluted shapes.