Spatiotemporal shifts in thermal climate in responses to urban cover changes: a-case analysis of major cities in Punjab, Pakistan

Dilawar, Adil; Chen, Baozhang; Trisurat, Yongyut; Tuankrua, Venus; Arshad, Arfan; Hussain, Yawar; Measho, Simon; Guo, Lifeng; Kayiranga, Alphonse; Zhang, Huifang; Wang, Fei; Sun, Shaobo

doi:10.1080/19475705.2021.1890235

Cited by 30 publications

(13 citation statements)

References 84 publications

(94 reference statements)

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“…The inner-city areas became congested due to the low availability of land for new development, resulting in other environmental and social issues. The LST for each category of LULC was also evaluated in this study, and it was observed that barren land and built-up area have the highest LST and similar results have been observed in other six urban centers in Pakistan (Dilawar et al, 2021). The mean, maximum, and minimum LST of all categories of LULC recorded a consistent increase, and a similar increase was also observed in other studies (Ibrahim and Rasul, 2017;Dilawar et al, 2021;Moazzam et al, 2022).…”

Section: Figuresupporting

confidence: 83%

Urban expansion impacts on agricultural land and thermal environment in Larkana, Pakistan

Rahman

Chandio

Moazzam

et al. 2023

Front. Environ. Sci.

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Urban area expansion and the increase in the built-up area are major threats to agriculture, the natural environment, and ecology throughout the world. The population of the city of Larkana is rapidly increasing due to natural growth and uncontrolled migration from the surrounding areas, which have resulted in a haphazard increase in the built-up area over the fertile agricultural land and affected the city’s thermal environment. This research aims to evaluate the impacts of urban area expansion on agricultural land and the thermal environment of the study area by assessing the change in land use/ land cover (LULC) from 1990 to 2020 and land surface temperature (LST). For this purpose, the Random Forest (RF) algorithm was applied, and LST was calculated in Google Earth Engine (GEE) using Landsat imageries for the years 1990, 2000, 2010, and 2020. For the RF classifier algorithm, 3500 reference random points were generated for each year, which were then randomly divided into two datasets, i.e., a training sample consisting of 70% of the points and a validation dataset (30% of the points). After LULC classification, the results were validated for 1990, 2000, 2010, and 2020, and the accuracy was 88.3%, 89%, 90.01%, and 90.8%, respectively. The study results showed that the built-up area increased from 12.31 to 43.83 km2 while the barren land in the study region decreased from 56.51 km2 to 11.62 km2. The agricultural land was 66.66 km2 in 1990, expanded to 101.38 km2, and then decreased to 79.49 km2 in 2020. The results also revealed that most of the urban expansion in the last decade (2010-2020) took place on agricultural land. The urban thermal environment also showed a gradual increase in surface temperatur,e as recorded by the LST results. The LST results revealed that the maximum LST was 33.4°C in 1990, which increased to 36.1°C in 2020, and similarly, the minimum LST was 25.1°C, which also increased to 26.6°C in 2020. This study provides useful results for stakeholders to devise better policies and plans to control further haphazard urban expansion on fertile agricultural land in the study area.

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Section: Figuresupporting

confidence: 83%

Urban expansion impacts on agricultural land and thermal environment in Larkana, Pakistan

Rahman

Chandio

Moazzam

et al. 2023

Front. Environ. Sci.

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“…An important feature observed concerning LULC changes in Karachi during 2000-2020 was that the cropland and open bare land were first converted into areas of open land before becoming part of the built-up area. This type of change pattern was also observed in high-density metropolitan cities, such as Hyderabad [33] and Faisalabad [66]. This process was due to the fact that agricultural land and other types of land acquired by real estate companies were left open for many years before being rebuilt or restructured.…”

Section: Discussionmentioning

confidence: 64%

Characterizing Spatiotemporal Variations in the Urban Thermal Environment Related to Land Cover Changes in Karachi, Pakistan, from 2000 to 2020

Baqa

Fang

et al. 2022

Remote Sensing

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Understanding the spatiotemporal patterns of urban heat islands and the factors that influence this phenomenon can help to alleviate the heat stress exacerbated by urban warming and strengthen heat-related urban resilience, thereby contributing to the achievement of the United Nations Sustainable Development Goals. The association between surface urban heat island (SUHI) effects and land use/land cover features has been studied extensively, but the situation in tropical cities is not well-understood due to the lack of consistent data. This study aimed to explore land use/land cover (LULC) changes and their impact on the urban thermal environment in a tropical megacity—Karachi, Pakistan. Land cover maps were produced, and the land surface temperature (LST) was estimated using Landsat images from five different years over the period 2000–2020. The surface urban heat island intensity (SUHII) was then quantified based on the LST data. Statistical analyses, including geographically weighted regression (GWR) and correlation analyses, were performed in order to analyze the relationship between the land cover composition and LST. The results indicated that the built-up area of Karachi increased from 97.6 km² to 325.33 km² during the period 2000–2020. Among the different land cover types, the areas classified as built-up or bare land exhibited the highest LST, and a change from vegetation to bare land led to an increase in LST. The correlation analysis indicated that the correlation coefficients between the normalized difference built-up index (NDBI) and LST ranged from 0.14 to 0.18 between 2000 and 2020 and that NDBI plays a dominant role in influencing the LST. The GWR analysis revealed the spatial variation in the association between the land cover composition and the SUHII. Parks with large areas of medium- and high-density vegetation play a significant role in regulating the thermal environment, whereas the scattered vegetation patches in the urban core do not have a significant relationship with the LST. These findings can be used to inform adaptive land use planning that aims to mitigate the effects of the UHI and aid efforts to achieve sustainable urban growth.

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“…The subject of how urbanization affects groundwater depletion has received extensive attention [7]. The urban expansion of human settlements and industrial development has affected urban growth patterns, resulting in the conversion of many fertile land surfaces into built-up regions [8]. Many business organizations and enterprises in various regions of the world use groundwater as well, especially for industries, such as paper, marble cutting, food, beverages, and other materials [9].…”

Section: Introductionmentioning

confidence: 99%

Impact of Climate and Land-Use Change on Groundwater Resources, Study of Faisalabad District, Pakistan

et al. 2022

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Groundwater depletion has become a major concern all over the world. Recently, the rapid population growth and need for water and food have placed a massive strain on land and water resources. In this study, groundwater depletion resulting from land-use and climate change was investigated in the Faisalabad district, Pakistan, from 2000 to 2015. A Pearson correlation analysis between climatic parameters and land-use indices with groundwater was conducted to explore the major influencing factors. Interpolation maps of groundwater were generated using the inverse distance weighting interpolation (IDW) method. The Normalized Difference Built-up Index (NDBI) of five-year intervals demonstrated a strong increasing trend, whereas the Normalized Difference Vegetation Index (NDVI) presented a declining trend. The results also indicated a significant declining trend in groundwater levels in the region, with the annual average groundwater level decreasing at a rate of approximately 0.11 m/year. Climatic parameters (i.e., precipitation and temperature) further reveal an insignificant increasing trend estimated using the Mann–Kendall test and Sens’s slope. Overall, spatial analysis results showed a statistically significant positive trend in the groundwater level of the Faisalabad district, where the NDBI ratio is high and the NDVI is low, owing to the extensive extraction of groundwater for domestic and industrial use. These findings may be useful for a better understanding of groundwater depletion in densely populated areas and could also aid in devising safety procedures for sustainable groundwater management.

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Spatiotemporal shifts in thermal climate in responses to urban cover changes: a-case analysis of major cities in Punjab, Pakistan

Cited by 30 publications

References 84 publications

Urban expansion impacts on agricultural land and thermal environment in Larkana, Pakistan

Urban expansion impacts on agricultural land and thermal environment in Larkana, Pakistan

Characterizing Spatiotemporal Variations in the Urban Thermal Environment Related to Land Cover Changes in Karachi, Pakistan, from 2000 to 2020

Impact of Climate and Land-Use Change on Groundwater Resources, Study of Faisalabad District, Pakistan

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