Saini Jyoti, Gupta Anil Kumar, Dhupper Renu, Shrivastava Anamika
Amity Institute of Environmental Sciences, Amity University Uttar Pradesh, Sector 125, Noida, Uttar Pradesh, 201313, India.
Integrated Centre for Adaptation, Disaster Risk Resilience and Sustainability (ICARS), Greater Noida Campus, IIT Roorkee, Noida, Uttar Pradesh, India.
Environ Monit Assess. 2025 Jul 24;197(8):946. doi: 10.1007/s10661-025-14392-w.
Prompt urbanization is one of the irreversible anthropogenic activities that is a major challenge for ecosystems and climate change. This global challenge needs to be addressed as urbanization significantly affects land surface temperature (LST) and contributes to the urban heat island (UHI) effect. Urban development converts natural landscapes into impermeable surfaces, elevating LST, particularly in densely populated regions where heat-absorbent materials are abundant. To better understand these impacts and support evidence-based mitigation, this study analyses spatial patterns and transformations in land use and temperature. Accordingly, the study utilized remote sensing data, from Landsat 4-5 TM (2000) and 8-9 OLI/TIRS (2022), which were used to assess land use dynamics using spectral indices (normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI), and modified normalized difference water index (MNDWI)), and thermal band data was utilized to derive LST and examine their spatio-temporal dynamics and interrelationships with UHI and the consequent ecological (urban thermal field variance index (UTFVI)) implications, in Gurugram, India. The Landsat satellite images were processed in ArcGIS 10.8 and ERDAS IMAGINE 2015, and the data analysis of spectral indices was done through MATLAB and Excel. The land use land cover (LULC) map was classified with a supervised classification method based on the maximum likelihood classifier (MLC) method, with the kappa coefficients of 0.959 (2000) and 0.956 (2022), which reflected acceptable results for classifications and mapping of LULC. Compared with field-level surveys, the study achieved a classified accuracy of around 97.2% and 96.8%, respectively. The findings of the study reveal that over two decades, built-up areas increased by about 13%, agricultural fields decreased by 26%, and average LST rose by 2-3 °C, which also indicates different ecological status in various regions. These insights can be useful for urban planners, municipal authorities, and environmental protection organizations to create climate-resilient urban landscape ecoregions with specific targeting of vulnerable areas associated with urban hybrid heat islands and ecological degradation based on location. Statistical analysis of linear regression presented high NDBI values, which shows the strongest positive association with LST, and high NDVI and MNDWI values displayed a significant cooling effect, with the R-squared value 0.97 for the year 2000, and for 2022, it is 0.98. This study underscores the necessity for a comprehensive policy framework that incorporates geospatial data for urban planning to mitigate UHI effects via green infrastructure, afforestation, and water body restoration projects. Future studies should employ advanced technologies like LiDAR and UAVs for improved urban surveillance and investigate multi-hazard assessments that combine urban heat with flood and air quality concerns.
快速城市化是不可逆转的人为活动之一,对生态系统和气候变化构成重大挑战。这一全球挑战需要得到应对,因为城市化显著影响地表温度(LST)并导致城市热岛(UHI)效应。城市发展将自然景观转变为不透水表面,提高了地表温度,特别是在人口密集且吸热材料丰富的地区。为了更好地理解这些影响并支持基于证据的缓解措施,本研究分析了土地利用和温度的空间格局及变化。因此,该研究利用了来自Landsat 4 - 5 TM(2000年)和8 - 9 OLI/TIRS(2022年)的遥感数据,通过光谱指数(归一化差异植被指数(NDVI)、归一化差异建筑指数(NDBI)和改进的归一化差异水体指数(MNDWI))评估土地利用动态,并利用热波段数据推导地表温度,研究其时空动态以及与城市热岛和随之而来的生态(城市热场方差指数(UTFVI))影响的相互关系,研究地点为印度古鲁格拉姆。Landsat卫星图像在ArcGIS 10.8和ERDAS IMAGINE 2015中进行处理,光谱指数的数据分析通过MATLAB和Excel完成。土地利用土地覆盖(LULC)地图采用基于最大似然分类器(MLC)方法的监督分类法进行分类,2000年和2022年的kappa系数分别为0.959和0.956,这反映了LULC分类和制图的可接受结果。与实地调查相比,该研究的分类准确率分别约为97.2%和96.8%。研究结果表明,在二十多年间,建成区面积增加了约13%,农田面积减少了26%,平均地表温度上升了2 - 3摄氏度,这也表明不同地区具有不同的生态状况。这些见解对城市规划者、市政当局和环境保护组织可能有用,有助于他们创建具有气候适应能力的城市景观生态区域,根据位置具体针对与城市混合热岛和生态退化相关的脆弱地区。线性回归的统计分析显示NDBI值较高,表明与地表温度的正相关最强,而高NDVI和MNDWI值显示出显著的降温效果,2000年的R平方值为0.97,2022年为0.98。本研究强调了制定综合政策框架的必要性,该框架应纳入地理空间数据用于城市规划,通过绿色基础设施、造林和水体修复项目减轻城市热岛效应。未来的研究应采用激光雷达和无人机等先进技术以改善城市监测,并调查结合城市热与洪水及空气质量问题的多灾害评估。