Environmental Science
P. Kumar; D. Deka; A. Yadav; Ashwani .; M. Kumar; J.P. Das; A. Singh; A. Gurjar
Abstract
BACKGROUND AND OBJECTIVES: Evapotranspiration is an important component of water balance associated with the hydrological cycle and biological processes. Accurately estimating the rate of evapotranspiration is crucial for understanding fluctuations in water availability and effectively managing water ...
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BACKGROUND AND OBJECTIVES: Evapotranspiration is an important component of water balance associated with the hydrological cycle and biological processes. Accurately estimating the rate of evapotranspiration is crucial for understanding fluctuations in water availability and effectively managing water resources in a sustainable manner. The study aims to examine the correlation between actual evapotranspiration and potential evapotranspiration by assessing the linkages with vegetation and snow cover in an ecologically fragile located in the northwestern Himalaya.MATERIALS AND METHODS: The present study uses remote sensing Landsat satellite data series to map vegetation cover and snow cover in the area. Remote sensing data accessed from Moderate Resolution Imaging Radiometer evapotranspiration project data was used for calculating evapotranspiration and potential evaporation. The data from the Climatic Research Unit (2000–2022) was additionally utilized for the computation of potential evapotranspiration. The study investigates variances in evapotranspiration and explores correlations between normalized difference vegetation index and normalized difference snow index. It further examines the correlation between potential evapotranspiration and actual evapotranspiration.FINDINGS: The study conducted from 1991 to 2021 demonstrates a notable rise in vegetation cover by 20.18 percent, showcasing spatial variations across the region. Conversely, there has been a significant decline in the extent of snow cover throughout this period. A positive correlation was identified between vegetation cover and evapotranspiration, whereas a negative correlation was observed between snow cover and evapotranspiration. Actual evapotranspiration is on the rise while potential evapotranspiration is declining throughout the region.CONCLUSION: Hydrological cycle of a region is governed by many factors such as climate (precipitation, temperature), geohydrology, land use and land cover, socio-economic condition of habitants and institutions. Vegetation cover, snow cover, actual evapotranspiration and potential evapotranspiration and their relationship indicates changes in local and regional climate. An incremental rise in plant growth across the study site, coupled with spatial variability and a reduction in snow cover in the elevated mountainous zone, is influencing both actual evapotranspiration and potential evapotranspiration. Increase in actual evapotranspiration in the High Himalayan area of Himachal Pradesh attribute to substantial increase in vegetation cover in the dry cold desert region. The findings of the study will contribute to the comprehension of essential elements of water cycles and water budgets, facilitating improved resource allocation for climate-resilient sustainable initiatives.
Environmental Engineering
A. Suharyanto; A. Maulana; D. Suprayogo; Y.P. Devia; S. Kurniawan
Abstract
BACKGROUND AND OBJECTIVES: This study aims to determine the relationships between land cover presented by vegetation index and land surface temperature, between vegetation index and the built-up index, between built-up index and land surface temperature, and between land surface temperature and rainfall ...
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BACKGROUND AND OBJECTIVES: This study aims to determine the relationships between land cover presented by vegetation index and land surface temperature, between vegetation index and the built-up index, between built-up index and land surface temperature, and between land surface temperature and rainfall characteristics in East Java Province, Indonesia.METHODS: Three cities and four regencies were used as examples. Landsat imagery scanned in 1995, 2001, 2015, and 2020 were used. Daily rainfall data recorded in the same years with Landsat data are used. The pixel values along the urban heat island line were used to analyze the interrelationships between vegetation index, built-up index, and land surface temperature. The land surface temperature and daily rainfall data from each Thiessen polygon were used to analyze the relationship between land surface temperature and rainfall characteristics. Image processing analysis was used to analyze the vegetation index, built-up index, and land surface temperature. The mathematical interrelationship between vegetation index, built-up index, land surface temperature, and rainfall intensity was analyzed using linear regression.FINDINGS: The results of the analysis show that the relationship between vegetation index and built-up index is inversely proportional and with land surface temperature is nearly inversely proportional to a coefficient of determination greater than 0.5. For the relationship between the built-up index and land surface temperature, the results of the analysis show that both have a directly proportional relationship, with a significant coefficient of determination (R2>0.5). For the relationship between land surface temperature and rainfall characteristics, the results of the analysis show that land surface temperature has a directly proportional but weak relationship with rainfall intensity and an inversely proportional but weak relationship with the number of rainfall days. Decreasing environmental conditions indicated by decreasing vegetation index will influence increasing land surface temperature and its effect on increasing rainfall intensity and decreasing rainfall days.CONCLUSION: Changes in land use/land cover are characterized by a change in vegetation cover to built-up land. These changes affect the land surface temperature. Changes in land surface temperature affect the occurrences of rainfall intensity. When the vegetation index decreases, the built-up index increases, and the land surface temperature increases as well. The increase in land surface temperature will increase the rainfall intensity. Satellite remote sensing imagery is effective and efficient for analyzing vegetation index, built-up index, and land surface temperature.
