An Analysis of Spatio-Temporal Trends of Land Surface Temperature in the Dhaka Metropolitan Area by Applying Landsat Images

Land surface temperature (LST) is a basic determinant of the global thermal behavior of the Earth surface. LST is a vital consideration for the appraisal of gradual thermal change for urban areas to examine the strength of the thermal intensity of the surface of urban heat island (SUHI) and to see how hot the surface of the Earth would be in a particular location. In this respect, the most developed urban city like Dhaka Metropolitan Area (DMA), Bangladesh is considered for estimation of LST, and Normalized Difference Vegetation Index (NDVI) changes trend in more developed and growing developing areas. The focus of this study is to find out the critical hotspot zones for further instantaneous analysis between these two types of areas. The trends of long-term spatial and temporal LST and NDVI are estimated applying Landsat images-Landsat 5-TM and Landsat OLI_TIRS-8 for the period of 1988 to 2018 for DMA and for developed and growing developing areas during the summer season like for the month of March. The supervised classification was used to estimate the land cover categories and to generate the LST trends maps of the different percentiles of LSTs over time using the emissivity and effective at sensor brightness temperature. The study found the change in land cover patterns by different LST groups based on 50th, 75th, and 90th percentile where the maximum LST for the whole DMA went up by 2.48°C, 1.01°C, and 3.76°C for the months of March, April, and May, respectively for the period of 1988 to 2018. The highest difference in LST was found for the most recently developed area. The moderate change of LST increased in the built-up areas where LST was found more sensitive to climate change than the growing developed areas. The vegetation coverage area decreased by 6.74% in the growing, developing areas compared to the developed areas from 1988 to 2018. The findings of the study might be helpful for urban planners and researchers to take up appropriate measures to mitigate the thermal effect on urban environment.

Spatiotemporal Patterns and Drivers of Forest Change from 1985–2000 in the Beijing-Tianjin-Hebei Region of China

Forests are fundamental to maintaining ecological security and achieving regional sustainable development in China. Forest land change can result in many ecological problems including soil erosion, water shortages drought and biodiversity loss. Based on landscape ecology and logistic regression we explored the spatiotemporal patterns and factors affecting forest land changes from 1985 to 2000 in the Beijing-Tianjin-Hebei Region of China. The results show decreased local fragmentation of woodland landscapes and that the shapes of forest patches have become more regular. For forest land cover change, soil organic matter content, slope type I （〈5°）, distance to the nearest village and per capita GDP were the most important independent variables from 1985 to 2000. This study indicates that spatial heterogeneity can affect the predictability of logistic regression models for forest land change.

Integrated assessment of the supply-demand relationship of ecosystem services in the Loess Plateau during 1992-2015

Landscape alterations and ecosystem services(ES)are crucial elements that affect the socioecological development of ecologically fragile regions.To provide scientific support for the land-use planning and regional ecological restoration to achieve sustainable development goals(SDGs)in the Loess Plateau from 1992 to 2015,this study proposes an integrated assessment framework for assessing the supply-demand match and equilibrium of ES combining potential relationships between landscape alterations,ES,and sustainable development at the county and regional scales.Results show that more than 85%of local counties have a supply-demand mismatch in terms of ecosystem services.Supply-demand distributions for provisioning and supporting services were relatively balanced compared to cultural services,which were imbalanced.Although the overall supply-demand relationship is relatively balanced because of the significant influence of ecological restoration,it shows an increasing trend toward imbalance as human-land conflict is prominent in some regions.SDGs emphasize on specific ES information such as ecosystem conservation,sustainable agriculture,and urban construction.Furtherly,positive impacts from landscape dynamics can improve the supply capacity of the ES and contribute to regional sustainability.