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Abstract: Remote sensing has become an important method for monitoring urban thermal environment, but, it is still difficult to analysis the spatio-temporal change of urban thermal environment quantitatively only by ground surface temperature (or brightness temperature). Three indexes on urban thermal environment monitoring are proposed in this paper: heat island intensity, heat field intensity index and heat island proportion index. Based on MODIS surface temperature products and FY3A/MERSI data of two years, urban thermal environment is monitored by remote sensing method in Beijing. The empirical results verify that three indexes proposed in this paper are meaningful in monitoring of urban heat island. It can not only monitor the intensity and changes of the urban heat island in Beijing effectively, but also, it is positive to carrying out meteorological operations in city thermal environment monitoring. [Copyright &y& Elsevier]

Abstract: Land utilization is mainly the one of the human conscious activity in natural environment, Remote sensing is a most common and most effective method of testing the changes in the economic environment and the type of land development. This paper conducts a preliminary analysis based on the land use in Beijing that land-use change in Beijing and the reasons according to data analysis, and pointed out the advantages and disadvantages and limitations of various methods. according to data analysis, land-use change in Beijingland the reasons For future land development and utilization of analytical basis. [Copyright &y& Elsevier]

In this paper, we report the results and analysis of a recent field campaign in August 2007 investigating the impacts of emissions from transportation on air quality and community concentrations in Beijing, China. We conducted measurements in three different environments, on-road, roadside and ambient. The carbon monoxide, black carbon and ultrafine particle number emission factors for on-road light-duty vehicles are derived to be 95gkg−1-fuel, 0.3gkg−1-fuel and 1.8×1015 particleskg−1-fuel, respectively. The emission factors for on-road heavy-duty vehicles are 50gkg−1-fuel, 1.3gkg−1-fuel and 1.1×1016 particleskg−1-fuel, respectively. The carbon monoxide emission factors from this study agree with those derived from remote sensing and on-board vehicle emission testing systems in China. The on-road black carbon and particle number emission factors for Chinese vehicles are reported for the first time in the literature. Strong traffic impacts can be observed from the concentrations measured in these different environments. Most clear is a reflection of diesel truck traffic activity in black carbon concentrations. The comparison of the particle size distributions measured at the three environments suggests that the traffic is a major source of ultrafine particles. A four-day traffic control experiment conducted by the Beijing Government as a pilot to test the effectiveness of proposed controls was found to be effective in reducing extreme concentrations that occurred at both on-road and ambient environments. [Copyright &y& Elsevier]

Lidar is a powerful active remote sensing technique to monitor the planetary boundary layer (PBL), and there have already been many algorithms to retrieve the planetary boundary layer height (PBLH) using aerosol lidars. However, the algorithm suitable for all atmospheric conditions doesn't exist. This study evaluates the capability of nine lidar algorithms under different pollution scenarios in terms of the instantaneous performance and the diurnal evolution, which are derived from classical theories and expressed as GM, LGM, CRGM, IPM, VAR, VGM, WCT, WCTD, and POLARIS in this paper. Based on the nine algorithms, the continuous PBLHs are obtained from the observation dataset of a Beijing urban site in 2017. In order to verify the lidar results, the statical comparison analysis with radiosonde is also presented. On the premise of the inversion hypothesis, such as sufficient mixing in the PBL, the consistency of lidar results was the best, with the difference being not more than 200 m. And what's different from our cognition is that the concentration of pollutants near the ground under the light pollution condition makes the lidar results tend to be consistent. In fact, LGM prefers to get higher PBLHs because of filtering the information near the ground, whereas POLARIS is apt to underestimate unless the actual morphology can be captured by the depolarization ratio. VAR and IPM are more vulnerable to the conspicuous stratification. GM, CRGM, and WCTD have better consistency with radiosonde and capture the evolution characteristic no matter in clean or polluted days. Compared with the clean days, PBLH from lidar algorithms under the polluted condition reduced about 500 m overall, as well as the standard deviation. Generally speaking, the comprehensive comparison provides a reference to choose the proper lidar algorithm when retrieving the PBLH. GM is appropriate for the detection of clean days, while CRGM is robust for polluted days. WCTD is more suitable for the judgment of PBLH in the morning and evening and will underestimate at noon. As to the situation with cloud, WCTD is also the best choice. • The nine algorithms are compared both internally and with radiosonde. • The difference of lidar results with sufficient mixing is not more than 200 m. • GM, WCT and WCTD are robust to meet the retrieval requirements. • WCTD is much better for the inversion of residual layer height at night. [ABSTRACT FROM AUTHOR]

In the acceleration of industrialization and urbanization, brownfield is an important resource for land regeneration and restoration targeting to recover its ecosystem function. Landfills, as a type of brownfield distributed in the highly populated areas, occupy massive land resources. The ecological restoration of landfills becomes an engineering approach to achieve multiple effects of society, environment, and economy. This paper aims to monitor and assess the restoration microclimatic effects of landfills restoration in China with remote sensing data and techniques. We selected representative landfill restoration projects, including Nanhaizi Park in Beijing, Nanhu Park in Tangshan, and Tianziling Park in Hangzhou, as the study cases. Using the Landsat imagery, the scenes of the pre-restoration, mid-restoration, and post-restoration were retrieved, and the surface energy balance equation was applied to calculate normalized difference vegetation index (NDVI), land surface temperature (T s), and evapotranspiration (ET), representing vegetation conditions and hydro-heat microclimate conditions. The study areas are divided into four subzones and extracted the calculated values for statistics and comparison. We defined an indicator of restoration intensity (RI) using the different subzones to the outer contour distance radius and restoration phases to evaluate the spatial-temporal restoration degrees. The spatial pattern dynamics was displayed in the urbanization context in the cases of Beijing and Tangshan. We examined and quantified the relations between RI and the key indicators, NDVI, T s , and ET. The overall results revealed that with higher restoration intensity, NDVI and ET became higher, and T s became lower. It suggested that the ecological restoration on the landfills brought better vegetation, cooling, and humidification effects for the microclimatic environment. Our research has the implications for monitoring and assessing the climatic effects of ecological restoration in the brownfield regeneration in a macroscopic and ecosystem perspective. Unlabelled Image • With satellite dataset, we developed a way to monitor vegetation and microclimatic changes in the restored landfills. • The indicator to quantify the ecological restoration intensity was invented with spatial distance and restoration phase. • Overall, with higher restoration intensity, vegetation and evapotranspiration improved, and surface temperature declined. [ABSTRACT FROM AUTHOR]