Trends in normalized difference vegetation index (NDVI) associated with urban development in northern West Siberia

Abstract

<p><strong>Abstract.</strong> Exploration and exploitation of oil and gas reserves of northern West Siberia has promoted rapid industrialization and urban development in the region. This development leaves significant footprints on the sensitive northern environment, which is already stressed by the global warming. This study reports the region-wide changes in the vegetation cover as well as the corresponding changes in and around 28 selected urbanized areas. The study utilizes the normalized difference vegetation index (NDVI) from high-resolution (250 m) MODIS data acquired for summer months (June through August) during 15 years (2000–2014). The results reveal the increase of NDVI (or “greening”) over the northern (tundra and tundra-forest) part of the region. Simultaneously, the southern, forested part shows the widespread decrease of NDVI (or “browning”). These region-wide patterns are, however, highly fragmented. The statistically significant NDVI trends occupy only a small fraction of the region. Urbanization destroys the vegetation cover within the developed areas and at about 5–10 km distance around them. The studied urbanized areas have the NDVI values by 15 % to 45 % lower than the corresponding areas at 20–40 km distance. The largest NDVI reduction is typical for the newly developed areas, whereas the older areas show recovery of the vegetation cover. The study reveals a robust indication of the accelerated greening near the older urban areas. Many Siberian cities become greener even against the wider browning trends at their background. Literature discussion suggests that the observed urban greening could be associated not only with special tending of the within-city green areas but also with the urban heat islands and succession of more productive shrub and tree species growing on warmer sandy soils.</p>

Meteorological context of the onset and end of the rainy season in Central Amazonia during the 2014–15 Go-Amazon Experiment

“…The data used for this study comes from the Go Amazon Project (Martin et al 2016), designed to study some of the characteristics on the rainy season in Amazonia, such as onset and demise of dry and wet seasons and we have used some of the CHUVA and Go Amazon 2014/15 rainfall and surface and upper air meteorology data available from 2014 to 2015. 10…”

“…The mean climatic features of the Manaus region are described elsewhere (Greco et al 1990;Cohen et al 1995;Machado et al 2004;Martin et al 2016), where the peak of the rainy season occurs around March-May. The GPCC rainfall (Figure 1a As seen in the previous section, despite the oceanic and atmospheric conditions in the equatorial Pacific (Niño 1 + 2 and 3) which show ENSO-Neutral conditions during the period before the onset it is noted that the patterns of regional precipitation distribution over the Central and Eastern Amazonia were consistent with that expected for a ENSO event (Figures 1 and 3).…”

“…hydrology of the region, as well as an increased the number of fires in the region (CPTEC-www.cptec.inpe.br). The length of the dry season has a strong temporal and spatial variability, and is strongly associated with dry conditions that may impact the occurrence of fires and their impacts on the release of carbon and aerosols, and also affecting human systems (Aragao et al 2016;Martin et al 2016).…”

“…The Latent (LE), sensible (H) turbulent heat fluxes and the Bowen ratio derived 15from these fluxes at the T3 site and the EMBRAPA Flux for 2014-15 in order to quantify their values before, during and after the onset and end (or demise) of the rainy season, so we can investigate the energy partition and convective processes that accompany the evolution of the rainy season during the days of the Go Amazon campaign. More details about the instrumentation used can be found inMachado et al (2004),Martin et al (2016) andWang et al (2016).…”

Modeling of the heat island in the period of extreme frost in Moscow in January 2017

“…исследованиями последних десятилетий установлено воздействие городов на облачность, осадки, мезомасштабные циркуляции и загрязнение атмосферы [1][2][3][4]. Также урбанизация оказывает существенное влияние на свойства почвы, грунтовых вод [5,6] и растительных сообществ [7,8]. Влияние городов не ограничено границами застроенных территорий, а выходит далеко за их пределы.…”