scholarly journals New inventory of dust sources in Central Asia derived from the daily MODIS imagery

2019 ◽  
Vol 99 ◽  
pp. 01001 ◽  
Author(s):  
Mohamad Nobakht ◽  
Maria Shahgedanova ◽  
Kevin White
Keyword(s):  
Central Asia ◽  
Salt Lake ◽  
Dust Emission ◽  
Point Sources ◽  
Western China ◽  
Study Region ◽  
Dust Emissions ◽  
Lop Nur ◽  
Modis Imagery ◽  
Ustyurt Plateau

This paper presents the first inventory of dust emission sources in Central Asia and western China (35-50°N, 50-100°E) derived from the twice daily MODIS imagery from 2003-2012. The high-resolution (1 km) dust enhancement product was generated and used to produce maps of dust point sources and gridded data sets of dust emission frequencies. The most active dust emissions were observed in the eastern part of the Tarim basin (Lop Nur salt lake) followed by the Aralkum. A high frequency of dust emissions was recorded in the regions which were not reported in literature to date: the upper Amudarya region in northern Afghanistan and the Pre-Aral region (from the Ustyurt Plateau to the Betpak Dala desert). Dust emissions were associated mainly with the fluvial features (dry river beds and lakes), agricultural activities and fire damage to vegetation. In the eastern and northern parts of the study region and in the Aralkum, dust emissions peaked in spring while in the western and southern parts, they peaked in summer. The Aralkum exhibited a consistent growth in the frequency and intensity of dust emissions and similar but weaker trends were observed in the Karakum and Kyzylkum.

Investigating the consequences of the desiccation of lakes in the Middle East and Central Asia for regional dust activity

2020 ◽  
Author(s):  
Jamie Banks ◽  
Bernd Heinold ◽  
Kerstin Schepanski
Keyword(s):  
Surface Water ◽  
Middle East ◽  
Central Asia ◽  
Far East ◽  
Dust Storms ◽  
Aral Sea ◽  
Western China ◽  
Worst Case ◽  
Dust Emissions ◽  
Dust Sources

<p>Over the past several decades, new sources of dust aerosol have appeared in the Middle East and Central Asia due to the desiccation of lakes in the region. It is known that recently dry lakebeds can be efficient dust sources, due to the availability of readily erodible alluvial sediments. Such lake source regions include: Lake Urmia in western Iran; the Sistan Basin in the border area between Afghanistan, Iran, and Pakistan; and most notably, the Aral Sea on the border between Uzbekistan and Kazakhstan. A particularly large area (over 50,000 km<sup>2</sup>) of the former lakebed of the Aral Sea has become exposed to aeolian wind erosion, leaving Central Asia susceptible to dust storms originating from the young ‘Aral Kum’ (Aral Desert).</p><p>In this work we update the dust transport model COSMO-MUSCAT in order to simulate dust emissions from these relatively new dust sources. Making use of the Global Surface Water dataset (produced by the Copernicus Programme) in order to define the surface water coverage, we make estimates of dust emissions under three scenarios: 1) the ‘Past’, representative of water coverage in the 1980s; 2) the ‘Present’, representative of water coverage in the 2010s; and 3) the ‘Dry’ scenario, a worst-case future scenario in which currently drying lake regions are assumed to dry out completely under the pressure of climate change and water overuse. These scenarios are applied to the ‘Dustbelt’ modelling domain, covering North Africa, the Middle East and the Arabian Peninsula, and Central Asia as far east as western China.</p>

scholarly journals Marine Coastline Polygonal Ridges and Surface Roughness Development on a Salt-Crusted Playa: Recognition by Structure-from-Motion Photogrammetry

2019 ◽  
Vol 7 (3) ◽  
pp. 76
Author(s):  
Yuyang Geng ◽  
Yun Shao ◽  
Huaze Gong ◽  
Brian Brisco ◽  
Yang Zhi ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Structure From Motion ◽  
Salt Lake ◽  
Dust Emission ◽  
Field Work ◽  
Surface Evolution ◽  
Digital Elevation ◽  
Lop Nur ◽  
Salt Crust ◽  
Elevation Model

Salt crust is a normal landform in drying-out salt lake basins or marine regression coastlines, but the surface evolution processes over a decadal or even centenary period are not well understood due to poor data records. Microrelief characteristics control erodibility and erosivity, which will significantly influence wind erosion and dust emission. It is essential to classify the microrelief pattern of salt crust for mapping its spatial distribution and evaluating the environmental process. A desiccated inland tail-end lake would be an example of the coastline surface evolution after regression and represent a good case study of salt crust because of the fewer exogenic process interruptions. For this paper, field work was performed in the Lop Nur playa in China, about 90° E, 40° N, which used to be a salt lake half a century ago. Ground-based photos of the salt crust were acquired and imported into structure-from-motion (SfM) software to produce a fine centimeter-scale digital elevation model (DEM). Two indexes were introduced and extracted from the digital elevation model to classify various types of salt crust: roughness was calculated to evaluate the magnitude and the gray-level co-occurrence matrix (GLCM) score was derived to describe the structure pattern of the salt crust. Moreover, in this paper, sedimentary features during different parts of a playa evaporation cycle are reviewed and peculiar kinds of salt crust found on Lop Nur are further discussed.

scholarly journals Phenological Analysis of Sub-Alpine Forest on Jeju Island, South Korea, Using Data Fusion of Landsat and MODIS Products

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 286
Author(s):  
Sang-Jin Park ◽  
Seung-Gyu Jeong ◽  
Yong Park ◽  
Sang-hyuk Kim ◽  
Dong-kun Lee ◽  
...  
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Data Fusion ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Fusion Model ◽  
Fusion Algorithm ◽  
Study Region ◽  
Modis Imagery ◽  
Increasing Temperature

Climate change poses a disproportionate risk to alpine ecosystems. Effective monitoring of forest phenological responses to climate change is critical for predicting and managing threats to alpine populations. Remote sensing can be used to monitor forest communities in dynamic landscapes for responses to climate change at the species level. Spatiotemporal fusion technology using remote sensing images is an effective way of detecting gradual phenological changes over time and seasonal responses to climate change. The spatial and temporal adaptive reflectance fusion model (STARFM) is a widely used data fusion algorithm for Landsat and MODIS imagery. This study aims to identify forest phenological characteristics and changes at the species–community level by fusing spatiotemporal data from Landsat and MODIS imagery. We fused 18 images from March to November for 2000, 2010, and 2019. (The resulting STARFM-fused images exhibited accuracies of RMSE = 0.0402 and R2 = 0.795. We found that the normalized difference vegetation index (NDVI) value increased with time, which suggests that increasing temperature due to climate change has affected the start of the growth season in the study region. From this study, we found that increasing temperature affects the phenology of these regions, and forest management strategies like monitoring phenology using remote sensing technique should evaluate the effects of climate change.

scholarly journals Inverting the East Asian Dust Emission Fluxes Using the Ensemble Kalman Smoother and Himawari-8 AODs: A Case Study with WRF-Chem v3.5.1

Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 543
Author(s):  
Dai ◽  
Cheng ◽  
Goto ◽  
Schutgens ◽  
Kikuchi ◽  
...  
Keyword(s):  
Dust Emission ◽  
Asian Dust ◽  
Geostationary Satellite ◽  
Satellite Observations ◽  
Dust Emissions ◽  
Total Dust ◽  
Kalman Smoother ◽  
Independent Observations ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Horizontal And Vertical Distributions

We present the inversions (back-calculations or optimizations) of dust emissions for a severe winter dust event over East Asia in November 2016. The inversion system based on a fixed-lag ensemble Kalman smoother is newly implemented in the Weather Research and Forecasting model and is coupled with Chemistry (WRF-Chem). The assimilated observations are the hourly aerosol optical depths (AODs) from the next-generation geostationary satellite Himawari-8. The posterior total dust emissions (2.59 Tg) for this event are 3.8 times higher than the priori total dust emissions (0.68 Tg) during 25–27 November 2016. The net result is that the simulated aerosol horizontal and vertical distributions are both in better agreement with the assimilated Himawari-8 observations and independent observations from the ground-based AErosol RObotic NETwork (AERONET), the satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). The developed emission inversion approach, combined with the geostationary satellite observations, can be very helpful for properly estimating the Asian dust emissions.

An Investigation into the Processes and Quantity of Dust Emissions over Gravel and Sand Deserts in North-Western China

2017 ◽  
Vol 163 (3) ◽  
pp. 523-535 ◽  
Author(s):  
Zhengcai Zhang ◽  
Zhibao Dong ◽  
Guangqian Qian ◽  
Guoxi Wu ◽  
Xujia Cui
Keyword(s):  
Western China ◽  
Dust Emissions ◽  
North Western

scholarly journals ROADS OF CENTRAL ASIA. THE NEW INTERNATIONAL TRANSIT PROJECTS

2020 ◽  
pp. 51-60
Author(s):  
Ekaterina Borisova ◽  
Keyword(s):  
Central Asia ◽  
Western Europe ◽  
Western China ◽  
State Budget ◽  
Mountain Ranges ◽  
Relevant Today ◽  
Central Asian ◽  
International Transport ◽  
Political Background ◽  
Central Asian Republics

The development of international trade implies the use of the territory of Central Asia as a transit zone, through which the routes China–Europe, China – the middle East should be laid. The existing communication capabilities are not enough, so new directions are being developed (Railways “China–Kazakhstan – Turkmenistan–Iran”, “Turkmenistan– Afghanistan–Tajikistan”, ”China–Kyrgyzstan–Uzbekistan”; multimodal transit corridors” Lazurit”,” TRANS – Caspian international transport route”; such highways as “Western China– Western Europe”). However, paved roads, both rail and road, do not always meet expectations in terms of the volume of cargo passing through them (projects “China – Kazakhstan – Turkmenistan – Iran” and the Lapis lazuli corridor). Their loading is delayed “until better times” either due to the unstable political background, or due to the lack of necessary commodity flows in both directions. In some cases, there is a lack of political will to make appropriate decisions. Finished projects are unprofitable. None of the international transit projects announced or even completed over the past 20 years through the Central Asian republics has been fully operational. Meanwhile, international transit allows not only to fill the state budget, but also to solve issues of internal connectivity of territories. This task is most relevant today for Kyrgyzstan and Tajikistan, which have become hostages of their own geography, with localities separated by impassable mountain ranges.

Sr isotope and major ion compositional evidence for formation of Qarhan Salt Lake, western China

2018 ◽  
Vol 497 ◽  
pp. 128-145 ◽  
Author(s):  
QiShun Fan ◽  
Tim K. Lowenstein ◽  
HaiCheng Wei ◽  
Qin Yuan ◽  
ZhanJie Qin ◽  
...  
Keyword(s):  
Salt Lake ◽  
Western China ◽  
Sr Isotope ◽  
Major Ion ◽  
Qarhan Salt Lake
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