SAND DUNES ON TITAN AND PLUTO AS REVEALED BY REMOTE SENSING MORPHOLOGICAL AND FIELD ANALOGUES

2018 ◽  
Author(s):  
Jani Radebaugh ◽  
◽  
Matt Telfer ◽  
Ralph Lorenz ◽  
Jason W. Barnes ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Sand Dunes

scholarly journals A Study of Desertification Using Remote Sensing Techniques in Basra Governorate, South Iraq

2021 ◽  
pp. 912-926
Author(s):  
Fadel Abbas Zwain ◽  
Thair Thamer Al-Samarrai ◽  
Younus I. Al-Saady
Keyword(s):  
Remote Sensing ◽  
Land Degradation ◽  
Land Surface ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Arid Zone ◽  
Sand Dunes ◽  
Risk Index ◽  
Anthropogenic Factors ◽  
Landsat Images

Iraq territory as a whole and south of Iraq in particular encountered rapid desertification and signs of severe land degradation in the last decades. Both natural and anthropogenic factors are responsible for the extent of desertification. Remote sensing data and image analysis tools were employed to identify, detect, and monitor desertification in Basra governorate. Different remote sensing indicators and image indices were applied in order to better identify the desertification development in the study area, including the Normalized difference vegetation index (NDVI), Normalized Difference Water Index (NDWI), Salinity index (SI), Top Soil Grain Size Index (GSI) , Land Surface Temperature (LST) , Land Surface Soil Moisture (LSM), and Land Degradation Risk Index (LDI) which was used for the assessment of degradation severity .Three Landsat images, acquired in 1973, 1993, and 2013, were used to evaluate the potential of using remote sensing analysis in desertification monitoring. The approach applied in this study for evaluating this phenomenon was proven to be an effective tool for the recognition of areas at risk of desertification. The results indicated that the arid zone of Basra governorate encounters substantial changes in the environment, such as decreasing surface water, degradation of agricultural lands (as palm orchards and crops), and deterioration of marshlands. Additional changes include increased salinization with the creeping of sand dunes to agricultural areas, as well as the impacts of oil fields and other facilities.

scholarly journals MONITORING DESERTIFICATION IN SOME REGIONS OF IRAQ USING GIS TECHNIQUES

2021 ◽  
Vol 52 (3) ◽  
pp. 620-625
Author(s):  
Y. K. Al-Timimi
Keyword(s):  
Remote Sensing ◽  
Environmental Economic ◽  
Vegetation Cover ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Marked Decrease ◽  
Social Systems ◽  
Sand Dunes ◽  
Rate Of Increase ◽  
Remote Sensing Techniques

Desertification is one of the phenomena that threatening the environmental, economic, and social systems. This study aims to evaluate and monitor desertification in the central parts of Iraq between the Tigris and Euphrates rivers through the use of remote sensing techniques and geographic information systems. The Normalized difference vegetation index NDVI and the crust index CI were used, which were applied to two of the Landsat ETM + and OLI satellite imagery during the years 1990 and 2019. The research results showed that the total area of ​​the vegetation cover was 2620 km2 in 1990, while there was a marked decrease in the area Vegetation cover 764 km2 in 2019, accounting for 34.8% (medium desertification) and 10.2% (high desertification), respectively. Also, the results showed that sand dunes occupied an area of ​​767 km2 in 1990, while the area of ​​sand dunes increased to 1723 km2 in 2019, with a rate of 10.2%) medium desertification (and 22.9% (severe desertification), respectively. It was noted that the overall rate of decrease in vegetation cover was 21.33 km2year-1 while the overall rate of increase in ground erosion in the area is 10.99 km2year-1.

scholarly journals Evaluation of Different Soil Salinity Mapping Using Remote Sensing Techniques in Arid Ecosystems, Saudi Arabia

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Mohamed Elhag
Keyword(s):  
Remote Sensing ◽  
Saudi Arabia ◽  
Soil Salinity ◽  
Sand Dunes ◽  
Vegetation Indices ◽  
Agricultural Practices ◽  
Remote Sensing Data ◽  
Arid Ecosystems ◽  
Groundwater Levels ◽  
Sensing Applications

Land covers in Saudi Arabia are generally described as salty soils with sand dunes and sand sheets. Waterlogging and higher soil salinity are major challenges to sustaining agricultural practices in Saudi Arabia principally within closed drainage basins. Agricultural practices in Saudi Arabia were flourishing in the last two decades. The newly reclaimed lands were added annually and distributed all over the country. Irrigation techniques are mostly modernized to fulfill water saving strategies. Nevertheless, water resources in Saudi Arabia are under stress and groundwater levels are depleted rapidly due to heavy abstraction that may exceed crop water requirements in most of the cases due to high evaporation rates. The excess use of irrigational water leads to severe soil salinity problems. Applications of remote sensing technique in agricultural practices became widely distinctive and cover multidisciplinary principal interests on both local and regional levels. The most important remote sensing applications in agricultural practices are vegetation indices which are related to vegetation and water especially in an arid environment. Soil salinity mapping in an arid ecosystem using remote sensing data is a demanding task. Several soil salinity indices were implemented and evaluated to detect soil salinity effectively and quantitatively. Thematic maps of soil salinity were satisfactorily produced and assessed.

scholarly journals Desertification in the Sahel Region: A Product of Climate Change or Human Activities? A Case of Desert Encroachment Monitoring in North-Eastern Nigeria Using Remote Sensing Techniques

2022 ◽  
Author(s):  
Esther Shupel Ibrahim ◽  
Bello Ahmed ◽  
Oludunsin Tunrayo Arodudu ◽  
Bitrus Akila Dang ◽  
Jibril Babayo Abubakar ◽  
...  
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Land Cover ◽  
Human Activities ◽  
Sand Dune ◽  
Sand Dunes ◽  
Positive Feedbacks ◽  
Climate Records ◽  
Ground Truthing ◽  
Sahel Region

In Nigeria, desertification has become one of the most pronounced ecological disasters, with the impacts mostly affecting eleven frontline States. This has been attributed to a range of both nat-ural and man-made factors. This study applied a remote sensing-based change detection and indicator analysis to explore land use/land cover changes and detect major conversions from ecologically active land covers to sand dunes. Results indicate that areas covered by sand dunes (a major indicator of desertification) have doubled over the 25 years under consideration (1990 to 2015). Although about 0.71 km2 of dunes have been converted to vegetation, indicative of the success of various international, national, local, and individual afforestation efforts, conversely about 10.1 km2 of vegetation were converted to sand dunes, implying around 14 times more de-forestation compared to afforestation. Juxtaposing the progression of sand dune with climate records of the study area and examining the relationship between indicators of climate change and desertification suggested a mismatch between both processes as increasing rainfall and lower temperatures observed in 1994, 2005, 2012, and 2014 did not translated into positive feedbacks for desertification in the study area. On average, our results reveal that sand dune is progressing at a mean annual rate of about 15.2 km2 in the study area. Based on this study’s land cover change, trend and conversion assessment, visual reconciliation of climate records with land cover data, statistical analysis, observations from ground-truthing, as well as previous literature, it can be inferred that desertification in Nigeria is less a function of climate change, but more a product of human activities driven by poverty, population growth and failed government policies. Further projections by this study also reveal a high probability of more farmlands being converted to sand dunes by the year 2030 and 2045 if current practices prevail.

scholarly journals Detection of Changes in Land Use/ Land Cover Using Remote Sensing and GIS Techniques in Area East of the Nile Khartoum State-Sudan

2018 ◽  
Vol 10 (2) ◽  
pp. 12
Author(s):  
Babiker, E.M.A ◽  
Ibrahim, M.M ◽  
Elhag, A.M.H ◽  
Nser, S.H ◽  
Elsheikh, M.A ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Land Cover ◽  
Sandy Soil ◽  
Sand Dunes ◽  
Unsupervised Classification ◽  
Bare Soil ◽  
Water Bodies ◽  
Sand Sheet ◽  
Remote Sensing Techniques

<p>The study area lies to the east of the Nile (Sharg Elneel), Khartoum State (latitudes 15<sup>o</sup> 25̎ 1̍ and 16° 19̎ 1̍ N and longitudes 33° 19̎ 8̍ and 33°02̎ 9̍ E). Using remote sensing techniques and geographic information system (GIS), the changes in land cover/land use have been estimated using two methods: supervised and unsupervised classification. the images were those of the years 1973, 2001, and 2015 MSS, ETM, ETM+, respectively(173/49 &amp; 173/48 path/ row). The study area was classified into the following nine LU/LC types: water bodies, vegetation, rocky area, sandy soil, sandy sheet, clayey soil, bare soil, sand dunes and settlement areas. The individual areas covered by each type of land use/ land cover were calculated for each image using supervised and unsupervised classification. Then the areas were compared among the different years (images). The results indicated a decrease in areas of sandy soil, water bodies, vegetation cover, sand dunes, clay soil, and bare soil for years 1973-2001 and 1973-2015.  That was associated with significant increase in settlement area, sand sheet for the same period. As for the period 2001 and 2015 was an increase in the areas of vegetation, sandy soil, dunes, clay soil, and settlement. While there was a decrease in water bodies, rocky area, sand sheet and bar soil. A striking result of his study was an increase of 50% in the settlement area for the period 1973 – 2015. This indicated that more drift of people towards the Capital took place during this period possibly due to drought and civil strife. Also people come to Khartoum to have better living conditions, education, health care and to work and may be they look at Khartoum as a spring board for going abroad. This study recommended the use of remote sensing techniques and geographic information system in the follow up of desertification and land degradation by following changes in land cover and land use. It also recommended that sand movement (sand encroachment) shall be retarded possibly through increasing vegetation cover through seed broadcasting of pasture and range plants during the rainy season and to exploit the ground water of the NSS aquifer for irrigation.</p>

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