Land classification of part of central Macedonia (Greece) by the use of remote-sensing techniques

1984 ◽  
Vol 5 (2) ◽  
pp. 289-302 ◽  
Author(s):  
T. ASTARAS ◽  
N. SILLEOS
2018 ◽  
Vol 247 ◽  
pp. 00017
Author(s):  
Anna Szajewska

The use of remote sensing techniques allows obtaining information about processes that occur on the surface of the Earth. In the aspects of fire protection and forest protection, it is important to know a burnt area which was created as a result of a fire of the soil cover or a total fire. The knowledge of this area is necessary to assess losses. Remote sensing techniques allow obtaining images in various spectral ranges. Remote sensing satellites offer multi-band data. Mathematical operations that operate on values coming from different spectral ranges allow determining various remote sensing indicators. The manuscript presents the possibility of using the NDVI (Normalized Difference Vegetation Index) to classify the burnt area. The NDVI is relatively easy to obtain because it operates in the spectral ranges from 630 up to 915 nm, and is obtainable with one detector only. Thus, it can be obtained without any major problems using unmanned aerial vehicles, regardless of time and cloudiness, as is the case when acquiring satellite images. The manuscript describes experimental research and presents the results.


Rangifer ◽  
2017 ◽  
Vol 37 (1) ◽  
pp. 59-68
Author(s):  
Catherine Fauvelle ◽  
Rianne Diepstraten

Remote sensing techniques are becoming more advanced and commonplace in conservation biology, and are used to study spatial patterns of various taxa. The main objective of this study was to determine whether supervised classification of landcover types within Landsat imagery could be accurately used to find or locate islands on lakes that may have been overlooked during ground transects in central Saskatchewan. Additionally, we used telemetry data from collared female caribou to determine which islands were used and in which season(s), and to determine island char­acteristics that make caribou more likely to select them. We were able to successfully identify all islands within bodies of water relevant to collared caribou using a supervised classification method, which suggests that our methods were adequate. We also determined that none of the island characteristics significantly influenced caribou selection accord­ing to an occupancy model, however females tended to choose islands with a higher vegetation cover (NDVI) during the summer months and a proportionally lower snow cover during the winter months, likely as forage and predator avoidance strategies respectively. Finally, we suggest directions for future studies as well as implications for both wildlife managers and land-use planners in Saskatchewan, Canada.


2020 ◽  
Vol 17 (2) ◽  
pp. 6-11
Author(s):  
N. D. Tagoe ◽  
S. Mantey

Man has contributed to land cover alteration since time-immemorial through clearing of land for residential, agriculture, recreational and industrial purposes. The emergence of adapting wild plants and animals for human use as well as industrialisation have also contributed to the alteration of land cover. Over the years, anthropogenic activities have had great impact on the Weija catchment. This study seeks to map the catchment and determine the impact of anthropogenic activities using Remote Sensing techniques. Observations and measurements were made on the field as well as classification of land cover using Landsat images of years 1991, 2003 and 2017. Results showed an increase in built-up areas by 18% from 1991 to 2017. Other classes such as shrubs increased due to decrease in dense vegetation. This study confirms the use of Remote Sensing as a valuable tool for detecting change in land cover and determining the impact of anthropogenic activities in the Weija Catchment. Keywords: Land Cover, GIS, Remote Sensing, Weija Catchment, Anthropogenic Activities


2018 ◽  
Author(s):  
Νικόλαος Σιώμος

Στη διατριβή αυτή μελετήθηκε η κλιματολογία και η ταξινόμηση των οπτικών και μικροφυσικών ιδιοτήτων των αιωρούμενων σωματιδίων με τη χρήση μεθόδων επίγειας τηλεπισκόπησης. Οι τεχνικές αυτές περιλαμβάνουν κατά βάση μία διάταξη lidar και ένα φωτόμετρο. Αν και η ανάλυση στο μεγαλύτερό της μέρος αφορά μετρήσεις του εργαστηρίου Φυσικής της Ατμόσφαιρας στην Θεσσαλονίκη, εντούτοις, στο πλαίσιο της διατριβής αξιοποιήθηκαν επίσης μετρήσεις του Ευρωπαϊκού δικτύου των lidar, European Lidar Network (EARLINET). Η ανάλυση συνοψίζεται σε τέσσερις κύριες θεματολογίες. Αρχικά, γίνεται παρουσίαση των διεργασιών συντήρησης και βελτιστοποίησης ενός συστήματος depolarization Raman lidar. Στη συνέχεια, περιγράφονται εκτενώς η μεθοδολογία και τα αποτελέσματα της κλιματολογικής ανάλυσης των μετρήσεων της χρονοσειράς του lidar και του φωτόμετρου στην περιοχή της Θεσσαλονίκης. Επιπρόσθετα, γίνεται υπολογισμός κάποιων μικροφυσικών ιδιοτήτων των αεροζόλ με τη συνδυαστική χρήση των δύο οργάνων και τα αποτελέσματα χρησιμοποιούνται για την αξιολόγηση ενός μοντέλου ποιότητας αέρα στην περιοχή της Θεσσαλονίκης. Τέλος, κάποια από τα προϊόντα τα οποία προέκυψαν από την ανάλυση, μαζί με μετρήσεις της βάσης δεδομένων του EARLINET αξιοποιήθηκαν στην αξιολόγηση δορυφορικών παρατηρήσεων.


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