scholarly journals Zero Deforestation Agreement Assessment at Farm Level in Colombia Using ALOS PALSAR

2018 ◽  
Vol 10 (9) ◽  
pp. 1464 ◽  
Author(s):  
Carlos Pedraza ◽  
Nicola Clerici ◽  
Cristian Forero ◽  
América Melo ◽  
Diego Navarrete ◽  
...  
Keyword(s):  
Ad Hoc ◽  
Weather Conditions ◽  
Forest Change ◽  
Alos Palsar ◽  
Change Analysis ◽  
Farm Level ◽  
Deforestation Rates ◽  
Agreement Assessment ◽  
The Tropics ◽  
Consistent Information

Due to the fast deforestation rates in the tropics, multiple international efforts have been launched to reduce deforestation and develop consistent methodologies to assess forest extension and change. Since 2010 Colombia implemented the Mainstream Sustainable Cattle Ranching project with the participation of small farmers in a payment for environmental services (PES) scheme where zero deforestation agreements are signed. To assess the fulfillment of such agreements at farm level, ALOS-1 and ALOS-2 PALSAR fine beam dual imagery for years 2010 and 2016 was processed with ad-hoc routines to estimate stable forest, deforestation, and stable nonforest extension for 2615 participant farms in five heterogeneous regions of Colombia. Landsat VNIR imagery was integrated in the processing chain to reduce classification uncertainties due to radar limitations. Farms associated with Meta Foothills regions showed zero deforestation during the period analyzed (2010–2016), while other regions showed low deforestation rates with the exception of the Cesar River Valley (75 ha). Results, suggests that topography and dry weather conditions have an effect on radar-based mapping accuracy, i.e., deforestation and forest classes showed lower user accuracy values on mountainous and dry regions revealing overestimations in these environments. Nevertheless, overall ALOS Phased Array L-band SAR (PALSAR) data provided overall accurate, relevant, and consistent information for forest change analysis for local zero deforestation agreements assessment. Improvements to preprocessing routines and integration of high dense radar time series should be further investigated to reduce classification errors from complex topography conditions.

Zero Deforestation Agreement Assessment at Farm Level in Colombia Using Alos Palsar: Challenges of Monitoring Systems Aimed to Reduce Deforestation

2021 ◽  
Author(s):  
Carlos Pedraza ◽  
Nicola Clerici ◽  
Cristian Fabian Forero ◽  
America Melo ◽  
Diego Navarrete ◽  
...  
Keyword(s):  
Monitoring Systems ◽  
Alos Palsar ◽  
Farm Level ◽  
Agreement Assessment

scholarly journals Evaluating Forest Cover and Fragmentation in Costa Rica with a Corrected Global Tree Cover Map

2020 ◽  
Vol 12 (19) ◽  
pp. 3226
Author(s):  
Daniel Cunningham ◽  
Paul Cunningham ◽  
Matthew E. Fagan
Keyword(s):  
Costa Rica ◽  
Forest Cover ◽  
Agricultural Land ◽  
Forest Area ◽  
Tree Cover ◽  
Agricultural Crop ◽  
Forest Change ◽  
Alos Palsar ◽  
Tropical Regions ◽  
The Impact

Global tree cover products face challenges in accurately predicting tree cover across biophysical gradients, such as precipitation or agricultural cover. To generate a natural forest cover map for Costa Rica, biases in tree cover estimation in the most widely used tree cover product (the Global Forest Change product (GFC) were quantified and corrected, and the impact of map biases on estimates of forest cover and fragmentation was examined. First, a forest reference dataset was developed to examine how the difference between reference and GFC-predicted tree cover estimates varied along gradients of precipitation and elevation, and nonlinear statistical models were fit to predict the bias. Next, an agricultural land cover map was generated by classifying Landsat and ALOS PalSAR imagery (overall accuracy of 97%) to allow removing six common agricultural crops from estimates of tree cover. Finally, the GFC product was corrected through an integrated process using the nonlinear predictions of precipitation and elevation biases and the agricultural crop map as inputs. The accuracy of tree cover prediction increased by ≈29% over the original global forest change product (the R2 rose from 0.416 to 0.538). Using an optimized 89% tree cover threshold to create a forest/nonforest map, we found that fragmentation declined and core forest area and connectivity increased in the corrected forest cover map, especially in dry tropical forests, protected areas, and designated habitat corridors. By contrast, the core forest area decreased locally where agricultural fields were removed from estimates of natural tree cover. This research demonstrates a simple, transferable methodology to correct for observed biases in the Global Forest Change product. The use of uncorrected tree cover products may markedly over- or underestimate forest cover and fragmentation, especially in tropical regions with low precipitation, significant topography, and/or perennial agricultural production.

scholarly journals Mapping Mangrove Forest Change in Nijhum Dwip Island

2019 ◽  
Vol 11 (1-2) ◽  
pp. 217-225
Author(s):  
MM Rahman ◽  
MAT Pramanik ◽  
MI Islam ◽  
S Razia
Keyword(s):  
Mangrove Forest ◽  
Forest Cover ◽  
Storm Surges ◽  
Forest Loss ◽  
Forest Conversion ◽  
Forest Cover Change ◽  
Forest Change ◽  
Change Analysis ◽  
Coastal Belt ◽  
Land Covers

Mangroves have been planting in the coastal belt of Bangladesh to protect the inhabitants of the coastal areas from cyclones and storm surges. Nijhum Dwip is located at the southern part of Hatiya Island. Most part of the island has been planted with the mangroves in the 1970s and 1980s; while parts of the mangroves have been deforested during the past few decades. The objectives of this research were to delineate and quantify the changes in the extent of mangroves in the island. The Landsat data of 1989, 2001, 2010 and 2018 have been utilized in the study. Three major land covers, namely forest, water and other land have been interpreted and delineated by using on-screen digitizing. The quantity of mangrove forest loss in the island is estimated as 1,024 ha, while 395 ha were afforested during 1989-2018. In the decadal change analysis, it was revealed that net forest cover change was higher in 2000s compared to other two decades and it was -425 ha. The result of the study is helpful to understand the extent and pattern of forest conversion in the island and to halt further forest loss and conserve the remaining forest. J. Environ. Sci. & Natural Resources, 11(1-2): 217-225 2018

The Radar Detection of Dangerous Storms

1953 ◽  
Vol 6 (3) ◽  
pp. 238-239
Author(s):  
R. E. Perry
Keyword(s):  
Weather Conditions ◽  
Radar Detection ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Effective System ◽  
The Tropics

Aircraft such as the Comet normally fly above cloud formations, but their approach to the airport involves a long and more or less gradual descent which may take them through adverse weather conditions. Violent thunderstorms, for example, which are fairly common in some parts of the tropics, constitute an obvious danger, and the provision at airports of an effective system of cloud warning could provide an added measure of safety along air routes.

scholarly journals Introduction: The trouble with forest: definitions, values and boundaries

2018 ◽  
Vol 73 (4) ◽  
pp. 253-260 ◽  
Author(s):  
Muriel Côte ◽  
Flurina Wartmann ◽  
Ross Purves
Keyword(s):  
Information Science ◽  
Geographic Information Science ◽  
Academic Disciplines ◽  
Epistemic Communities ◽  
Forest Loss ◽  
Special Issue ◽  
Forest Change ◽  
Deforestation Rates ◽  
The Relationship ◽  
Resources Assessment

Abstract. Forest is in trouble. The most recent (2015) FAO Forest Resources Assessment shows an encouraging trend towards a decrease in deforestation rates, but it also points out that since 1990 total forest loss corresponds to an area the size of South Africa. Efforts to curtail deforestation require reliable assessments, yet current definitions for what a forest exactly is differ significantly across countries, institutions and epistemic communities. Those differences have implications for forest management efforts: they entail different understandings about where exactly a forest starts and ends, and therefore also engender misunderstandings about where a forest should start and end, and about how forests should be managed. This special issue brings together different perspectives from practitioners and academic disciplines – including linguistics, geographic information science and human geography – around the problem of understanding and characterizing forest. By bringing together different disciplinary viewpoints, we hope to contribute to ongoing interdisciplinary efforts to analyse forest change. In this introduction, we propose that interrogating the relationship between forest definitions, boundaries and ways of valuing forests constitutes a productive way to critically conceptualize the trouble that forest is in.

scholarly journals Detection of Traffic Congestion and Marine Border Intrusion using Vehicular ad-hoc Networks

2019 ◽  
Vol 8 (10) ◽  
pp. 818-825
Keyword(s):  
Real Time ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Safety Information ◽  
Mobile Network ◽  
Weather Conditions ◽  
Border Crossing ◽  
Driving Experience ◽  
Wireless Router ◽  
Road Side Units

The Vehicular Ad-hoc network, or VANET, is for sharing of emergency and safety information among vehicles to ensure safe travelling of users in road. It is the technology that considers moving cars as nodes to create a mobile network. VANET turns every participating car into wireless router or node, allowing cars to establish communication. Vehicles can communicate within themselves (V2V) and also with the road side units (V2I). Vehicles communicating with other vehicles are likely to enhance the driving experience, awareness, situation perception and thus safety. In response to the problem of drastically increasing road accidents and climatic disasters like smoke, fog etc., we have designed and tested in various traffic scenarios of Kathipara(area in Chennai Tamilnadu), T.Nagar(area in Chennai, Tamilnadu), highway and a village . Each scenario is very different from each other; like Kathipara having moderate real time traffic, T.Nagar having extensive dense traffic, highways with irregular traffic and villages which having very few vehicles for most time. We designed the placement of RSUs(Road Side Units) in each scenario and we analyzed the delay and packet delivery ratios(PDR) in each scenario. These results would guarantee the use of VANET in real time. Yet another traffic scenario we have considered is what happens in marine environment. Unintentional International border crossing by fishermen and hardships encountered by fishermen due to extreme weather conditions are the motivation behind our conceptualizing a network for communication among boats which can be called a BANET (Boat Adhoc Vehicular Network)

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