scholarly journals Biomass Estimation Using Satellite-Based Data

Author(s):  
Patrícia Lourenço

Comprehensive measurements of global forest aboveground biomass (AGB) are crucial information to promote the sustainable management of forests to mitigate climate change and preserve the multiple ecosystem services provided by forests. Optical and radar sensors are available at different spatial, spectral, and temporal scales. The integration of multi-sources sensor data with field measurements, using appropriated algorithms to identify the relationship between remote sensing predictors and reference measurements, is important to improve forest AGB estimation. This chapter aims to present different types of predicted variables derived from multi-sources sensors, such as original spectral bands, transformed images, vegetation indices, textural features, and different regression algorithms used (parametric and non-parametric) that contribute to a more robust, practical, and cost-effective approach for forest AGB estimation at different levels.

Author(s):  
G. Ronoud ◽  
A. A. Darvish Sefat ◽  
P. Fatehi

Abstract. Obtaining information about forest attributes is essential for planning, monitoring, and management of forests. Due to the time and cost consuming of Tree Density (TD) using field measurements especially in the vast and remote areas, remote sensing techniques have gained more attention in scientific community. Khyroud forest, a part of Hyrcanian forest of Iran, with a high species biodiversity and growing volume stock plays an important role in carbon storage. The aim of this study was to assess the capability of Sentinel-2 data for estimating the tree density in the Khyroud forest. 65 square sample plots with an area of 2025 m2 were measured. In each sample plot, trees with diameter at the breast height (DBH) higher than 7.5-cm were recorded. The quality of Sentinel-2 data in terms of geometric correction and cloud effect were investigated. Different processing approaches such as vegetation indices and Tasseled Cap transformation on spectral bands in combination with an empirical approach were implemented. Also, some of biophysical variables were computed. To assess the model performance, the data were randomly divided into parts, 70% of sample plots were used for modelling and 30% for validation. The results showed that the SVR algorithm (linear kernel) with a relative RMSE of 23.09% and a R2 of 0.526 gained the highest performance for tree density estimation.


Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1151 ◽  
Author(s):  
Siyu Zhu ◽  
Baojian Liu ◽  
Wei Wan ◽  
Hongjie Xie ◽  
Yu Fang ◽  
...  

The availability of lake bathymetry maps is imperative for estimating lake water volumes and their variability, which is a sensitive indicator of climate. It is difficult, if not impossible, to obtain bathymetric measurements from all of the thousands of lakes across the globe due to costly labor and/or harsh topographic regions. In this study, we develop a new digital lake bathymetry model (DLBM) using the step-wise water recession method (WRM) to generate 3-dimensional lake bathymetric maps based on the digital elevation model (DEM) alone, with two assumptions: (1) typically, the lake’s bathymetry is formed and shaped by geological processes similar to those that shaped the surrounding landmasses, and (2) the agent rate of water (the thickness of the sedimentary deposit proportional to the lake water depth) is uniform. Lake Ontario and Lake Namco are used as examples to demonstrate the development, calibration, and refinement of the model. Compared to some other methods, the estimated 3D bathymetric maps using the proposed DLBM could overcome the discontinuity problem to adopt the complex topography of lake boundaries. This study provides a mathematically robust yet cost-effective approach for estimating lake volumes and their changes in regions lacking field measurements of bathymetry, for example, the remote Tibetan Plateau, which contains thousands of lakes.


2019 ◽  
Vol 118 (6) ◽  
pp. 90-93
Author(s):  
L. Terina Grazy ◽  
Dr.G. Parimalarani

E-commerce is a part of Internet Marketing. The arrival of Internet made the world very simple and dynamic in all the areas. Internet is the growing business as a result most of the people are using it in their day to day life. E-commerce is attractive and efficient way for both buyers and sellesr as it reduce cost, time and energy for the buyer. No surprise the insurance sector has become quite active within the internet sphere. Most insurance companies are offering policies to be brought online and also the portals for paying premiums. It actually saves from hassles involved in going to an insurance office and spend hours to get the insurance work done. Insurance has become an important and crucial aspect of life. Online insurance is the best and most cost effective approach of taking the insurance deal. This paper focused on influence of online marketing on the insurance industry in India, usage of internet in India , the internet penetration in India and the online sale of insurance product by the insurance sector.


Author(s):  
Yogesh Awasthi

Agriculture is the backbone of the developing country. In old era agriculture was based on the experience which was shared by people to people but in this digital era technology play a very important and significant role in agriculture. Now agriculture become a business hub therefore farmers are focusing on precision farming. They introduced the technology in agriculture to define the accurate information about seed, soil, weather, disease and all factors which affecting the farming. Artificial Intelligence uses predictive analysis, image analysis, learning techniques and Pattern analysis to declare the best cost effective and maximum gain for the agriculturist. The aim of this paper is to provide the crucial information with the help of technology which a farmers can use to harvest the variety of crops as per the demand in world so that they can get maximum benefits.


Author(s):  
Muhammad Danish Siddiqui ◽  
Arjumand Z Zaidi

<span>Seaweed is a marine plant or algae which has economic value in many parts of the world. The purpose of <span>this study is to evaluate different satellite sensors such as high-resolution WorldView-2 (WV2) satellite <span>data and Landsat 8 30-meter resolution satellite data for mapping seaweed resources along the coastal<br /><span>waters of Karachi. The continuous monitoring and mapping of this precious marine plant and their <span>breeding sites may not be very efficient and cost effective using traditional survey techniques. Remote <span>Sensing (RS) and Geographical Information System (GIS) can provide economical and more efficient <span>solutions for mapping and monitoring coastal resources quantitatively as well as qualitatively at both <span>temporal and spatial scales. Normalized Difference Vegetation Indices (NDVI) along with the image <span>enhancement techniques were used to delineate seaweed patches in the study area. The coverage area of <span>seaweed estimated with WV-2 and Landsat 8 are presented as GIS maps. A more precise area estimation <span>wasachieved with WV-2 data that shows 15.5Ha (0.155 Km<span>2<span>)of seaweed cover along Karachi coast that is <span>more representative of the field observed data. A much larger area wasestimated with Landsat 8 image <span>(71.28Ha or 0.7128 Km<span>2<span>) that was mainly due to the mixing of seaweed pixels with water pixels. The <span>WV-2 data, due to its better spatial resolution than Landsat 8, have proven to be more useful than Landsat<br /><span>8 in mapping seaweed patches</span></span></span></span></span></span></span></span></span></span></span></span></span></span><br /><br class="Apple-interchange-newline" /></span></span></span></span></span>


Author(s):  
Yana van der Meulen Rodgers

Chapter 7 concludes by highlighting the three biggest messages from the analysis presented in this book: (1) the global gag rule has failed to achieve its goal of reducing abortions; (2) restrictive legislation is associated with more unsafe abortions; and (3) the expanded global gag rule is likely to have negative repercussions across a range of health outcomes for women, children, and men. They are simple but powerful messages that should be heard by policymakers over the voices calling for an ideologically based policy that fails to achieve its desired outcome. The chapter closes with a more constructive and cost-effective approach for US family-planning assistance that targets integrated reproductive health services.


2021 ◽  
Vol 10 (5) ◽  
pp. 971
Author(s):  
Kristoff Hammerich ◽  
Jens Pollack ◽  
Alexander F. Hasse ◽  
André El Saman ◽  
René Huber ◽  
...  

Background: A major disadvantage of current spacers for two-stage revision total knee arthroplasty (R-TKA) is the risk of (sub-) luxation during mobilization in the prosthesis-free interval, limiting their clinical success with detrimental consequences for the patient. The present study introduces a novel inverse spacer, which prevents major complications, such as spacer (sub-) luxations and/or fractures of spacer or bone. Methods: The hand-made inverse spacer consisted of convex tibial and concave femoral components of polymethylmethacrylate bone cement and was intra-operatively molded under maximum longitudinal tension in 5° flexion and 5° valgus position. Both components were equipped with a stem for rotational stability. This spacer was implanted during an R-TKA in 110 knees with diagnosed or suspected periprosthetic infection. Postoperative therapy included a straight leg brace and physiotherapist-guided, crutch-supported mobilization with full sole contact. X-rays were taken before and after prosthesis removal and re-implantation. Results: None of the patients experienced (sub-) luxations/fractures of the spacer, periprosthetic fractures, or soft tissue compromise requiring reoperation. All patients were successfully re-implanted after a prosthesis-free interval of 8 weeks, except for three patients requiring an early exchange of the spacer due to persisting infection. In these cases, the prosthetic-free interval was prolonged for one week. Conclusion: The inverse spacer in conjunction with our routine procedure is a safe and cost-effective alternative to other articulating or static spacers, and allows crutch-supported sole contact mobilization without major post-operative complications. Maximum longitudinal intra-operative tension in 5° flexion and 5° valgus position appears crucial for the success of surgery.


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