scholarly journals Desertification Extraction Based on a Microwave Backscattering Contribution Decomposition Model at the Dry Bottom of the Aral Sea

2021 ◽  
Vol 13 (23) ◽  
pp. 4850
Author(s):  
Yubin Song ◽  
Hongwei Zheng ◽  
Xi Chen ◽  
Anming Bao ◽  
Jiaqiang Lei ◽  
...  
Keyword(s):  
Fine Particles ◽  
Least Squares Method ◽  
Microwave Remote Sensing ◽  
Aral Sea ◽  
Vegetation Coverage ◽  
Material Source ◽  
Sparse Vegetation ◽  
Desertification Process ◽  
Sensing Technology ◽  
Rich Material

The fine particles produced during the desertification process provide a rich material source for sand and dust activities. Accurately locating the desertified areas is a prerequisite for human intervention in sand and dust activities. In arid and semi-arid regions, due to very sparse vegetation coverage, the microwave surface scattering model is very suitable for describing the variation of topsoil property during the process of desertification. However, the microwave backscattering coefficient (MBC) trend of the soil during the desertification process is still unclear now. Moreover, the MBC of a resolution unit usually involves the contribution of soil and vegetation. These problems seriously limit the application of microwave remote sensing technology in desertification identification. In this paper, we studied the soil MBC change trend during the desertification process and proposed a microwave backscattering contribution decomposition (MBCD) model to estimate the soil MBC of a resolution unit. Furthermore, a simple microwave backscattering threshold (SMSBT) model was established to describe the severity of desertification. The MBCD and SMSBT models were verified qualitatively through landscape photos of sampling points from a field survey in November 2018. The results showed that the MBC would gradually decline with the deepening degree of desertification. The MBCD model and the corresponding least squares method can be used to estimate the soil MBC accurately, and the SMSBT model can accurately distinguish different degrees of desertification. The results of desertification classification showed that more than 68% of the dry bottom of the Aral Sea is suffering from different degrees of desertification.

scholarly journals Estimation Model of Soil Freeze-Thaw Erosion in Silingco Watershed Wetland of Northern Tibet

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bo Kong ◽  
Huan Yu
Keyword(s):  
Microwave Remote Sensing ◽  
Summation Method ◽  
Vegetation Coverage ◽  
Impact Factors ◽  
Slope Aspect ◽  
Estimation Model ◽  
Freeze Thaw ◽  
Northern Tibet ◽  
Sensing Technology ◽  
First Time

The freeze-thaw (FT) erosion is a type of soil erosion like water erosion and wind erosion. Limited by many factors, the grading evaluation of soil FT erosion quantities is not well studied. Based on the comprehensive analysis of the evaluation indices of soil FT erosion, we for the first time utilized the sensitivity of microwave remote sensing technology to soil moisture for identification of FT state. We established an estimation model suitable to evaluate the soil FT erosion quantity in Silingco watershed wetland of Northern Tibet using weighted summation method of six impact factors including the annual FT cycle days, average diurnal FT phase-changed water content, average annual precipitation, slope, aspect, and vegetation coverage. Finally, with the support of GIS, we classified soil FT erosion quantity in Silingco watershed wetland. The results showed that soil FT erosion are distributed in broad areas of Silingco watershed wetland. Different soil FT erosions with different intensities have evidently different spatial and geographical distributions.

scholarly journals Ecotourism as a Forest Conservation Tool: An NDVI Analysis of the Sitakunda Botanical Garden and Ecopark in Chattogram, Bangladesh

2021 ◽  
Vol 13 (21) ◽  
pp. 12190
Author(s):  
Nazifa Rafa ◽  
Samiha Nuzhat ◽  
Sayed Mohammad Nazim Uddin ◽  
Mukesh Gupta ◽  
Rahul Rakshit
Keyword(s):  
Forest Conservation ◽  
Anthropogenic Activities ◽  
Botanical Garden ◽  
Sustainable Land Use ◽  
Vegetation Coverage ◽  
Gis And Remote Sensing ◽  
Sparse Vegetation ◽  
Sensing Technology ◽  
Land Use Policies

Ecotourism, a sustainable form of tourism, is increasingly being viewed as a tool that can promote global biodiversity and forest conservation. This study explored the scope of ecotourism in forest conservation practices in the developing context by taking the Sitakunda Botanical Garden and Ecopark (SBGE), Bangladesh’s first ecopark established in 2000, as a case study. Using GIS and remote sensing technology, NDVI analysis revealed that, unlike the anticipated outcomes of the SBGE project, after a brief increase in vegetation coverage of 84.6% from 1995 to 2000, the vegetation coverage fell drastically from 2000 to 2015, wherein 33.4% of vegetation had been completely removed, and much of the dense and medium vegetation had been converted to sparse vegetation or other land uses. Anthropogenic activities, namely, unplanned urbanization, are suggested as the major contributors to this decline. From the period of 2015 to 2020, however, vegetation was seen to regenerate, potentially due to the decelerating urbanization or the possible manifestation of the ‘U’ shape relationship between the changes in vegetation and rates of urbanization. Sustainable land-use policies may help attain the targets of the project and lead the SBGE to emerge as a success story of the Bangladeshi ecotourism industry.

scholarly journals Optimal Estimation of Mass Partition in a Centrifugal Separator by Metallurgical Balance

2016 ◽  
Vol 4 (1) ◽  
pp. 7
Author(s):  
Siney Viana
Keyword(s):  
Fine Particles ◽  
Least Squares Method ◽  
Optimal Estimation ◽  
Separation Process ◽  
Centrifugal Separator ◽  
Input Stream ◽  
Processing Plants ◽  
Chemical Content ◽  
Chemical Segregation ◽  
To Receive

Mineral processing plants make use of several types of equipments for size separation (size classification) to segregate ore particles by size. A particular type of such equipments is the centrifugal separator, which is intended to receive an input stream of ore slurry to be partitioned into two output streams: a coarse and a fines one. The coarse stream contains most of the coarse solids particles of the slurry, whereas the fines stream contains most of the fine particles. Although a centrifugal separator intends to perform a physical segregation of the solids particles by their size, a chemical segregation also results, in such a way that the chemical content of the coarse and the fines streams are normally different from the content of the input stream. When evaluating the performance of the separation process, three fundamental aspects should be analyzed: 1) the size distribution of the solids particles in each stream; 2) the amount of solids mass from the input stream that goes to the coarse stream and to the fines stream, that is, the mass partition; and 3) the chemical content of each stream. This work presents the application of the Least Squares method of optimization to calculate the mass partition, based on the measured chemical content of the streams, and on the metallurgical balance equations of the separation process.

Assessment on 2000-2010 Ecosystem Function Changes of Yiwulvshan National Nature Scenic Area

2014 ◽  
Vol 1051 ◽  
pp. 489-494
Author(s):  
Xiao Chen Wang ◽  
Jing Hai Zhu ◽  
Yuan Man Hu ◽  
Wei Ling Liu
Keyword(s):  
Remote Sensing ◽  
Ecosystem Function ◽  
Primary Productivity ◽  
Water Conservation ◽  
Net Primary Productivity ◽  
Remote Sensing Data ◽  
Vegetation Coverage ◽  
The Past ◽  
Remote Sensing Technology ◽  
Sensing Technology

Based on the remote-sensing data and ground data, this study is conducted on the ecosystem function of Yiwulvshan National Nature Scenic Area (hereinafter as “Yiwulvshan Scenic Area”) from 2000 to 2010 with the GIS (geographic information system) and RS (remote sensing) technology, so as to provide reference for better environmental protection of the scenic area. It is shown from the results that there is no obvious change of land use in Yiwulvshan Scenic Area; while the capacity for soil and water conservation is slightly improved mainly due to increase of vegetation coverage; the vegetation net primary productivity declines somewhat about 5.27% in past 10 years; and biodiversity is slightly increased. As a whole, the ecosystem function of Yiwulvshan Scenic Area basically kept stable in the past 10 years, which indicated that the existing regulations can effectively protect the ecological function of the Scenic Area.

ON A COMPARATIVE LANDSCAPE STUDIES OF DELTAS UNDER DESERTIFICATION PROCESS WITH LANDSCAPE PATTERTNS STRUCTURAL METRICS

2020 ◽  
Author(s):  
P. Reymov ◽  
◽  
Viktor Statov ◽  
G. Khudaybergenov ◽  
N. Mamutov ◽  
...  
Keyword(s):  
Image Processing ◽  
Landscape Metrics ◽  
Comparative Studies ◽  
Landscape Patterns ◽  
Aral Sea ◽  
Aral Sea Basin ◽  
Landscape Studies ◽  
Desertification Process ◽  
Input Layer ◽  
Structural Metrics

The report disputes some possibilities of landscape patterns structural metrics fot comparative studies of structural and functional affinity for intra-continental arid deltas, such us Aral Sea basin and Caspian plains. We suggest using optical indexes (NDVI, SAVI et al.) as a input layer for the statistical image processing and landscape metrics extracting.

The application of microwave remote sensing technology in rock mechanics

1995 ◽  
Vol 8 (4) ◽  
pp. 593-597 ◽  
Author(s):  
Nai-Guang Geng ◽  
Zheng-Fang Fan ◽  
Quan-Quan Ji ◽  
Cheng-Yu Cui ◽  
Ming-De Deng
Keyword(s):  
Remote Sensing ◽  
Rock Mechanics ◽  
Microwave Remote Sensing ◽  
Remote Sensing Technology ◽  
Sensing Technology

Using classification and NDVI differencing methods for monitoring sparse vegetation coverage: a case study of saltcedar in Nevada, USA

2008 ◽  
Vol 29 (14) ◽  
pp. 3987-4011 ◽  
Author(s):  
Ruiliang Pu ◽  
Peng Gong ◽  
Yong Tian ◽  
Xin Miao ◽  
Raymond I. Carruthers ◽  
...  
Keyword(s):  
Vegetation Coverage ◽  
Sparse Vegetation ◽  
Ndvi Differencing

scholarly journals Estimation of Evapotranspiration in Sparse Vegetation Areas by Applying an Optimized Two-Source Model

2021 ◽  
Vol 13 (7) ◽  
pp. 1344
Author(s):  
Changlong Li ◽  
Zengyuan Li ◽  
Zhihai Gao ◽  
Bin Sun
Keyword(s):  
Arid Region ◽  
Source Region ◽  
Aerodynamic Resistance ◽  
Estimation Method ◽  
Source Model ◽  
Vegetation Coverage ◽  
Estimation Accuracy ◽  
Estimation Model ◽  
Sparse Vegetation ◽  
Improved Model

Evapotranspiration (ET) is an important part of the water, carbon, and energy cycles in ecosystems, especially in the drylands. However, due to the particularity of sparse vegetation, the estimation accuracy of ET has been relatively low in the drylands. Therefore, based on the dry climate and sparse vegetation distribution characteristics of the drylands, this study optimized the core algorithms (canopy boundary resistance, aerodynamic resistance, and sparse vegetation coverage) and explored an ET estimation method in the Shuttleworth–Wallace two-layer model (SW model). Then, the Beijing–Tianjin sandstorm source region (BTSSR) was used as the study area to evaluate the applicability of the improved model in the drylands. Results show that: (1) The R2 value of the improved model results was increased by 1.4 and the RMSE was reduced by 1.9 mm, especially in extreme value regions of ET (maximum or minimum). (2) Regardless of the spatial distribution and seasonal changes of the ET (63–790 mm), the improved ET estimation model could accurately capture the differences. Furtherly, the different vegetation regions could stand for the different climate regions to a certain extent. The accuracy of the optimized model was higher in the semi-arid region (R2 = 0.92 and 0.93), while the improved model had the best improvement effect in the arid region, with R2 increasing by 0.12. (3) Precipitation was the decisive factor affecting vegetation transpiration and ET, with R2 value for both exceeding 0.9. The effect of vegetation coverage (VC) was less. This method is expected to provide a more accurate and adaptable model for the estimation of ET in the drylands.

Sign in / Sign up

Export Citation Format

Share Document