scholarly journals Applying Multi-Index approach from Sentinel-2 Imagery to Extract Urban Area in dry season (Semi-Arid Land in North East Algeria)

2020 ◽  
pp. 89
Author(s):  
K. Rouibah ◽  
M. Belabbas
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Bare Soil ◽  
Dry Season ◽  
Spectral Indices ◽  
Multi Index ◽  
North East ◽  
Sensing Applications ◽  
Semi Arid ◽  
Sentinel 2

<p>The mapping of urban areas mostly presents a big difficulty, particularly, in arid and semi-arid environments. For that reason, in this research, we expect to increase built up accuracy mapping for Bordj Bou Arreridj city in semi-arid regions (North-East Algeria) by focusing on the identification of appropriate combination of the remotely sensed spectral indices. The study applies the ‘k–means’ classifier. In this regard, four spectral indexes were selected, namely normalized difference tillage index (NDTI) for built-up, and both bare soil index (BSI) and dry bare-soil index (DBSI), which are related to bare soil, as well as the normalized difference vegetation index (NDVI). All previous spectral indices mentioned were derived from Sentinel-2 data acquired during the dry season. Two combinations of them were generated using layer stack process, keeping both of NDTI and NDVI index constant in both combinations so that the multi-index NDTI/BSI/NDVI was the first single dataset combination, and the multi-index NDTI/DBSI/NDVI as the second component. The results show that BSI index works better with NDTI index compared to the use of DBSI index. Therefore, BSI index provides improvements: bare soil classes and built-up were better discriminated, where the overall accuracy increased by 5.67% and the kappa coefficient increased by 12.05%. The use of k-means as unsupervised classifier provides an automatic and a rapid urban area detection. Therefore, the multi-index dataset NDTI/ BSI / NDVI was suitable for mapping the cities in dry climate, and could provide a better urban management and future remote sensing applications in semi-arid areas particularly.</p>

scholarly journals Home range areas of koalas in an urban area of north-east New South Wales

2014 ◽  
Vol 36 (1) ◽  
pp. 74 ◽  
Author(s):  
Ross L. Goldingay ◽  
Barbara Dobner
Keyword(s):  
Home Range ◽  
Urban Area ◽  
Urban Areas ◽  
Tree Planting ◽  
Home Ranges ◽  
Minimum Convex Polygon ◽  
Phascolarctos Cinereus ◽  
North East ◽  
South Wales ◽  
Primary Habitat

Conserving wildlife within urban areas requires knowledge of habitat requirements and population processes, and the management of threatening factors. The koala (Phascolarctos cinereus) is one species that is adversely affected by urban development. Sick and injured koalas in the Lismore urban area are regularly taken into care. We radio-tracked koalas released from care in order to estimate home-range areas and to determine their fate. Koalas were tracked for periods of 90–742 days; 7 of 10 survived for a period of at least one year. Home ranges defined by the minimum convex polygon (MCP100%) were large (mean ± s.e. = 37.4 ± 8.2 ha). Analysis using the 95% Fixed Kernel revealed home-range areas of 8.0 ± 1.7 ha. Analysis of the habitat composition of each MCP home range showed that they included 4.3 ± 0.9 ha of primary habitat (dominated by their primary food trees). These home ranges contained 27.6 ± 6.8 ha of non-habitat (cleared or developed land). Koalas crossed roads within their home ranges at least 5–53 times; one crossed the Bruxner Highway near a roundabout at least 32 times over his 2-year tracking period. Future management should include strategic food tree planting that enhances habitat connectivity and minimises the risk of car strike or dog attack.

Cultivated Lands within Urban Area

2013 ◽  
pp. 143-157
Author(s):  
G. Mauro
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Suburban Areas ◽  
North East ◽  
The North ◽  
Relevant Role ◽  
Agricultural Areas ◽  
The City ◽  
The Town

Several studies put in evidence the relevant role of cultivated lands in the urban areas. Using GIS methodologies in order to map agricultural areas near or within the town, it is possible to analyze their relationship with the urban area. In this study, the author used several different cartography sources, like digital cartography and orthophotos, in order to locate the urban domestic gardens and the terraced landscapes accurately. The study area is a medium city of a North-East Region of Italy, Trieste. Built on a hill morphology, it had a great and fast growth in the 19th and 20th centuries. These changes deeply transformed its landform, mainly reducing its surrounding cultivated lands. At present, the residual terraced landscapes are mainly placed in the north side of the city and they represent a kind of “cultural heritage.” On the contrary, the most important garden areas are located in the terrain embankments of the south suburban areas.

Evaluating the accuracy of spectral indices from Sentinel-2 data for estimating forest biomass in urban areas of the tropical savanna

2021 ◽  
Vol 22 ◽  
pp. 100484
Author(s):  
Bashir Adamu ◽  
Sa'ad Ibrahim ◽  
Azad Rasul ◽  
Shittu J. Whanda ◽  
Philemon Headboy ◽  
...  
Keyword(s):  
Urban Areas ◽  
Forest Biomass ◽  
Tropical Savanna ◽  
Spectral Indices ◽  
Sentinel 2

scholarly journals Temporal Variability of Particulate Matter in Urban Area of Port Harcourt, Nigeria

2019 ◽  
pp. 1-7
Author(s):  
Christopher U. Onuorah ◽  
T. G. Leton ◽  
O. L. Y. Momoh
Keyword(s):  
Particulate Matter ◽  
Urban Area ◽  
Atmospheric Stability ◽  
Dry Season ◽  
Health Concern ◽  
Trade Wind ◽  
Elevated Concentration ◽  
North East ◽  
Port Harcourt ◽  
Particle Pollution

Particulate matter pollution poses serious health concern to public health in Nigeria especially at elevated concentration. Its size is very vital in determination of its long stay in the atmosphere as well as its deposition in human respiratory system. This study analyzes the temporal variation of particulate matter (PM10 and PM2.5) concentrations and its ratio in urban area of Port Harcourt. The study was carried out in Woji, area of Port Harcourt, Nigeria, from May to December 2018 using Aerocet 531 particulate monitor while meteorological variables were monitored via Misol wireless weather station mounted 10 m above the ground level. The highest particle pollution occurred in the month of December with an average daily PM2.5 concentration of 58.8 μgm-3 and PM10 concentration of 164.5 μgm-3, which exceeds WHO and USEPA daily threshold. These particle pollution exceedances recorded the dry season month of December was due to high atmospheric stability with dry dusty north east trade wind associated with harmattan. Also,  Particulate matter concentration are usually lower during the weekends than weekdays with high PM level occurring at night from 8:00 PM to 9:00 AM in the morning with the peak at 8.00 AM. This shows that the weekdays experienced elevated PM level than weekend as a result of high industrial, commercial and traffic activities emitting particles within the weekdays. Also the average PM2.5/PM10 ratio for wet and dry season was 0.3 respectively. This shows that the town is town is predominated by coarse particle. 

scholarly journals A Simplified Framework for High-Resolution Urban Vegetation Classification with Optical Imagery in the Los Angeles Megacity

2020 ◽  
Vol 12 (15) ◽  
pp. 2399 ◽  
Author(s):  
Red Willow Coleman ◽  
Natasha Stavros ◽  
Vineet Yadav ◽  
Nicholas Parazoo
Keyword(s):  
Los Angeles ◽  
Land Cover ◽  
Spatial Resolution ◽  
Urban Areas ◽  
High Spatial Resolution ◽  
Water Cycle ◽  
Bare Soil ◽  
Urban Vegetation ◽  
Optical Imagery ◽  
Sentinel 2

High spatial resolution maps of Los Angeles, California are needed to capture the heterogeneity of urban land cover while spanning the regional domain used in carbon and water cycle models. We present a simplified framework for developing a high spatial resolution map of urban vegetation cover in the Southern California Air Basin (SoCAB) with publicly available satellite imagery. This method uses Sentinel-2 (10–60 × 10–60 m) and National Agriculture Imagery Program (NAIP) (0.6 × 0.6 m) optical imagery to classify urban and non-urban areas of impervious surface, tree, grass, shrub, bare soil/non-photosynthetic vegetation, and water. Our approach was designed for Los Angeles, a geographically complex megacity characterized by diverse Mediterranean land cover and a mix of high-rise buildings and topographic features that produce strong shadow effects. We show that a combined NAIP and Sentinel-2 classification reduces misclassified shadow pixels and resolves spatially heterogeneous vegetation gradients across urban and non-urban regions in SoCAB at 0.6–10 m resolution with 85% overall accuracy and 88% weighted overall accuracy. Results from this study will enable the long-term monitoring of land cover change associated with urbanization and quantification of biospheric contributions to carbon and water cycling in cities.

scholarly journals Effects of supplementing lactating camels with Acacia tortilis pods and ‘Chalbi salt’ on milk yield and calf growth in the peri-urban area of Marsabit town, Kenya

2021 ◽  
Vol 11 (1) ◽  
pp. 117-122
Author(s):  
JI Sagala ◽  
CK Gachuiri ◽  
SG Kuria ◽  
MM Wanyoike
Keyword(s):  
Urban Area ◽  
Milk Yield ◽  
Urban Areas ◽  
Post Partum ◽  
Live Weight ◽  
Experimental Period ◽  
Dry Season ◽  
Acacia Tortilis ◽  
Calf Growth ◽  
Randomized Design

Camel milk production and marketing within the peri-urban areas within pastoral areas is emerging and has high potential due to sendentarization and urbanization of an increasing number of local inhabitants. Performance of grazing camels in these areas is poor due to inadequate feed resources, particularly during the dry season. The objective of this study was to determine the effect of supplementing lactating camels with milled Acacia tortilis pods and ‘Chalbi salt’ on milk yield, calf growth and its economic potential in the peri-urban area of Marsabit town, Kenya. Twenty Somali camels in early lactation (1-4 weeks post-partum) and parities 2 or 3 and their calves were recruited for the study. The dams and their calves were penned and fed individually with the supplements where applicable. The treatments were: browsing only (B), browsing and ‘Chalbi salt’ (BC), 2 kg/day milled Acacia tortilis pods, ‘Chalbi salt’ and browsing (BC2A) and 4 kg/day milled Acacia tortilis pods, ‘Chalbi salt’ and browsing (BC4A). Five camels were randomly allocated to each treatment based on initial live weight in a completely randomized design and data collection done for 90 days. During each milking, the two left or right quarters were alternately reserved for the calf, while the remaining two were milked by hand. Milk yields were recorded daily in the morning and evening for 90 days while the calves were weighed on weekly basis for the same period. The overall total mean milk yield during the experimental period ranged from 233.0 to 298.0 litres during the short rains and dry season, respectively. The mean calf weight gains over the study period were 15.2, 19.0, 32.2 and 39.0 kg for B, BC, BC2A and BC4A, respectively, with BC4A and BC2A being higher than B. Supplementing camels under treatment BC4A was profitable as it resulted in both higher milk yield and calf weight gain and hence positive net gain. Int. J. Agril. Res. Innov. Tech. 11(1): 117-122, June 2021

scholarly journals Comparative assessment of drought monitoring indices susceptibility using geospatial techniques

2021 ◽  
Author(s):  
Hui Yue ◽  
Ying Liu ◽  
Jiaxin Qian
Keyword(s):  
Feature Space ◽  
Bare Soil ◽  
Landsat 8 ◽  
Soil Line ◽  
Coordinate Origin ◽  
Dryness Index ◽  
Semi Arid Region ◽  
Semi Arid ◽  
Better Than ◽  
Sentinel 2

Abstract There are two main categories of dryness monitoring indices based on spectral feature space. One category uses the vertical distance from any point to a line passing through the coordinate origin, which is perpendicular to a soil line, to monitor the dryness conditions. The most popular indices are the Perpendicular Dryness Index (PDI) and the modified perpendicular dryness index (MPDI). The other category uses the distance from any point in feature space to the coordinate origin to represent the dryness status, for instance, the soil moisture (SM) monitoring index (SMMI) and the modified soil moisture monitoring index (MSMMI). In this study, the performances and differences of these four indicators were evaluated using field-measured SM (FSM) data based on Gaofen-1 (GF-1) wide field of view (WFV), Landsat-8 Operational Land Imager (OLI), and Sentinel-2 Multi-Spectral Instrument (MSI) sensors. Performance evaluations were conducted in two study areas, namely an arid and semi-arid region of northwest China and a humid agricultural region of southwest Canada. We employed gradient-based structural similarity (GSSIM) to quantitatively assess the similarity of the structural information and structural characteristics among these four indicators. Monitoring SM in bare soil or low vegetation-covered areas in the semi-arid region, the SMMI, PDI, MSMMI, and MPDI from Near-infrared (NIR)-Red had significantly negative linear correlations with the FSM at 0-5 cm depth (P < 0.01). However, SMMI was better than PDI in estimating SM in bare soil, which was better than MSMMI and MPDI for GF-1. Moreover, the PDI and SMMI had similar SM evaluation abilities, which were better than those of MPDI and MSMMI for Landsat-8. The GSSIM map of the SMMI/PDI and the MSMMI/MPDI showed that the low change areas accounted for 99.89% and 98.89% for GF-1, respectively, and 95.78% and 94.45% for Landsat-8, respectively. This result indicated that the SMMI, PDI, MSMMI, and MPDI values from NIR-Red in low vegetation cover were similar. In monitoring SM in agricultural vegetation areas, the accuracy of the four indices from Short-wave Infrared (SWIR) feature space was higher than that from NIR-Red feature space for Sentinel-2. The SM monitoring effect of MSMMI and MPDI was better than that of SMMI and PDI. Due to the lack of SWIR band, GF-1 was limited in monitoring SM in vegetation-covered areas. The SMMI and MSMMI, which do not rely on the soil line, were more suitable than PDI and MPDI for retrieving SM in the complex surface environment depending on the soil line and the number of parameters. GF-1 with 16 m resolution had higher accuracy in SM assessment than Landsat-8 with 30 m resolution and had almost the same accuracy as Sentinel-2 with 20 m.

The Status of Livelihood Vulnerability and Its CopingCapacities of Urban Squatters in Kathmandu Metropolitan City, Nepal

Patan Pragya ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 19-32
Author(s):  
Chhabi Ram Baral
Keyword(s):  
Data Collection ◽  
Urban Area ◽  
Urban Areas ◽  
Quantitative Methods ◽  
Urban Poverty ◽  
Rural Poverty ◽  
Poor People ◽  
Qualitative And Quantitative ◽  
Qualitative And Quantitative Methods ◽  
The Status

Urban poverty is one of multidimensional issue in Nepal. Increasing immigration from the outer parts of Kathmandu due to rural poverty, unemployment and weak security of the lives and the properties are core causes pushing people into urban areas. In this context how squatter urban area people sustain their livelihoods is major concern. The objectives of the study are to find out livelihood assets and capacities squatters coping with their livelihood vulnerability in adverse situation. Both qualitative and quantitative methods are applied for data collection. It is found that squatters social security is weak, victimized by severe health problems earning is not regular with lack of physical facilities and overall livelihood is critical. This study helps to understand what the changes that have occurred in livelihood patterns and how poor people survive in urban area.

scholarly journals The Wood Quality of Small-Leaved Lime (Tilia cordata Mill.) Trees in an Urban Area: A Pilot Study

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 420
Author(s):  
Benas Šilinskas ◽  
Aistė Povilaitienė ◽  
Gintautas Urbaitis ◽  
Marius Aleinikovas ◽  
Iveta Varnagirytė-Kabašinskienė
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Wood Quality ◽  
Wood Products ◽  
Urban Trees ◽  
Measuring System ◽  
Forest Site ◽  
Tilia Cordata ◽  
Mean Values ◽  
Wood Development

This study performed a pilot evaluation of the wood quality—defined by a single parameter: dynamic modulus of elasticity (MOEdyn, N mm−2)—of small-leaved lime (Tilia cordata Mill.) trees in urban areas. A search of the literature revealed few studies which examined the specifics of tree wood development in urban areas. Little is known about the potential of wood from urban trees wood of their suitability for the timber industry. In this study, an acoustic velocity measuring system was used for wood quality assessment of small-leaved lime trees. The MOEdyn parameter was evaluated for small-leaved lime trees growing in two urban locations (along the streets, and in an urban park), with an additional sample of forest sites taken as the control. MOEdyn was also assessed for small-leaved lime trees visually assigned to different health classes. The obtained mean values of MOEdyn of 90–120-year old small-leaved lime trees in urban areas ranged between 2492.2 and 2715.8 N mm−2. For younger trees, the values of MOEdyn were lower in the urban areas than in the forest site. Otherwise, the results of the study showed that the small-leaved lime wood samples were of relatively good quality, even if the tree was classified as moderately damaged (which could cause a potential risk to the community). Two alternatives for urban tree management can be envisaged: (1) old trees could be left to grow to maintain the sustainability of an urban area until their natural death, or (2) the wood from selected moderately damaged trees could be used to create wood products, ensuring long-term carbon retention.

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