scholarly journals Dinâmica do uso e cobertura da terra em uma bacia hidrográfica transfonteiriça Brasil-Uruguai entre 1985 e 2017

2021 ◽  
Vol 14 (4) ◽  
pp. 2304-2321
Author(s):  
Alexandro Gularte Schafer ◽  
John Roger Roldan Aleixo

This study aims to investigate the dynamics of land use and land cover (LULC) in the São Luiz river watershed, Brazil-Uruguay, between 1985 and 2017, using remote sensing and geographic information systems techniques. The study included the delimitation of the watershed and its drainage network, mapping of LULC, the calculation of landscape metrics and the determination of transitions and persistence. Severe changes in LULC patterns were detected in both the Brazilian and Uruguayan territories, caused by changes in economic activities related to the agricultural and livestock sector. Although the changes occurred similarly in both parts of the watershed based on he initial (1985) and final (2017) scenarios - reduction in the grassland and forest areas and increase in the agricultural areas and water bodies - were found that they occurred at different periods and intensities in brazilian and uruguayan territories. The conversion of grassland into agricultural areas was more intense in uruguayan territory, while inbBrazilian territory the fragmentation of the grassland occurred with greater intensity. Forest areas have reduced with similar intensity in both countries, accompanied by reduction in the fragmentation. The areas occupied by water bodies increased throughout the study period, with greater intensity in uruguayan territory between 1985 and 1996 and in brazilian territory between 2003 and 2017.

Author(s):  
B. Varpe Shriniwas D. Payal Sandip

In the present study, an effort has been made to study in detail of Land Use/Land Cover Mapping for Sambar watershed by using Remote Sensing and GIS technique was carried out during the year of 2020-2021 in Parbhani district. In this research the Remote Sensing and Geographical Information system technique was used for identifying the land use/land cover classes with the help of ArcGIS 10.8 software. The Sambar watershed is located in 19º35ʹ78.78˝ N and 76º87ʹ88.44˝ E in the Parbhani district of Marathwada region in Maharashtra. It is covered a total area 97.01 km2. The land use/land cover map and its classes were identified by the Supervised Classification Method in ArcGIS 10.8 software by using the Landsat 8 satellite image. Total six classes are identified namely as Agricultural area, Forest area, Urban area, Barren land, Water bodies and Fallow land. The Agricultural lands are well distributed throughout the watershed area and it covers 4135 ha. (43 per cent). Forest occupies 502 ha area and sharing about 5 per cent of the total land use land cover of the study area. The Urban land occupies 390 ha. area (4 per cent) and there was a rapid expansion of settlement area. Barren land occupies 3392 ha. area (35 per cent). A water bodies occupy 630 ha. area (6 per cent) and the Fallow land occupies 650 ha (7 per cent) but well-developed dendritic drainage pattern and good water availability is in the Sambar watershed.


Author(s):  
Andrius Litvinaitis ◽  
Lina Bagdžiūnaitė-Litvinaitienė ◽  
Laurynas Šaučiūnas

On preparing of the first management plans of River Basin Districts have been found that diffuse agricultural pol-lution is one of the most important causing factor and the most significant impact on the quality of water bodies. Diffuse agricultural pollution can be from 45% to 80% of nitrate nitrogen pollution load of water bodies. Pollution is transported by water surface and subsurface runoff through sediments from agricultural territories. This article aims at evaluating of relation between the Quaternary sediments and Land use dissemination. The lithological factor (sandy, loamy, argillaceous) of the basin was calculated based on Quaternary map of Lithuania M 1:200000 and Lithuanian river map M 1:50000. The land-use factor of the basin was calculated based on Corine Land cover M 1:100000 using ArcGis software. In order to carry out more thorough analysis of the determination of relation between the Quaternary sediments and Land use dissemination in given territories, sections of 0–50 m, 50–200 m, 200–500 m, 500–800 m, 800–1000 m and >1000 m were established, calculating the distance in meters from the riverbank.


2020 ◽  
Vol 12 (9) ◽  
pp. 3925 ◽  
Author(s):  
Sonam Wangyel Wang ◽  
Belay Manjur Gebru ◽  
Munkhnasan Lamchin ◽  
Rijan Bhakta Kayastha ◽  
Woo-Kyun Lee

Understanding land use and land cover changes has become a necessity in managing and monitoring natural resources and development especially urban planning. Remote sensing and geographical information systems are proven tools for assessing land use and land cover changes that help planners to advance sustainability. Our study used remote sensing and geographical information system to detect and predict land use and land cover changes in one of the world’s most vulnerable and rapidly growing city of Kathmandu in Nepal. We found that over a period of 20 years (from 1990 to 2010), the Kathmandu district has lost 9.28% of its forests, 9.80% of its agricultural land and 77% of its water bodies. Significant amounts of these losses have been absorbed by the expanding urbanized areas, which has gained 52.47% of land. Predictions of land use and land cover change trends for 2030 show worsening trends with forest, agriculture and water bodies to decrease by an additional 14.43%, 16.67% and 25.83%, respectively. The highest gain in 2030 is predicted for urbanized areas at 18.55%. Rapid urbanization—coupled with lack of proper planning and high rural-urban migration—is the key driver of these changes. These changes are associated with loss of ecosystem services which will negatively impact human wellbeing in the city. We recommend city planners to mainstream ecosystem-based adaptation and mitigation into urban plans supported by strong policy and funds.


2018 ◽  
Vol 4 (2) ◽  
pp. 378 ◽  
Author(s):  
Gilles A Kandissounon ◽  
Ajay Kalra ◽  
Sajjad Ahmad

The goal of this study was twofold; first analyze the patterns of water consumption in Lagos, Nigeria and use them in a System Dynamics (SD) model to make projections about future demand. The second part used remote sensing to quantify the contribution of extensive land use/cover change to urban flooding. Land use/cover dynamics over the past decade was analyzed using satellite imagery provided by Landsat Thematic Mapping (TM). Unsupervised classification was performed with false color composite using the Iterative Self-Organizing Data Analysis (ISODATA) technique in a Geographic Information Systems (GIS). The study area was divided into four different land use types during image classification: bare land, built-up area, water bodies, and vegetation. For water demand, two different scenarios of population growth including 5.5% and 2.75 % annual increase were considered. The results showed that water demand dropped by 67% of its current value when losses in distribution were reduced by 20% and population annual growth rate kept at 2.75% over the study period. Bare land and water bodies lost 1.31% and 1.61% of their current area respectively while built-up area grew by 1.11%. These changes in land use/cover changes led to a 64% increase in average surface runoff, mostly attributable to increasing surface imperviousness and the absence of an adequate urban drainage system.


Author(s):  
Babiker, E.M.A ◽  
Ibrahim, M.M ◽  
Elhag, A.M.H ◽  
Nser, S.H ◽  
Elsheikh, M.A ◽  
...  

<p>The study area lies to the east of the Nile (Sharg Elneel), Khartoum State (latitudes 15<sup>o</sup> 25̎ 1̍ and 16° 19̎ 1̍ N and longitudes 33° 19̎ 8̍ and 33°02̎ 9̍ E). Using remote sensing techniques and geographic information system (GIS), the changes in land cover/land use have been estimated using two methods: supervised and unsupervised classification. the images were those of the years 1973, 2001, and 2015 MSS, ETM, ETM+, respectively(173/49 &amp; 173/48 path/ row). The study area was classified into the following nine LU/LC types: water bodies, vegetation, rocky area, sandy soil, sandy sheet, clayey soil, bare soil, sand dunes and settlement areas. The individual areas covered by each type of land use/ land cover were calculated for each image using supervised and unsupervised classification. Then the areas were compared among the different years (images). The results indicated a decrease in areas of sandy soil, water bodies, vegetation cover, sand dunes, clay soil, and bare soil for years 1973-2001 and 1973-2015.  That was associated with significant increase in settlement area, sand sheet for the same period. As for the period 2001 and 2015 was an increase in the areas of vegetation, sandy soil, dunes, clay soil, and settlement. While there was a decrease in water bodies, rocky area, sand sheet and bar soil. A striking result of his study was an increase of 50% in the settlement area for the period 1973 – 2015. This indicated that more drift of people towards the Capital took place during this period possibly due to drought and civil strife. Also people come to Khartoum to have better living conditions, education, health care and to work and may be they look at Khartoum as a spring board for going abroad. This study recommended the use of remote sensing techniques and geographic information system in the follow up of desertification and land degradation by following changes in land cover and land use. It also recommended that sand movement (sand encroachment) shall be retarded possibly through increasing vegetation cover through seed broadcasting of pasture and range plants during the rainy season and to exploit the ground water of the NSS aquifer for irrigation.</p>


2016 ◽  
Vol 47 (3) ◽  
Author(s):  
Ali & Muhaimeed

This study was carried out in order to identify and mapping the temporal changes for land covers in Baghdad province using Remote Sensing and GIS. Three images were used of land sate taken in 1976, 2000 and 2014 the study area. Suppervised classification and SAVI Index were used to identify land cover classes dominated in the study area. The results of supper classification indicated the presence of five land cover classes including water bodies, bare land, urban, low dense vegetation, and dense vegetation classes. There were four classes of land cover when was used SAVI index: water, no vegetation (bare land and urban), low dense vegetation, and dense vegetation. The results showed that Remote Sensing is a very active and useful tool that can be used to detect land core types. The results showed a decline in class of water bodies from 2.8% to 1.5% for 1976 to 1990 while in 2014 increased to 2.1%. class Urban areas increased continuously with time and accounted for 17.6% , 23.5% and 28.2 % for years of study, indicating  the existence of the phenomenon of urban encroachment. Bare land areas accounted for 29.3% , 26.8% and 33.5% of stady years, respectively. The class of low dense vegetation decreased from 44.8% to 31.7% and 29.4% for 1976, 1990 and 2014 respectively, while the class-Dense vegetation increased at 1976-1990 from 5.5% to 16.4% and  decreased in 2014 to 6.8%. The SAVI had a role in the detection of agriculture and gave results same to the results of super classification. Results indicated that urban land and salinization process can be consider as the most phenomenon which negatively affected on agriculture area.


2014 ◽  
Vol 35 ◽  
pp. 1-24 ◽  
Author(s):  
Marion Kandziora ◽  
Katja Dörnhöfer ◽  
Natascha M. Oppelt ◽  
Felix Müller

Land use and land cover (LULC) and their changes in share and number of classes can be documented by remote sensing techniques. Information on LULC is needed for the assessment of ecosystem services and is used as input data for mapping and modelling. This information is important for decision-making and management of ecosystems and landscapes. In this study, LULC were analysed in two agricultural areas in Northern Germany by means of a pixel-based maximum likelihood classification approach of 11 Landsat TM 5 scenes between 1987 and 2011 followed by a post-classification refinement using the tool IRSeL. In this time period, grassland declined by about 50 % in both case study areas. This loss in grassland area can be associated with changes in provisioning ecosystem services as the supply of fodder and crops and the number of livestock declined from 1987 to 2007. Furthermore, an on-going increase in maize cultivation area, which is nowadays more and more used as biomass for biogas production, documents the addition of another provisioning service, i.e., biomass for energy. Combining remote sensing and research on ecosystem services supports the assessment and monitoring of ecosystem services on different temporal, spatial, and semantic scales.


2020 ◽  
Vol 28 ◽  
pp. 499-511
Author(s):  
Rodrigo Lacerda Brito Neto ◽  
Cristiano Tagliaferre ◽  
Odair Lacerda Lemos ◽  
Felizardo Adenilson Rocha ◽  
Alessandro de Paula ◽  
...  

ABSTRACT The spatial analysis of watersheds, as well as the evaluation off the changes occurring in their catchment area along the time are essential for the qualification of environmental changes. This study aims to characterize morphometrically the Pardo river watershed, as well as to evaluate the changes in soil use and occupation occurring between 2001 and 2016. The morphometric analysis consisted of the determination of the geometric parameters, relief information and drainage network using Geographic Information Systems. The land use and occupation information was collected through data from the online mapping platform of the Brazilian Mapping and Land Use Mapping (MapBiomas). According to the results, morphometry indicated that the watershed has low propensity to flood occurrence and tendency to conservation; great part of its area is between 600 and 1000 m of altitude, with predominance of undulating and soft-undulating slopes. The analysis of land use and occupation showed that the area devoted to agricultural activities increased during the period evaluated and occupies most of the basin, while the area of ??forests was reduced, the second in size, and these two classes occupy more than 96 % of catchment area.


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