scholarly journals MULTI-TEMPORAL ANALYSIS OF LAND USE AND VEGETATION COVER IN SÃO FRANCISCO DO SUL AND ITAPOÁ, SANTA CATARINA STATE - BRAZIL: IMPLICATIONS TO GROUNDWATER CONTAMINATION

Author(s):  
A. C. S. J. V. Ferreira ◽  
L. S. Osako

Abstract. By means of the multitemporal approach, we analyze the changes in land use and vegetation cover in the São Francisco do Sul and Itapoá municipalities, located in the northern coast of the State of Santa Catarina, Brazil. LANDSAT satellite images from 1991 to 2019 were analyzed and classified into four classes of soil use and occupation (vegetated area, bare soil, urbanized area, and water body) by the GEOBIA method. Weighted sum analysis was applied to the ‘urbanized area’ class and the data available on geologic units, so as to identify areas vulnerable to groundwater contamination. The vegetated areas of São Francisco do Sul and Itapoá have diminished along the 2000’s, but recovery measures, such as reforesting and restraint of soil exposure, have been adopted, with 89.61% success. The urban zone has increased 3.36% in the last 28 years. The achieved overall accuracy for the classification was of 79.33% and the Kappa coefficient was 0.69. The analysis of groundwater vulnerability to contamination helped identify regions more susceptible to pollution, which coincide almost entirely with those where urbanization was more intense in areas where unconsolidated sediments predominate.

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2492 ◽  
Author(s):  
Tien-Duc Vu ◽  
Chuen-Fa Ni ◽  
Wei-Ci Li ◽  
Minh-Hoang Truong

The groundwater vulnerability (GV) assessment for contamination is an effective technique for the planning, policy, and decision-making, as well as for sustainable groundwater resource protection and management. The GV depends strongly on local hydrogeological settings and land-use conditions that may vary in response to the activities of agricultural development. In this study, a modified DRASTIC model, which employs an additional factor of land use coupled with the analytic hierarchy process (AHP) theory, was used to quantify the spatial and temporal variation of GV and groundwater contamination risk in the Pingtung groundwater basin. The results show that the GV slightly decreased due to the decrease in agricultural areas under the change of land use over two decades (1995–2017). The yearly changes or a shorter period of observations incorporated with the accurate land-use map in DRASTIC parameters could improve GV maps to obtain a better representation of site-specific conditions. Meanwhile, the maps of yearly contamination risk indicated that the counties of Jiuru and Ligang are at high risk of nitrate pollution since 2016. In other agriculture-dominated regions such as Yanpu, Changzhi, and Gaoshu in the Pingtung groundwater basin, the climate conditions influence less the temporal variations of groundwater contamination risk. The results of this study are expected to support policy-makers to adopt the strategies of sustainable development for groundwater resources in local areas.


Author(s):  
A. E. Oseni ◽  
G. O. Ode

The south western states of Nigeria have witnessed urban growth over time and the effect of this is urban growth has resulted in loss of vegetation, waterbody, bare soil, mangroves and gain in built up area for residential and commercial purposes. This research utilizes Remote Sensing techniques in mapping of Land Use/Land Cover changes that has taken place in south western states of Nigeria between a period of 15 years from 2003 to 2018 at a five year interval using Multi temporal Landsat satellite images (MSS, TM, and ETM+).Using supervised classification algorithm, the images were classified into bare soil, built-up area, vegetation and water body, which was used to carry out change detection analysis or time series analysis. Change detection analyses were carried out on the imageries to obtain the physical expansion of the area due to various land use. Results obtained from the analysis of built-up area dynamics for fifteen years revealed that the states have been undergoing urban expansion processes at the detriment of other landcover. The expansion of the built-up area from the analysis shows that the urban center is spreading to adjoining non-built-up areas in all directions. The analysis and quantification of the spatial trend revealed that urban expansion patterns and developmental processes of the past trends and present trends can provide better understanding of the dynamics of spatial increase in built up area and guide for sustainable urban development planning for future urban growth.


2007 ◽  
Vol 2 (3) ◽  
Author(s):  
M. V. Civita ◽  
M. De Maio ◽  
A. Fiorucci

In the early 1980's the Italian scientific community, together with a number of institutional decision-makers, realized how urgent it was to protect natural and environmental resources. They agreed that an adequate level of scientifically organized knowledge allows the accurate planning and development of environmental systems through management and direction of the actual development process, without hindering it. Since the special project was first set up in 1984, as part of the GNDCI-CNR (National Group for the Defence against Hydrogeologic Disasters, of the Italian National Council of Research) scientific context, it has been the cardinal point of Research Line 4 “Assessment of Aquifer Vulnerability”. The problem of groundwater contamination was examined in this project for the very first time in Italy in an organic and extensive manner as a key for forecasting and prevention purposes. The Italian approaches to assessing and mapping groundwater vulnerability to contamination are essentially based on two main methodologies:- The GNDCI Basic Method a HCS (Hazard Contamination Source) type approach that can be used for any type of Italian hydrogeologic situation, even where there is a limited amount of data. A unified legend and symbols are also defined for each hydrogeologic level.- The SINTACS [Soggiacenza (depth to groundwater); Infiltrazione (effective infiltration); Non saturo (unsaturated zone attenuation capacity); Tipologia della copertura (soil/overburden attenuation capacity); Acquifero (saturated zone characteristics); Conducibilità (hydraulic conductivity); Superficie topografica (Slope)] method, a PCSM (Point Count System Model) developed for use prevalently in areas with good data base coverage. The methodological approaches described in this paper now make up the Italian standard which has been set in the recent very important Italian Law (152/99) and which has now been ratified in the national guidelines produced by ANPA, the Italian National Agency for Environment Protection. In this paper the structure of the Research Line, the progress obtained by the 21 Research units (over 100 researchers) in 20 years of activity, the results gained etc. are briefly highlighted.


2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Ratha Phok ◽  
Nandalal Kosgallana Duwage Wasantha ◽  
Weerakoon Sumana Bandara ◽  
Pitawala Herath Mudiyanselage Thalapitiye Ge ◽  
Dharmagunawardhane Hingure Arachchilage

AbstractGroundwater vulnerability assessment has become a crucial step in successfully protecting groundwater against pollution. An attempt of this study has been made to evaluate groundwater contamination risk using intrinsic vulnerability and land-uses in Vanathavillu, Kalpitiya and Katana area in Sri Lanka, using coupled DRASTIC with GIS as feasible methodology. The findings reveal that the groundwater in the areas under study falls under very low to high contamination risk. The higher risk of contamination has been identified in most of the Kalpitiya (about 82%) with the moderate along the beach in the west and next to Puttalam lagoon in the northeast and southeast. This is mainly due to pollution risk inherent with intense vegetable cultivation, over pumping, shallow groundwater tables and permeable sandy soil. Vanathavillu is under very low to moderate contamination risk, in which the moderate risk (about 13%) has especially been found the center, central southwest and west of the area. The relative less deep groundwater tables, possible seepage from the underlying limestone aquifer and less permeable red earth soil could be cause for the moderate risk in the area. Furthermore, results show that the Katana has low to moderately high groundwater contamination risk. Nitrate has a good agreement with the different pollution risk classes and that nitrate can be used as an indicator of aquifer degradation inherent with land-use activities in the coastal areas. Groundwater quality monitoring network should be set up to minimize the anthropogenic acts, particularly in high and moderate contamination risk zones.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vít Zelinka ◽  
Johana Zacharová ◽  
Jan Skaloš

AbstractThe term Sudetenland refers to large regions of the former Czechoslovakia that had been dominated by Germans. German population was expelled directly after the Second World War, between 1945 and 1947. Almost three million people left large areas in less than two years. This population change led to a break in the relationship between the people and the landscape. The aim of the study is to compare the trajectories of these changes in agricultural landscapes in lower and higher altitudes, both in depopulated areas and areas with preserved populations. This study included ten sites in the region of Northern Bohemia in Czechia (18,000 ha in total). Five of these sites represent depopulated areas, and the other five areas where populations remained preserved. Changes in the landscape were assessed through a bi-temporal analysis of land use change by using aerial photograph data from time hoirzons of 2018 and 1953. Land use changes from the 1950s to the present are corroborated in the studied depopulated and preserved areas mainly by the trajectory of agricultural land to forest. The results prove that both population displacement and landscape type are important factors that affect landscape changes, especially in agricultural landscapes.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Hamza Islam ◽  
Habibuulah Abbasi ◽  
Ahmed Karam ◽  
Ali Hassan Chughtai ◽  
Mansoor Ahmed Jiskani

In this study, the Land Use/Land Cover (LULC) change has been observed in wetlands comprises of Manchar Lake, Keenjhar Lake, and Chotiari Reservoir in Pakistan over the last four decades from 1972 to 2020. Each wetland has been categorized into four LULC classes; water, natural vegetation, agriculture land, and dry land. Multitemporal Landsat satellite data including; Multi-Spectral Scanner (MSS), Thematic Mapper (TM), and Operational Land Imager (OLI) images were used for LULC changes evaluation. The Supervised Maximum-likelihood classifier method is used to acquire satellite imagery for detecting the LULC changes during the whole study period. Soil adjusted vegetation index technique (SAVI) was also used to reduce the effects of soil brightness values for estimating the actual vegetation cover of each study site. Results have shown the significant impact of human activities on freshwater resources by changing the natural ecosystem of wetlands. Change detection analysis showed that the impacts on the land cover affect the landscape of the study area by about 40% from 1972 to 2020. The vegetation cover of Manchar Lake and Keenjhar Lake has been decreased by 6,337.17 and 558.18 ha, respectively. SAVI analysis showed that soil profile is continuously degrading which vigorously affects vegetation cover within the study area. The overall classification accuracy and Kappa statistics showed an accuracy of >90% for all LULC mapping studies. This work demonstrates the LULC changes as a critical monitoring basis for ongoing analyses of changes in land management to enable decision-makers to establish strategies for effectively using land resources.


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