scholarly journals Space-time variability of the Roncador river basin in the change of land use and cover and its correlation with climatic variables

2019 ◽  
Vol 35 (4) ◽  
Author(s):  
Raquel de Oliveira Santos ◽  
Rafael Coll Delgado ◽  
Marcos Gervasio Pereira ◽  
Leonardo Paula de Souza ◽  
Paulo Eduardo Teodoro ◽  
...  
Keyword(s):  
River Basin ◽  
Air Temperature ◽  
Vegetation Index ◽  
Space Time ◽  
Google Earth ◽  
Climatic Variables ◽  
Computer Application ◽  
Coefficient Of Determination ◽  
Native Forest ◽  
Time Dynamics

The objective of this study was to evaluate the space-time dynamics of the soil use and occupation of the Rio Roncador river basin between 1985 and 2010. The scenes were classified by two methods (partially unsupervised - K-Means and supervised - Maximum likelihood), the Thematic Mapper sensor products on the LANDSAT 5 orbital platform were used for both images of a 25-year time series (1985 to 2000). In order to measure the accuracy of the field the computer application Google Earth was used, in which nine classes (urban area, agricultural area, pasture, exposed soil, native forest, secondary vegetation, mangrove, altitude field and water) were collected. A multiple linear regression was performed, correlating the Normalized Difference Vegetation Index - mean NDVI (dependent variable) with the independent climatic variables (global solar radiation - MJm-2day-1, average air temperature - °C, relative humidity -%, evapotranspiration - mm d-1, and rain - mm). According to the general classification by Kappa parameter of the images for 2005 and 2010, they were identified as very good (68% and 74%). These results confirm that the Roncador River Basin is undergoing transformation in its landscape, with an average reduction of -49% in native vegetation areas due to the increase in urban areas (25%) and agriculture (31%). The statistical analysis showed that rainfall and air temperature were the only variables that presented significant sigma (0.04) and (0.02). The obtained coefficient of determination indicated that 47% of the variations of the "vegetation index" are explained by the environmental variables.  

scholarly journals Economic and climatic models for estimating coffee supply

2017 ◽  
Vol 52 (12) ◽  
pp. 1158-1166
Author(s):  
Adriana Ferreira de Moraes-Oliveira ◽  
Lucas Eduardo de Oliveira Aparecido ◽  
Sérgio Rangel Fernandes Figueira
Keyword(s):  
Air Temperature ◽  
Potential Evapotranspiration ◽  
Climatic Variables ◽  
Coefficient Of Determination ◽  
Percentage Error ◽  
Agricultural Credit ◽  
Rural Credit ◽  
Accuracy And Precision ◽  
Production Value ◽  
Water Surplus

Abstract: The objective of this work was to estimate the coffee supply by calibrating statistical models with economic and climatic variables for the main producing regions of the state of São Paulo, Brazil. The regions were Batatais, Caconde, Cássia dos Coqueiros, Cristais Paulista, Espírito Santo do Pinhal, Marília, Mococa, and Osvaldo Cruz. Data on coffee supply, economic variables (rural credit, rural agricultural credit, and production value), and climatic variables (air temperature, rainfall, potential evapotranspiration, water deficit, and water surplus) for each region, during the period from 2000-2014, were used. The models were calibrated using multiple linear regression, and all possible combinations were tested for selecting the variables. Coffee supply was the dependent variable, and the other ones were considered independent. The accuracy and precision of the models were assessed by the mean absolute percentage error and the adjusted coefficient of determination, respectively. The variables that most affect coffee supply are production value and air temperature. Coffee supply can be estimated with multiple linear regressions using economic and climatic variables. The most accurate models are those calibrated to estimate coffee supply for the regions of Cássia dos Coqueiros and Osvaldo Cruz.

scholarly journals Farmland Changes and Their Ecological Impact in the Huangshui River Basin

Land ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1082
Author(s):  
Hui Wei ◽  
Changhe Lu ◽  
Yaqun Liu
Keyword(s):  
River Basin ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Negative Impact ◽  
Ecological Impact ◽  
Google Earth ◽  
Ecological Effect ◽  
Grain Production ◽  
Land Occupation ◽  
Qinghai Province

The Huangshui River Basin (HRB) is the main grain production and key implementation region of the “Grain for Green Program” (GGP) of Qinghai Province, and has experienced a quick urbanization during the last 20 years. Therefore, identifying the farmland change and its ecological effects is significant for farmland and ecological protection in the HRB. To this end, this study analyzed the farmland change between 2000 and 2018, based on 1 m spatial resolution farmland data visually interpreted from Google Earth high-resolution images, and then estimated its ecological impact based on the Normalized Difference Vegetation Index (NDVI) data of MODIS, using an ecological impact index of farmland change. The study found that: (1) The farmland area in the HRB decreased from 320.15 k ha in 2000 to 245.01 k ha in 2018, reduced by 23.47% or 1.48% per year, as mainly caused by ecological restoration and built-up land occupation; (2) from 2000 to 2018, the natural environment showed a greening trend in the HRB, with the mean NDVI increasing by 0.74% per year; (3) the farmland changes had a positive ecological effect, contributing 6.67% to the regional increase in the NDVI, but had a negative impact on grain production; (4) it is suggested to strengthen farmland protection by strictly controlling the urban land occupation and over-conversion of farmland in the HRB.

scholarly journals CRESCIMENTO DA AGRICULTURA IRRIGADA POR PIVÔ CENTRAL NA BACIA HIDROGRÁFICA DO ALTO RIO DAS MORTES - MT

Irriga ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 661-670
Author(s):  
Juan Vicente Liendro Moncada ◽  
Jefferson Vieira José ◽  
Jéfferson de Oliveira Costa ◽  
Carlos Alberto Quiloango-Chimarro ◽  
Niclene Ponce Rodrigues de Oliveira ◽  
...  
Keyword(s):  
River Basin ◽  
Satellite Images ◽  
Vegetation Index ◽  
Sao Paulo ◽  
Google Earth ◽  
São Paulo ◽  
Mato Grosso ◽  
Center Pivot ◽  
Google Earth Engine ◽  
E Mail

CRESCIMENTO DA AGRICULTURA IRRIGADA POR PIVÔ CENTRAL NA BACIA HIDROGRÁFICA DO ALTO RIO DAS MORTES - MT     JUAN VICENTE LIENDRO MONCADA1; JEFFERSON VIEIRA JOSÉ2; JÉFFERSON DE OLIVEIRA COSTA3; CARLOS ALBERTO QUILOANGO-CHIMARRO4; NICLENE PONCE RODRIGUES DE OLIVEIRA5 E TONNY JOSÉ DE ARAÚJO DA SILVA6   1 Instituto de Ciências Agrárias e Tecnológicas, Universidade Federal de Mato Grosso (UFMT), Avenida dos Estudantes, 5055, Cidade Universitária, 78736-900, Rondonópolis, MT, Brasil. E-mail: [email protected]. 2 Centro Multidisciplinar Campus Floresta, Universidade Federal do Acre (UFA), Estrada do Canela Fina, Km 12, Colônia São Francisco, 69980-000, Cruzeiro do Sul, AC, Brasil. E-mail: [email protected]. 3 Departamento de Engenharia de Biossistemas, Universidade de São Paulo (USP/ESALQ), Avenida Pádua Dias, 235, Agronomia, 13418-900, Piracicaba, SP, Brasil. E-mail: [email protected]. 4 Departamento de Engenharia de Biossistemas, Universidade de São Paulo (USP/ESALQ), Avenida Pádua Dias, 235, Agronomia, 13418-900, Piracicaba, SP, Brasil. E-mail: [email protected]. 5 Instituto de Ciências Agrárias e Tecnológicas, Universidade Federal de Mato Grosso (UFMT), Avenida dos Estudantes, 5055, Cidade Universitária, 78736-900, Rondonópolis, MT, Brasil. E-mail: [email protected]. 6 Instituto de Ciências Agrárias e Tecnológicas, Universidade Federal de Mato Grosso (UFMT), Avenida dos Estudantes, 5055, Cidade Universitária, 78736-900, Rondonópolis, MT, Brasil. E-mail: [email protected].     1 RESUMO   O uso do solo e o seu tipo de cobertura tem sofrido modificações significativas nos últimos anos com o crescimento populacional e desenvolvimento da agricultura. Para obtenção de incrementos de produtividade agrícola uma das tecnologias mais empregadas no Brasil e no mundo é a irrigação. O objetivo dessa pesquisa foi identificar o número de equipamentos e as áreas equipadas com pivôs centrais na bacia hidrográfica do Alto Rio das Mortes no Estado de Mato Grosso, utilizando imagens de satélite de média resolução espacial. A bacia hidrográfica do Rio das Mortes está localizada no Centro-Oeste do Brasil, a qual está inserida na bacia do Rio Araguaia-Tocantins. Foram utilizadas imagens de satélite Landsat e a plataforma do Google Earth Engine (GEE). Foram construídas camadas de Índice de Vegetação por Diferença Normalizada (NDVI) e a partir desses dados procedeu-se a identificação e quantificação das áreas irrigadas por pivô central no local de estudo. Verificamos que a maior concentração de pivôs ocorre nas sub-bacias de Primavera do Leste (213 pivôs, 28 mil hectares) e Poxoréu (31 pivôs, 5 mil hectares). A bacia do Alto Rio das Mortes no ano de 2018 apresentava 271 pivôs centrais, ocupando uma área irrigada de aproximadamente 36,5 mil hectares.   Keywords: geotecnologias, índice de vegetação, irrigação, sensoriamento remoto.     MONCADA, J. V. L.; JOSÉ, J. V.; COSTA, J. O.; QUILOANGO-CHIMARRO, C. A.; OLIVEIRA, N. P. R.; SILVA, T. J. A. INCREASE IN CENTER PIVOT-IRRIGATED AGRICULTURE IN THE RIO DAS MORTES-MT RIVER BASIN     2 ABSTRACT   Land use and land cover have changed significantly in recent years with population growth and the development of agriculture. To obtain increases in agricultural productivity, one of the most used technologies in Brazil and around the world is irrigation. This research identified the amount of equipment and areas equipped by center pivots in the Rio das Mortes River basin in the State of Mato Grosso, using satellite images of medium spatial resolution. The Rio das Mortes River basin is located in center-western Brazil, which is inserted in the Araguaia-Tocantins River basin. Landsat satellite images and the Google Earth Engine (GEE) platform were used. Normalized Difference Vegetation Index (NDVI) layers were constructed, and then the identification and quantification of the areas irrigated by center pivot in the study area were performed. The highest concentration of pivots in the Rio das Mortes River basin is in the sub-basins of Primavera do Leste (213 pivots, 28 thousand hectares) and Poxoréu (31 pivots, 5 thousand hectares). The Rio das Mortes River basin in 2018 had 271 center pivots, occupying an irrigated area of approximately 36.5 thousand hectares.   Keywords: geotechnologies, vegetation index, irrigation, remote sensing.

scholarly journals Severity of the present-day climate in the Polar regions of Siberia

2019 ◽  
Vol 59 (2) ◽  
pp. 258-266 ◽  
Author(s):  
E. V. Maksyutova ◽  
L. B. Bashalkhanova
Keyword(s):  
Local Time ◽  
Air Temperature ◽  
Temperature Rise ◽  
Thermal State ◽  
Severity Index ◽  
Space Time ◽  
Climatic Conditions ◽  
Polar Regions ◽  
The West ◽  
Time Dynamics

Over the period 1981–2015 severe climatic conditions on the North of Siberia (area within 66–162° E above the Polar Circle) were characterized by significant space-time variations of air temperature at the cold period of the year. This conclusion is made on the basis of analysis of observations made about 13 hour of local time. Positive changes in the mean seasonal air temperature were observed here in October–April. The largest rates of air temperature rise with a pronounced gradient to the West were noted in high latitudes, i.e. in Arctic glacial and polar desert landscapes. The change in weather severity which is one of characteristics of the climate discomfort was analyzed by means of the Arnoldi index (TA). This index reflects the combined effect of negative temperatures and stiff wind on the thermal state of the open surface of the human body. Together with the space-time dynamics of the actual TA values, important values of TA are its threshold values (more than 30 and more than 45 units) which determine a degree of discomfort. Duration of these periods, limiting a possibility of a person's stay in the open air, is also extremely important as well. In recent decades (1981–2015), the spatial differentiation of the number of days (from 80 to 160) limiting the human’s stay in the open air reflects in the main fluctuations of the air temperature and wind regime in polar landscapes. Slight warming (a rise of the air temperature) and small wind speed variability during the period from October to April in 1981–2015 resulted in a certain decrease in the index of weather severity in relation to the period 1966–1980, since the last one did not did not go beyond limit of the interannual variability. Despite the stable increase in the air temperature in 1981–2015, no tendency to reduction of the number of days limiting human’s stay in the open air was noted. The duration of this period for 1981–2015 is similar to that observed in 1936–1964, and we believe that this is suggestive of manifestation of the cyclicity of atmospheric processes and is agreed with a gradual decrease in the rate of the temperature rise. In the last period duration of the period limiting human stay in the open air in the considered area remains high and ranges from 3.5 (to the west of 80° E) to 5 months on islands and capes of the region. So, as is demonstrated by the above example of space-time dynamics of the weather severity index at the time about 13 hours of local time, no decrease in the level of discomfort in polar Siberia is found.

scholarly journals Consistent Long-Term Monthly Coastal Wetland Vegetation Monitoring Using a Virtual Satellite Constellation

2021 ◽  
Vol 13 (3) ◽  
pp. 438
Author(s):  
Subrina Tahsin ◽  
Stephen C. Medeiros ◽  
Arvind Singh
Keyword(s):  
Vegetation Index ◽  
Coastal Wetland ◽  
Thermal Emission ◽  
Mean Squared Error ◽  
Wetland Vegetation ◽  
Coefficient Of Determination ◽  
Landsat 8 ◽  
Vegetation Monitoring ◽  
Time Space

Long-term monthly coastal wetland vegetation monitoring is the key to quantifying the effects of natural and anthropogenic events, such as severe storms, as well as assessing restoration efforts. Remote sensing data products such as Normalized Difference Vegetation Index (NDVI), alongside emerging data analysis techniques, have enabled broader investigations into their dynamics at monthly to decadal time scales. However, NDVI data suffer from cloud contamination making periods within the time series sparse and often unusable during meteorologically active seasons. This paper proposes a virtual constellation for NDVI consisting of the red and near-infrared bands of Landsat 8 Operational Land Imager, Sentinel-2A Multi-Spectral Instrument, and Advanced Spaceborne Thermal Emission and Reflection Radiometer. The virtual constellation uses time-space-spectrum relationships from 2014 to 2018 and a random forest to produce synthetic NDVI imagery rectified to Landsat 8 format. Over the sample coverage area near Apalachicola, Florida, USA, the synthetic NDVI showed good visual coherence with observed Landsat 8 NDVI. Comparisons between the synthetic and observed NDVI showed Root Mean Squared Error and Coefficient of Determination (R2) values of 0.0020 sr−1 and 0.88, respectively. The results suggest that the virtual constellation was able to mitigate NDVI data loss due to clouds and may have the potential to do the same for other data. The ability to participate in a virtual constellation for a useful end product such as NDVI adds value to existing satellite missions and provides economic justification for future projects.

scholarly journals Remote Sensing for Plant Water Content Monitoring: A Review

2021 ◽  
Vol 13 (11) ◽  
pp. 2088
Author(s):  
Carlos Quemada ◽  
José M. Pérez-Escudero ◽  
Ramón Gonzalo ◽  
Iñigo Ederra ◽  
Luis G. Santesteban ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Continuous Wave ◽  
Technological Development ◽  
Water Status ◽  
Irrigation Management ◽  
Coefficient Of Determination ◽  
Plant Water ◽  
Monitoring Methods

This paper reviews the different remote sensing techniques found in the literature to monitor plant water status, allowing farmers to control the irrigation management and to avoid unnecessary periods of water shortage and a needless waste of valuable water. The scope of this paper covers a broad range of 77 references published between the years 1981 and 2021 and collected from different search web sites, especially Scopus. Among them, 74 references are research papers and the remaining three are review papers. The different collected approaches have been categorized according to the part of the plant subjected to measurement, that is, soil (12.2%), canopy (33.8%), leaves (35.1%) or trunk (18.9%). In addition to a brief summary of each study, the main monitoring technologies have been analyzed in this review. Concerning the presentation of the data, different results have been obtained. According to the year of publication, the number of published papers has increased exponentially over time, mainly due to the technological development over the last decades. The most common sensor is the radiometer, which is employed in 15 papers (20.3%), followed by continuous-wave (CW) spectroscopy (12.2%), camera (10.8%) and THz time-domain spectroscopy (TDS) (10.8%). Excluding two studies, the minimum coefficient of determination (R2) obtained in the references of this review is 0.64. This indicates the high degree of correlation between the estimated and measured data for the different technologies and monitoring methods. The five most frequent water indicators of this study are: normalized difference vegetation index (NDVI) (12.2%), backscattering coefficients (10.8%), spectral reflectance (8.1%), reflection coefficient (8.1%) and dielectric constant (8.1%).

scholarly journals Vegetation Dynamic Assessment by NDVI and Field Observations for Sustainability of China’s Wulagai River Basin

2021 ◽  
Vol 18 (5) ◽  
pp. 2528
Author(s):  
Panpan Chen ◽  
Huamin Liu ◽  
Zongming Wang ◽  
Dehua Mao ◽  
Cunzhu Liang ◽  
...  
Keyword(s):  
Species Diversity ◽  
River Basin ◽  
Vegetation Change ◽  
Vegetation Index ◽  
Dynamic Assessment ◽  
Indicator System ◽  
Vegetation Changes ◽  
Vegetation Dynamic ◽  
Management Policies ◽  
The Impact

Accurate monitoring of grassland vegetation dynamics is essential for ecosystem restoration and the implementation of integrated management policies. A lack of information on vegetation changes in the Wulagai River Basin restricts regional development. Therefore, in this study, we integrated remote sensing, meteorological, and field plant community survey data in order to characterize vegetation and ecosystem changes from 1997 to 2018. The residual trend (RESTREND) method was utilized to detect vegetation changes caused by human factors, as well as to evaluate the impact of the management of pastures. Our results reveal that the normalized difference vegetation index (NDVI) of each examined ecosystem type showed an increasing trend, in which anthropogenic impact was the primary driving force of vegetation change. Our field survey confirmed that the meadow steppe ecosystem increased in species diversity and aboveground biomass; however, the typical steppe and riparian wet meadow ecosystems experienced species diversity and biomass degradation, therefore suggesting that an increase in NDVI may not directly reflect ecosystem improvement. Selecting an optimal indicator or indicator system is necessary in order to formulate reasonable grassland management policies for increasing the sustainability of grassland ecosystems.

Sign in / Sign up

Export Citation Format

Share Document