scholarly journals Landscape variables influencing forest fires in central Spain

2011 ◽  
Vol 20 (5) ◽  
pp. 678 ◽  
Author(s):  
José M. Moreno ◽  
Olga Viedma ◽  
Gonzalo Zavala ◽  
Belén Luna
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Resource Selection ◽  
Selection Index ◽  
Fire Risk ◽  
Land Cover Type ◽  
Land Use Land Cover ◽  
Central Spain ◽  
Landscape Variables ◽  
Cover Type

In assessing fire risk, it is important to determine whether all areas in a landscape burn at similar rates. This goal is complicated by the limitations of burned-area data and the temporally dynamic nature of landscapes. We assessed the differential degree of forest-fire burning for six landscape variables (land-use–land-cover type, distances to roads and towns, topography (slope, aspect, elevation)), each comprising several categories. The study area (95 × 55 km) was located in central Spain, and the study period covered 16 years. Landsat multispectral scanner images were used to annually map fire perimeters and to classify the landscape. We calculated an annual resource selection index for each category within a variable. The sizes and shapes of all fires occurring within a year were randomly distributed into the landscape 1000 times, and the corresponding resource selection index was calculated. This provided a null random-burning model against which we tested the actual resource selection index of the fires in each year. Pine woodlands showed consistent and significant positive fire selectivity, whereas deciduous woodlands showed consistent and significant negative selectivity. No differences in the resource selection indices of land-use–land-cover types were found between large (>100 ha) and small fires (<100 ha). Fires positively selected (resource selection index >1) areas at small or intermediate distances to towns and intermediate distances to roads. Selectivity for topographic variables was less marked. Our study demonstrates that landscape variables defining composition (land-use–land-cover type) or proximity to human influence are important factors for fire risk.

scholarly journals Urban Heat and Urban Cool Islands of Different Land Use Types in Cuiabá, Brazil

2021 ◽  
Author(s):  
Natallia Sanches e Souza ◽  
Marta Cristina de Jesus Albuquerque Nogueira ◽  
Flávia Maria de Moura Santos ◽  
Luciana Sanches
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Urban Areas ◽  
Urban Heat Islands ◽  
Land Cover Type ◽  
Land Use Land Cover ◽  
Local Climate ◽  
Land Cover Types ◽  
Cover Type ◽  
Urban Heat

Abstract Urban heat islands (UHIs), urban cool islands (UCIs), and their varying effects due to land use/land cover types and the local climate were investigated from 2014 to 2015 in three urban zones located in Cuiabá city, Brazil, during hot-humid, and hot-dry periods. All the urban zones were analysed for land use/land cover type, local climate, and rate of warming and cooling based on the difference in air temperature (ΔT) between the urban zones and the rural zone located outside the urban perimeter. The annual UHI effect in all the urban zones exhibited varying intensities during the day, with the highest daytime intensity recorded after the sunrise. The duration of UHI effect varied with land use/land cover type; a consequence of high built-up density, verticalization, waterproof surface, and other peculiarities of urban areas. In the urban zones with high built-up density, the duration of UHI effect was observed for up to 24 h, while in the urban areas with low built-up density, the maximum duration of UHI effect was 8 h. On an average, during the daytime, the urban zone with approximately 70% of vegetation cover and water bodies recorded a UCI value of approximately –8 °C, whereas the urban zones with approximately 80% waterproof surface and bare land recorded a UCI value close to +2 °C during the hot-dry and hot-humid periods. The results indicate that land use and land cover types directly influence UHI intensity.

scholarly journals Land Use and Land Cover Change Assessment in the Context of Flood Hazard in Lagos State, Nigeria

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1105
Author(s):  
Dorcas Idowu ◽  
Wendy Zhou
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Flood Hazard ◽  
The State ◽  
Land Cover Type ◽  
Lulc Change ◽  
Cover Type ◽  
Lulc Changes ◽  
Lagos State ◽  
Very High

Incessant flooding is a major hazard in Lagos State, Nigeria, occurring concurrently with increased urbanization and urban expansion rate. Consequently, there is a need for an assessment of Land Use and Land Cover (LULC) changes over time in the context of flood hazard mapping to evaluate the possible causes of flood increment in the State. Four major land cover types (water, wetland, vegetation, and developed) were mapped and analyzed over 35 years in the study area. We introduced a map-matrix-based, post-classification LULC change detection method to estimate multi-year land cover changes between 1986 and 2000, 2000 and 2016, 2016 and 2020, and 1986 and 2020. Seven criteria were identified as potential causative factors responsible for the increasing flood hazards in the study area. Their weights were estimated using a combined (hybrid) Analytical Hierarchy Process (AHP) and Shannon Entropy weighting method. The resulting flood hazard categories were very high, high, moderate, low, and very low hazard levels. Analysis of the LULC change in the context of flood hazard suggests that most changes in LULC result in the conversion of wetland areas into developed areas and unplanned development in very high to moderate flood hazard zones. There was a 69% decrease in wetland and 94% increase in the developed area during the 35 years. While wetland was a primary land cover type in 1986, it became the least land cover type in 2020. These LULC changes could be responsible for the rise in flooding in the State.

Interactions between land use/land cover change, forest fires and landscape structure in Sierra de Gredos (Central Spain)

2006 ◽  
Vol 33 (3) ◽  
pp. 212-222 ◽  
Author(s):  
OLGA VIEDMA ◽  
JOSÉ M. MORENO ◽  
IGNACIO RIEIRO
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Land Cover Change ◽  
Landscape Structure ◽  
Landscape Patterns ◽  
Land Use Land Cover ◽  
Central Spain ◽  
Lulc Change ◽  
Burned Areas ◽  
In Fire

In fire-prone areas, like the Mediterranean, land abandonment and forestation may interact with fire to alter landscape properties and eventually fire hazard and occurrence. However, the spatial interactions among the two processes (land-use/land cover change [LULC] and fire) are poorly known. Here, we analysed the relative effect of LULC change and fire on the landscape structure of an area of Central Spain frequently affected by fire. A series of Landsat MSS images from 1975 to 1990 was analysed to quantify annual changes in LULC, map fire perimeters and evaluate the changes in landscape properties. The temporal dynamics were analysed by annually computing the fraction occupied by each LULC type and landscape structural properties (number, size, shape and arrangement of patches) that might play a role in fire propagation. All of these were calculated separately for the unburned or the burned areas during the study period, as well as for the entire area. At the whole landscape level, or in the unburned area, LULC changes were small, yet the two more flammable LULC types tended to increase, and the landscape tended to become more homogeneous. In the burned area, the area covered by pine woodlands tended to decrease, and that covered by shrublands to increase. Burned areas turned into shrublands only five years after fire. Landscape indices indicative of reduced fragmentation were also found. Both LULC change and fire altered landscape patterns in the whole area to create a less fragmented and more contiguous landscape than in 1975. The changes induced in the whole landscape by fire, in spite of the overall low disturbance rate, were sufficient to closely determine the changes in landscape composition (LULC types) and patterns.

Physical Landscape Correlates of the Expansion of Mechanized Agriculture in Mato Grosso, Brazil

2005 ◽  
Vol 9 (16) ◽  
pp. 1-18 ◽  
Author(s):  
Ellen Jasinski ◽  
Douglas Morton ◽  
Ruth DeFries ◽  
Yosio Shimabukuro ◽  
Liana Anderson ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Soil Type ◽  
Land Cover Type ◽  
Land Area ◽  
Mato Grosso ◽  
Land Use Conversion ◽  
Cover Type ◽  
Landscape Characteristics ◽  
Mechanized Agriculture

Abstract Mechanized agriculture is rapidly expanding in the state of Mato Grosso, Brazil. In the past five years, land area planted with soybeans, the state’s principal crop, has increased at an average rate of 19.4% yr−1. Drivers of this large-scale land-use conversion are principally economic and sociopolitical, but physical properties of the landscape make some areas more attractive than others for expansion of mechanized agriculture. The goal of this study is to evaluate several physical characteristics of land in Mato Grosso and to quantify their respective weights in determining the likelihood of land-use conversion to crop production. A 2003 land-cover classification at 250-m resolution was compared to maps of five physical landscape characteristics (surface slope, soil type, total November precipitation, distance from paved roads, and previous land-cover type based on a 2001 classification). A land-cover transition matrix was generated to inform analysis of the role of previous land-cover type, and statewide distributions of the other four landscape characteristics were examined across agricultural and nonagricultural land. Finally, logistic regressions were performed to quantify the respective correlations of these various characteristics with the probability of conversion to mechanized agriculture. Areas of new cropland in 2003 (converted since the 2001 classification) were nearly 3 times as likely to have been converted from pasture/cerrado as from all other land-cover types combined, but in terms of class original extent, bare soil was by far the most likely class to be converted to cropland, with 56% of its 2001 land area being converted by 2003. The physical landscape parameter found most highly correlated with conversion to mechanized agriculture between 2001 and 2003 was that of the previous land-cover type, followed by topographic slope and distance from paved roads. Soil type and total November precipitation were poorly correlated with mechanized agriculture. Findings from this study suggest that holistic, spatially explicit models of likelihood of conversion to mechanized agriculture should consider land cover, slope, and proximity to main roads in addition to political and economic parameters to generate realistic scenarios for sustainable land-use planning.

scholarly journals Analysis of the Current and Future Prediction of Land Use/Land Cover Change Using Remote Sensing and the CA-Markov Model in Majang Forest Biosphere Reserves of Gambella, Southwestern Ethiopia

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Semegnew Tadese ◽  
Teshome Soromessa ◽  
Tesefaye Bekele
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Markov Model ◽  
Fire Risk ◽  
Land Use Land Cover ◽  
Fuel Wood ◽  
Biosphere Reserves ◽  
Southwestern Ethiopia ◽  
Wood Extraction ◽  
Land Use Plan

This study aimed to evaluate land use/land cover changes (1987–2017), prediction (2032–2047), and identify the drivers of Majang Forest Biosphere Reserves. Landsat image (TM, ETM+, and OLI-TIRS) and socioeconomy data were used for the LU/LC analysis and its drivers of change. The supervised classification was also employed to classify LU/LC. The CA-Markov model was used to predict future LU/LC change using IDRISI software. Data were collected from 240 households from eight kebeles in two districts to identify LU/LC change drivers. Five LU/LC classes were identified: forestland, farmland, grassland, settlement, and waterbody. Farmland and settlement increased by 17.4% and 3.4%, respectively; while, forestland and grassland were reduced by 77.8% and 1.4%, respectively, from 1987 to 2017. The predicted results indicated that farmland and settlement increased by 26.3% and 6.4%, respectively, while forestland and grassland increased by 66.5% and 0.8%, respectively, from 2032 to 2047. Eventually, agricultural expansion, population growth, shifting cultivation, fuel wood extraction, and fire risk were identified as the main drivers of LU/LC change. Generally, substantial LU/LC changes were observed and will continue in the future. Hence, land use plan should be proposed to sustain resource of Majang Forest Biosphere Reserves, and local communities’ livelihood improvement strategies are required to halt land conversion.

Sign in / Sign up

Export Citation Format

Share Document