Responses of Spatiotemporal Vegetative Land Cover To Meteorological Changes in Bangladesh

Urban Expansion ◽

Climatic Variables ◽

Landsat Images ◽

Natural Landscape ◽

Impact Of Urbanization ◽

Rainfall Statistics ◽

Abstract Quantifying the response of vegetation cover change (VCC) to climatic variables is a gap that is mandatory for the conservation and rehabilitation of natural landscape to ensure sustainability. This study aims to assess the response of VCC to temperature and rainfall change in Bangladesh. We used (i) Landsat images to analyze VCC using image classification method, Normalized Difference Vegetation Index (NDVI) (ii) temperature and rainfall statistics to investigate the spatiotemporal variations (SV) of meteorological factors, urban lands, VCC in all the 64 districts of Bangladesh during 1990-2018 and examined their correlation. To quantify the impact of urbanization on VCC, two regression models were built between growing-season NDVI (GNDVI) and urban land proportion (PLU). Results show that the SV of precipitation, temperature, GNDVI, and PUL varied greatly among the districts. GNDVI was found closely related to climatic variables and less sensitive to climatic factor changes. There has been found a significant correlation between the trend of GNDVI and GP while the negative correlation between GNDVI trend and GT, ΔPUL. Strong sensitivity of GNDVI change to GP was calculated in the range of precipitation 2200-3000mm and GNDVI to GT change in the range of temperature 300C-310C. Besides, urban expansion was found mostly responsible for VCC in the study area.

Impacts of tropical hurricanes on the vegetation cover of the lower basin and estuary of San José del Cabo, Baja California Sur, Mexico

REVISTA CHAPINGO SERIE CIENCIAS FORESTALES Y DEL AMBIENTE ◽

10.5154/r.rchscfa.2020.03.011 ◽

2020 ◽

Vol 27 (1) ◽

pp. 165-180

Author(s):

Marcos Shiba-Reyes ◽

◽

Enrique Troyo ◽

Raúl Martínez-Rincón ◽

Aurora Breceda ◽

...

Keyword(s):

Vegetation Cover ◽

Vegetation Index ◽

Vegetation Type ◽

Stability Loss ◽

San Jose ◽

Landsat Images ◽

Precipitation Decrease ◽

One Year ◽

Introduction: Tropical hurricanes modify composition and structure of ecosystems. Objective: To analyze the impact of tropical hurricanes on the recovery and resilience of vegetation cover.Materials and methods: The resilience of the lower basin and estuary of San Jose del Cabo was evaluated by studying the impact of 11 tropical hurricanes (2013-2017) on the vegetation cover. Landsat images were analyzed for each event and two SPOT-6 images for the Hurricane Lidia. The areas of gain, stability, loss and recovery of vegetation types were estimated based on the analysis of changes in the Normalized Difference Vegetation Index (NDVI).Results and discussion: Average stability of vegetation cover was 90 %; however, in the case of hurricane Odile (2014) and Lidia (2017), stability decreased considerably, with a loss of 35.4 and 20.5 %, respectively, being the perennial herbaceous vegetation the most affected. One year after Odile and Lidia, recovery was 8.4 % and 25.4 %, respectively; the most recovered vegetation type was reed-tree. The analysis of SPOT-6 images allowed the detailed observation of Lidia's effect on palm grove. The main cause of its loss was runoff from the stream, which favored the growth of invasive species (Arundo donax L. and Tamarix sp.); furthermore, it was estimated that 1.4 ha were deforested, and an area of 20 ha affected by fire in 2017.Conclusion: Vegetation is resilient to tropical hurricanes; however, events that provide more than 50 % of annual precipitation decrease the capacity of vegetation to recover.

Urban Fire Severity and Vegetation Dynamics in Southern California

Remote Sensing ◽

10.3390/rs13010019 ◽

2020 ◽

Vol 13 (1) ◽

pp. 19

Author(s):

Lauren E. H. Mathews ◽

Alicia M. Kinoshita

Keyword(s):

Vegetation Cover ◽

Vegetation Index ◽

Current Knowledge ◽

Fire Severity ◽

Satellite Image ◽

Burn Severity ◽

Native Vegetation ◽

Riparian Areas ◽

A combination of satellite image indices and in-field observations was used to investigate the impact of fuel conditions, fire behavior, and vegetation regrowth patterns, altered by invasive riparian vegetation. Satellite image metrics, differenced normalized burn severity (dNBR) and differenced normalized difference vegetation index (dNDVI), were approximated for non-native, riparian, or upland vegetation for traditional timeframes (0-, 1-, and 3-years) after eleven urban fires across a spectrum of invasive vegetation cover. Larger burn severity and loss of green canopy (NDVI) was detected for riparian areas compared to the uplands. The presence of invasive vegetation affected the distribution of burn severity and canopy loss detected within each fire. Fires with native vegetation cover had a higher severity and resulted in larger immediate loss of canopy than fires with substantial amounts of non-native vegetation. The lower burn severity observed 1–3 years after the fires with non-native vegetation suggests a rapid regrowth of non-native grasses, resulting in a smaller measured canopy loss relative to native vegetation immediately after fire. This observed fire pattern favors the life cycle and perpetuation of many opportunistic grasses within urban riparian areas. This research builds upon our current knowledge of wildfire recovery processes and highlights the unique challenges of remotely assessing vegetation biophysical status within urban Mediterranean riverine systems.

Coastal Mangrove Response to Marine Erosion: Evaluating the Impacts of Spatial Distribution and Vegetation Growth in Bangkok Bay from 1987 to 2017

Remote Sensing ◽

10.3390/rs12020220 ◽

2020 ◽

Vol 12 (2) ◽

pp. 220 ◽

Cited By ~ 2

Author(s):

Han Xiao ◽

Fenzhen Su ◽

Dongjie Fu ◽

Qi Wang ◽

Chong Huang

Keyword(s):

Spatial Distribution ◽

Vegetation Index ◽

Mangrove Ecosystem ◽

Early Growth ◽

Growth Stages ◽

Human Disturbances ◽

Vegetation Growth ◽

Two Parameters ◽

Long time-series monitoring of mangroves to marine erosion in the Bay of Bangkok, using Landsat data from 1987 to 2017, shows responses including landward retreat and seaward extension. Quantitative assessment of these responses with respect to spatial distribution and vegetation growth shows differing relationships depending on mangrove growth stage. Using transects perpendicular to the shoreline, we calculated the cross-shore mangrove extent (width) to represent spatial distribution, and the normalized difference vegetation index (NDVI) was used to represent vegetation growth. Correlations were then compared between mangrove seaside changes and the two parameters—mangrove width and NDVI—at yearly and 10-year scales. Both spatial distribution and vegetation growth display positive impacts on mangrove ecosystem stability: At early growth stages, mangrove stability is positively related to spatial distribution, whereas at mature growth the impact of vegetation growth is greater. Thus, we conclude that at early growth stages, planting width and area are more critical for stability, whereas for mature mangroves, management activities should focus on sustaining vegetation health and density. This study provides new rapid insights into monitoring and managing mangroves, based on analyses of parameters from historical satellite-derived information, which succinctly capture the net effect of complex environmental and human disturbances.

Seasonal Variations of Daytime Land Surface Temperature and Their Underlying Drivers over Wuhan, China

Remote Sensing ◽

10.3390/rs13020323 ◽

2021 ◽

Vol 13 (2) ◽

pp. 323

Author(s):

Liang Chen ◽

Xuelei Wang ◽

Xiaobin Cai ◽

Chao Yang ◽

Xiaorong Lu

Keyword(s):

Surface Temperature ◽

Land Surface Temperature ◽

Land Surface ◽

Vegetation Index ◽

Maximum Temperature ◽

Maximum Temperature Difference ◽

Rapid Urbanization ◽

The Impact ◽

The City

Rapid urbanization greatly alters land surface vegetation cover and heat distribution, leading to the development of the urban heat island (UHI) effect and seriously affecting the healthy development of cities and the comfort of living. As an indicator of urban health and livability, monitoring the distribution of land surface temperature (LST) and discovering its main impacting factors are receiving increasing attention in the effort to develop cities more sustainably. In this study, we analyzed the spatial distribution patterns of LST of the city of Wuhan, China, from 2013 to 2019. We detected hot and cold poles in four seasons through clustering and outlier analysis (based on Anselin local Moran’s I) of LST. Furthermore, we introduced the geographical detector model to quantify the impact of six physical and socio-economic factors, including the digital elevation model (DEM), index-based built-up index (IBI), modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), population, and Gross Domestic Product (GDP) on the LST distribution of Wuhan. Finally, to identify the influence of land cover on temperature, the LST of croplands, woodlands, grasslands, and built-up areas was analyzed. The results showed that low temperatures are mainly distributed over water and woodland areas, followed by grasslands; high temperatures are mainly concentrated over built-up areas. The maximum temperature difference between land covers occurs in spring and summer, while this difference can be ignored in winter. MNDWI, IBI, and NDVI are the key driving factors of the thermal values change in Wuhan, especially of their interaction. We found that the temperature of water area and urban green space (woodlands and grasslands) tends to be 5.4 °C and 2.6 °C lower than that of built-up areas. Our research results can contribute to the urban planning and urban greening of Wuhan and promote the healthy and sustainable development of the city.

A Study of Desertification Using Remote Sensing Techniques in Basra Governorate, South Iraq

Iraqi Journal of Science ◽

10.24996/ijs.2021.62.3.22 ◽

2021 ◽

pp. 912-926

Author(s):

Fadel Abbas Zwain ◽

Thair Thamer Al-Samarrai ◽

Younus I. Al-Saady

Keyword(s):

Remote Sensing ◽

Land Degradation ◽

Land Surface ◽

Vegetation Index ◽

Arid Zone ◽

Sand Dunes ◽

Risk Index ◽

Anthropogenic Factors ◽

Landsat Images

Iraq territory as a whole and south of Iraq in particular encountered rapid desertification and signs of severe land degradation in the last decades. Both natural and anthropogenic factors are responsible for the extent of desertification. Remote sensing data and image analysis tools were employed to identify, detect, and monitor desertification in Basra governorate. Different remote sensing indicators and image indices were applied in order to better identify the desertification development in the study area, including the Normalized difference vegetation index (NDVI), Normalized Difference Water Index (NDWI), Salinity index (SI), Top Soil Grain Size Index (GSI) , Land Surface Temperature (LST) , Land Surface Soil Moisture (LSM), and Land Degradation Risk Index (LDI) which was used for the assessment of degradation severity .Three Landsat images, acquired in 1973, 1993, and 2013, were used to evaluate the potential of using remote sensing analysis in desertification monitoring. The approach applied in this study for evaluating this phenomenon was proven to be an effective tool for the recognition of areas at risk of desertification. The results indicated that the arid zone of Basra governorate encounters substantial changes in the environment, such as decreasing surface water, degradation of agricultural lands (as palm orchards and crops), and deterioration of marshlands. Additional changes include increased salinization with the creeping of sand dunes to agricultural areas, as well as the impacts of oil fields and other facilities.

The impact of urbanization expansion on agricultural land in Ethiopia: A review

Environmental & Socio-economic Studies ◽

10.2478/environ-2020-0024 ◽

2020 ◽

Vol 8 (4) ◽

pp. 73-80

Author(s):

Assefa Ayele ◽

Kassa Tarekegn

Keyword(s):

Urban Areas ◽

Agricultural Land ◽

Urban Expansion ◽

Rural Livelihoods ◽

Vital Role ◽

Rapid Urbanization ◽

Economic Resource ◽

House Construction ◽

Impact Of Urbanization ◽

AbstractIn a country like Ethiopia where the vast majority of the populations are employed in agriculture, land is an important economic resource for the development of rural livelihoods. Agricultural land in peri-urban areas is, however, transformed into built-up regions through horizontal urban expansion that has an effect on land use value. In recent years Ethiopia has been experiencing rapid urbanization, which has led to an ever-increasing demand for land in peri-urban areas for housing and other nonagricultural activities that pervades agricultural land. There is a high demand for informal and illegal peri-urban land which has been held by peri-urban farmers, and this plays a vital role in the unauthorized and sub-standard house construction on agricultural land. This urbanization has not been extensively reviewed and documented. In this review an attempt has been made to assess the impacts of rapid urbanization on agricultural activities. Urban expansion has reduced the areas available for agriculture, which has seriously impacted upon peri-urban farmers that are often left with little or no land to cultivate and which has increased their vulnerability. Housing encroachments have been observed to be uncontrolled due to a weak government response to the trend of unplanned city expansion. This has left peri-urban farmers exposed to the negative shocks of urbanization because significant urbanization-related agricultural land loss has a positive correlation with grain production decrease. Appropriate governing bodies should control urban development in order to control the illegal and informal spread of urbanization on agricultural land that threatens food production.

Comparative Study of Change Detection and Urban Expansion Using Multi-Date Multi-Source Data: A Case Study of Greater Khartoum

Journal of King Abdulaziz University-Engineering Sciences ◽

10.4197/eng.23-2.8 ◽

2012 ◽

Vol 23 (2) ◽

pp. 139-172

Author(s):

Abdullah Salman Alsalman Abdullah Salman Alsalman

Keyword(s):

Image Processing ◽

Change Detection ◽

Vegetation Index ◽

Urban Expansion ◽

Remote Sensing Data ◽

Principal Component ◽

Test Area ◽

Image Differencing ◽

Erdas Imagine

Noting that Khartoum represents the most rapidly expanding city in the Sudan and taking into account that change detection operations are seldom , the present study has been initiated to attempt to produce work that synthesizes land use/land cover (LULC) to investigate change detection using GIS, remote sensing data and digital image processing techniques; estimate, evaluate and map changes that took place in the city from 1975 to 2003. The experiment used the techniques of visual inspection, write-function-memoryinsertion, image differencing, image transformation i.e. normalized difference vegetation index (NDVI), tasseled cap, principal component analysis (PCA), post-classification comparison and GIS. The results of all these various techniques were used by the authors to study change detection of the geographic locale of the test area. Image processing and GIS techniques were performed using Intergraph Image analyst 8.4 and GeoMedia professional version 6, ERDAS Imagine 8.7, and ArcGIS 9.2. Results obtained were discussed and analyzed in a comparative manner and a conclusion regarding the best method for change detection of the test area was derived.

Monitoring of Inland Surface Water Quality Using Remote Sensing on the Example of Wigry Lake

E3S Web of Conferences ◽

10.1051/e3sconf/20186300017 ◽

2018 ◽

Vol 63 ◽

pp. 00017

Author(s):

Michał Lupa ◽

Katarzyna Adamek ◽

Renata Stypień ◽

Wojciech Sarlej

Keyword(s):

Water Quality ◽

Surface Water ◽

Vegetation Index ◽

Surface Water Quality ◽

Lake Area ◽

Landsat Images ◽

Secchi Disc ◽

Water Index ◽

Normalized Difference Water Index

The study examines how LANDSAT images can be used to monitor inland surface water quality effectively by using correlations between various indicators. Wigry lake (area 21.7 km2) was selected for the study as an example. The study uses images acquired in the years 1990–2016. Analysis was performed on data from 35 months and seven water condition indicators were analyzed: turbidity, Secchi disc depth, Dissolved Organic Material (DOM), chlorophyll-a, Modified Normalized Difference Water Index (MNDWI), Normalized Difference Water Index (NDWI) and Normalized Difference Vegetation Index (NDVI). The analysis of results also took into consideration the main relationships described by the water circulation cycle. Based on the analysis of all indicators, clear trends describing a systematic improvement of water quality in Lake Wigry were observed.

Resident vegetation modifies climate-driven elevational shift of a mountain sedge

Alpine Botany ◽

10.1007/s00035-020-00243-6 ◽

2020 ◽

Author(s):

Harald Crepaz ◽

Georg Niedrist ◽

Johannes Wessely ◽

Mattia Rossi ◽

Stefan Dullinger

Keyword(s):

Vegetation Index ◽

Species Distribution Model ◽

Distribution Model ◽

Distribution Data ◽

Study Region ◽

Potential Competitor ◽

Elevational Shift ◽

The Impact ◽

Mountain Plant

Abstract Mountain plant species are changing their ranges in response to global warming. However, these shifts vary tremendously in rate, extent and direction. The reasons for this variation are yet poorly understood. A process potentially important for mountain plant re-distribution is a competition between colonizing species and the resident vegetation. Here, we focus on the impact of this process using the recent elevational shift of the sedge Carex humilis in the northern Italian Alps as a model system. We repeated and extended historical sampling (conducted in 1976) of the species in the study region. We used the historical distribution data and historical climatic maps to parameterize a species distribution model (SDM) and projected the potential distribution of the species under current conditions. We compared the historical and the current re-survey for the species in terms of the cover of important potential competitor species as well as in terms of the productivity of the resident vegetation indicated by the Normalized Difference Vegetation Index (NDVI). We found that Carex humilis has shifted its leading range margin upward rapidly (51.2 m per decade) but left many sites that have become climatically suitable since 1976 according to the SDM uncolonized. These suitable but uncolonized sites show significantly higher coverage of all dwarf shrub species and higher NDVI than the sites occupied by the sedge. These results suggest that resistance of the resident vegetation against colonization of migrating species can indeed play an important role in controlling the re-distribution of mountain plants under climate change.

Assessing the Urban Eco-Environmental Quality by the Remote-Sensing Ecological Index: Application to Tianjin, North China

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10070475 ◽

2021 ◽

Vol 10 (7) ◽

pp. 475

Author(s):

Ting Zhang ◽

Ruiqing Yang ◽

Yibo Yang ◽

Long Li ◽

Longqian Chen

Keyword(s):

Remote Sensing ◽

Quality Assessment ◽

Urban Expansion ◽

Assessment Method ◽

Landsat Images ◽

Ecological Index ◽

Environment Quality ◽

Quality Assessment Method ◽

The remote-sensing ecological index (RSEI), which is built with greenness, moisture, dryness, and heat, has become increasingly recognized for its use in urban eco-environment quality assessment. To improve the reliability of such assessment, we propose a new RSEI-based urban eco-environment quality assessment method where the impact of RSEI indicators on the eco-environment quality and the seasonal change of RSEI are examined and considered. The northern Chinese municipal city of Tianjin was selected as a case study to test the proposed method. Landsat images acquired in spring, summer, autumn, and winter were obtained and processed for three different years (1992, 2005, and 2018) for a multitemporal analysis. Results from the case study show that both the contributions of RSEI indicators to eco-environment quality and RSEI values vary with the season and that such seasonal variability should be considered by normalizing indicator measures differently and using more representative remote-sensing images, respectively. The assessed eco-environment quality of Tianjin was, overall, improving owing to governmental environmental protection measures, but the damage caused by rapid urban expansion and sea reclamation in the Binhai New Area still needs to be noted. It is concluded that our proposed urban eco-environment quality assessment method is viable and can provide a reliable assessment result that helps gain a more accurate understanding of the evolution of the urban eco-environment quality over seasons and years.