Tropical peat subsidence rates are related to decadal LULC changes: Insights from InSAR analysis

Urbanization has been contributing more in global climate warming, with more than 50% of the population living in cities. Rapid population growth and change in land use / land cover (LULC) are closely linked. The transformation of LULC due to rapid urban expansion significantly affects the functions of biodiversity and ecosystems, as well as local and regional climates. Improper planning and uncontrolled management of LULC changes profoundly contribute to the rise of urban land surface temperature (LST). This study evaluates the impact of LULC changes on LST for 1997, 2007 and 2017 in the Rajshahi district (Bangladesh) using multi-temporal and multi-spectral Landsat 8 OLI and Landsat 5 TM satellite data sets. The analysis of LULC changes exposed a remarkable increase in the built-up areas and a significant decrease in the vegetation and agricultural land. The built-up area was increased almost double in last 20 years in the study area. The distribution of changes in LST shows that built-up areas recorded the highest temperature followed by bare land, vegetation and agricultural land and water bodies. The LULC-LST profiles also revealed the highest temperature in built-up areas and the lowest temperature in water bodies. In the last 20 years, LST was increased about 13ºC. The study demonstrates decrease in vegetation cover and increase in non-evaporating surfaces with significantly increases the surface temperature in the study area. Remote-sensing techniques were found one of the suitable techniques for rapid analysis of urban expansions and to identify the impact of urbanization on LST.

Download Full-text

Investigating impact of land-use and land cover changes on hydro-ecological balance using GIS: insights from IIT Bombay, India

SN Applied Sciences ◽

10.1007/s42452-021-04328-7 ◽

2021 ◽

Vol 3 (3) ◽

Cited By ~ 1

Author(s):

Aman Srivastava ◽

Pennan Chinnasamy

Keyword(s):

Land Use ◽

Land Cover ◽

Surface Runoff ◽

Forest Cover ◽

Google Earth ◽

Negative Consequences ◽

Ecological Stability ◽

Barren Land ◽

Ecological Balance ◽

Lulc Changes

AbstractThe present study, for the first time, examined land-use land cover (LULC), changes using GIS, between 2000 and 2018 for the IIT Bombay campus, India. Objective was to evaluate hydro-ecological balance inside campus by determining spatio-temporal disparity between hydrological parameters (rainfall-runoff processes), ecological components (forest, vegetation, lake, barren land), and anthropogenic stressors (urbanization and encroachments). High-resolution satellite imageries were generated for the campus using Google Earth Pro, by manual supervised classification method. Rainfall patterns were studied using secondary data sources, and surface runoff was estimated using SCS-CN method. Additionally, reconnaissance surveys, ground-truthing, and qualitative investigations were conducted to validate LULC changes and hydro-ecological stability. LULC of 2018 showed forest, having an area cover of 52%, as the most dominating land use followed by built-up (43%). Results indicated that the area under built-up increased by 40% and playground by 7%. Despite rapid construction activities, forest cover and Powai lake remained unaffected. This anomaly was attributed to the drastically declining barren land area (up to ~ 98%) encompassing additional construction activities. Sustainability of the campus was demonstrated with appropriate measures undertaken to mitigate negative consequences of unwarranted floods owing to the rise of 6% in the forest cover and a decline of 21% in water hyacinth cover over Powai lake. Due to this, surface runoff (~ 61% of the rainfall) was observed approximately consistent and being managed appropriately despite major alterations in the LULC. Study concluded that systematic campus design with effective implementation of green initiatives can maintain a hydro-ecological balance without distressing the environmental services.

Download Full-text

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

Water ◽

10.3390/w13081105 ◽

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.

Download Full-text

Influence of disturbances and environmental changes on albedo in tropical peat ecosystems

Agricultural and Forest Meteorology ◽

10.1016/j.agrformet.2021.108348 ◽

2021 ◽

Vol 301-302 ◽

pp. 108348

Author(s):

Shinjiro Ohkubo ◽

Takashi Hirano ◽

Kitso Kusin

Keyword(s):

Environmental Changes ◽

Tropical Peat

Download Full-text

Effects of Climate and Land Use/Land Cover Changes on Water Yield Services in the Dongjiang Lake Basin

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10070466 ◽

2021 ◽

Vol 10 (7) ◽

pp. 466

Author(s):

Wenbo Mo ◽

Yunlin Zhao ◽

Nan Yang ◽

Zhenggang Xu ◽

Weiping Zhao ◽

...

Keyword(s):

Land Use ◽

Land Cover ◽

Water Resource Management ◽

Water Source ◽

Water Yield ◽

Lake Basin ◽

Lake Area ◽

Land Use Land Cover ◽

Lulc Changes ◽

Regional Water

Spatial and quantitative assessments of water yield services in watershed ecosystems are necessary for water resource management and improved water ecological protection. In this study, we used the InVEST model to estimate regional water yield in the Dongjiang Lake Basin in China. Moreover, we designed six scenarios to explore the impacts of climate and land use/land cover (LULC) changes on regional water yield and quantitatively determined the dominant mechanisms of water yield services. The results are expected to provide an important theoretical reference for future spatial planning and improvements of ecological service functions at the water source site. We found that (1) under the time series analysis, the water yield changes of the Dongjiang Lake Basin showed an initial decrease followed by an increase. Spatially, water yield also decreased from the lake area to the surrounding region. (2) Climate change exerted a more significant impact on water yield changes, contributing more than 98.26% to the water yield variability in the basin. In contrast, LULC had a much smaller influence, contributing only 1.74 %. (3) The spatial distribution pattern of water yield services in the watershed was more vulnerable to LULC changes. In particular, the expansion of built-up land is expected to increase the depth of regional water yield and alter its distribution, but it also increases the risk of waterlogging. Therefore, future development in the basin must consider the protection of ecological spaces and maintain the stability of the regional water yield function.

Download Full-text

Changes in ecosystem service values strongly influenced by human activities in contrasting agro-ecological environments

Ecological Processes ◽

10.1186/s13717-021-00325-1 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Mulatu Liyew Berihun ◽

Atsushi Tsunekawa ◽

Nigussie Haregeweyn ◽

Mitsuru Tsubo ◽

Ayele Almaw Fenta

Keyword(s):

Population Growth ◽

Ecosystem Service ◽

Cultivated Land ◽

Nile Basin ◽

Grazing Land ◽

Blue Nile ◽

Lulc Changes ◽

Blue Nile Basin ◽

The Impact ◽

Upper Blue Nile Basin

Abstract Background Evaluating the impacts of land-use/land-cover (LULC) changes on ecosystem service values (ESVs) is essential for sustainable use and management of ecosystems. In this study, we evaluated the impact of human activity driven LULC changes on ESVs over the period 1982–2016/17 in contrasting agro-ecological environments: Guder (highland), Aba Gerima (midland), and Debatie (lowland) watersheds of the Upper Blue Nile basin, Ethiopia. Results During the study period, the continuous expansion of cultivated land at the expense of natural vegetation (bushland, forest, and grazing land) severely reduced the total ESV by about US$ 58 thousand (35%) in Aba Gerima and US$ 31 thousand (29%) in Debatie watersheds. In contrast, the unprecedented expansion of plantations, mainly through the planting of Acacia decurrens, led, from 2006, to a ESV rebound by about US$ 71 thousand (54%) in Guder watershed, after it had decreased by about US$ 61 thousand (32%) between 1982 and 2006. The reduction in natural forest area was the major contributor to the loss of total ESV in the study watersheds, ranging from US$ 31 thousand (63%) in Debatie to US$ 96.9 thousand (70%) in Guder between 1982 and 2016/17. On an area-specific basis, LULC changes reduced the average ESV from US$ 560 ha−1 year−1 (1982) in Guder to US$ 306 ha−1 year−1 (2017) in Debatie watersheds. Specific ESVs such as provisioning (mainly as food production) and regulating services (mainly as erosion control and climate regulation) accounted for most of the total ESVs estimated for the study watersheds. Conclusions In most cases, the total and specific ESVs of the watersheds were negatively associated with the population growth, which in turn was positively associated with the expansion of cultivated land over the study period. In Guder, however, ESVs were positively associated with population growth, especially after 2012. This is mainly due to the expansion of Acacia decurrens plantations. Our results suggest, therefore, that future policy measures and directions should focus on improving vegetation cover through planting multipurpose trees such as Acacia decurrens to prevent future loss of ESV in the midland and lowland regions of the Upper Blue Nile basin and beyond. However, caution must be taken during plantation of invasive species as they may have undesirable consequences.

Download Full-text

The Use of Subsidence to Estimate Carbon Loss from Deforested and Drained Tropical Peatlands in Indonesia

Forests ◽

10.3390/f12060732 ◽

2021 ◽

Vol 12 (6) ◽

pp. 732

Author(s):

Gusti Z. Anshari ◽

Evi Gusmayanti ◽

Nisa Novita

Keyword(s):

Water Table ◽

Carbon Emission ◽

Bottom Layer ◽

Groundwater Table ◽

Microbial Oxidation ◽

Tropical Peat ◽

Subsidence Rate ◽

Tier 1 ◽

Tropical Peatlands ◽

Physical Changes

Drainage is a major means of the conversion of tropical peat forests into agriculture. Accordingly, drained peat becomes a large source of carbon. However, the amount of carbon (C) loss from drained peats is not simply measured. The current C loss estimate is usually based on a single proxy of the groundwater table, spatially and temporarily dynamic. The relation between groundwater table and C emission is commonly not linear because of the complex natures of heterotrophic carbon emission. Peatland drainage or lowering groundwater table provides plenty of oxygen into the upper layer of peat above the water table, where microbial activity becomes active. Consequently, lowering the water table escalates subsidence that causes physical changes of organic matter (OM) and carbon emission due to microbial oxidation. This paper reviews peat bulk density (BD), total organic carbon (TOC) content, and subsidence rate of tropical peat forest and drained peat. Data of BD, TOC, and subsidence were derived from published and unpublished sources. We found that BD is generally higher in the top surface layer in drained peat than in the undrained peat. TOC values in both drained and undrained are lower in the top and higher in the bottom layer. To estimate carbon emission from the top layer (0–50 cm) in drained peats, we use BD value 0.12 to 0.15 g cm−3, TOC value of 50%, and a 60% conservatively oxidative correction factor. The average peat subsidence is 3.9 cm yr−1. The range of subsidence rate per year is between 2 and 6 cm, which results in estimated emission between 30 and 90 t CO2e ha−1 yr−1. This estimate is comparable to those of other studies and Tier 1 emission factor of the 2013 IPCC GHG Inventory on Wetlands. We argue that subsidence is a practical approach to estimate carbon emission from drained tropical peat is more applicable than the use of groundwater table.

Download Full-text

Geospatial analysis of wetlands based on land use/land cover dynamics using remote sensing and GIS in Sindh, Pakistan

Science Progress ◽

10.1177/00368504211026143 ◽

2021 ◽

Vol 104 (2) ◽

pp. 003685042110261

Author(s):

Hamza Islam ◽

Habibuulah Abbasi ◽

Ahmed Karam ◽

Ali Hassan Chughtai ◽

Mansoor Ahmed Jiskani

Keyword(s):

Land Use ◽

Land Cover ◽

Vegetation Cover ◽

Vegetation Index ◽

Kappa Statistics ◽

Natural Ecosystem ◽

Land Use Land Cover ◽

Dry Land ◽

Lulc Changes ◽

Manchar Lake

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.

Download Full-text

Does Land-Use Policy Moderate Impacts of Climate Anomalies on LULC Change in Dry-Lands? An Empirical Enquiry into Drivers and Moderators of LULC Change in Southern Ethiopia

Sustainability ◽

10.3390/su12156261 ◽

2020 ◽

Vol 12 (15) ◽

pp. 6261

Author(s):

Misginaw Arficho ◽

Andreas Thiel

Keyword(s):

Land Use ◽

Adverse Effects ◽

Natural Resource ◽

Governance System ◽

Dry Land ◽

Lulc Changes ◽

Climate Anomalies ◽

Land Use Policies ◽

Natural Resource Development ◽

Development Objectives

The study set out to understand drivers of Land-Use Land Cover (LULC) changes in dry-land areas and investigate factors helping mitigate the adverse impacts of climate anomalies on LULC changes. By employing a mixed-methods design, it combined LULC data with socioeconomic and climatic data, to analyze the pattern of LULC changes and its socioeconomic and climatic driving forces along with moderating factors. It was found that rangeland decreased by 764 km2 (13% of total area) between 1986 and 2015. The results from the Seemingly Unrelated time series regression models confirmed preliminary evidence that climate variability, as well as adaptive land-use policies lacking components of sustainability increase the likelihood of degradation and contraction of rangelands. We also found an indication from the qualitative data that a widening power gap between the customary and statutory governance system reinforces unsustainable land use by obscuring the values of the customary land governance system. However, those policies encompassing economic and natural resource development objectives abate adverse effects of climate variability on land degradation and shrinkage of rangelands. The results suggest that a land governance system with natural resource development objectives fitting to the local context could be an effective policy instrument to lessen the adverse effects of climate anomalies on LULC changes. Although this study focused on analyzing the LULC changes and its drivers in dry-land area, the findings may well have a bearing on the formulation and implementation of effective adaptation and sustainable land-use policies.

Download Full-text