scholarly journals Effects of Climate Change on Land Cover Change and Vegetation Dynamics in Xinjiang, China

2020 ◽  
Vol 17 (13) ◽  
pp. 4865 ◽  
Author(s):  
Haochen Yu ◽  
Zhengfu Bian ◽  
Shouguo Mu ◽  
Junfang Yuan ◽  
Fu Chen
Keyword(s):  
Climate Change ◽  
Land Cover ◽  
Land Cover Change ◽  
Extreme Precipitation ◽  
Vegetation Dynamics ◽  
Pearson Correlation ◽  
Extreme Temperature ◽  
Climate Extremes ◽  
Linear Regression Method ◽  
Vegetation Growth

Since the Silk-road Economic belt initiatives were proposed, Xinjiang has provided a vital strategic link between China and Central Asia and even Eurasia. However, owing to the weak and vulnerable ecosystem in this arid region, even a slight climate change would probably disrupt vegetation dynamics and land cover change. Thus, there is an urgent need to determine the Normalized Difference Vegetation Index (NDVI) and Land-use/Land-cover (LULC) responses to climate change. Here, the extreme-point symmetric mode decomposition (ESMD) method and linear regression method (LRM) were applied to recognize the variation trends of the NDVI, temperature, and precipitation between the growing season and other seasons. Combining the transfer matrix of LULC, the Pearson correlation analysis was utilized to reveal the response of NDVI to climate change and climate extremes. The results showed that: (1) Extreme temperature showed greater variation than extreme precipitation. Both the ESMD and the LRM exhibited an increased volatility trend for the NDVI, with the significant improvement regions mainly located in the margin of basins. (2) Since climate change had a warming trend, the permanent snow has been reduced by 20,436 km2. The NDVI has a higher correlation to precipitation than temperature. Furthermore, the humid trend could provide more suitable conditions for vegetation growth, but the warm trend might prevent vegetation growth. Spatially, the response of the NDVI in North Xinjiang (NXC) was more sensitive to precipitation than that in South Xinjiang (SXC). Seasonally, the NDVI has a greater correlation to precipitation in spring and summer, but the opposite occurs in autumn. (3) The response of the NDVI to extreme precipitation was stronger than the response to extreme temperature. The reduction in diurnal temperature variation was beneficial to vegetation growth. Therefore, continuous concentrated precipitation and higher night-time-temperatures could enhance vegetation growth in Xinjiang. This study could enrich the understanding of the response of land cover change and vegetation dynamics to climate extremes and provide scientific support for eco-environment sustainable management in the arid regions.

scholarly journals Impacts of land cover change on climate trend in Padang Indonesia

2014 ◽  
Vol 46 (2) ◽  
pp. 138 ◽  
Author(s):  
Dedi Hermon
Keyword(s):  
Climate Change ◽  
Land Cover ◽  
Land Cover Change ◽  
Extreme Temperature ◽  
Extreme Rainfall ◽  
Land Cover Changes ◽  
Forest Land ◽  
Climate Trend ◽  
Extreme Climatic Events ◽  
Expert Team

ἀe purpose of this study was to analyze the trend of climate change through changes in the elements of Green House Gases (GHGs),   includes the trend of CO2, N2O, and CH4. ἀe change of the  extreme rainfall and temperature  indices due to land cover change into developed area in Padang. IdentiḀcation and analysis trends of climate change and extreme climatic events were analyzed by using RclimDex the Expert Team for Climate Change Detection and Indices (ETCCDMI) technique. Where as the analysis and interpretation of  land cover changes  into developed area used Landsat TM 5 and Landsat 1985 7 ETM +  of 2011 by ERDAS 9.2 GIS with the supervised classiḀcation method and GIS Matrix. ἀe results of the study provide informations of land cover changes into developed area at forest land  (11,758.9 ha), shrub (3,337.3 ha), rice Ḁelds (5,977.1 ha), and garden (5,872.4 ha). It has an implication on increasing of  the ele-ments of GHGs concentration such as CO2 (14,1 ppm), N2O (5,4 ppb) and CH4 (24,8 ppb). ἀis condition lead to an extreme temperature and presipitation indexs trends in Padang.

scholarly journals Separate and Combined Impacts of Land Cover and Climate Changes on Hydrological Responses of Dhidhessa River Basin, Ethiopia

2020 ◽  
Author(s):  
Gizachew Kabite ◽  
Misgana Muleta ◽  
Berhan Gessesse
Keyword(s):  
Climate Change ◽  
Land Cover ◽  
Groundwater Recharge ◽  
Land Cover Change ◽  
River Basin ◽  
Surface Runoff ◽  
Climate Changes ◽  
Negative Impacts ◽  
Hydrologic Responses ◽  
Soil And Water

Land cover and climate changes greatly influence hydrologic responses of a basin. However, the response vary from basin to basin depending on the nature and severity of the changes and basin characteristics. Moreover, the combined impacts of the changes affect hydrologic responses of a basin in an offsetting or synergistic manner. This study quantified the separate and combined impacts, and the relative contributions of land cover and climate changes on multiple hydrological regimes (i.e., surface runoff, streamflow, groundwater recharge evapotranspiration) for the Dhidhessa Subbasin. Land cover and climate change data were obtained from a recent study completed for the basin. Calibrated Soil and Water Analysis Tool (SWAT) was used to quantify the impacts. The result showed that SWAT model performed well for the Dhidhessa Subbasin in predicting the water balance components. Substantial land cover change as well as an increasing temperature and rainfall trends were reported in the river basin during the past three decades. In response to these changes, surface runoff, streamflow and actual evapotranspiration (AET) increased while groundwater recharge declined. Surface runoff was more sensitive to land cover than to climate changes whereas streamflow and AET were more sensitive to climate change than to land cover change. The combined impacts played offsetting effect on groundwater recharge and AET while inconsistent effects within study periods for other hydrologic responses. Overall, the predicted hydrologic responses will have negative impacts on agricultural production and water resources availability. Therefore, the implementation of integrated watershed management strategies such as soil and water conservation and afforestation could reverse the negative impacts.

scholarly journals Effect of Land Cover Change on Atlantic Forest Fragmentation in Rio Largo, Al, Brazil

2020 ◽  
pp. 102-114
Author(s):  
Lucas Galdino da Silva ◽  
Arthur Costa Falcão Tavares ◽  
Carlos Frederico Lins E. Silva Brandão ◽  
João Pedro dos Santos Verçosa ◽  
Raquel Elvira Cola ◽  
...  
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Forest Fragmentation ◽  
Atlantic Forest ◽  
Pearson Correlation ◽  
Aerial Images ◽  
Forest Fragments ◽  
Case Scenario ◽  
Worst Case ◽  
Digital Format

This study's objective was to analyze the effect of land cover change, between 1965 and 2018, using statistical metrics and geoprocessing tools. And consequently, to provide information of area (ha) and spatial fragmentation of the Atlantic Forest in the municipality of Rio Largo/AL, Brazil. The samples were collected and transferred by CECA, CADEH, and INCRA, between November 2019 and April 2020. The basic materials used in this work were multi-temporal aerial images in digital format, derived from the 1965 aerophotogrametric survey on the scale 1:25000, belonging to the collection of the Engineering and Agrarian Sciences Campus - UFAL, and images of Landsat satellites (5 and 8) processed and made available by the Mapbiomas Project. The statistic landscape metrics were calculated using Landscape ecology Statistics (LECOs), a QGIS plugin. The analysis of forest fragmentation areas over the 53 years showed a reduction between 32.17% (1965) and 12.04% (2018) concerning the total extension of the municipality. In 1965, the average area obtained from 49 fragments was 201.13 ha. The values show a higher distance of forest fragments between 1965 and 1989, and disappearance by 2018.The Pearson correlation coefficient for 1965 and 2018 presented the value of r = -0.525, indicating a moderate and negative correlation between the mean values of areas (ha) of forest fragments and the number of forest fragments. The worst-case scenario for the maintenance of native forests occurred in 1989, where the reduction of continuous forest areas had 10.87 ha for forest area average, being spaced in 327 fragments. In the period 1986 and 1996, there was a decrease in fragmentation, reaching 200 fragments. In 1996 and 1997, there was an imbalance in forest maintenance, again increasing the number of fragments to 250 areas, and being explained by the loosening of surveillance in previous years, followed by deforestation.

scholarly journals Long-term effects of climate and land cover change on freshwater provision in the tropical Andes

2015 ◽  
Vol 12 (6) ◽  
pp. 5219-5250 ◽  
Author(s):  
A. Molina ◽  
V. Vanacker ◽  
E. Brisson ◽  
D. Mora ◽  
V. Balthazar
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Land Cover ◽  
Land Cover Change ◽  
Catchment Area ◽  
Strong Increase ◽  
Tropical Andes ◽  
Evaporative Water ◽  
Exotic Tree

Abstract. Andean headwater catchments play a pivotal role to supply fresh water for downstream water users. However, few long-term studies exist on the relative importance of climate change and direct anthropogenic perturbations on flow regimes. In this paper, we assess multi-decadal change in freshwater provision based on long time series (1974–2008) of hydrometeorological data and land cover reconstructions for a 282 km2 catchment located in the tropical Andes. Three main land cover change trajectories can be distinguished: (1) rapid decline of native vegetation in montane forest and páramo ecosystems in ~1/5 or 20% of the catchment area, (2) expansion of agricultural land by 14% of the catchment area, (3) afforestation of 12% of native páramo grasslands with exotic tree species in recent years. Given the strong temporal variability of precipitation and streamflow data related to El Niño–Southern Oscillation, we use empirical mode decomposition techniques to detrend the time series. The long-term increasing trend in rainfall is remarkably different from the observed changes in streamflow that exhibit a decreasing trend. Hence, observed changes in streamflow are not the result of long-term climate change but very likely result from direct anthropogenic disturbances after land cover change. Partial water budgets for montane cloud forest and páramo ecosystems suggest that the strongest changes in evaporative water losses are observed in páramo ecosystems, where progressive colonization and afforestation of high alpine grasslands leads to a strong increase in transpiration losses.

scholarly journals Land Cover/ Land Use Change and Climate Change in Dhofar Governorate, Oman

2021 ◽  
pp. 41-47
Author(s):  
E. Ramadan ◽  
T. Al-Awadhi ◽  
Y. Charabi
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Cover ◽  
Land Cover Change ◽  
Land Use Changes ◽  
Spatial Differentiation ◽  
Study Results ◽  
Vegetation Activity ◽  
The Status ◽  
Landsat Satellite

The study of land cover/land use dynamics under climate change conditions is of great significance for improving sustainable ecological management. Understanding the relationships between land cover and land use changes and climate change is thus very important. Understanding the interactive and cumulative effects of climate and land-use changes are a priority for urban planners and policy makers. The present investigation is based on Landsat satellite imagery to explore changes in vegetation spatial distribution between the years from 2000 to2018 The methodology is focused on vegetation indexes tracking and algebraic overlay calculation to analyzed vegetation and their spatial differentiation, land cover change pattern, and the relationships between vegetation dynamics and land cover change in Dhofar Governorate. The study results have revealed that the vegetation vigor is lower in all years compared to 2000. The scene of 2010 shows the minimum vegetation vigor, overall. Besides, the investigation shows a statistical relationship between rainfall and the status of the health of vegetation. Monsoon rainfall has an impact of the growth of vegetation. Between 2012 and 2013, the vegetation activity shows a decreasing trend. The analysis diagnoses an area affected by the worst degree of aridity situated in the southeastern of Dhofar Mountains. Climate change is the main driving factor resulted from both human activities and rainfall fluctuation.

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