scholarly journals Analysis of land cover change and its driving forces in a desert oasis landscape of Xinjiang, northwest China

Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 1071-1085 ◽  
Author(s):  
T. Amuti ◽  
G. Luo
Keyword(s):  
Land Cover ◽  
Land Degradation ◽  
Driving Forces ◽  
Northwest China ◽  
Landsat Images ◽  
Desert Oasis ◽  
Standard Classification ◽  
Effects Of Drought ◽  
Arid Desert ◽  
Southern Xinjiang

Abstract. The combined effects of drought, warming and the changes in land cover have caused severe land degradation for several decades in the extremely arid desert oases of southern Xinjiang, northwest China. Land cover classifications of Landsat images in 1990, 2000 and 2008 were performed based on the multistage supervised classification scheme using the maximum likelihood classifier integrated with conventional vegetation and soil indexes, which improved overall accuracies by 4–5% compared to the standard classification method. Based on the detection of changes in land cover during 1990–2008 using remote sensing (RS) and a geographic information system (GIS), it can be found that the oasis significantly (+35%) increased, while the area of ecotone decreased (−43%). The major trends of the land cover changes were the notable growth of the oasis and the reduction of the desert–oasis ecotone. These changes were mainly a result of the intensified human activities such as land and water exploitation as well as overgrazing. The results of this study indicate that the oasis environment will be deteriorated by increase in potential areas of land degradation if the trend of desert moving further inward and the shrinking of the ecotone continues over the next decades.

scholarly journals Analysis of land cover change and its driving forces in a desert oasis landscape of southern Xinjiang, China

2014 ◽  
Vol 6 (2) ◽  
pp. 1907-1947
Author(s):  
T. Amuti ◽  
G. Luo
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Land Degradation ◽  
Agricultural Land ◽  
Driving Forces ◽  
Soil Salinization ◽  
Land Cover Changes ◽  
Detection Techniques ◽  
Desert Oasis ◽  
Southern Xinjiang

Abstract. The combined effects of drought, warming and the changes in land cover have caused severe land degradation for several decades in the extremely arid desert oases of Southern Xinjiang, Northwest China. This study examined land cover changes during 1990–2008 to characterize and quantify the transformations in the typical oasis of Hotan. Land cover classifications of these images were performed based on the supervised classification scheme integrated with conventional vegetation and soil indexes. Change-detection techniques in remote sensing (RS) and a geographic information system (GIS) were applied to quantify temporal and spatial dynamics of land cover changes. The overall accuracies, Kappa coefficients, and average annual increase rate or decrease rate of land cover classes were calculated to assess classification results and changing rate of land cover. The analysis revealed that major trends of the land cover changes were the notable growth of the oasis and the reduction of the desert–oasis ecotone, which led to accelerated soil salinization and plant deterioration within the oasis. These changes were mainly attributed to the intensified human activities. The results indicated that the newly created agricultural land along the margins of the Hotan oasis could result in more potential areas of land degradation. If no effective measures are taken against the deterioration of the oasis environment, soil erosion caused by land cover change may proceed. The trend of desert moving further inward and the shrinking of the ecotone may lead to potential risks to the eco-environment of the Hotan oasis over the next decades.

Analysis of spatiotemporal patterns and driving forces for land degradation and restoration in Mongolia from 1990 to 2015

2020 ◽  
Author(s):  
Juanle Wang ◽  
Haishuo Wei ◽  
Jinyi Yao ◽  
Yating Shao ◽  
Xiya Liang ◽  
...  
Keyword(s):  
Land Cover ◽  
Land Degradation ◽  
Driving Forces ◽  
Global Climate ◽  
Image Interpretation ◽  
Land Restoration ◽  
Barren Land ◽  
Distribution Maps ◽  
Land Cover Data ◽  
Development Goals

<p>      Land degradation is an important ecological and environmental problem facing the world. “Land Degradation Neutrality” is one of the core indicators in the United Nations Sustainable Development Goals for 2030. However, achieving this is a serious challenge in Mongolia where land degradation continues. The increasingly serious land degradation in Mongolia has had a direct impact on the ecology of the entire Mongolian plateau and adjacent regions. Land degradation and restoration in this region fluctuate spatially and temporally because of the impacts of global climate change and human activity.</p><p>      We obtained land cover data for Mongolia for 1990, 2000, 2010, and 2015 with a resolution of 30 m using the object-oriented remote sensing image interpretation method.Land cover types include forest, real steppe, meadow steppe, desert steppe, cropland, built area, water, sand, and barren land. Based on a spatial analysis module in a geographic information system, the multi-period land cover data were superimposed and calculated. We defined the land degradation cover types and restoration cover types in the processing. Thus, a serials of high-resolution distribution maps of land degradation and restoration for fixed monitoring time intervals were obtained for first time.</p><p>      We analyzed trends in land degradation and restoration and estimated the typical areas of each in Mongolia. We specifically analyzed the process of land cover change in these areas, comprehensively considered natural factors and human activities driving this change. Finally, we proposed targeted strategies to control the land degradation and promote land restoration in different regions in Mongolia.</p>

Effects of land use and land cover change on ecosystem services in an arid desert-oasis ecotone along the Yellow River of China

2022 ◽  
Vol 176 ◽  
pp. 106512
Author(s):  
Genbatu Ge ◽  
Jingbo Zhang ◽  
Xiaona Chen ◽  
Xiangjie Liu ◽  
Yuguang Hao ◽  
...  
Keyword(s):  
Land Use ◽  
Ecosystem Services ◽  
Land Cover ◽  
Land Cover Change ◽  
Yellow River ◽  
The Yellow River ◽  
Desert Oasis ◽  
Arid Desert ◽  
Effects Of Land Use

scholarly journals Land Use Land Cover Change Analysis in Fagge Local Government, Kano State from 1991-2019

2020 ◽  
Author(s):  
Al-amin Abbas Ahmad
Keyword(s):  
Land Use ◽  
Local Government ◽  
Land Cover ◽  
Driving Forces ◽  
Urban Expansion ◽  
Land Use Land Cover ◽  
Economic Activities ◽  
Landsat Images ◽  
Change Analysis ◽  
Barren Land

Abstract Land Use and Land Cover (LULC) are important components of the environmental system and changes in it mirror the impacts of human activities on the environment. These impacts needed to be determined in order to get a clear picture of the extent at which different land use practices change over time. This study focused on the Land use and land cover changes of Fagge local government Kano state between 1991 and 2019 and also identify the driving forces of such changes. The data for the study two 30m x 30m Landsat images (Landsat 4&8) of the two years i.e. 2019 and 1991. The two images undergo series of image analysis and classification using ArcGIS 10.7 and ENVI 5.1 and the result where presented in form of maps, charts and tables. The result also shows that the changes that occurred from 1991 to 2019 in Fagge local government to be positive and negative changes. There happen to be a positive in the size of built-up areas in Fagge from 1991 – 2019 with a change of +4.678km2. The vegetation cover experienced a negative change of -8.87km2 while the barren land also had an increase in size with a positive change of +4.199. The data collected from previous studies indicated that the main driving behind the various changes may include; urban expansion, population growth, commercial and economic activities, security, and Government law and policies. It was recommended that Sufficient land use/land cover information should be acquired, Sensitization programs on land use / land cover, Geospatial techniques should be adopted by Government and NGO’s and lastly Government policies should geared to ensuring that there is balance in the utilization of the available land in the country

scholarly journals Male parent birds exert more effort to reproduce in two desert passerines

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Donghui Ma ◽  
Mengjie Lu ◽  
Zhichang Cheng ◽  
Xingnan Du ◽  
Xiaoyu Zou ◽  
...  
Keyword(s):  
Reproductive Output ◽  
Female Parent ◽  
Northwest China ◽  
Reproductive Behaviour ◽  
Male Parent ◽  
Hatching Rate ◽  
Feeding Rates ◽  
Passerine Species ◽  
Arid Desert ◽  
Habitat Environment

Abstract Background Parental investment by birds is limited by the habitat environment, and a male parent increases its effort to reproduce in birds that live in high-altitude areas. Methods A study of the reproductive behaviour of the Saxaul Sparrow (Passer ammodendri) and the Isabelline Shrike (Lanius isabellinus) was carried out at the Gansu An’xi Extremely Arid Desert National Nature Reserve in northwest China to determine the reproductive input of passerine species in desert habitats. Results In Saxaul Sparrows, compared to the female parent, the male parent exhibited a significantly higher frequency of nest-defense behaviour (chirping and warning) during nesting, hatching and feeding periods. In addition, in comparison to the female parent, the male parent exhibited almost equal frequencies of nesting and incubation but fed nestlings significantly more times. Similar to the male sparrows, the feeding rates of the male Isabelline Shrikes were significantly higher than those of the females. The hatching rate and fledging rate of the Saxaul Sparrow on average in this study were 81.99 and 91.92%, respectively, while those of the shrike were 69.00 and 96.53%, respectively. Conclusions These two different passerine species living in the same desert environment exhibited the same trend in their reproductive investments. Adapting to desert environments is a strategy that may have evolved in passerines where male parent birds put more effort than females into reproduction to ensure high reproductive output.

scholarly journals Historical Changes in Land Use and Suitability for Future Agriculture Expansion in Western Bahia, Brazil

2021 ◽  
Vol 13 (6) ◽  
pp. 1088
Author(s):  
Fernando Martins Pimenta ◽  
Allan Turini Speroto ◽  
Marcos Heil Costa ◽  
Emily Ane Dionizio
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Land Suitability ◽  
Agricultural Area ◽  
Landsat Images ◽  
Historical Changes ◽  
Cropland Area ◽  
Irrigated Area ◽  
Agriculture Expansion ◽  
Forest Code

Western Bahia is a critical region in Brazil’s recent expansion of agricultural output. Its outstanding increase in production is associated with strong growth in cropland area and irrigation. Here we present analyses of Western Bahian historical changes in land use, including irrigated area, and suitability for future agricultural expansion that respects permanent protection areas and the limits established by the Brazilian Forest Code in the Cerrado biome. For this purpose, we developed a land use and land cover classification database using a random forest classifier and Landsat images. A spatial multicriteria decision analysis to evaluate land suitability was performed by combining this database with precipitation and slope data. We demonstrate that between 1990 and 2020, the region’s total agricultural area increased by 3.17 Mha and the irrigated area increased by 193,480 ha. Throughout the region, the transition between the different classes of land use and land cover followed different pathways and was strongly influenced by land suitability and also appears to be influenced by Brazil’s new Forest Code of 2012. We conclude that even if conservation restrictions are considered, agricultural area could nearly double in the region, with expansion possible mostly in areas we classify as moderately suitable for agriculture, which are subject to climate hazards when used for rainfed crops but are otherwise fine for pastures and irrigated croplands.

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