scholarly journals Effects of Climate and Land Use changes on Vegetation Dynamics in the Yangtze River Delta, China Based on Abrupt Change Analysis

2020 ◽  
Vol 12 (5) ◽  
pp. 1955
Author(s):  
Lei Wan ◽  
Huiyu Liu ◽  
Haibo Gong ◽  
Yujia Ren
Keyword(s):  
Land Use ◽  
Vegetation Dynamics ◽  
Abrupt Change ◽  
Land Use Changes ◽  
Yangtze River Delta ◽  
Change Analysis ◽  
Land Use Types ◽  
Natural Land ◽  
Abrupt Change Analysis ◽  
Relationship Of

Vegetation dynamics is thought to be affected by climate and land use changes. However, how the effects vary after abrupt vegetation changes remains unclear. Based on the Mann-Kendall trend and abrupt change analysis, we monitored vegetation dynamics and its abrupt change in the Yangtze River delta during 1982–2016. With the correlation analysis, we revealed the relationship of vegetation dynamics with climate changes (temperature and precipitation) pixel-by-pixel and then with land use changes analysis we studied the effects of land use changes (unchanged or changed land use) on their relationship. Results showed that: (1) the Normalized Vegetation Index (NDVI) during growing season that is represented as GSN (growing season NDVI) showed an overall increasing trend and had an abrupt change in 2000. After then, the area percentages with decreasing GSN trend increased in cropland and built-up land, mainly located in the eastern, while those with increasing GSN trend increased in woodland and grassland, mainly located in the southern. Changed land use, except the land conversions from/to built-up land, is more favor for vegetation greening than unchanged land use (2) after abrupt change, the significant positive correlation between precipitation and GSN increased in all unchanged land use types, especially for woodland and grassland (natural land use) and changed land use except built-up land conversion. Meanwhile, the insignificant positive correlation between temperature and GSN increased in woodland, while decreased in the cropland and built-up land in the northwest (3) after abrupt change, precipitation became more important and favor, especially for natural land use. However, temperature became less important and favor for all land use types, especially for built-up land. This research indicates that abrupt change analysis will help to effectively monitor vegetation trend and to accurately assess the relationship of vegetation dynamics with climate and land use changes.

scholarly journals Recent Land Use Changes on an Urban Watershed in Moncton, New Brunswick, Canada

2016 ◽  
Vol 9 ◽  
Author(s):  
Mélanie LeBlanc ◽  
Guillaume Fortin
Keyword(s):  
Land Use ◽  
Urban Areas ◽  
Land Use Changes ◽  
Land Uses ◽  
Urban Watershed ◽  
Surface Areas ◽  
Run Off ◽  
Land Use Types ◽  
Natural Land ◽  
The City

Changes in land use, which threaten ecosystems and habitats, have an impact on run-off and water quality on urban areas. Using a GIS program we have classified the land use of the Humphreys Brook watershed and quantified the changes that have occurred using landscape metrics. A rapid growth of the city emerges from our results. All land use types of urban nature have seen an increase in surface areas to the detriment of natural land uses. Moreover the landscape indices are showing signs of rectangularity, where humans have introduced straight edges, and other common processes of transformation to the landscape.

scholarly journals Assessing the Impacts of Urban Expansion on Habitat Quality by Combining the Concepts of Land Use, Landscape, and Habitat in Two Urban Agglomerations in China

2020 ◽  
Vol 12 (11) ◽  
pp. 4346 ◽  
Author(s):  
Huina Wang ◽  
Lina Tang ◽  
Quanyi Qiu ◽  
Huaxiang Chen
Keyword(s):  
Land Use ◽  
Habitat Quality ◽  
Habitat Degradation ◽  
Early Stage ◽  
Urban Expansion ◽  
Land Use Changes ◽  
Yangtze River Delta ◽  
Spatiotemporal Variability ◽  
Quality Model ◽  
Urban Agglomerations

Understanding the spatiotemporal variability of habitat quality as a function of land-use changes is important for expanding scientific knowledge of ecological conservation. In this study, the impacts of land-use change on habitat quality were assessed in two urban agglomerations in China at different stages of development, namely (1) the Yangtze River Delta Urban Agglomeration (YRDUA), which has reached the middle and late stage of urbanization, and (2) the Golden Triangle of Southern Fujian (GTSF), which has reached the middle and early stage. The Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) habitat quality model was applied to determine the habitat quality and the degree of habitat degradation in these two agglomerations. Overall, the habitat quality in the YRDUA was found to be clearly inferior to that in the GTSF. In the GTSF, more than 65% of the habitat was of good or excellent quality, whereas in the YRDUA, less than 45% of the habitat reached this quality. By combining the concepts of land use, landscape, and habitat, the boundary of degradation and the general increase in habitat quality from 2000 to 2015 were found to be mainly related to the landform, the dominant landscape, and the concentration of non-habitat areas. Additionally, the type, distribution, and fragmentation of the dominant habitat were shown to play important roles in habitat quality. Moreover, changes in industrial composition over time were demonstrated to be critical drivers of changes in areas of construction land.

scholarly journals Dinamika Kepentingan dan Interaksi Sosial Pedesaan: Studi Implikasi Alih Fungsi Lahan

2016 ◽  
Vol 3 (2) ◽  
pp. 64
Author(s):  
Dhina Yuliana ◽  
Faris Rahmadian ◽  
Nana Kristiawan ◽  
Selvy Anggriani Syarif
Keyword(s):  
Land Use ◽  
Rural Communities ◽  
Social Interactions ◽  
Social Relations ◽  
Land Use Changes ◽  
Land Conversion ◽  
The West ◽  
The Social ◽  
Relationship Of ◽  
Housing Estates

Land-use changes or land conversion issues not only poses a threat of ecological or environmental, but also trigger a variety of dynamics and complexity of social relations in it. West Cilebut Villages has been the target of investors and developers of housing since the 1990s, and now the West Cilebut Villages has changed from an area full of green “romantic” village, into the region filled with concrete. Therefore, this study was conducted to answer fundamental issues related to the issue of land conversion in the West Cilebut Village, first is to see the map and interests between actors in relation to land conversion in the West Cilebut Village, and second to know the social interactions dynamics that occur in West Cilebut community, following the land conversion from the farm into housing estates. The results showed that there are three main actors in relation to issues of land use change in West Cilebut Village: (1) The Housing Developer; (2) Village Apparatus / Government; (3) Society; where the three actors have a role and importance of different orientations. Meanwhile, social interaction between housing and rural communities basically shows a relationship of mutual need. Construction of housing community that luxurious and exclusive slowly turns into inclusive and reflect a resiprocity of the two communities. 

scholarly journals Using Landsat Thematic Mapper (TM) sensor to detect change in land surface temperature in relation to land use change in Yazd, Iran

Solid Earth ◽  
2016 ◽  
Vol 7 (6) ◽  
pp. 1551-1564 ◽  
Author(s):  
Sajad Zareie ◽  
Hassan Khosravi ◽  
Abouzar Nasiri ◽  
Mostafa Dastorani
Keyword(s):  
Land Use ◽  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Land Use Changes ◽  
Thermal Conditions ◽  
Kappa Coefficient ◽  
Thematic Mapper ◽  
Landsat Thematic Mapper ◽  
Land Use Types

Abstract. Land surface temperature (LST) is one of the key parameters in the physics of land surface processes from local to global scales, and it is one of the indicators of environmental quality. Evaluation of the surface temperature distribution and its relation to existing land use types are very important to the investigation of the urban microclimate. In arid and semi-arid regions, understanding the role of land use changes in the formation of urban heat islands is necessary for urban planning to control or reduce surface temperature. The internal factors and environmental conditions of Yazd city have important roles in the formation of special thermal conditions in Iran. In this paper, we used the temperature–emissivity separation (TES) algorithm for LST retrieving from the TIRS (Thermal Infrared Sensor) data of the Landsat Thematic Mapper (TM). The root mean square error (RMSE) and coefficient of determination (R2) were used for validation of retrieved LST values. The RMSE of 0.9 and 0.87 °C and R2 of 0.98 and 0.99 were obtained for the 1998 and 2009 images, respectively. Land use types for the city of Yazd were identified and relationships between land use types, land surface temperature and normalized difference vegetation index (NDVI) were analyzed. The Kappa coefficient and overall accuracy were calculated for accuracy assessment of land use classification. The Kappa coefficient values are 0.96 and 0.95 and the overall accuracy values are 0.97 and 0.95 for the 1998 and 2009 classified images, respectively. The results showed an increase of 1.45 °C in the average surface temperature. The results of this study showed that optical and thermal remote sensing methodologies can be used to research urban environmental parameters. Finally, it was found that special thermal conditions in Yazd were formed by land use changes. Increasing the area of asphalt roads, residential, commercial and industrial land use types and decreasing the area of the parks, green spaces and fallow lands in Yazd caused a rise in surface temperature during the 11-year period.

scholarly journals Larval Ecology of Anopheles Mosquitoes in Kudat, Sabah

2021 ◽  
Author(s):  
Wilfredo Escalante Aure ◽  
Nelia Palaria Salazar ◽  
Tock Hing Chua
Keyword(s):  
Land Use ◽  
Plasmodium Knowlesi ◽  
Land Use Changes ◽  
Rubber Tree ◽  
Tree Plantation ◽  
Breeding Sites ◽  
Larval Habitats ◽  
Anopheles Mosquitoes ◽  
Land Use Types ◽  
Average Maximum

The emergence of human Plasmodium knowlesi malaria appeared to have been precipitated by the displacement of the natural environment of macaques and Anopheles mosquitoes resulting from deforestation and land-use changes in Malaysia. A longitudinal survey of larval habitats was conducted from May 2015 to April 2016 in the District of Kudat, Sabah to better understand how these changes have affected mosquitoes across six land use categories. Larvae were collected by dipping and reared in the laboratory for the identification of adults. Five anopheline and three culicine species were present: Anopheles balabacensis, An. barbirostris, An. lesteri, An. borneensis, An. umbrosus, Aedes albopictus, Culex gelidus, and Toxorhynchites sp. An. balabacensis was found in all six land-use types. Biodiversity by genera was high in all land-use types. The relative importance of land use types and larval habitats as sources of potential vectors was analyzed by the Kruskal-Wallis H test by ranks. In decreasing order Anopheles larvae were found in rubber tree plantation > coconut plantation > clearing site > palm oil plantation > forest > settlement area. Important larval habitats were intermittent stream > ditch > pond > artificial container > puddle > river > slow-flowing stream. Eighteen breeding sites of An. balabacensis were within (500 m) the average maximum flight range of the species and houses at risk for malaria. Knowledge gained from the study can be used to assess the need for vector control in preventing the spread of P. knowlesi in vulnerable areas.  

scholarly journals Spatiotemporal Assessment of Temperature Data Products for the Detection of Warming Trends and Abrupt Transitions over the Largest Irrigated Area of Pakistan

2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Zain Nawaz ◽  
Xin Li ◽  
Yingying Chen ◽  
Xufeng Wang ◽  
Kun Zhang ◽  
...  
Keyword(s):  
Abrupt Change ◽  
Reference Data ◽  
Temperature Data ◽  
Trend Detection ◽  
Preliminary Evaluation ◽  
Change Analysis ◽  
Study Region ◽  
Data Products ◽  
Abrupt Change Analysis ◽  
Temperature Indices

Reliable and accurate temperature data acquisition is not only important for hydroclimate research but also crucial for the management of water resources and agriculture. Gridded data products (GDPs) offer an opportunity to estimate and monitor temperature indices at a range of spatiotemporal resolutions; however, their reliability must be quantified by spatiotemporal comparison against in situ records. Here, we present spatial and temporal assessments of temperature indices (Tmax, Tmin, Tmean, and DTR) products against the reference data during the period of 1979–2015 over Punjab Province, Pakistan. This region is considered as a center for agriculture and irrigated farming. Our study is the first spatiotemporal statistical evaluation of the performance and selection of potential GDPs over the study region and is based on statistical indicators, trend detection, and abrupt change analysis. Results revealed that the CRU temperature indices (Tmax, Tmin, Tmean, and DTR) outperformed the other GDPs as indicated by their higher CC and R2 but lower bias and RMSE. Furthermore, trend and abrupt change analysis indicated the superior performances of the CRU Tmin and Tmean products. However, the Tmax and DTR products were less accurate for detecting trends and abrupt transitions in temperature. The tested GDPs as well as the reference data series indicate significant warming during the period of 1997–2001 over the study region. Differences between GDPs revealed discrepancies of 1-2°C when compared with different products within the same category and with reference data. The accuracy of all GDPs was particularly poor in the northern Punjab, where underestimates were greatest. This preliminary evaluation of the different GDPs will be useful for assessing inconsistencies and the capabilities of the products prior to their reliable utilization in hydrological and meteorological applications particularly over arid and semiarid regions.

Influences of land use changes on the dynamics of water quantity and quality in the German lowland catchment of the Stör

2021 ◽  
Author(s):  
Chaogui Lei ◽  
Paul Wagner ◽  
Nicola Fohrer
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Arable Land ◽  
Hydrologic Model ◽  
Water Quantity ◽  
Water Yield ◽  
Near Surface ◽  
Daily Streamflow ◽  
Land Use Types ◽  
Water Quantity And Quality

<p>Understanding the impacts of land use changes (LUCC) on the dynamics of water quantity and quality is necessary to identify suitable mitigation measures that are needed for sustainable watershed management. Lowland catchments are characterized by a strong interaction of streamflow and near-surface groundwater that intensifies the risk of nutrient pollution. In this study, a hydrologic model (Soil and Water Assessment Tool, SWAT) and partial least squares regression (PLSR) were used to quantify the impacts of different land use types on the variations in actual evapotranspiration (ET), surface runoff (SQ), base flow (BF), and water yield (WYLD) as well as on sediment (SED), total phosphorus (TP), and total nitrogen (TN). To this end, the model was calibrated and validated with daily streamflow data (30 years) and daily sediment and nutrient data from measurement campaigns (3 years in total). Three model runs over thirty years were performed using the different land use maps of 1987, 2010, and 2019, respectively. Land use changes between those years were used to explain the modelled changes in water quantity and quality on the subbasin scale applying PLSR. SWAT achieved a good performance for streamflow (calibration: NSE=0.8, PBIAS=5.5%; validation: NSE=0.78, PBIAS=5.1%) and for TN (calibration: NSE=0.65, PBIAS= -11.3%; validation: NSE=0.87, PBIAS=2.7%) and an acceptable performance for sediment and TP (calibration: NSE=0.49-0.53, PBIAS=25.8% -29.7%; validation: 0.51-0.7, PBIAS= -23.9% - -8.7%) in Stör catchment. The variations in ET, SQ, BF, WYLD, SED, TP, and TN could be explained to an extent of 67%-88% by changes in the area, shape, dominance, and aggregation of individual land use types. They were largely correlated with the major LUCC in the study area i.e. a decrease of arable land, and a respective increase of pasture and settlement. The change in the percentage of arable land affected the dynamics of SED, TP, TN and BF, indicated by a Variable Influence on Projection (VIP) > 1.2 and largest absolute regression coefficients (RCs: 0.45-0.72 for SED, TP, TN; -0.84 for BF). The change in pasture area affected ET, SED, TP, and TN, as indicated by VIPs >1.  The change in settlement percentage had VIP up to 1.62 for SQ and was positively and significantly influenced it (RC: 1.28). PLSR helped to identify the key contributions from individual land use changes on water quantity and quality dynamics. These provide a quantitative basis for targeting most influential land use changes to mitigate impacts on water quality in the future.</p>

scholarly journals Land-use changes influence soil bacterial communities in a meadow grassland in Northeast China

Solid Earth ◽  
2017 ◽  
Vol 8 (5) ◽  
pp. 1119-1129 ◽  
Author(s):  
Chengyou Cao ◽  
Ying Zhang ◽  
Wei Qian ◽  
Caiping Liang ◽  
Congmin Wang ◽  
...  
Keyword(s):  
Land Use ◽  
Bacterial Community ◽  
Bacterial Communities ◽  
Land Use Changes ◽  
Chemical Properties ◽  
Soil Bacterial Communities ◽  
Land Use Types ◽  
Soil Bacterial ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract. The conversion of natural grassland into agricultural fields is an intensive anthropogenic perturbation commonly occurring in semiarid regions, and this perturbation strongly affects soil microbiota. In this study, the influences of land-use conversion on the soil properties and bacterial communities in the Horqin Grasslands in Northeast China were assessed. This study aimed to investigate (1) how the abundances of soil bacteria changed across land-use types, (2) how the structure of the soil bacterial community was altered in each land-use type, and (3) how these variations were correlated with soil physical and chemical properties. Variations in the diversities and compositions of bacterial communities and the relative abundances of dominant taxa were detected in four distinct land-use systems, namely, natural meadow grassland, paddy field, upland field, and poplar plantation, through the high-throughput Illumina MiSeq sequencing technique. The results indicated that land-use changes primarily affected the soil physical and chemical properties and bacterial community structure. Soil properties, namely, organic matter, pH, total N, total P, available N and P, and microbial biomass C, N, and P, influenced the bacterial community structure. The dominant phyla and genera were almost the same among the land-use types, but their relative abundances were significantly different. The effects of land-use changes on the structure of soil bacterial communities were more quantitative than qualitative.

scholarly journals Soil Organic Carbon Shapes AMF Communities in Soils and Roots of Cynodon dactylon under Anti-Seasonal Drying-Wetting Cycles

Diversity ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 197 ◽  
Author(s):  
Xie Luo ◽  
Xinhua He ◽  
Xiumei Luo ◽  
Yining Liu ◽  
Junqi Wang ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Community Composition ◽  
Cynodon Dactylon ◽  
Land Use Changes ◽  
Soil Microbial Communities ◽  
Rhizosphere Soils ◽  
Land Use Types ◽  
Amf Communities

Anti-seasonal drying-wetting cycles since 2010 have substantially altered its soil and vegetation status in the drawdown zone of China’s Three Gorges Reservoir (TGR). Such alternations may thus affect the composition and functioning of soil microbial communities, including the beneficial arbuscular mycorrhizal fungi (AMF), which enhance plant performance. Moreover, limited information is available if AMF communities are different in soils and roots, particularly under contrasting land-use changes. By combining the Illumina Miseq sequencing with bioinformatics analyses, AMF communities in both rhizosphere soils and roots of a stoloniferous and rhizomatous C4 perennial of Cynodon dactylon were characterized under three land-use types: (1) crop cultivated, (2) non-cultivated non-disturbed, and (3) disturbed non-cultivated land. A total of 35 and 26 AMF taxa were respectively detected from C. dactylon rhizosphere soils and roots from these three land-use types, which had endured four anti-seasonal drying/summer-wetting/winter cycles. Contrasting differentiations in the AMF community composition and structure were displayed in the C. dactylon rhizosphere soils and roots, and between land-use types. Nonmetric multidimensional scaling analyses revealed that AMF communities significantly correlated to soil organic carbon in the rhizosphere soils and roots of C. dactylon, to land-use types only in rhizosphere soils, whereas to soil moisture only in roots. Our results highlight the effects of soil nutrients and land-use changes on AMF community composition and diversity under the canopy of C. dactylon in TGR. The identified dominant AMF taxa can be employed to vegetation restoration in such degraded habitats globally.

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