scholarly journals Topographic Dependence of Cropland Transformation in China during the First Decade of the 21st Century

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yuejiao Li ◽  
Xiaohuan Yang ◽  
Wenli Long
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Land Reclamation ◽  
Southern China ◽  
Critical Role ◽  
Northern China ◽  
Limiting Factor ◽  
Spatial Statistical Analysis ◽  
Level Of Economic Development

Terrain plays a critical role in the selection of cropland. As a physical and geographical element of the landscape, terrain is an important limiting factor in land use change and has a strong influence on human activities. The objectives of this study are to investigate the topographic characteristics of cropland-related transformations in China during the first decade of the 21st century and to explore the implications of land use change as it relates to securing a national food supply. A 2010 satellite-based land use dataset and the DEM data were used to conduct spatial statistical analysis using altitude, slope, and fragmentation data. The results showed the following. (1) As the urbanization and industrialization of China occur, and China attempts to replace this occupied cropland with newly reclaimed cropland, the topography of the most recently reclaimed cropland has been more poorly suited to farming than the topography of the occupied cropland it replaces in most provinces. (2) The area of occupied cropland was much larger than of those reclaimed; the qualities of occupied and reclaimed cropland were significantly different. (3) Land reclamation mainly occurred in northern China, instead of in southern China, which has a higher level of economic development. Our findings imply that the potential area available for cropland production may be limited.

scholarly journals Impacts of changes in land use and land cover on atmospheric chemistry and air quality over the 21st century

2011 ◽  
Vol 11 (5) ◽  
pp. 15469-15495 ◽  
Author(s):  
S. Wu ◽  
L. J. Mickley ◽  
J. O. Kaplan ◽  
D. J. Jacob
Keyword(s):  
Land Use ◽  
Air Quality ◽  
Land Use Change ◽  
Land Cover ◽  
21St Century ◽  
Secondary Organic Aerosols ◽  
Surface Ozone ◽  
Organic Aerosols ◽  
Ozone Concentrations ◽  
Anthropogenic Land Use

Abstract. The effects of future land use and land cover change on the chemical composition of the atmosphere and air quality are largely unknown. To investigate the potential effects associated with future changes in vegetation driven by atmospheric CO2 concentrations, climate, and anthropogenic land use over the 21st century, we performed a series of model experiments combining a general circulation model with a dynamic global vegetation model and an atmospheric chemical-transport model. Our results indicate that climate- and CO2-induced changes in vegetation composition and density could lead to decreases in summer afternoon surface ozone of up to 10 ppb over large areas of the northern mid-latitudes. This is largely driven by the substantial increases in ozone dry deposition associated with changes in the composition of temperate and boreal forests where conifer forests are replaced by those dominated by broadleaf tree types, as well as a CO2-driven increase in vegetation density. Climate-driven vegetation changes over the period 2000–2100 lead to general increases in isoprene emissions, globally by 15 % in 2050 and 36 % in 2100. These increases in isoprene emissions result in decreases in surface ozone concentrations where the NOx levels are low, such as in remote tropical rainforests. However, over polluted regions, such as the northeastern United States, ozone concentrations are calculated to increase with higher isoprene emissions in the future. Increases in biogenic emissions also lead to higher concentrations of secondary organic aerosols, which increase globally by 10 % in 2050 and 20 % in 2100. Surface concentrations of secondary organic aerosols are calculated to increase by up to 1 μg m−3 for large areas in Eurasia. When we use a scenario of future anthropogenic land use change, we find less increase in global isoprene emissions due to replacement of higher-emitting forests by lower-emitting cropland. The global atmospheric burden of secondary organic aerosols changes little by 2100 when we account for future land use change, but both secondary organic aerosols and ozone show large regional changes at the surface.

scholarly journals Revolutionary Land Use Change in the 21st Century: Is (Rangeland) Science Relevant?

2012 ◽  
Vol 65 (6) ◽  
pp. 590-598 ◽  
Author(s):  
J.E. Herrick ◽  
J.R. Brown ◽  
B.T. Bestelmeyer ◽  
S.S. Andrews ◽  
G. Baldi ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
21St Century

scholarly journals Effects of Urbanization on Watershed Evapotranspiration and Its Components in Southern China

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 645 ◽  
Author(s):  
Qingzhou Zheng ◽  
Lu Hao ◽  
Xiaolin Huang ◽  
Lei Sun ◽  
Ge Sun
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Land Surface ◽  
Southern China ◽  
Hydrologic Model ◽  
Water Evaporation ◽  
Water Yield ◽  
Positive Trend ◽  
Significant Downward Trend ◽  
Effects Of Land Use

Understanding the effects of land use change on evapotranspiration (ET) and its partitioning to transpiration and evaporation is important for accurately evaluating the likely environmental impacts on watershed water supply, climate moderation, and other ecosystem services (e.g., carbon sequestration and biodiversity). This study used a distributed hydrologic model, MIKE SHE, to partition evapotranspiration into soil evaporation, transpiration, ponded water evaporation, and interception, and examined how the ET partitions affected the water balance in the Qinhuai River Basin from 2000 to 2013. Simulated daily ET was compared to measurements at an eddy flux research site during 2016–2017 (R2 = 0.72). Degradation in rice-wheat rotation fields and expansion of impervious surfaces impacted not only total watershed evapotranspiration, which showed a significant downward trend (p < 0.05), but also its partitioning. A significant (p < 0.01) decrease in transpiration was detected. Ponded water evaporation was the only ET partition that exhibited a significant positive trend (p < 0.05). We concluded that the reduced transpiration as a result of land use and land cover change was the primary factor driving the variation of watershed scale evapotranspiration. In addition, there was an increase in annual water yield (23%) as a response to significant reduction in ET (7%) due to a 175% expansion of urban area in the study watershed. Our study provided insights to the mechanisms of land surface–water cycle interaction and better understanding of the effects of land use change on urban micro-climate such as “urban dry island” and “urban heat island” effects.

scholarly journals Influence of future climate and cropland expansion on isoprene emissions and tropospheric ozone

2014 ◽  
Vol 14 (2) ◽  
pp. 1011-1024 ◽  
Author(s):  
O. J. Squire ◽  
A. T. Archibald ◽  
N. L. Abraham ◽  
D. J. Beerling ◽  
C. N. Hewitt ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Tropospheric Ozone ◽  
Climate Model ◽  
Anthropogenic Emissions ◽  
Change Scenario ◽  
Dynamic Global Vegetation Model ◽  
The Tropics

Abstract. Over the 21st century, changes in CO2 levels, climate and land use are expected to alter the global distribution of vegetation, leading to changes in trace gas emissions from plants, including, importantly, the emissions of isoprene. This, combined with changes in anthropogenic emissions, has the potential to impact tropospheric ozone levels, which above a certain level are harmful to animals and vegetation. In this study we use a biogenic emissions model following the empirical parameterisation of the MEGAN model, with vegetation distributions calculated by the Sheffield Dynamic Global Vegetation Model (SDGVM) to explore a range of potential future (2095) changes in isoprene emissions caused by changes in climate (including natural land use changes), land use, and the inhibition of isoprene emissions by CO2. From the present-day (2000) value of 467 Tg C yr−1, we find that the combined impact of these factors could cause a net decrease in isoprene emissions of 259 Tg C yr−1 (55%) with individual contributions of +78 Tg C yr−1 (climate change), −190 Tg C yr−1 (land use) and −147 Tg C yr−1 (CO2 inhibition). Using these isoprene emissions and changes in anthropogenic emissions, a series of integrations is conducted with the UM-UKCA chemistry-climate model with the aim of examining changes in ozone over the 21st century. Globally, all combined future changes cause a decrease in the tropospheric ozone burden of 27 Tg (7%) from 379 Tg in the present-day. At the surface, decreases in ozone of 6–10 ppb are calculated over the oceans and developed northern hemispheric regions, due to reduced NOx transport by PAN and reductions in NOx emissions in these areas respectively. Increases of 4–6 ppb are calculated in the continental tropics due to cropland expansion in these regions, increased CO2 inhibition of isoprene emissions, and higher temperatures due to climate change. These effects outweigh the decreases in tropical ozone caused by increased tropical isoprene emissions with climate change. Our land use change scenario consists of cropland expansion, which is most pronounced in the tropics. The tropics are also where land use change causes the greatest increases in ozone. As such there is potential for increased crop exposure to harmful levels of ozone. However, we find that these ozone increases are still not large enough to raise ozone to such damaging levels.

Analysis of Land Use Change in Binhai New Area Based on Remote Sensing Images

2014 ◽  
Vol 933 ◽  
pp. 1014-1018
Author(s):  
Chun Zhe Xia ◽  
Xiao Shen Zheng ◽  
Meng Yin Zhao
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Economic Development ◽  
Land Use Change ◽  
Land Reclamation ◽  
Ecological Environment ◽  
Remote Sensing Images ◽  
Construction Sites ◽  
Salt Works ◽  
Unused Land

Based on the TM remote sensing images in autumn 1992, 2001 and 2009, the land use change of Binhai New Area is analyzed through the ENVI software. During remote sensing images processed, Binhai New Area is collected according to the administrative zoning maps. The results of land use change are vegetation cover and water changing little, which show the ecological environment remained stable in overall Binhai New Area. At that time, the area of unused land and salt works area is reduced, and the area of land reclamation and construction sites is increased, which indicates the rapid economic development of Binhai new area in past 20 years.

scholarly journals Assessment of impacts of agricultural and climate change scenarios on watershed water quantity and quality, and crop production

2016 ◽  
Author(s):  
Awoke D. Teshager ◽  
Philip W. Gassman ◽  
Justin T. Schoof ◽  
Silvia Secchi
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Agricultural Land ◽  
Agricultural Landscapes ◽  
Water Quantity ◽  
Agricultural Land Use ◽  
Water Quantity And Quality

Abstract. Modeling impacts of agricultural scenarios and climate change on surface water quantity and quality provides useful information for planning effective water, environmental, and land use policies. Despite the significant impacts of agriculture on water quantity and quality, limited literature exists that describes the combined impacts of agricultural land use change and climate change on future bioenergy crop yields and watershed hydrology. In this study, the Soil and Water Assessment Tool (SWAT) eco-hydrological model was used to model the combined impacts of five agricultural land use change scenarios and three downscaled climate pathways (representative concentration pathways, RCPs) that were created from an ensemble of eight atmosphere-ocean general circulation models (AOGCMs). These scenarios were implemented in a well calibrated SWAT model for the Raccoon River watershed (RRW) located in western Iowa. The scenarios were executed for the historical baseline, early-century, mid-century, and late-century periods. The results indicate that historical and more corn intensive agricultural scenarios with higher CO2 emissions consistently result in more water in the streams and greater water quality problems, especially late in the 21st century. Planting more switchgrass, on the other hand, results in less water in the streams and water quality improvements relative to the baseline. For all given agricultural landscapes simulated, all flow, sediment and nutrient outputs increase from early-to-late century periods for the RCP4.5 and RCP8.5 climate scenarios. We also find that corn and switchgrass yields are negatively impacted under RCP4.5 and RCP8.5 scenarios in the mid and late 21st century.

scholarly journals PERUBAHAN PENGGUNAAN LAHAN DAN POTENSI PERLUASAN LAHAN UNTUK SAWAH DI KABUPATEN CIANJUR

2019 ◽  
Vol 19 (1) ◽  
pp. 33-40
Author(s):  
Chaida Chairunnisa ◽  
Khursatul Munibah ◽  
Widiatmaka Widiatmaka
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Paddy Field ◽  
Agricultural Land ◽  
Landsat Imagery ◽  
Land Suitability ◽  
Limiting Factor ◽  
Land Use Land Cover ◽  
Land Use Plan ◽  
Field Area

Population growth, increasing income, and the rapid economic development create complexity of land issues. Land has a central role in  food production, however demand for land increased significantly to meet the needs of the population. Cianjur Regency is one of regencies in the southern part of West Java Province with the largest paddy field area. However, paddy field conversion into non agricultural land or another agricultural land resulted in the decrease of paddy field area. Therefore, in the context of maintaining the availability of rice in Cianjur Regency, this study aimed to: (1) analyze the patterns of land use/land cover, (2) evaluate land suitability for paddy field, and (3) analyze the potency of land for paddy field expansion. Land use change was identified using Landsat imagery of 2000 and 2015 by using fusion techniques. Land suitability for paddy field was analyzed using limiting factor method. Potential for paddy field expansion was analyzed according to land suitability and agricultural land allocation in official regional land use plan map (“RTRW”). The results showed that in the period of 2000 to 2015, most of paddy field were converted into settlements. Land suitability classes for paddy field in Cianjur Regency were not suitable (N) (61.19%), suitable (S2) (9.53%), and marginally suitable (S3)(29.28%). Cianjur Regency still has the potency of land to be used for paddy field expansion of 148,980 ha. Keywords: Land use change, potential area for paddy field priority, land suitability for paddy field

Changes in land use in the last two centuries in the Po lowlands (northern Italy)

2021 ◽  
Author(s):  
Matteo Meli ◽  
Luigi Bruno
Keyword(s):  
Land Use ◽  
Salt Marshes ◽  
Coastal Wetlands ◽  
Land Reclamation ◽  
Urban Expansion ◽  
Critical Role ◽  
Blue Carbon ◽  
Historical Maps ◽  
High Quality ◽  
Seagrass Meadows

&lt;p&gt;Changes in land use represent, after fossil-fuel combustion, the greatest cause of greenhouse-gases emission into the atmosphere. Coastal wetlands, also referred as coastal blue carbon ecosystems (e.g. salt marshes, mangrove forests, seagrass meadows, swamps), represent one of the most powerful C sinks among the Earth&amp;#8217;s ecosystems, being capable to sequester organic carbon (OC) at rates ca. 30-50 times higher than terrestrial forests. Historically, land reclamation for agriculture, farming and urban expansion, severely impacted coastal wetlands, causing their loss and degradation. Wetlands drainage lead to the oxidation of organic matter previously stored under anaerobic conditions and the release of CO&lt;sub&gt;2&lt;/sub&gt; into the atmosphere. Only recently the critical role of blue carbon ecosystems in climate-change mitigation has been recognised, highlighting the importance of protecting and studying these precious environments.&lt;/p&gt;&lt;p&gt;In this work, changes in land use in the last two centuries are reconstructed through comparison with historical maps. At the beginning of the 19&lt;sup&gt;th&lt;/sup&gt; century Napoleon Bonaparte requested the development of high-quality maps of occupied territories. Among these, the so-called &amp;#8216;Carta del Ferrarese&amp;#8217; (CdF), completed between 1812 and 1814, is composed of 38 sheets and represents, to a scale of 1:15.000, 240.000 hectares of the Po lowlands, roughly corresponding to the present-day Ferrara district. The CdF, archived at the Kriegsarchiv in Vienna, is an extraordinary example among historical maps for its high quality and accuracy, which constitute a two-centuries-old reliable paleo-landscape picture.&lt;/p&gt;&lt;p&gt;Within the Historical Land Use Change research project, leaded by the Emilia-Romagna Statistical and GIS Service, the CdF was scanned, accurately georeferenced and orthorectified, showing a surprising generalized match with recent maps. More than 31.000 polygons were digitized in a GIS environment and interpreted on the basis of the European Corine Land Cover codes, properly modified for the land uses at the time.&lt;/p&gt;&lt;p&gt;Comparison with the recent land use analysis, carried out in 2014, highlights changes in land use, mainly related to land reclamation. Salt marshes and swamps, originally extended for 100.000 hectares, were reduced of about 85%, starting from 1861. Major phases of land reclamation occurred in 1870s and 1960s. Geochemical analyses on shallow samples (depth &lt; 50 cm), depict OC content of artificially drained soils &lt; 5% of the total volume. Soil texture testifies to the almost complete mineralization of OC after reclamation. Only recently drained soils show higher OC content, in the range of 10-15%.&lt;/p&gt;

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