scholarly journals Outmigration Drives Cropland Decline and Woodland Increase in Rural Regions of Southwest China

Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 443
Author(s):  
Yi Yu ◽  
Tingbao Xu ◽  
Tao Wang
Keyword(s):  
Land Use ◽  
Vegetation Index ◽  
Agricultural Sector ◽  
Southwest China ◽  
Labour Force ◽  
Arable Land ◽  
Sustainable Land Use ◽  
Land Use Patterns ◽  
Rural Regions ◽  
Normalised Difference Vegetation Index

Rapid urbanisation in China has led to massive outmigration in rural regions, which has changed the regional labour force structure and can have various profound impacts as a result. This research used a case study in Southwest China to investigate how regional land use patterns have been changed in the context of rural outmigration and assessed the resulting dynamics on local ecological environment. The key findings include: (1) The local land conversion process was mainly characterised by the conversion of farmland (−18.3%) to residential area (+268.3%) and woodland (+55.6%) during 2000–2018; (2) about 83.7% of area showed a statistically significant increase in the normalised difference vegetation index (NDVI), which was not due to human interference factors (e.g., afforestation). Correlation analyses showed that depopulation (R = −0.514, p < 0.01) and local mild temperature (R = 0.505, p < 0.01) could be the main contributors. Only 2.5% of the area had decreased NDVI and this was directly caused by human activities (e.g., urban area expansion). These results implied that vegetation improvement can occur in the context of depopulation and farmland reduction, which did not significantly threaten the local agricultural sector. It then could be a good choice to allow those high-slope and biophysically poor farmlands to undergo forest succession rather than cultivation. Farmers in Southwest China should make a full use of the existing low-slope arable land to curb the declining trend of local farmland amount, in order to meet the future challenges brought by urbanisation. Enhanced agricultural infrastructure, mechanised farming and guide from local government can help achieve this goal. This study provided new insights and more realistic scenarios for rural development in Southwest China. The research findings are expected to provide a better understanding to enable sustainable land use management in Southwest China.

Corrigendum to: Influence of climatic factors on variation in the Normalised Difference Vegetation Index in Mongolian Plateau grasslands

2018 ◽  
Vol 40 (2) ◽  
pp. 205
Author(s):  
Xu-Juan Cao ◽  
Qing-Zhu Gao ◽  
Ganjurjav Hasbagan ◽  
Yan Liang ◽  
Wen-Han Li ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Vegetation Index ◽  
Climatic Factors ◽  
Growing Season ◽  
Limiting Factor ◽  
Spatial And Temporal Variability ◽  
Climate Factors ◽  
Mongolian Plateau ◽  
Normalised Difference Vegetation Index

Climate change will affect how the Normalised Difference Vegetation Index (NDVI), which is correlated with climate factors, varies in space and over time. The Mongolian Plateau is an arid and semi-arid area, 64% covered by grassland, which is extremely sensitive to climate change. Its climate has shown a warming and drying trend at both annual and seasonal scales. We analysed NDVI and climate variation characteristics and the relationships between them for Mongolian Plateau grasslands from 1981 to 2013. The results showed spatial and temporal differences in the variation of NDVI. Precipitation showed the strongest correlation with NDVI (43% of plateau area correlated with total annual precipitation and 44% with total precipitation in the growing season, from May to September), followed by potential evapotranspiration (27% annual, and 30% growing season), temperature (7% annual, 16% growing season) and cloud cover (10% annual, 12% growing season). These findings confirm that moisture is the most important limiting factor for grassland vegetation growth on the Mongolian Plateau. Changes in land use help to explain variations in NDVI in 40% of the plateau, where no correlation with climate factors was found. Our results indicate that vegetation primary productivity will decrease if warming and drying trends continue but decreases will be less substantial if further warming, predicted as highly likely, is not accompanied by further drying, for which predictions are less certain. Continuing spatial and temporal variability can be expected, including as a result of land use changes.

scholarly journals Optimization of the National Land Space Based on the Coordination of Urban-Agricultural-Ecological Functions in the Karst Areas of Southwest China

2019 ◽  
Vol 11 (23) ◽  
pp. 6752 ◽  
Author(s):  
Xiaoqing Zhao ◽  
Sinan Li ◽  
Junwei Pu ◽  
Peipei Miao ◽  
Qian Wang ◽  
...  
Keyword(s):  
Land Use ◽  
Southwest China ◽  
Arable Land ◽  
Ecological Environment ◽  
Spatial Structures ◽  
Ecological Functions ◽  
Land Protection ◽  
Karst Areas ◽  
Functional Areas ◽  
Land Space

National land spatial planning is dominated by urban-agricultural-ecological functions and has become a Chinese national strategic issue. However, the three functional spaces have serious conflicts in the karst areas, causing inconsistencies in regional development and triggering poverty and a more serious situation for the ecological environment. In this study, we used the gray multi-objective dynamic programming model and the conversion of land use and its effects at small region extent model to simulate the developmental structures of future land use in the karst areas of Southwest China under a socioeconomic development scenario, an arable land protection scenario and an ecological security scenario. Finally, based on the coordination of the urban-agricultural-ecological functions, we used a functional space classification method to optimize the spatial structures of the national land space for 2035 year and to identify different functional areas. The results showed that the three scenarios with different objectives had differences in the quantities and spatial structures of land use but that the area of forestland was the largest and the area of water was the smallest in each scenario. The optimization of the national land space was divided into seven functional areas—urban space, agricultural space, ecological space, urban-agricultural space, urban-ecological space, agricultural-ecological space and urban-agricultural-ecological space. The ecological space was the largest and the urban-ecological space was the smallest among seven functional areas. The different types of functional spaces had significant differentiation characteristics in the layouts. The urban-agricultural space, urban-ecological space, agricultural-ecological space and urban-agricultural-ecological space can effectively alleviate the impacts of human activities and agricultural production activities in karst areas, promote the improvement of rocky desertification and improve the quality of the regional ecological environment. The results of this research can provide support for decisions about the balanced development of the national land space and the improvement of environmental quality in the karst areas.

scholarly journals Analysis of meteorological variations on wheat yield and its estimation using remotely sensed data. A case study of selected districts of Punjab Province, Pakistan (2001-14)

2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Rafia Mumtaz ◽  
Shahbaz Baig ◽  
Iram Fatima
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Crop Yield ◽  
Vegetation Index ◽  
Wheat Yield ◽  
Least Square ◽  
Wheat Crop ◽  
Main Challenge ◽  
Normalised Difference Vegetation Index ◽  
The Impact

Land management for crop production is an essential human activity that supports life on Earth. The main challenge to be faced by the agriculture sector in coming years is to feed the rapidly growing population while maintaining the key resources such as soil fertility, efficient land use, and water. Climate change is also a critical factor that impacts agricultural production. Among others, a major effect of climate change is the potential alterations in the growth cycle of crops which would likely lead to a decline in the agricultural output. Due to the increasing demand for proper agricultural management, this study explores the effects of meteorological variation on wheat yield in Chakwal and Faisalabad districts of Punjab, Pakistan and used normalised difference vegetation index (NDVI) as a predictor for yield estimates. For NDVI data (2001-14), the NDVI product of Moderate Resolution Imaging spectrometer (MODIS) 16-day composites data has been used. The crop area mapping has been realised by classifying the satellite data into different land use/land covers using iterative self-organising (ISO) data clustering. The land cover for the wheat crop was mapped using a crop calendar. The relation of crop yield with NDVI and the impact of meteorological parameters on wheat growth and its yield has been analysed at various development stages. A strong correlation of rainfall and temperature was found with NDVI data, which determined NDVI as a strong predictor of yield estimation. The wheat yield estimates were obtained by linearly regressing the reported crop yield against the time series of MODIS NDVI profiles. The wheat NDVI profiles have shown a parabolic pattern across the growing season, therefore parabolic least square fit (LSF) has been applied prior to linear regression. The coefficients of determination (<em>R</em><sup>2</sup>) between the reported and estimated yield was found to be 0.88 and 0.73, respectively, for Chakwal and Faisalabad. This indicates that the method is capable of providing yield estimates with competitive accuracies prior to crop harvest, which can significantly aid the policy guidance and contributes to better and timely decisions.

Environmental Acidification due to Soil Acid Changes of Different Land Use Patterns

2013 ◽  
Vol 361-363 ◽  
pp. 888-891
Author(s):  
Yue Shen ◽  
Yan Li Yi
Keyword(s):  
Land Use ◽  
Magnetic Susceptibility ◽  
Cation Exchange ◽  
Paddy Soil ◽  
Cation Exchange Capacity ◽  
Arable Land ◽  
Exchange Capacity ◽  
Land Use Patterns ◽  
Use Patterns ◽  
Orchard Soil

A survey was carried out to investigate the acidification due to acid changes of different land use patterns. The results showed that soil acidification happened in the arable land and forest land in topsoil of 0~10 cm depth, 0.42 and 0.24 pH unit-1 lower than that of in 80~100 cm depth. The lowest cation exchange capacity (CEC) (11.99 cmol·kg-1) was got in the topsoil of paddy soil, while the highest one was in the topsoil of grassland with 19.26 cmol·kg-1. A catastrophe point of cation exchange capacity of soils was found between 20~30 cm except for orchard soil. Organic matter in forest soil decreased sharply by 2.21% in 0~10 cm as compared with that of in 80~100 cm and little decrease about 0.97% was found in the orchard soil. The pH and magnetic susceptibility showed similar variation trend. Multiple linear regression analysis showed that there was a negative relationship between pH and low magnetic susceptibility. Our results also showed that the free iron, low magnetic susceptibility and amorphous ferric oxide were the main factors on the changes of pH in the arable land and forest soil, grassland and paddy soil, and the orchard soil, respectively.

scholarly journals Urban green and grey space in relation to respiratory health in children

2017 ◽  
Vol 49 (6) ◽  
pp. 1502112 ◽  
Author(s):  
Christina Tischer ◽  
Mireia Gascon ◽  
Ana Fernández-Somoano ◽  
Adonina Tardón ◽  
Aitana Lertxundi Materola ◽  
...  
Keyword(s):  
Built Environment ◽  
Vegetation Index ◽  
Respiratory Health ◽  
Estimating Equation ◽  
Urban Land Use ◽  
Green Spaces ◽  
Land Use Patterns ◽  
Residential Proximity ◽  
Use Patterns ◽  
Normalised Difference Vegetation Index

We assessed the effect of three different indices of urban built environment on allergic and respiratory conditions.This study involved 2472 children participating in the ongoing INMA birth cohort located in two bio-geographic regions (Euro-Siberian and Mediterranean) in Spain. Residential surrounding built environment was characterised as 1) residential surrounding greenness based on satellite-derived normalised difference vegetation index (NDVI), 2) residential proximity to green spaces and 3) residential surrounding greyness based on urban land use patterns. Information on wheezing, bronchitis, asthma and allergic rhinitis up to age 4 years was obtained from parent-completed questionnaires. Logistic regression and generalised estimating equation modelling were performed.Among children from the Euro-Siberian region, higher residential surrounding greenness and higher proximity to green spaces were negatively associated with wheezing. In the Mediterranean region, higher residential proximity to green spaces was associated with a reduced risk for bronchitis. A higher amount of residential surrounding greyness was found to increase the risk for bronchitis in this region.Associations between indices of urban residential greenness and greyness with respiratory diseases differ by region. The pathways underlying these associations require further exploration.

scholarly journals The Impact of Climate Change on Major Agricultural Crops: Evidence from Punjab, Pakistan

2012 ◽  
Vol 51 (4II) ◽  
pp. 261-276 ◽  
Author(s):  
Rehana Siddiqui ◽  
Ghulam Samad ◽  
Muhammad Nasir ◽  
Hafiz Hanzla Jalil
Keyword(s):  
Climate Change ◽  
Economic Growth ◽  
Agricultural Sector ◽  
Labour Force ◽  
Arable Land ◽  
Developed Countries ◽  
Least Developed Countries ◽  
Impact Of Climate Change ◽  
Agriculture Sector ◽  
The Impact

It is necessary for a country to make its agriculture sector efficient to enhance food security, quality of life and to promote rapid economic growth. The evidence from least developed countries (LDCs) indicates that agriculture sector accounts for a large share in their gross domestic product (GDP). Thus the development of the economy cannot be achieved without improving the agriculture sector. According to the Economic Survey of Pakistan (2011-12) its main natural resource is arable land and agriculture sector’s contribution to the GDP is 21 percent. The agricultural sector absorbs 45 percent of labour force and its share in exports is 18 percent. Given the role of agricultural sector in economic growth and its sensitivity to change in temperature and precipitation it is important to study the impact of climate change on major crops in Pakistan. There are two crops seasons in Pakistan namely, Rabi and Kharif. Rabi crops are grown normally in the months of November to April and Kharif crops are grown from May to October. These two seasons make Pakistan an agricultural economy and its performance depends on the climate during the whole year. Climate change generally affects agriculture through changes in temperature, precipitation.

scholarly journals Unraveling Latent Aspects of Urban Expansion: Desertification Risk Reveals More

2020 ◽  
Vol 17 (11) ◽  
pp. 4001
Author(s):  
Gianluca Egidi ◽  
Ilaria Zambon ◽  
Ilaria Tombolin ◽  
Luca Salvati ◽  
Sirio Cividino ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Quality ◽  
Land Use Planning ◽  
Urban Expansion ◽  
High Sensitivity ◽  
Sustainable Land Use ◽  
Land Use Patterns ◽  
High Quality ◽  
Regulatory Constraints ◽  
Desertification Risk

Urban expansion results in socioeconomic transformations with relevant impacts for peri-urban soils, leading to environmental concerns about land degradation and increased desertification risk in ecologically fragile districts. Spatial planning can help achieve sustainable land-use patterns and identify alternative locations for settlements and infrastructure. However, it is sometimes unable to comprehend and manage complex processes in metropolitan developments, fueling unregulated and mainly dispersed urban expansion on land with less stringent building constraints. Using the Mediterranean cities of Barcelona and Rome as examples of intense urbanization and ecological fragility, the present study investigated whether land use planning in these cities is (directly or indirectly) oriented towards conservation of soil quality and mitigation of desertification risk. Empirical results obtained using composite, geo-referenced indices of soil quality (SQI) and sensitivity to land desertification (SDI), integrated with high-resolution land zoning maps, indicated that land devoted to natural and semi-natural uses has lower soil quality in both contexts. The highest values of SDI, indicating high sensitivity to desertification, were observed in fringe areas with medium-high population density and settlement expansion. These findings reveal processes of land take involving buildable soils, sometimes of high quality, and surrounding landscapes in both cities. Overall, the results in this study can help inform land use planers and policymakers for conservation of high-quality soils, especially under weak (or partial) regulatory constraints.

scholarly journals Evaluation and Tradeoff Analysis of Ecosystem Service for Typical Land-Use Patterns in the Karst Region of Southwest China

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 451 ◽  
Author(s):  
Zhigang Zou ◽  
Fuping Zeng ◽  
Kelin Wang ◽  
Zhaoxia Zeng ◽  
Hui Tang ◽  
...  
Keyword(s):  
Land Use ◽  
Southwest China ◽  
Fruit Trees ◽  
Karst Area ◽  
Karst Region ◽  
Land Use Patterns ◽  
Cultural Services ◽  
Use Patterns ◽  
Regulating Services ◽  
Provisioning Services

Although many land-use patterns have been established to restore vegetation and eliminate poverty in the karst area in southwest China, the ecosystem services (ESs) of these patterns are still not fully understood. To compare the differences in seven typical monoculture patterns and three agroforestry patterns, their ESs and tradeoffs were analyzed within the Millennium Ecosystem Assessment Framework. Compared with the local traditional corn pattern, the marigold pattern improved provisioning, regulating, and cultural services by >100%. The pomegranate pattern provided far more provisioning services than the other patterns. The apple + soybean intercropping pattern reduced regulating services, and eventually, its Total ESs (TES) and ecosystem multifunctionality index (EMF) also decreased. Cultural services will be enhanced by the introduction of fruit trees, as well as intercropping. Orange + peach had the greatest negative tradeoffs between provisioning and regulating services (P-R), provisioning and supporting services (P-S), and provisioning and cultural services (P-C), which indicates that the provisioning services urgently require improvement. Peach + pumpkin intercropping decreased the negative tradeoffs of P-R, P-S, and P-C (all > 10%), while pomegranate + grass intercropping increased the negative tradeoffs of R-S and R-C (all > 100%). Our results suggest that all six of these patterns are worthy of promotion but the pomegranate pattern should be given priority. Among the three intercropping patterns studied herein, the apple + soybean pattern should be redesigned to improve performance.

scholarly journals Sustainable Land-Use Allocation Model at a Watershed Level under Uncertainty

2021 ◽  
Vol 18 (24) ◽  
pp. 13411
Author(s):  
Yao Lu ◽  
Min Zhou ◽  
Guoliang Ou ◽  
Zuo Zhang ◽  
Li He ◽  
...  
Keyword(s):  
Land Use ◽  
Economic Development ◽  
Land Use Planning ◽  
Ecological Factors ◽  
Sustainable Land Use ◽  
Land Use Patterns ◽  
Allocation Model ◽  
Watershed Land Use ◽  
Use Patterns ◽  
Land Use Allocation

Land-use allocation models can effectively support sustainable land use. A large number of studies solve the problems of land-use planning by constructing models, such as mathematical models and spatial analysis models. However, these models fail to fully and comprehensively consider three uncertain factors of land-use systems: randomness, interval and fuzziness. 33Therefore, through the study of the watershed land-use system, this paper develops a land-use allocation model considering the regional land–society–economy–environment system under uncertain conditions. On the basis of this model, an interval fuzzy two-stage random land-use allocation model (IFTSP-LUAM) combining social, economic and ecological factors is proposed to provide sustainable development strategies at the basin level. In addition, the proposed IFTSP-LUAM takes into account the above three uncertainties and multistage, multiobjective, dynamic, systematic and complex characteristics of typical land-use planning systems. The results showed that the model considers more socioeconomic and ecological factors and can effectively reflect the quantitative relationship between the increase in economic benefits and the decrease in environmental costs of a land-use system. The model was applied to land-use planning of Nansihu River Basin in Shandong Province. The results provided a series of suitable land-use patterns and environmental emission scenarios under uncertain conditions, which can help the watershed environmental protection bureau and watershed land-use decision-makers to formulate appropriate land-use policies, so as to balance social and economic development and ecological protection. The simulation results can provide support for an in-depth analysis of land-use patterns and the trade-off between economic development and ecological environment protection.

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