Cultivated Land Occupation Research Articles

Spatio-Temporal Land-Use/Land-Cover Change Dynamics in Coastal Plains in Hangzhou Bay Area, China from 2009 to 2020 Using Google Earth Engine

Land-use classification is fundamental for environmental and water resource evaluation in coastal plain areas. However, comprehensive remote sensing image-based land-use analysis is challenged by the lack of massive remote sensing images and the massive computing power of large-scale server systems. In this paper, the spatial-temporal land-use change characteristics of the Hangzhou Bay area coastal plain are investigated on the Google Earth Engine platform. The proposed model uses a random forest algorithm to assist the land-use classification. The dataset is selected from the year 2009 to 2020 and classified with an average classification accuracy of 89% and Kappa coefficient of 88%. The results show that the land use in the selected region is affected by urbanization, the balance of cultivated land occupation and compensation, construction of economic development zone, and other activities. The investigation also shows that in the past 12 years, land use has changed rapidly, and each land-use type maintains the dynamic balance of occupation and compensation. Although the overall land-use distribution is stable, the information entropy fluctuates at a high level, with an average value of 1.15, and the multi-year average value of equilibrium is as high as 0.83. The driving force of land-use change is analyzed and accounted as demographics and human population dynamics, social-economic development, urbanization, and coupling effects of the above-mentioned factors.

N,N-Dimethylformamide solvent assisted hydrothermal pretreatment of Chlorella for coproduction of sugar, nitrogenous compounds and carbon dots

Microalgae are considered as a promising alternative to fossil fuels due to their ease of cultivation, short growth cycle and no occupation of cultivated land. In this study, N,N-Dimethylformamide (DMF) solvent was employed to assist hydrothermal pretreatment of Chlorella for coproduction of sugar, nitrogenous compounds and carbon dots (CDs). The effect of pretreatment conditions on the composition and pyrolysis bio-oil distribution of hydrothermal solid residues as well as CDs characteristic were investigated by varying the temperature (180–220 ℃) and reaction time (1–9 h). The results showed that pretreated residues had higher cellulose. And the yield of sugar and N-contained compounds reached 41.59% and 63.57% in the pyrolysis bio-oil of pretreated algae residues, respectively. Moreover, CDs obtained from hydrothermal solution fluoresced red under 365 nm excitation. The paper provides a new method for the complete utilization of microalgae.

Impact of Port Construction on the Spatial Pattern of Land Use in Coastal Zones Based on CLDI and LUT Models: A Case Study of Qingdao and Yantai

Ports are an important type of land use in coastal cities, and the development of ports has a significant influence on the spatial pattern of land use in port cities. However, the research focusing on economic indicators hardly reflects the process of changes in the spatial distribution of land development in coastal port cities. This paper introduces a spatial association rule method to establish a coastline and land development intensity (CLDI) model and land use transfer (LUT) model in the vertical direction of coastal zones to mine the association rules between shoreline change and land development intensity along the sea–land gradient in the Qingdao and Yantai coastal zones and to explore the important land development sequence patterns. The results showed that, in the early stage of regional development, the land development intensity decreased from sea to land. In the later stage, as the industry transferred to nearby towns, the land units with extremely strong and strong levels started to move to the end or middle of the sequence. With the improvement of the urban construction level, the simple LUT pattern sequence that increased building land through the occupation of cultivated land and forestland was replaced gradually by complex sequences with multiple components. The relationship between land development and distance from the port showed that the areas with strong land development intensity gradually moved from coastal to inland areas over time. Port shipping has a profound influence on port city land use patterns. Industrial transfer drives the development of surrounding towns during the metaphase. This trend was used to build a second port to realize the division of transportation capacity, as the old port’s carrying capacity tended to become saturated. This paper revealed the general changes in the important land use patterns in port areas through a comparative study of the Qingdao and Yantai port areas and the differences among different geographical locations and development processes. This study provides a reference for the rational planning of coastal zone spatial layouts and provides a model basis for the analysis of the spatial structure of coastal zones. This information can be used to coordinate the relationship between ports and cities and promote the sustainable development of coastal zones.

Assessing the relative role of climate and human activities on vegetation cover changes in the up–down stream of Danjiangkou, China

AbstractDanjiangkou Reservoir is water source of Middle Route Project of the South-to-North Water Diversion (SNWD) Project, research on the dynamic changes in vegetation cover and its influencing factors is of great significance for understanding the ecological environment of the water diversion area and formulating protection measures. In this study, the normalized difference in vegetation index (NDVI) was used to analyze the dynamic changes and influencing factors of vegetation in the upstream and downstream of Danjiangkou Dam from 1982 to 2018. The results showed that the NDVI exhibited an upward trend of 0.017 year−1 (P < 0.05), and that the significantly increased area was located near the valley upstream of the dam, while the significantly decreased area was mainly distributed in the basin downstream of the dam and around the central city. The comprehensive contributions of climate and human activity factors to NDVI changes were 92.03% and 7.97%, respectively. The human activities in the upstream of the dam were mainly reflected in the ecological measures such as returning farmland to forest; the human activities at the downstream of the dam were mainly reflected in urban expansion, occupation of cultivated land and forest land by construction land.

Cultivated land protection and rational use in China

Cultivated land protection is an important way to ensure food security, social stability and sustainable development. As one of the main causes of cultivated land loss, the spatio-temporal pattern of illegal cultivated land use and driving forces have not been systematically investigated. This study first reviewed the evolution of China’s cultivated land protection policy in the past four decades, then used spatial analysis technology to explore the spatio-temporal patterns of China’s illegal cultivated land use, and finally applied an econometric model to assess the impact of population growth, economic development and rising housing prices on illegal cultivated land use at the national and regional levels based on the balanced provincial panel data from 1999 to 2017. The results show that in the past 40 years, China has attached great importance to the protection of cultivated land, and established a relatively perfect cultivated land protection system. The quantity of cultivated land in China kept a dynamic balance on the whole, but the quality of cultivated land has dropped sharply, and regional human-land conflicts has become prominent. The driving forces of cultivated land loss in China varied across regions. Illegal use of cultivated land was also one of the important driving forces of cultivated land reduction in China. The number of illegal land use cases and the area appropriated have experienced a process of first increase and then decrease over the past two decades. The accumulated cases and area of illegal farmland use in the eastern region were larger than that in the central and western regions, but both showed a rapid downward trend over the past two decades, demonstrating that the illegal use of cultivated land in eastern China has been controlled to a certain extent. Population growth and land urbanization have a significant positive impact on illegal cultivated land use area in China and its three regions, while economic development has not driven but curbed illegal land use. The rise of commercial housing prices has no significant impact on illegal farmland use in rural China. We proposed measures to further control the illegal use of cultivated land, and believed that it is necessary and urgent to stop illegal occupation of cultivated land from the source

Remote Sensing Monitoring and Ecological Risk Assessment of Landscape Patterning in the Agro-Pastoral Ecotone of Northeast China

The agro-pastoral ecotone, an ecological transition zone connecting adjacent areas of agricultural planting area and grassland animal husbandry, has three features: a complex natural condition, relatively pronounced population pressure, and a fragile ecological environment. In this study, we conducted an ecosystem risk assessment in the western part of Jilin Province, China, based on multiscale and multitemporal remote sensing images and land-use data. Furthermore, we focused on land-use change from 1995 to 2015 by applying the dynamic change information survey method and carrying out a transfer track analysis. The results revealed three main findings. (1) The ecological risk index at the scale of 3 km × 3 km harbors significant spatial correlation. (2) The ecological risk index of unutilized land, forest land, and grassland is relatively high for each, and their anti-interference ability is weak, while the ecological risk index of construction land and water area is the lowest. (3) Human interference, e.g., construction activities and cultivated land occupation, is the leading factor driving the exacerbation of ecological risk and frequent land-use type conversions. At the study period’s end, a trend of slight contraction in the high-risk areas was found, indicating that land-use regulation and land protection policies have had significantly positive impact upon the lands’ ecological value. The overall study identified a reasonable research scale for eco-environmental risk assessment and discerned relationships between regional land-use changes through geospatial analysis. Moreover, our findings can help provide practical case study information applicable to similar regions with agro-pastoral ecotones.

Dynamic change of land use/land cover patterns and driving factors of Nansihu Lake Basin in Shandong Province, China

Anthropogenic activities and natural factors have a significant effect on land use/land cover (LULC) patterns of Nansihu Lake basin. Understanding the LULC change is essential for regional sustainable development. Based on LULC change detection methods, we characterized the spatial–temporal change of LULC patterns. Logistic regression model and the Conversion of Land Use and its Effects at Small regional extent (CLUE-S) model were used in driving factors analysis and scenario simulation. The results showed that cultivated land and construction land were the dominant LULC types. As construction land gradually expanded to the surrounding areas, a large amount of cultivated land was occupied, especially in the peripheral areas of the central cities. During 1987–2017, 4109.22 km2 of cultivated land was converted into construction land, accounting for 86.38% of cultivated land change, and the contribution rate to construction land was 95.24%. Because of the severe drought in 2002, waters first decreased and then increased. The dynamic degree of waters reached 2.11%, and the increment of waters was mainly converted from cultivated land and unused land. The degree of LULC fragmentation was strengthened, and the distribution showed a diversified trend. The LULC changes were deeply influenced by natural environment and socio-economic factors. Under different scenarios, the expansion of construction land and occupation of cultivated land will continue to be the main features of LULC changes in the future. The LULC patterns will become more regular and more aggregated. This study can help address the interwoven challenges of urbanization development and ecological protection.

浅谈我国耕地占补平衡政策落实的挑战与对策

浅谈我国耕地占补平衡政策落实的挑战与对策

Spatial-temporal characteristics of construction land expansion and occupation of cultivated land in urban agglomeration of central and southern Liaoning Province based on Remote Sensing

Spatial-temporal characteristics of construction land expansion and occupation of cultivated land in urban agglomeration of central and southern Liaoning Province based on Remote Sensing

Land use change and driving factors in rural China during the period 1995-2015

Land use/cover change (LUCC) is the result of interaction between human activities and biophysical processes. Extensive researches have been done on LUCC in urban China, but the understanding on rural land-use remains relatively inadequate. Based on land use, socio-economic, topographic and climate data from 1995–2015, taking China’s 31,275 townships as the research object, this study applied land-use dynamic degree (LUDD), geo-detector model and bivariate spatial autocorrelation analysis to explore the spatio-temporal pattern and driving factors of LUCC in rural China. Results show that over the past two decades, significant changes have taken place in the type and structure of land use in rural China. The cultivated land increased in northeast and northwest China, and the built-up area increased in Yangtze River Delta, Pearl River Delta and Beijing-Tianjin-Hebei region as well as Henan and Anhui provinces. More than 80 % of built-up land expansion came from the occupation of cultivated land. The Loess Plateau, Sichuan Basin, Hebei, Henan, western Xinjiang and southern Jiangsu have experienced the most serious decline in arable land. The driving force of LUCC varied greatly with space, time and land use type. Socio-economic development was the main driving force for the built area expansion, and geographical differentiation was the dominant factor in the conversion of cultivated land, forest land and grassland. The intensity of population and economic growth driving built-up land expansion decreases from east to west, while that of terrain-driven conversion of cultivated land into forest land gradually increases from west to east. These findings would provide decision support for policy-makers to formulation future sustainable land use policies. At the same time, it would help to further promote the exploration of China’s complicated human-land relationship.

Correlation Studies between Land Cover Change and Baidu Index: A Case Study of Hubei Province

Current land cover research focuses primarily on spatial changes in land cover and the driving forces behind these changes. Among such forces is the influence of policy, which has proven difficult to measure, and no quantitative research has been conducted. On the basis of previous studies, we took Hubei Province as the research area, using remote sensing (RS) images to extract land cover change data using a single land use dynamic degree and a comprehensive land use dynamic degree to study land cover changes from 2000 to 2015. Then, after introducing the Baidu Index (BDI), we explored its relationship with land cover change and built a tool to quantitatively measure the impact of changes in land cover. The research shows that the key search terms in the BDI are ‘cultivated land occupation tax’ and ‘construction land planning permit’, which are closely related to changes in cultivated land and construction land, respectively. Cultivated land and construction land in all regions of Hubei Province are affected by policy measures with the effects of policy decreasing the greater the distance from Wuhan, while Wuhan is the least affected region.

THE RELATIONSHIP BETWEEN CULTIVATED LAND CHANGE AND ECONOMIC DEVELOPMENT BASED ON GIS IN HENAN PROVINCE: AN EMPIRICAL STUDY

Abstract. Cultivated land resources are the basic production factors that carry human survival and economic development. Exploring the relationship between cultivated land change and economic development has become a hot issue for scholars.in this paper,The methods of regression analysis, land use elastic coefficient method, location entropy are used to empirically describe the relationship between cultivated land change and economic development.The results show: Since the 20th century, the change of cultivated land area has experienced three distinct stages of change, showing a process of recovery, decline, and steady evolution in Henan Province. The per capita cultivated land area is characterized by an upward trend, and the per capita cultivated land area is increasing year by year. In general, the intensive use of cultivated land in Henan Province is still not high, but the momentum of a sharp decline in cultivated land is basically controlled. The change of cultivated land area and economic development showed a four-time curve fitting relationship, which indicates that the path dependence of economic development on cultivated land occupation still exists, and cultivated land supports the rapid development of economy.The research results of the relationship between cultivated land change and economic development by using location entropy show that the spatial layout of the urban area is less than 0, and the regularity is not strong.The location where the location entropy is between 0–1 is mainly located in the central part of Henan Province;The cities with location entropy greater than 1 are mainly located in the eastern part of Henan.

Evaluation of Urban Ecosystem Service Value under New Urbanization—A Case Study of Chengdu City

In order to evaluate the change of ecosystem service value in Chengdu, GIS technology was used to obtain the land use type data of Chengdu from 2009 to 2018. The equivalent factor method was used as the core evaluation method, and an ecosystem value evaluation model was established to explore the impact of various land use types on ecosystem service value. The results show that: (1) the trend of land use change is that both the area and the proportion of land use change in different degrees. The area of cultivated land, water area and unused land are greatly reduced, and the area of construction land expands rapidly, mainly through the occupation of cultivated land and unused land. (2) The intensity of land use in Chengdu is greater and continues to increase, and the contribution rate of construction land is larger, which indicates that the land use structure is developing towards the structural direction of mainly construction land. (3) Changes in ecosystem service value are not only related to land use structure, but also to the economic development, willingness to pay and ability of the whole society. (4) Ecosystem service value is negatively correlated with construction land and unused land; it is positively correlated with cultivated land, forest land and grassland. Generally speaking, Chengdu’s land use change has not caused obvious damage to the ecosystem, but the impact of human lifestyle on the environment in the process of economic development cannot be ignored. The growth of construction land area should be appropriately controlled, ecological land should be protected, and the sustainable development of social-economic-ecological benefits should be realized.

Land use transitions and the associated impacts on ecosystem services in the Middle Reaches of the Yangtze River Economic Belt in China based on the geo-informatic Tupu method

Rapid urbanization in China has greatly exacerbated land use transitions (LUTs), which seriously threaten the ecosystem. The existing literature lacks information on the spatio-temporal analysis of LUTs, and assessments of ecosystem services remain incomplete. This lack of information may limit the formation and implementation of landscape plans and ecologically oriented policies. This study attempts to fill this gap by analysing the geographic features of LUTs with the geo-informatic Tupu method and exploring the responses of ecosystem services to LUTs. A newly revised benefit transfer method that utilizes the land use/land cover change data derived from the Landsat Enhanced Thematic Mapper (ETM) in the Middle Reaches of the Yangtze River Economic Belt (MRYREB) is implemented. The results indicate that the area of construction land continued to increase markedly, while the area of cultivated land declined continuously from 1995 to 2015. This increase in construction land was mainly derived from the occupation of cultivated land. The Tupu units of “forestland → cultivated land,” “cultivated land → forestland,” “cultivated land → water area,” and “water area → cultivated land” were the dominant driving forces of the changes in ecosystem services value (ESV) in the MRYREB. Hotspots of ESV changes were mainly located in the surrounding mountainous areas during 1995–2005 and 2005–2010, while the coldspots during 2010–2015 were mainly located in the plains. The findings in this study have important implications for ecosystem conservation, ecological function zoning, ecological compensation decision-making, and related land development in the MRYREB.

A New Trend in the Space–Time Distribution of Cultivated Land Occupation for Construction in China and the Impact of Population Urbanization

Rapid urbanization has brought huge development dividends to China. At the same time, its negative effects have aroused people’s attention. For example, a large amount of cultivated land has been occupied for urban expansion and construction. Using exploratory spatial data analysis (ESDA) and the spatial Durbin model (SDM), we analyzed the spatial distribution of cultivated land occupation for construction (CLOC) and its driving factors in 31 provinces in China from 2005 to 2016. The results indicated that (1) the CLOC rate presented a significant spatial clustering feature, and its distribution showed a new trend of “homogenization” after the year 2012; (2) as the core driving factor, the population urbanization rate significantly promoted the growth of the CLOC rate in the local province, while showing a negative effect on that rate in the neighboring provinces; (3) in addition, behind the new trend of the CLOC rate, there was a transformation from being “investment driven” to being “population and industry driven”. Therefore, this paper suggests that the government should link each city’s construction land supply to the constantly changing trend of population migrations in China. Further, promoting the tertiary industry can be a win–win strategy for easing the tension between cultivated land and construction land.

Impact of urbanization on the eco-efficiency of cultivated land utilization: A case study on the Yangtze River Economic Belt, China

Abstract Today, scholars and governments focus on the loss of cultivated land resources as a result of urbanization, but ignore urbanization's impact on the eco-efficiency of cultivated land utilization (ECLU), which causes the wastage of cultivated land resources and environmental pollution. Hence, this study systematically analyzes how urbanization influences the ECLU and proposes four of the former's effects on the latter: agglomeration, barrier, driving, and feedback effects. Further, it uses the System Generalized Method of Moments (GMM) and threshold models to estimate urbanization's impact on the ECLU. The estimation results of System GMM model reveal that agglomeration and barrier effects have a significant negative effect on the ECLU, with regression coefficients of −0.6725 and −0.0415, respectively. Contrarily, driving and feedback effects have a significant positive effect on the ECLU, with regression coefficients of 0.0274 and 0.1423, respectively. Further, the threshold analysis demonstrates that the barrier, driving, and feedback effects of urbanization have single threshold values of 20.7%, 22.8%, and 18.2%, respectively, whereas the agglomeration effect by itself has two threshold values of 18.3% and 49.5%. The study concludes that focusing only on the urbanization-related occupation of cultivated land while ignoring the urbanization's effects on the ECLU will jeopardize food security and the ecological environment. After considering the effects of different levels of urbanization on the ECLU, the government should formulate appropriate policies and measures to realize the sustainable utilization of cultivated land resources.

Ecological Land Fragmentation Evaluation and Dynamic Change of a Typical Black Soil Farming Area in Northeast China

Ecological land is a land use category provided with considerable ecological value and a vital indicator reflecting regional eco-environmental quality. However, it has experienced severe fragmentation during the rapid urbanization in China which strongly threatened the regional ecological security, land use pattern and human living environment. Therefore, analysis of spatiotemporal change of ecological land use and ecological landscape pattern is particularly essential. In this paper, a case study was made in Nong’an County, which is a typical black soil farming area located in northeast China facing severe conflicts among cultivated land protection, urban expansion and ecological security. A landscape fragmentation evaluation model was proposed to measure the degree of regional ecological land fragmentation. We also determined the land use change features through the methods of dynamic change information exploration and by performing transfer trajectory analysis during the period from 1996 to 2014. The results showed that the ecological land in Nong’an County has experienced increasing fragmentation during the past 18 years. The statistical results showed that the land transition between ecological land and other land categories was quite frequent, and it especially appeared as a dramatic decline of grassland and severe increase of saline-alkali land. In addition, human interferences especially construction activities and cultivated land occupation were still the dominant factors to the fragmentation of ecological land and the frequent transition among the land use categories. The fragmentation degree showed a downward tendency at the end of the study, which indicated noticeable benefits of land use regulation and land protection policies directed towards land ecological value. This study aims to provide a scientific evaluation model for measuring ecological land fragmentation degree, and figure out the regional land use transition relationships to offer suggestions for decision-making and provide a practical case in a typical region.

Quality Perspective on the Dynamic Balance of Cultivated Land in Wenzhou, China

Cultivated land in China has faced severe challenges in recent years due to rapid urbanization. In 1997, the “cultivated land requisition-compensation balance” policy was implemented by the government to maintain the quantity and quality of cultivated land. Previous studies mainly focused on the quantity changes of cultivated land. In this study, from a quality perspective, we characterized the occupation and compensation of cultivated land in Wenzhou City utilizing remote sensing and geographic information systems during 2005–2010 and 2010–2014. Our results indicated that although the quantity balance of cultivated land has been achieved in Wenzhou, there was a trend of consuming prime cultivated land for urbanization while compensating with less productive land. It was also found that topography, water resources, and accessibility play important roles in cultivated land changes, with urbanization occurring on the eastern coastal plain where high quality lands are prevalent. Less than 60% of the gained lands were under cultivation, with the majority of reclaimed land from forests and coastal areas and located in remote regions. Therefore, we suggest that a “cultivated land protection red line” policy should be implemented to protect the best cultivated lands, while preventing random land reclamation to secure agricultural and environmental sustainability.

Analyses of traits and driving forces on urban land expansion in a typical coal-resource-based city in a loess area

The development of coal-resource-based cities is cyclical and presents different traits affected by different socio-economic driving forces in each stage. In this paper, we study urban land expansion in the Pinglu District in Shuozhou City, Shanxi Province, China, by interpreting six-phase remote sensing images to reveal the traits and driving forces of urban land expansion during different stages. Overall, the following results were observed. (1) Urban land expansion was obvious from 1986 to 2013, with an increase of 992.80 ha, mainly due to the occupation of cultivated land. Urban land expansion mainly occurred along the periphery of the city, which was 1–2 km from the urban centre. (2) The influence of the coal industry on urban land expansion can be divided into two stages, the establishment stage of the coal industry system and the development stage of coal industry promotion and urbanization. (3) The traits of urban land expansion matched economic models and traits. The non-agricultural population and industrial electricity consumption can reflect how economic development can impact urban land expansion. The periodic traits of urban land expansion and the coal industry life cycle have shown a high degree of consistency. Furthermore, the results of this study could serve as a reference for resource-based cities regarding urban land use and sustainable development.

The impact of land examination and approval system reform on cultivated land occupation by construction according to provincial level panel data in China from 1995 to 2013

The impact of land examination and approval system reform on cultivated land occupation by construction according to provincial level panel data in China from 1995 to 2013