Decrease In Cultivated Land Research Articles

Characteristics of Landscape (Land Use) Change and its Driving Force in County - A Case Study of Shunyi District of Beijing

Based on land use data and social economy data in 1999 and 2005, this article analyzed the spatial-temporal characteristics and driving factors of the land use change in Shunyi district by GIS technology and logistic regression analysis method. The result showed that transformation among different land use was dramatically changed from 1999 to 2005, such as the increase of construction land and the decrease of cultivated land and water area. Land transfer was mainly cultivated land to construction land, forest land, garden land, other land use; forest land to grass land and water area to cultivated land. The area of land changed from cultivated land to construction land was 14250.2hm2, and the ratio of the change is 20.09%; the changed land area from forest land to grass land was 887.6hm2 with 17.85% of changed ratio; the transformation area from water area to agricultural land was 1099.7hm2 and 23.75% of transformation ratio. The development of secondary and tertiary industry is the major driving factor of land use change from cultivated land to construction land, while the major reason for the changes from forest land to grass land and from water area to cultivated land was that the Caobai river has been dried up.

Spatial simulation of land use based on terrestrial ecosystem carbon storage in coastal Jiangsu, China.

This paper optimises projected land-use structure in 2020 with the goal of increasing terrestrial ecosystem carbon storage and simulates its spatial distribution using the CLUE-S model. We found the following: The total carbon densities of different land use types were woodland > water area > cultivated land > built-up land > grassland > shallows. Under the optimised land-use structure projected for 2020, coastal Jiangsu showed the potential to increase carbon storage, and our method was effective even when only considering vegetation carbon storage. The total area will increase by reclamation and the original shallows will be exploited, which will greatly increase carbon storage. For built-up land, rural land consolidation caused the second-largest carbon storage increase, which might contribute the most as the rural population will continue to decrease in the future, while the decrease of cultivated land will contribute the most to carbon loss. The area near the coastline has the greatest possibility for land-use change and is where land management should be especially strengthened.

Spatial Variation of Soil Salinity in the Coastal Reclamation Area, Eastern China

ABSTRACT Xu, Y.; Pu, L.; Zhu, M.; Li, J.; Zhang, M.; Li, P., and Zhang, J., 2014. Spatial variation of soil salinity in the coastal reclamation area, eastern China. Reclamation of coastal saline tidal flats has become a common practice for coastal countries faced with a decrease in cultivated land and an increase in population. Because the variability of soil salinity is considerable, understanding the spatial distribution of this salinity and its components is essential for land use planning. This study was conducted in a coastal area in eastern China that has been reclaimed under various land use types at different times. The objective of the work was to assess the effect of the reclamation time and land use types on soil salinity and spatial variation of soil salinity by using conventional statistics and geostatistical techniques. The results indicate that reclamation times and land use types significantly influence soil salinity in coastal areas. Cropland and aquaculture pond have same effect on soil ...

MONITORING THE URBAN GROWTH OF DHAKA (BANGLADESH) BY SATELLITE IMAGERY IN FLOODING RISK MANAGEMENT PERSPECTIVE

Abstract. There is large consensus that demographic changes, the lack of appropriate environmental policies and sprawling urbanization result in high vulnerability and exposure to the natural disasters. This work reports some experiences of using multispectral satellite imagery to produce landuse/cover maps for the Dhaka city, the capital of Bangladesh, which is subject to frequent flooding events.The activity was conducted in collaboration with the non-profit organization ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action). The Landsat images acquired in 2000, 2002 and 2009 were used to evaluate the urban growth in order to support risk assessment studies; to identify areas routinely flooded during the monsoon season, the image of October 2009 (the most critical month for the effects of rain) was compared with two images acquired in January and February 2010. The analysis between 2000 and 2009 was able to quantify a very rapid growth of the metropolis, with an increase in built-up areas from 75 to 111 km2. The analysis highlights also a sharp rise of Bare soil class, likely related to the construction of embankments for the creation of new building space; consequently a decrease of cultivated land was observed. In particular, these artificial islands have been invading flooding areas. The change detection procedure also showed that the flooding in October 2009 affected about 20% (115 out of 591 km2) of the entire study area; furthermore these areas became wetlands and farmland over the next three/four months.

Urbanization and its environmental effects in Shanghai, China

This paper analyzes the processes and characteristics of urbanization in Shanghai, focusing on the population and land use and land cover (LULC) change, and its correlation with the evolution of climatic and ecological indicators based on the historical land use data, meteorological station data, social statistical data, normalized difference vegetation index (NDVI) and land surface temperature (LST) data. The possible association between urban heat island (UHI) and urbanization indicators are also discussed. Examination of the population variation indicates a continuously increase of registered population and a rapid increase of floating population that mainly comes from neighboring provinces in recent years. With rapid urban sprawl, a large amount of cultivated lands has been replaced with building lands around urban areas and towns of Shanghai. Urbanization is correlated with the increase of air temperature, hot days and the decrease of relative humidity, wind speed and vegetation NDVI in Shanghai. The growth of UHI in Shanghai has been driven by the continuous increase of buildings, paved roads, buses, population and GDP, as well as the decrease of cultivated land. Boosting the area of green land in urban areas has to a certain extent mitigated the UHI in Shanghai in recent years.

Remote sensing research issues of the National Land Use Change Program of China

In 1999, the Ministry of Land and Resources (MLR) of China launched the National Land Use Change Program especially to monitor the scale and distribution of urban expansion and the decrease in cultivated land through remote sensing technology. This Program has been carried out annually and continuously for seven years since then and played an important role in the policy-making of MLR about land management and planning. This paper gives an overview about this Program and discusses several research issues. First, the remote sensing data sources and other ancillary data used in this Program are presented. The approaches for image preprocessing, i.e. radiometric normalization, image geometric rectification and image fusion are then introduced with an emphasis on the algorithm development for image registration. Second, land use change detection technique is the most critical and complex aspect of the Program. The methodologies for change detection using either bi-temporal image pair or one existing land use map and one remotely sensed image are detailed. Third, since the data of land use changes derived from remote sensing will be operationally used for local and central government, field validation and accuracy assessment are crucial to ensure the reliability of change detection results. The strategy of field work and the resulting accuracy evaluations is presented. The land use and change information derived from remotely sensed data has wide applications for land management, including land use database updating, verification of land use planning and monitoring of national high-tech parks. Last, suggestions on how to make full use of the images and change detection result, to improve the consistency of land use classification and to develop change detection algorithms for diverse and complex remote sensing data are given.

Achieving a Nitrogen Balance for Japanese Domestic Livestock Waste: Testing the Scenario of Planting Feed Grain in Land Left Fallow

In this study, we assess the recent changes in the amount of excretion by the livestock industry, and discuss the effects of increasing the ratio of cultivated land on the reduction of surplus nitrogen from a cost-performance perspective. Nitrogen has contributed to acidification of ecosystems and nitrate concentrations in groundwater, especially in Europe. Therefore, we assessed the level of nitrogen waste from the domestic Japanese livestock industry, including cattle, swine and poultry during the period 1987-2001. This assessment assumed that 40% of the nitrogen from the domestic livestock industry was emitted as gas into the air and that 60% of the nitrogen was contained in manure used on domestic cultivated land. Nitrogen excreted from livestock, excluding gas emission, decreased by 11% from 0.504 million tons to 0.447 million tons during 1993-2001. Thus, the peak period of nitrogen excretion from livestock is already past in Japan. However, the area of cultivated land under management also decreased during 1990-2000. In addition, the area of paddy and upland fields left unplanted for a year increased during 1990-2000. Therefore, if all manure from the domestic livestock industry had been utilized on the fields as organic fertilizer, but not on arable land left uncultivated for the past year, the nitrogen per net area of cultivated land would have increased by 5%, from 125 to 131 N kg/ha, during 1990-2000. To reduce the nitrogen ratio on cultivated land through the planting of feed grain to utilize the nitrogen, a comparison of the cost performance of feed grains indicated that barley would be more suitable than wheat, rice or soybean. Had barley been planted in 100% of the land left fallow for the past year in 2000, 4% (20,000 tons) of the nitrogen from livestock waste would have been used in the harvest, and the nitrogen per land unit would have not increased but decreased from 125 to 121 N kg/ha during the same decade. Furthermore, when converted into Total Digestible Nutrients, 7% of imported feed corn could have been replaced with the harvested barley in 2000. Planting barley on this fallow land had three benefits; reducing the risk of manure overload on the land, slowing down the decrease in cultivated land, and raising the feed self-sufficiency ratio. Thus, it would be beneficial to plant feed grain such as barley in land left fallow for the past year through utilization of manure.

Measures of the EU Agri-Environmental Protection Scheme (GAEPS) and their impacts on the visual acceptability of Finnish agricultural landscapes

As a member of the European Union, Finland has committed itself to creating an environmental policy for agriculture. The aims of this study were to evaluate visual impacts of the General Agri-Environmental Protection Scheme (GAEPS) and Supplementary Protection Scheme (SPS) and general attitudes towards some activities in those policies and furthermore to examine the suitability of the method of Alho et al. (2001) for the scenic beauty assessment. The study areas consisted of three original, untreated, and 15 modified rural landscapes representing a variety of different activities. The scenic beauty of the landscapes was evaluated through pairwise comparisons of the responses of 68 people. Furthermore, attitudes towards environmental values, water protection, buffer strips and subsidies to agriculture were obtained. The respondents found the maintained buffer strips more pleasing than unmaintained strips and considered that the quality of watercourses was increased by buffer strips along them. A suitable width for the buffer strip along main ditches, brooks and waterways was regarded, on average, to be wider than the current recommendations. Although the opinions of farmers were basically in line with the existing recommendations, farmers' opininons on the second and third most important effects of buffer strips, an increase in weeds and a decrease in cultivated land, clearly differed from those of the other respondents. Afforestation, lack of building maintenance and abandoned fields were considered to be the most important factors impacting rural landscapes. This study indicates that the Finnish Agri-Environmental Protection Schemes have had positive impacts on the visual quality of landscapes. Attitudes towards other impacts are contradictory. This study also showed the improvement of the Alho et al. (2001) method in these kinds of studies relative to other methods of pairwise comparisons.

Measures of the EU Agri-Environmental Protection Scheme (GAEPS) and their impacts on the visual acceptability of Finnish agricultural landscapes

As a member of the European Union, Finland has committed itself to creating an environmental policy for agriculture. The aims of this study were to evaluate visual impacts of the General Agri-Environmental Protection Scheme (GAEPS) and Supplementary Protection Scheme (SPS) and general attitudes towards some activities in those policies and furthermore to examine the suitability of the method of Alho et al. (2001) for the scenic beauty assessment. The study areas consisted of three original, untreated, and 15 modified rural landscapes representing a variety of different activities. The scenic beauty of the landscapes was evaluated through pairwise comparisons of the responses of 68 people. Furthermore, attitudes towards environmental values, water protection, buffer strips and subsidies to agriculture were obtained. The respondents found the maintained buffer strips more pleasing than unmaintained strips and considered that the quality of watercourses was increased by buffer strips along them. A suitable width for the buffer strip along main ditches, brooks and waterways was regarded, on average, to be wider than the current recommendations. Although the opinions of farmers were basically in line with the existing recommendations, farmers' opininons on the second and third most important effects of buffer strips, an increase in weeds and a decrease in cultivated land, clearly differed from those of the other respondents. Afforestation, lack of building maintenance and abandoned fields were considered to be the most important factors impacting rural landscapes. This study indicates that the Finnish Agri-Environmental Protection Schemes have had positive impacts on the visual quality of landscapes. Attitudes towards other impacts are contradictory. This study also showed the improvement of the Alho et al. (2001) method in these kinds of studies relative to other methods of pairwise comparisons.

An investigation of changes in cultivated land in guangdong province of China using GIS

In order to make a thorough investigation about relationship between population increase and cultivated land decrease along with economic development over recent years in Guangdong province, this paper aims to study the relationship between the changes in cultivated land and the rapid economic development in Guangdong Province of China using GIS. The spatial database of administrative boundary in the province is captured and stored in GIS and then several county-based statistics produced by the National Statistical Bureau of China are linked to the spatial data. In the study, the correlation analysis between decrease of cultivated land in some metropolitan counties and population increase is conducted. Besides, similar analysis is carried out between decrease of cultivated land in the Zhujiang (Pearl) River Delta Region and gross industrial output. The result of the analysis is presented in GIS with the boundary data to show the spatial distribution and trend of the phenomenon. Some measures of conserving cultivated land in the province in order to achieve a sustainable development are also proposed.

Effect of land use changes on sediment transport in Goodwin Creek

The Goodwin Creek Research Watershed (21.3 km2) is located in the north central part of Mississippi in the bluff hills just east of the Mississippi River floodplain. Land use on the watershed has been surveyed annually and the percentage of cultivated land has decreased from 26% in 1982 to 12% in 1990. During this 9‐year period the concentration of fines (<0.062 mm) in Goodwin Creek have decreased by 62%, concentrations of sand (0.062–2.0 mm) have decreased by 66%, and concentrations of gravel (>2.0 mm) have decreased by 39%. The decrease in the percentage of cultivated land affects the sediment budget of the watershed in two ways. A source of readily eroded sediment is removed, and the energy of the flowing water available to erode and transport sediment is reduced. The reduced flow in the channels from the decrease in cultivated land in the watershed was probably the main cause for the lower transport rates of sand and gravel.