• Title/Summary/Keyword: Agricultural land use change

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Spatial and temporal dynamic of land-cover/land-use and carbon stocks in Eastern Cameroon: a case study of the teaching and research forest of the University of Dschang

  • Temgoua, Lucie Felicite;Solefack, Marie Caroline Momo;Voufo, Vianny Nguimdo;Belibi, Chretien Tagne;Tanougong, Armand
    • Forest Science and Technology
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    • v.14 no.4
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    • pp.181-191
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    • 2018
  • This study was carried out in the teaching and research forest of the University of Dschang in Belabo, with the aim of analysing land-cover and land-use changes as well as carbon stocks dynamic. The databases used are composed of three Landsat satellite images (5TM of 1984, 7ETM + of 2000 and 8OLI of 2016), enhanced by field missions. Satellite images were processed using ENVI and ArcGIS software. Interview, focus group discussion methods and participatory mapping were used to identify the activities carried out by the local population. An inventory design consisting of four transects was used to measure dendrometric parameters and to identify land-use types. An estimation of carbon stocks in aboveground and underground woody biomass was made using allometric models based on non-destructive method. Dynamic of land-cover showed that the average annual rate of deforestation is 0.48%. The main activities at the base of this change are agriculture, house built-up and logging. Seven types of land-use were identified; adult secondary forests (64.10%), young secondary forests (7.54%), wetlands (7.39%), fallows (3.63%), savannahs (9.59%), cocoa farms (4.28%) and mixed crop farms (3.47%). Adult secondary forests had the highest amount of carbon ($250.75\;t\;C\;ha^{-1}$). This value has decreased by more than 60% for mixed crop farms ($94.67\;t\;C\;ha^{-1}$), showing the impact of agricultural activities on both forest cover and carbon stocks. Agroforestry systems that allow conservation and introduction of woody species should be encouraged as part of a participatory management strategy of this forest.

A Spatio-temporal Change Analysis of Rural Landscape Patterns using Landscape Ecology Indices : Focused on a Part of Gyeonggi-do (경관생태지수를 활용한 농촌경관의 시계열적 변화 분석 - 경기도 일부 시.군을 대상으로 -)

  • Oh, Yun-Gyeong;Choi, Jin-Yong;Bae, Seung-Jong;Jang, Min-Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.6
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    • pp.65-76
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    • 2007
  • Studies in landscape ecology have emphasized on the relationship between landscape patterns and shapes. A variety of landscape metrics has been developed so far to quantify landscape structures. Therefore, their developments and widespread applications become possible with the advent of spatial information systems including geographic information systems(GIS) and remote sensing. This study is to grasp the change of land use and landscape ecology indices, and to analyze the change of landscape structure in a part of Gyeonggi-do during 15 years from 1985 to 2000. Green-area distribution maps and agricultural-area distribution maps for the analysis were reconstructed from land cover maps constructed by WAMIS(Water Management Information System). And then, 4 landscape ecology indices(TA, LPI, SHAPE_AM, CAI_MN) for the green-area and 5 landscape ecology indices(TA, PD, LPI, LSI, CAI_MN) for the agricultural-area were selected by using pearson correlation analysis. According to the spatio-temporal change analysis using landscape ecology indices, the green-area fragmentation of Yongin was the most severe of the study area and the agricultural-area fragmentation of Gwangju and Namyangju was more severe than any other regions.

Estimation of Carbon Absorption Distribution based on Satellite Image Considering Climate Change Scenarios (기후변화 시나리오를 고려한 위성영상 기반 미래 탄소흡수량 분포 추정)

  • Na, Sang-il;Ahn, Ho-yong;Ryu, Jae-Hyun;So, Kyu-ho;Lee, Kyung-do
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.833-845
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    • 2021
  • Quantification of carbon absorption and understanding the human induced land use changes forms one of the major study with respect to global climatic changes. An attempt study has been made to quantify the carbon absorption by land use changes through remote sensing technology. However, it focused on past carbon absorption changes. So prediction of future carbon absorption changes is insufficient. This study simulated land use change using the Conversion of Land Use and its Effects at Small regional extent (CLUE-S) model and predicted future changes in carbon absorption considering climate change scenarios 4.5 and 8.5 of the Representative Concentration Pathways (RCP). Results of this study, in the RCP 4.5 scenarios there predicted to be loss of 7.92% of carbon absorption, but in the RCP 8.5 scenarios was 13.02%. Therefore, the approach used in this study is expected to enable exploration of future carbon absorption change considering other climate change scenarios.

Duration-Related Variations in Archaeal Communities after a Change from Upland Fields to Paddy Fields

  • Jiang, Nan;Wei, Kai;Chen, Lijun;Chen, Rui
    • Journal of Microbiology and Biotechnology
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    • v.26 no.5
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    • pp.867-875
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    • 2016
  • Archaea substantially contribute to global geochemical cycling and energy cycling and are impacted by land-use change. However, the response of archaeal communities to a change from upland field to paddy field has been poorly characterized. Here, soil samples were collected at two depths (0-20 cm and 20-40 cm) from one upland field and six paddy fields that were established on former upland fields at different times (1, 5, 10, 20, 30, and 40 years before the study). Barcoded pyrosequencing was employed to assess the archaeal communities from the samples at taxonomic resolutions from phylum to genus levels. The total archaeal operational taxonomic unit (OTU) richness showed a significant positive correlation with the land-use change duration. Two phyla, Euryarchaeota and Crenarchaeota, were recorded throughout the study. Both the relative abundance and OTU richness of Euryarchaeota increased at both depths but increased more steadily at the subsurface rather than at the surface. However, these data of Crenarchaeota were the opposite. Additionally, the archaeal composition exhibited a significant relationship with C/N ratios, total phosphorus, soil pH, Olsen phosphorus, and the land-use change duration at several taxonomic resolutions. Our results emphasize that after a change from upland fields to paddy fields, the archaeal diversity and composition changed, and the duration is an important factor in addition to the soil chemical properties.

A Study on the Analysis of Landscape Preference in the Rural Settlement by Land Use Transition (토지이용변화를 이용한 농촌경관 선호성 분석에 관한 연구)

  • 서주환;최현상
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.2
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    • pp.69-79
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    • 1999
  • This study identifies the features of landscape elements on the fifteen districts with the idea of land use area and visual quantity of pictures by analyzing the air photo. Therefore, the sensibility of observer is comprehended through simulating the landscape evaluation and the landscape preference with using slide film. The study is divided into three periods to understand the transition of rural landscape as the social and cultural environments have been changed. The first period is the New Community Movement which affected the rapid change of social and cultural environments. The second and third periods are the prior and post time at the rearrangement of administration district in the Tae-Jeon Broad City. The result of this study is explained below part; 1. The transition of rural landscape has been occurred as the land use pattern has been altered. The change of pattern has affected an increase of the natural space and the structure change of agricultural productive space. 2. In the regression analysis, the regression model of landscape preference and land use ratio show; Landscape preference = 3.632 - 11.618 (Residential Area) - 4.227 (Equipped Farm). The explanation variables defined as Residential Area and Equipped Farm, and the relationship of those factors shows negative. Therefore, the increase of other building will make the rural landscape lower and worse.

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Analyzing the Future Land Use Change and its Effects for the Region of Yangpyeong-gun and Yeoju-gun in Korea with the Dyna-CLUE Model (Dyna-CLUE 모델을 이용한 양평·여주 지역의 토지이용 변화 예측 및 평가)

  • Lee, DongKun;Ryu, DaeHo;Kim, HoGul;Lee, SangHouck
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.6
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    • pp.119-130
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    • 2011
  • Land-use changes have made considerable impacts on humans and nature such as biodiversity and ecosystem services. It is recognized as important elements for land use planning and regional natural resources conservation to identify the major causes of land use changes and to predict a process of changes and effects. This study, by using a spatially explicit Dyna-CLUE model, analyzed correlations between driving factors, quantified location characteristics of different land use types using logistic regression analysis and examined future land use changes and its effects in Yangpyeong and Yeoju region. We expected land use changes based on the three scenarios with different future land demands and simulated future changes for spatial variations of land use for the 20 years. The outcomes shows that larger change was found in agricultural areas than forest areas, based on the change in built-up areas. The changes in forest areas, which were mainly occurred in edge area, were expected to affect a large impact on its ecotone. It was found to be the importance of the management of forest edge and the necessity of the environmentally sound and sustainable development in order to conserve natural resources of the region.

Analysis of River Channel Morphology and Riparian Land Use Changes Using Aerial Photographs and GIS (항공사진과 GIS를 이용한 하천형태 및 하천부지 변화추세 분석)

  • Park, Geun-Ae;Lee, Mi-Seon;Kim, Hyeon-Jun;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.2
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    • pp.15-21
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    • 2005
  • This study is to trace the change of stream shape using the past series of aerial photographs, and to compare the land use changes of riparian area along the stream. For the Gyeongan national stream, aerial photographs of 1966, 1981 and 2000 were selected and ortho-photographs were made with interior orientation and exterior orientation, respectively. Apparent changes of the stream were found that the consolidated reaches of stream by levee construction became straight together with widening of their stream widths. Especially the stream width of inlet part of Paldang lake widened almost twice because of the rise of water level by dam construction in 1974. The land use of riparian areas of three selected years were classified into six categories (water, forest, agricultural land, urban area, road, sandbar) by digitizing method. The forest and agricultural lands decreased and urban area increased as the stream maintenance had been performed.

Farmland Use Mapping Using High Resolution Images and Land Use Change Analysis (고해상도 영상을 이용한 농경지 지도 작성 및 토지이용 변화 분석)

  • Lee, Kyungdo;Hong, Sukyoung;Kim, Yihyun
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.6
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    • pp.1164-1172
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    • 2012
  • This study aims to make a "farmland use map" using high-resolution images and to analyze the land use change for about 8 years in Goyang, Namyangju, and Yongin cities. We have made a new numerical map named as a farmland use map using high-resolution images taken mostly in 2007 and digital topographical maps in Goyang, Namyangju, and Yongin cities near metropolitan areas to classify farmland use of paddy, upland, plastic film house, and orchard. We also made a land use map by overlaying the farmland use map and the land registration map of each city made in 2007, and compared the land use map made by RDA (Rural Development Administration) in 1999. Paddy areas decreased at a range of 3,000 to 5,000 ha during 8 years and were changed to residential areas in the cities. Upland and orchard areas also showed similar tendency and were changed to residential areas as well. On the other hand, the areas of the plastic film houses in the cities showed an increase or same in size. It is suggested that farmland use map can be broadly used as a base map for various survey projects including soil survey, statistics, and farmland information management.

Landuse and Landcover Change and the Impacts on Soil Carbon Storage on the Bagmati Basin of Nepal

  • Bastola, Shiksha;Lim, Kyuong Jae;Yang, Jae Eui;Shin, Yongchul;Jung, Younghun
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.12
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    • pp.33-39
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    • 2019
  • The upsurge of population, internal migration, economic activities and developmental works has brought significant land use and land cover (LULC) change over the period of 1990 and 2010 in the Bagmati basin of Nepal. Along with alteration on various other ecosystem services like water yield, water quality, soil loss etc. carbon sequestration is also altered. This study thus primary deals with evaluation of LULC change and its impact on the soil carbon storage for the period 1990 to 2010. For the evaluation, InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) Carbon model is used. Residential and several other infrastructural development activities were prevalent on the study period and as a result in 2010 major soil carbon reserve like forest area is decreased by 7.17% of its original coverage in 1990. This decrement has brought about a subsequent decrement of 1.39 million tons of carbon in the basin. Conversion from barren land, water bodies and built up areas to higher carbon reserve like forest and agriculture land has slightly increased soil carbon storage but still, net reduction is higher. Thus, the spatial output of the model in the form of maps is expected to help in decision making for future land use planning and for restoration policies.

The Land Use Change and the Desertification in the East Inner Mongolia, China - A Case Study on Horqin Desert - (중국 내몽고 동부지역의 토지이용 변화와 사막화 -커얼친 사지의 사례 -)

  • Lee Kang-Won
    • Journal of the Korean Geographical Society
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    • v.40 no.6 s.111
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    • pp.694-715
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    • 2005
  • I examine in this paper the change of land use and the development of desertification in Horqin desert, east Inner Mongolia, China. The change of land use in this area can be summarized as the increase of agricultural field and intensive livestock farming. The agriculture and livestock farming in semi-arid area such as Horqin desert raised the problem in the management and use of water and vegetation. This problem led to desertification. The types of development of desertification in this area could be classified as follows: the mobile sand dune extension, the riverside shifting sand flat extension, the shifting sand speck extension around settlements, and the shifting sand speck extension in agricultural Held and grassland. There have been political or social movements such as the Great Leap Forward, the Cultural Revolution and the Reform and Open Policy in the background of land use change and desertification. Specially, the Great Leap Forward and the Cultural Revolution played an important role in the land use change and desertification in this area. Since 1990s, there has been some kind of policy in the control of desertification. However, it is necessary for the controling desertification of this area to consider the globalization and marketization, the survival and profit of peasants and livestock farmers, and the disturbrd and fixed population and land use structure in this area since 1949.