scholarly journals Exploring Forest Change Spatial Patterns in Papua New Guinea: A Pilot Study in the Bumbu River Basin

Land ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 282 ◽  
Author(s):  
Willie Doaemo ◽  
Midhun Mohan ◽  
Esmaeel Adrah ◽  
Shruthi Srinivasan ◽  
Ana Paula Dalla Corte

Papua New Guinea is a country in Oceania that hosts unique rain forests and forest ecosystems which are crucial for sequestering atmospheric carbon, conserving biodiversity, supporting the livelihood of indigenous people, and underpinning the timber market of the country. As a result of urban sprawl, agricultural expansion, and illegal logging, there has been a tremendous increase in land-use land cover (LULC) change happening in the country in the past few decades and this has triggered massive deforestation and forest degradation. However, only a few studies have ventured into quantifying the long-term trends and their associated spatial patterns—and have often presented contrasting responses. Herein, we intended to assess the extent of deforestation and the rate of urbanization that happened in the past 33 years (1987–2020) in the Bumbu river basin in Papua New Guinea using satellite imagery—for the years 1987, 2002, 2010, and 2020—and Geographic Information System (GIS) tools. On performing image classification, land use maps were developed and later compared with Google Earth’s high-resolution satellite images for accuracy assessment purposes. For probing into the spatial aspects of the land-use change issues, the study area was divided into four urban zones and four forest zones according to the four main cardinal directions centered in the urban and forest area centers of the 1987 image; subsequently, the rate of urban area expansion in each urban zone was separately calculated. From our preliminary analysis and literature survey, we observed several hurdles regarding the classification of regenerative forests and mixed pixels and gaps in LULC studies that have happened in Papua New Guinea to date. Through this communication paper, we aim to disseminate our preliminary results, which highlight a rapid increase in urban extent from 14.39 km2 in 1987 to 23.06 km2 in 2020 accompanied by a considerable decrease in forest extent from 76.29 km2 in 1987 to 59.43 km2 in 2020; this observation favors the presumption that urban and agricultural land expansion is happening at the cost of forest cover. Moreover, strategies for addressing technical issues and for integrating land-use change with various socioeconomic and environmental variables are presented soliciting feedback.

2020 ◽  
Vol 12 (9) ◽  
pp. 3510 ◽  
Author(s):  
Dechao Chen ◽  
Acef Elhadj ◽  
Hualian Xu ◽  
Xinliang Xu ◽  
Zhi Qiao

Many catchments in northern Algeria, including the coastal Mitidja Basin in the north central part of the country have been negatively affected by the deterioration of water quality in recent years. This study aims to discover the relationship between land use change and its impact on water quality in the coastal Mitidja river basin. Based on the data of land use and water quality in 2000, 2010 and 2017, the relationship between land use change and surface water quality index in the Mitidja Watershed was discussed through GIS and statistical analysis. The results show that the physical and chemical properties of the Mitidja river basin have obvious spatial heterogeneity. The water quality of upstream was better than that of downstream. There was a significant spatial relationship between the eight water quality indicators and three land use types, including urban residential land, agricultural land and vegetation. In most cases, settlements and agricultural land are the dominant factors leading to river pollution, and higher vegetation coverage helps to improve water quality. The regression model revealed that percentage of urban settlement area was a predictor for NH4-N, BOD5, COD, SS, PO4-P, DO and pH, while vegetation was a predictor for NO3-N. The analysis also showed that during this period, urban settlement areas increased sharply, which has a significant impact on water quality variables. Agricultural land only had a significant positive correlation with PO4-P. The results provide an effective way to evaluate river water quality, control water pollution and land use management by landscape pattern.


2014 ◽  
Vol 42 (1) ◽  
pp. 12-19 ◽  
Author(s):  
CHRISTOPHER M. HAMILTON ◽  
WAYNE E. THOGMARTIN ◽  
VOLKER C. RADELOFF ◽  
ANDREW J. PLANTINGA ◽  
PATRICIA J. HEGLUND ◽  
...  

SUMMARYLand-use change around protected areas limits their ability to conserve biodiversity by altering ecological processes such as natural hydrologic and disturbance regimes, facilitating species invasions, and interfering with dispersal of organisms. This paper informs USA National Wildlife Refuge System conservation planning by predicting future land-use change on lands within 25 km distance of 461 refuges in the USA using an econometric model. The model contained two differing policy scenarios, namely a ‘business-as-usual’ scenario and a ‘pro-agriculture’ scenario. Regardless of scenario, by 2051, forest cover and urban land use were predicted to increase around refuges, while the extent of range and pasture was predicted to decrease; cropland use decreased under the business-as-usual scenario, but increased under the pro-agriculture scenario. Increasing agricultural land value under the pro-agriculture scenario slowed an expected increase in forest around refuges, and doubled the rate of range and pasture loss. Intensity of land-use change on lands surrounding refuges differed by regions. Regional differences among scenarios revealed that an understanding of regional and local land-use dynamics and management options was an essential requirement to effectively manage these conserved lands. Such knowledge is particularly important given the predicted need to adapt to a changing global climate.


GeoJournal ◽  
2018 ◽  
Vol 84 (3) ◽  
pp. 555-570 ◽  
Author(s):  
Murilo Rodrigues de Arruda ◽  
Maja Slingerland ◽  
José Zilton Lopes Santos ◽  
Ken E. Giller

Author(s):  
M. Yu ◽  
Q. Li ◽  
G. Lu ◽  
H. Wang ◽  
P. Li

Abstract. To investigate the agricultural land-use change on flood regime, the upper Huaihe River basin above the Dapoling station was selected as the case study site. Based on topography, land-use, hydrological and meteorological data in 1990s and 2010s, the improved distributed Xinanjiang model, with potential evapotranspiration being computed by coupling a dual-source evapotranspiration model with a simplified plant growth model, was adopted to simulate the daily and hourly rainfall-runoff processes over 1990s and 2010s, and then the effects of land-use change on flood volume, flood peak, occurring time of flood peak, the percentage of surface runoff component were investigated respectively. The results was interesting and indicated that impacts of land-use change on flood characteristics varied significantly with land-use types. The outputs could provide valuable references for flood risk management and water resources management in the Huaihe River basin.


2001 ◽  
Vol 42 (2‐3) ◽  
pp. 209-218 ◽  
Author(s):  
J.R. McAlpine ◽  
D.F. Freyne

Author(s):  
Anatoly Pogorelov ◽  
Dmitry Lipilin ◽  
Evgeny Kiselev

In the Krasnodar territory, agricultural land occupies 62 % of the territory; of which 79 % is arable land. Most of the agricultural land is located on the Azov-Kuban Plain in the northern part of the region in the steppe river basins. The basin of the Beysug river with an area of about 6,000 km2, in terms of its geographical characteristics, should be attributed to representative basins from the standpoint of the modern dynamics of agricultural landscapes and transformations of the river network. The article analyzes the changes in the steppe agricultural landscapes in the Beysug river basin for the period 1999–2020 in terms of changes in the structure of land use and hydrographic characteristics, based on the data of satellite images. The transformation of agrolandscapes is accompanied by redevelopment of the territory, massive construction of dams on rivers, violation of the conditions of natural drainage, which leads to the restructuring of water exchange processes in river basins. Changes in water exchange processes under semi-arid conditions can be sensitive to local landscapes and agriculture. Until now, insufficient attention has been paid to the hydrological aspects of the transformation of steppe landscapes. According to the DEM ASTER GDEM, 15 river basins were identified with the subsequent determination of land use types on the surface of the basins. In each of the basins, a land use structure has been established, which directly affects the hydrographic indicators, and a decrease in the length of watercourses and the density of the river network has been revealed. Over the past 20 years, in the studied basins, the total length of watercourses due to plowing and redevelopment of the surface has decreased by 8–37 %, and in general in the Beysug river basin—by 469 km.


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