Investigating the effect of land use changes on soil erosion using RS-GIS and AHP-Fuzzy based techniques (Case Study: Qaresu Watershed, Ardabil, Iran)

2020 ◽  
Vol 33 (02) ◽  
pp. 525-538
Author(s):  
Fereshteh Namdar ◽  
Shahla Mahmoudi ◽  
Abazar Esmali Ouri ◽  
Ebrahim Pazira

The intensity of soil erosion to occur in a region depends on multiple factors including climatic conditions, elevation, terrain, soil type, and land use. Among these factors, land use is one of the particular importance as it reflects the outsized role of humans in the exacerbation of erosion condition. This study aimed to investigate the effects of land use changes on soil erosion in Qaresu watershed, using Remote Sensing (RS) and Geographical Information System (GIS) techniques, a watershed with an area of ​​4370.8 km2 located in the center of Ardabil province, northwest of Iran. For this purpose, the 1985 and 2015 Landsat images captured by TM and OLI-TIRS sensors were used to develop the land use maps of the watershed area using the maximum likelihood method. The erosion zoning maps were then developed by integrating the maps of land use, slope, lithology, distance from roads, distance from streams, precipitation, and soil using the Weighted Linear Combination (WLC) method after an AHP-based weighting stage. The results showed that in the 30-year period from 1985 to 2015, the region has experienced a decrease in the area of forest, dry farming, and rangeland land uses and an increase in the area of land uses defined as urban, barren, irrigated farming, and water cover. In total, dry farming and rangeland were the largest land-uses in the studied area. According to the developed erosion zoning maps, in 1985, 14.4% and 36.84%, and in 2015, 15.64% and 32.3% of the studied area belonged to high and very high risk zones in terms of erosion potential, respectively. In defined two periods, high risk and very high risk zones were mostly positioned over dry and irrigated farmlands.

2012 ◽  
Vol 7 (No. 1) ◽  
pp. 10-17 ◽  
Author(s):  
S. Wijitkosum

Soil erosion has been considered as the primary cause of soil degradation since soil erosion leads to the loss of topsoil and soil organic matters which are essential for the growing of plants. Land use, which relates to land cover, is one of the influential factors that affect soil erosion. In this study, impacts of land use changes on soil erosion in Pa Deng sub-district, adjacent area of Kaeng Krachan National Park, Thailand, were investigated by applying remote sensing technique, geographical information system (GIS) and the Universal Soil Loss Equation (USLE). The study results revealed that land use changes in terms of area size and pattern influenced the soil erosion risk in Pa Deng in the 1990–2010 period. The area with smaller land cover obviously showed the high risk of soil erosion than the larger land cover did.


2018 ◽  
Vol 40 (3) ◽  
pp. 1476
Author(s):  
T. Mimides ◽  
E. Psomiadis ◽  
I. Trikili

The present paper focuses on the usefulness of aerial photographs and satellite data in the multitemporal detection of land use changes, soil degradation and erosion. The study was carried out in the watershed of Vathy in the Kalymnos Island, and the study period spanned from 1960 to 1999. Aerial photographs of two different periods of time and satellite SPOT data were used for this purpose. The synergistic use of a Geographical Information System for the manipulation of the data was the key for the Natural monitoring of the soil erosion and degradation. The results revealed many changes in the cultivations and in the land use of the watershed the last decades. These changes supplemented by village expansion and spatial reduction of natural vegetation led to the acceleration of soil erosion, to the degradation of water supplies and generally to an environmental deterioration of the wider area.


2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Matheus Supriyanto Rumetna ◽  
Eko Sediyono ◽  
Kristoko Dwi Hartomo

Abstract. Bantul Regency is a part of Yogyakarta Special Province Province which experienced land use changes. This research aims to assess the changes of shape and level of land use, to analyze the pattern of land use changes, and to find the appropriateness of RTRW land use in Bantul District in 2011-2015. Analytical methods are employed including Geoprocessing techniques and analysis of patterns of distribution of land use changes with Spatial Autocorrelation (Global Moran's I). The results of this study of land use in 2011, there are thirty one classifications, while in 2015 there are thirty four classifications. The pattern of distribution of land use change shows that land use change in 2011-2015 has a Complete Spatial Randomness pattern. Land use suitability with the direction of area function at RTRW is 24030,406 Ha (46,995406%) and incompatibility of 27103,115 Ha or equal to 53,004593% of the total area of Bantul Regency.Keywords: Geographical Information System, Land Use, Geoprocessing, Global Moran's I, Bantul Regency. Abstrak. Analisis Perubahan Tata Guna Lahan di Kabupaten Bantul Menggunakan Metode Global Moran’s I. Kabupaten Bantul merupakan bagian dari Provinsi Daerah Istimewa Yogyakarta yang mengalami perubahan tata guna lahan. Penelitian ini bertujuan untuk mengkaji perubahan bentuk dan luas penggunaan lahan, menganalisis pola sebaran perubahan tata guna lahan, serta kesesuaian tata guna lahan terhadap RTRW yang terjadi di Kabupaten Bantul pada tahun 2011-2015. Metode analisis yang digunakan antara lain teknik Geoprocessing serta analisis pola sebaran perubahan tata guna lahan dengan Spatial Autocorrelation (Global Moran’s I). Hasil dari penelitian ini adalah penggunaan tanah pada tahun 2011, terdapat tiga puluh satu klasifikasi, sedangkan pada tahun 2015 terdapat tiga puluh empat klasifikasi. Pola sebaran perubahan tata guna lahan menunjukkan bahwa perubahan tata guna lahan tahun 2011-2015 memiliki pola Complete Spatial Randomness. Kesesuaian tata guna lahan dengan arahan fungsi kawasan pada RTRW adalah seluas 24030,406 Ha atau mencapai 46,995406 % dan ketidaksesuaian seluas 27103,115 Ha atau sebesar 53,004593 % dari total luas wilayah Kabupaten Bantul. Kata Kunci: Sistem Informasi Georafis, tata guna lahan, Geoprocessing, Global Moran’s I, Kabupaten Bantul.


Land ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 627
Author(s):  
Duong H. Nong ◽  
An T. Ngo ◽  
Hoa P. T. Nguyen ◽  
Thuy T. Nguyen ◽  
Lan T. Nguyen ◽  
...  

We analyzed the agricultural land-use changes in the coastal areas of Tien Hai district, Thai Binh province, in 2005, 2010, 2015, and 2020, using Landsat 5 and Landsat 8 data. We used the object-oriented classification method with the maximum likelihood algorithm to classify six types of land uses. The series of land-use maps we produced had an overall accuracy of more than 80%. We then conducted a spatial analysis of the 5-year land-use change using ArcGIS software. In addition, we surveyed 150 farm households using a structured questionnaire regarding the impacts of climate change on agricultural productivity and land uses, as well as farmers’ adaptation and responses. The results showed that from 2005 to 2020, cropland decreased, while aquaculture land and forest land increased. We observed that the most remarkable decreases were in the area of rice (485.58 ha), the area of perennial crops (109.7 ha), and the area of non-agricultural land (747.35 ha). The area of land used for aquaculture and forest increased by 566.88 ha and 772.60 ha, respectively. We found that the manifestations of climate change, such as extreme weather events, saltwater intrusion, drought, and floods, have had a profound impact on agricultural production and land uses in the district, especially for annual crops and aquaculture. The results provide useful information for state authorities to design land-management strategies and solutions that are economic and effective in adapting to climate change.


2021 ◽  
Vol 13 (10) ◽  
pp. 5433
Author(s):  
Rui Alexandre Castanho ◽  
José Manuel Naranjo Gómez ◽  
Gualter Couto ◽  
Pedro Pimentel ◽  
Áurea Sousa ◽  
...  

The remarkable richness and singularity of the Azorean Region (located 38° North) and its landscapes require a sharp, well-defined, and comprehensive planning policy. Bearing in mind the significance of this issue in the enlightenment of sustainability, planning strategies should be based and supported by different studies and thematic domains to understand the problem thoroughly. Using GIS (Geographic Information Systems), the present article enables us to identify the dynamics and patterns of the evolution of the Land-Use Changes in the Azores Region from 1990 to 2018. In aggregate, the Azores islands showed growth in artificial surfaces and forest and seminatural land-uses by essentially decreasing agricultural areas—most resulting from the economic and social development strategy pursued by several Azorean governments. Moreover, this study permits us to reinforce that the Azores Archipelago’s land-uses has undergone multiple changes—marked by increasing and decreasing periods. In fact, some of these reducing dynamics are disturbing. They require closer monitorization by regional government actors to give protection, preservation, and conservation to these incomparable ultra-peripheral landscapes, environments, ecosystems, and the region as a whole.


Author(s):  
Hui Wei ◽  
Wenwu Zhao ◽  
Han Wang

Large-scale vegetation restoration greatly changed the soil erosion environment in the Loess Plateau since the implementation of the “Grain for Green Project” (GGP) in 1999. Evaluating the effects of vegetation restoration on soil erosion is significant to local soil and water conservation and vegetation construction. Taking the Ansai Watershed as the case area, this study calculated the soil erosion modulus from 2000 to 2015 under the initial and current scenarios of vegetation restoration, using the Chinese Soil Loess Equation (CSLE), based on rainfall and soil data, remote sensing images and socio-economic data. The effect of vegetation restoration on soil erosion was evaluated by comparing the average annual soil erosion modulus under two scenarios among 16 years. The results showed: (1) vegetation restoration significantly changed the local land use, characterized by the conversion of farmland to grassland, arboreal land, and shrub land. From 2000 to 2015, the area of arboreal land, shrub land, and grassland increased from 19.46 km2, 19.43 km2, and 719.49 km2 to 99.26 km2, 75.97 km2, and 1084.24 km2; while the farmland area decreased from 547.90 km2 to 34.35 km2; (2) the average annual soil erosion modulus from 2000 to 2015 under the initial and current scenarios of vegetation restoration was 114.44 t/(hm²·a) and 78.42 t/(hm²·a), respectively, with an average annual reduction of 4.81 × 106 t of soil erosion amount thanks to the vegetation restoration; (3) the dominant soil erosion intensity changed from “severe and light erosion” to “moderate and light erosion”, vegetation restoration greatly improved the soil erosion environment in the study area; (4) areas with increased erosion and decreased erosion were alternately distributed, accounting for 48% and 52% of the total land area, and mainly distributed in the northwest and southeast of the watershed, respectively. Irrational land use changes in local areas (such as the conversion of farmland and grassland into construction land, etc.) and the ineffective implementation of vegetation restoration are the main reasons leading to the existence of areas with increased erosion.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shamsollah Ayoubi ◽  
Nafiseh Sadeghi ◽  
Farideh Abbaszadeh Afshar ◽  
Mohammad Reza Abdi ◽  
Mojtaba Zeraatpisheh ◽  
...  

Abstract Background As one of the main components of land-use change, deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences. Specifically, one example could be the impacts of land-use changes from oak forests into agricultural ecosystems, which may have detrimental impacts on soil mobilization across hillslopes. However, to date, scarce studies are assessing these impacts at different slope positions and soil depths, shedding light on key geomorphological processes. Methods In this research, the Caesium-137 (137Cs) technique was applied to evaluate soil redistribution and soil erosion rates due to the effects of these above-mentioned land-use changes. To achieve this goal, we select a representative area in the Lordegan district, central Iran. 137Cs depth distribution profiles were established in four different hillslope positions after converting natural oak forests to rainfed farming. In each hillslope, soil samples from three depths (0–10, 10–20, and 20–50 cm) and in four different slope positions (summit, shoulder, backslope, and footslope) were taken in three transects of about 20 m away from each other. The activity of 137Cs was determined in all the soil samples (72 soil samples) by a gamma spectrometer. In addition, some physicochemical properties and the magnetic susceptibility (MS) of soil samples were measured. Results Erosion rates reached 51.1 t·ha− 1·yr− 1 in rainfed farming, whereas in the natural forest, the erosion rate was 9.3 t·ha− 1·yr− 1. Magnetic susceptibility was considerably lower in the cultivated land (χhf = 43.5 × 10− 8 m3·kg− 1) than in the natural forest (χhf = 55.1 × 10− 8 m3·kg− 1). The lower soil erosion rate in the natural forest land indicated significantly higher MS in all landform positions except at the summit one, compared to that in the rainfed farming land. The shoulder and summit positions were the most erodible hillslope positions in the natural forest and rainfed farming, respectively. Conclusions We concluded that land-use change and hillslope positions played a key role in eroding the surface soils in this area. Moreover, land management can influence soil erosion intensity and may both mitigate and amplify soil loss.


Land ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 57
Author(s):  
Fernando Allende Álvarez ◽  
Gillian Gómez-Mediavilla ◽  
Nieves López-Estébanez ◽  
Pedro Molina Holgado ◽  
Judith Ares Barajas

The present paper highlights the importance of hedgerows and enclosures in the mountains of Central Spain. Now, these landscapes have suffered profound variations in terms of agroforestry practices, especially in the Mediterranean mountains where the characteristic multifunctional has largely been lost. The article analyzes land uses changes, dynamics, and their morphological features between the first half of the 20th Century (1956) and the second decade of the present time (2019). The paper was divided into three sections. First, the identification of land uses using orthophotograph and aerial photograph; after that the info was checked with fieldwork. Eleven categories were identified according to the dominant use and land use changes and size of land parcels were taken into consideration. Second, the configuration and the information collected through the type and intensity of change in land uses made it possible to recognise and quantify their distribution and trend between these two dates. Also, the kernel density algorithm available in the Arcgis 10.5 software was used to obtain density and changes in land parcels. Finally, an overview is given of the main role that this agroforestry plays due to the social, ecological, and economic benefits that they provide for allowing sustainable development.


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