Environment Assessment
Fatemeh Mohammadyari; Mohsen Tavakoli
Abstract
Introduction: Cultural ecosystem services, as one of the components of ecosystem services, are intangible human benefits from ecosystems that play a fundamental role in promoting human well-being. Rapid changes in land use with damage to ecological assets in the Ilam urban watershed have reduced the ...
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Introduction: Cultural ecosystem services, as one of the components of ecosystem services, are intangible human benefits from ecosystems that play a fundamental role in promoting human well-being. Rapid changes in land use with damage to ecological assets in the Ilam urban watershed have reduced the capacity of ecosystem services, including aesthetic quality. Therefore, the evaluation of the supply of aesthetic ecosystem service, which shows the biological diversity in urban areas and favorable conditions for life, is considered essential for inclusion in the improvement plans of Ilam city in line with appropriate management measures. In this vein, in the current research, an integrated approach to prepare an aesthetic map with the aim of showing the spatial distribution of the supply of aesthetic services in the Ilam urban watershed has been presented, the results of which can greatly influence planning and managerial decisions regarding future development towards urban sustainability by preserving natural ecosystems.Materials and Methods: Spatial distribution of providing aesthetic ecosystem services in Ilam urban watershed using 12 visual and ecological criteria including: slope, Elevation, geomorphology, land use, habitat characteristics, visibility of various areas, visibility of roads, visibility of residential areas, visibility of the river, visibility of the park, type and density of vegetation were investigated. To prepare visibility layers, Viewshed function was used in TerrSet Idrisi software. Then, the input layers were integrated using fuzzy membership functions and using the weighted linear combination method in the ArcGIS 10.8 system. Among the multi-criteria decision-making methods, Analytic Hierarchy Process (AHP) method was used to prioritize the criteria.Results: Based on the results of the hierarchical analysis process and according to the results of the experts Among the input criteria, visibility of the river, type of vegetation and visibility of diverse areas were assigned the most weight with values of 0.14, 0.127 and 0.116 respectively. On the other hand, the least importance and weight was observed in the measure of road visibility. Based on the final map of aesthetic quality, the best quality of this service is in the parts of the north, east, southeast and west of the Ilam urban watershed, where these places have the best visibility of the river, visibility of various areas, high to medium altitude and with dominant forest cover.Discussion: The results of this study showed, that areas with forest cover and areas with human uses have the highest and lowest capacity of this service in the study area, respectively, which denotes the importance of natural green uses compared to artificial uses and human-made is in providing aesthetic service. These results indicate that the capacity of the watershed ecosystem of Ilam city in providing aesthetic services varies in different places and is influenced by various factors, especially topographic changes and land use patterns. That is to say, prevent land use change is an important factor for maintaining ecosystem services. Because the land use Changes pattern affects the capacity of the ecosystem to produce goods and services. The results of this research also, by presenting the spatial distribution model of aesthetic service potential can be useful for decision makers, managers and urban planners in order to monitor and protect aesthetic values and it is important and useful to adopt urban landscape management strategies and plans in the landscape of the studied area.
Environmental Economics
Ardavan Zarandian; Fatemeh Mohammadyari; Roya Mousazadeh; Majid Ramezani Mehrian; Jalil Badamfirooz
Abstract
Introduction: Soil resources play an important role in providing the necessary material goods for humans and other organisms and also deliver multiple ecosystem services that are essential for life on earth. They have also served for a long time as an important green infrastructure in protecting agricultural ...
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Introduction: Soil resources play an important role in providing the necessary material goods for humans and other organisms and also deliver multiple ecosystem services that are essential for life on earth. They have also served for a long time as an important green infrastructure in protecting agricultural and forest landscapes by providing plants a foothold for their roots and holding the necessary nutrients for their growth. In addition, soils can provide various ecosystem services such as contaminant immobilization, rainwater control, carbon sequestration, and habitat provision that are directly beneficial for humans. Services provided by ecosystems for humans are called ecosystem services. Soil retention, which refers to the potential of ecosystems for controlling soil erosion and conserving soil, is classified in the class of regulating services. Materials and Methods: The InVEST Sediment Delivery Ratio (SDR) model was used in InVEST Software to quantify soil retention and erosion. The required inputs for implementing this model include land use maps, K-factor (soil erodibility), R-factor (rain erosivity), C-factor (land use and land cover or LU/LC), P-factor (support practices), DEM (digital elevation model), and the biophysical table. Results: Based on the results, the potential of soil loss and sediment transport in the study area ranged from zero to 248.18 t/pixel and from zero to 57.25 tons per pixel, respectively. Soil retention is also estimated in a range from zero to 124.85 tons per pixel in the studied area. The largest amount of soil loss happened in sub-basin number 14 with 13716400 t/year and the smallest in sub-basin number 4 with 416594 t/year. Most of the ecosystem service of soil retention belonged to sub-basin number 13 with 4304414 t/ha/ year and the least to sub-basin number 4 with 5645 tons/ha/year. Discussion: The dense forests in the northernmost part of Semnan Province provide the most part of the ecosystem service of soil retention with more than 36 t/ha and the desert areas, the salt lake, and the salt marsh the least. Based on this, the province's forests, including dense, semi-dense, sparse and thin forests, contribute to the maintenance of soil in the province by a total of 4269166 tons per year. Also, good pastures maintain more than 18 tons per hectare of the province's soil every year, and the total function of soil maintenance by all types of pastures in the province, including good, medium and poor pastures, is 9395160 tons per year. Since the area covered by the pastures is 18 times more than that by the forests, we can say that most of the ecosystem service of soil retention is provided by the pastures due to the geographical distribution of this service in the province, despite the fact that forests are more capable in soil conservation than pastures. The orchards and rainfed agricultural land rank third and fourth, respectively, in soil retention with 7.86 and 2.15 tons of soil/ha, respectively. However, man-made land uses such as urban areas decrease this ecosystem service because they are usually accompanied by removing or reducing the vegetation. The urban areas are located in the northern part of the study area, and they have negative impacts on this ecosystem service. Therefore, protection of the forest and rangeland covers in the province is vitally important for the continued conservation of the ecosystem service of soil retention.