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Ecological impacts assessment of land use change on the natural structure of the Gharesoo Watershed
2018
Mehri, Azade | Salmanmahiny, Abdolrasoul | Mikaeili Tabrizi, Alireza | Mirkarimi, Seyed Hamed | Sadoddin, Amir
In order to evaluate the impacts of land use change, the quantification of landscape structure through relevant metrics can be used. These metrics are appropriate owing to the fact that they are measured easily and take low cost and time. The goal of the present study is to investigate the ecological impacts of land use change on the natural structure of the Gharesoo Watershed in order to identify the highly affected areas. Firstly, the amount of land use change between 1984 and 2013 was calculated. Then, landscape metrics were used to investigate the spatial patterns of land use change. Finally, an ecological impact index based on current land use was established. The results showed that during the period studied, areas of forest and agriculture have decreased by 12 and 5 percent respectively, and other uses including residential-industrial, rangeland, and transportations have increased by 292, 143, and 176 percent respectively. Landscape metrics analysis indicated a decrease in compactness and an increase in fragmentation and degradation of the landscape. According to the ecological impact index map, approximately 28 percent of the region is exposed to high and very high impacts. These areas can be used as a base for future studies and may be earmarked for intervention measures such as improving land management and decreasing fragmentation.
Показать больше [+] Меньше [-]Spatial and Temporal change of costal and non-costal urban form in Mazandaran province using landscape metrics
2017
Rezaei, Fatemeh | Falahatkar, Samereh | Dadashpoor, Hashem
Land cover always has changed due to human activities and natural phenomena,. Intensive and variety of these changes in urban environments are more than others. The objective of this research was assessment of the temporal and spatial changes for two coastal cities (Chalus and Babolsar) and two non-coastal cities (Ghaemshahr and Amol) in Mazandaran province with the view to compactness, complexity and centrality of urban form using landscape metrics. The research methodology was a quantify method and the land use maps were produced in three classes (urban, cropland and water) by maximum likelihood classificationusing Landsat satellite images. For landscape change analysis 12 landscape metrics were used in the class and landscape level. The results show that the NP for cropland in four cities increased, which represent fragmentation, loss of continuity and interference in cropland. Additionally, increasing trend of number of patches was observed in two cities Ghaemshahr and Babolsar in landscape level that showed fragmented structure in these cities. Also, ENN-MN decreased only for Ghaemshahr that means high centralization was occurred in this city. Generally, the significant difference was not observed between coastal and non-coastal cities with the view to compactness and complexity.
Показать больше [+] Меньше [-]Modeling the Spatial Distribution of the Supply and Demand of Water Provision Ecosystem Service in Ilam Watershed
2023
Mohammadyari, Fatemeh | Tavakoli, Mohsen | Zarandian, Ardavan
Water provision service is one of the most valuable ecosystem services that is important as a key service for the healthfulness and management of water resources. In this study, using the Water Yield model of InVEST software, the water supply and demand in Ilam watershed was modeled. The data related to average annual precipitation, annual evaporation and transpiration, root limiting depth, water available for plants, land use map, water consumption and estimation of water provision quantity, basin boundary, and subbasins of the watershed were the inputs of this model. The results of model application showed that in Ilam watershed, 45 million cubic meters of water provided annually, with the highest and lowest water provision volumes being in Arghavan (7 million cubic meters) and Chalimar (802 thousand cubic meters) subbasins, respectively. According to results, there are great differences in the water supply and demand in the subbasins of this watershed. Therefore, planner and policymakers should pay attention to this important issue in the layout of land uses and foresee sustainable use of rich forests in the high yield subbasins such as Arghavan subbasin. The results provided in this study, along with showing the importance of modeling surface water demand and its used in macro-policies of water allocation, can function as a guideline and help the managers and planners of Ilam city to adopt reasonable decisions in managing ecosystem and correctly using land in this area.
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