Geographic Data
Yaser Moarrab; Esmaiel Salehi; Mohammad Javad Amiri; Hassan Hoveidi
Abstract
Extended AbstractIntroductionThe global rise in urbanization and settlement of the majority of the world’s population in urban areas create opportunities and challenges for improving the quality and sustainability of life. Potential of cities for meeting the basic needs of people has become an ...
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Extended AbstractIntroductionThe global rise in urbanization and settlement of the majority of the world’s population in urban areas create opportunities and challenges for improving the quality and sustainability of life. Potential of cities for meeting the basic needs of people has become an important part of recent scientific and political debates. Covering only a small area of land, cities are responsible for many global environmental problems such as carbon emissions, energy and resource consumption, biodiversity degradation, and ecosystem degradation. They also convert natural forests to human settlements, farms, roads, gardens, and other human-made land uses, leaving many direct and indirect effects on natural conditions and ecological functions of upstream and downstream in forests (such as changes in quantity and quality of water, changes in water flow in rivers, changes in climatic condition and habitat quality). These structural and functional changes undermine environmental services provided by ecological infrastructure and threaten the environmental security of cities and their sustainable development. Therefore, urban managers and experts have always sought a suitable way for urban planning to regulate the structure of cities, support the stability of ecosystem and its performance, and maintain the ecological security of cities. Case studyLavasanat is a district in Shemiranat County in Tehran province of Iran, which is located in the northeast of Tehran. MethodsThe present study analyzes temporal-spatial changes of land use / land cover and then, uses InVEST 3.7.0 model to evaluate temporal-spatial changes of land uses. Results & DiscussionChanges occurring in the reference period were depicted in maps prepared for various land cover / land use classes. Validation of image classification shows a total accuracy of 95.72%, 96.26% and 95.32% and a Kappa coefficient of 0.948, 0.943 and 0.936 for classifications in 2000, 2010 and 2020, respectively, which is acceptable and indicates the compatibility of classified land uses and reality. Classification of images using maximum likelihood algorithm showed the presence of five classes of residential areas (urban area, villages, industries and roads), barren lands, pastures, water bodies and green space in the region.Land use maps and information derived from satellite images indicate that residential areas have experienced a growing trend due to increasing population, demand for land and consequent growth of urbanism, while green space had a decreasing trend during the reference period. Development of residential areas and reduction in green space are quite evident between 2010 and 2020. According to the present trend of land use change, there will be a sharp decline in green space in the coming years. Pastures experienced a decreasing trend from 2000 to 2010. However, it faces an increasing trend from 2010 to 2020 since more green areas were converted into pastures. Barren lands experienced a decreasing trend from 2000 to 2020. ConclusionThe present paper offers the results of modeling water production services in Lavasanat Basin in different decades. Results indicate that the water production in the entire Lavasanat basin equals 2641734.816 cubic meters in 2000, 3318950.915 cubic meters in 2010 and 7737201.215 cubic meters in 2020. Of these volumes, 1677926.367 cubic meters in 2000, 2287145.055 cubic meters in 2010, and 4908786.651 cubic meters in 2020 belonged to residential areas. This class contained an area of 4820578.505 square meters in 2000, 6885513.787 square meters in 2010 and 10407948.705 square meters in 2020 in the whole basin.The results obtained from InVEST scenario building model and water production model showed that the increasing trend of human-made land uses in the study area has a significant impact on increasing water production and, consequently, increases runoff. In fact, water production has experienced a growth rate of 1.25 or 125% from 2000 to 2010, and a growth rate of 2.33 or 233% from 2010 to 2020. Thus in 20 years, water production has increased by 2.92 (292%). The volume of water production in residential areas has increased by 1.36 times (136 %) from 2000 to 2010, 2.14 times (214 %) from 2010 to 2020 and 2.92 times (292%) in 20 years. Also, the total area covered by residential land use has grown 1.42 times from 2000 to 2010 (142 %), and 1.51 times (151%) from 2010 to 2020. Therefore, an increase of 2.15 or 215% was observed in residential areas over this 20 year period.
Esma'il Salehi; Saeed Negahban; Zohreh Ja'farian Dehkordi
Volume 19, Issue 76 , February 2011, , Pages 29-33
Abstract
Cities are open systems that have always been the origin of change and are themselves changing and evolving, and given the growing population of cities in today's world, the physical space of the city has also expanded and occupied the surrounding land. The physical growth of cities has absorbed and ...
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Cities are open systems that have always been the origin of change and are themselves changing and evolving, and given the growing population of cities in today's world, the physical space of the city has also expanded and occupied the surrounding land. The physical growth of cities has absorbed and destroyed high-quality land. Human societies have been established in the early stages of formation with the aim of using high quality soils for agriculture, alongside or among high quality agricultural land. Over time, along with the expansion of the villages and their conversion into cities, and then the development of cities, high-quality agricultural lands have been added to the urban area and agricultural activities are retreating to poor lands. This article tries to understand the environmental impacts of urban development using a method based on secondary sources, and the results show that this issue is taking place continuously in parts of the suburbs of any city with potential of development and expansion. This physical growth of cities causes the destruction of the environmental balance between the city and its surroundings, which not only reduces the quantity and quality of resources and living conditions, but also causes major complications such as air and water pollution, noise pollution, and In general, the destruction of the environment.
