- بررسی روند تغییرات کاربری اراضی حوضه ی آبریز علی آباد چای هوراند و ارزیابی تأثیرات آن بر روند مصرف آب در باغات میوه در بازه ی زمانی 1992-2017 (مقاله علمی وزارت علوم)
درجه علمی: نشریه علمی (وزارت علوم)
آرشیو
چکیده
حوضه ی آبریز علی آباد مهم ترین شبکه هیدرولوژی شهرستان هوراند می باشد و در دهه های اخیر از بحران تغییرات مخرب کاربری اراضی در امان نبوده است، بنابراین پژوهش حاضر سعی دارد، کشف و آشکارسازی تغییرات کاربری اراضی این حوضه را در بازه زمانی 25 ساله (2017- 1992) به منظور ارزیابی مسائل آبی مورد مطالعه قرار دهد. به همین منظور از تصاویر لندست با سنجنده هایTM) و (OLIبا مسیر 168 و ردیف 33 و طرح نیاز خالص آبیاری محصولات کشاورزی ایران و البته مطالعات میدانی و داده های آماری بارش و عمق چاه های نمونه استفاده گردید. با توجه به داده ها و روش تحقیق مشخص شد که اراضی کشت آبی، جنگل متراکم، مرتع درجه 1، بستر رودخانه و مناطق آبی در عرض 25 سال کاهش مساحت داشته اند در حالی که اراضی باغی، اراضی زراعت دیم، جنگل تنک، مرتع درجه 2 و 3 از افزایش مساحتی چشمگیری برخوردار بوده اند که در این خصوص اراضی باغی از مساحت 62/7 به 77/12 کیلومتر مربع افزایش یافته که این افزایش به میزان 67 درصد بوده است و این افزایش نیاز مصرفی باعث حذف جریان سطحی رودخانه و پایین رفتن سطح آب های زیرزمینی حوضه شده است و آزمون آماری پارامتریک پیرسون این نتایج را تأئید کرد.The Investigation of the Trend of Land Use Change in Ali Abad Horand Basin and Assessing its Impact on Water Use in Fruit Gardens During the Period of 1992-2017
Introduction Land-use studies, using remote sensing techniques, are vital tools for generating rational information for proper decision-making in natural resource management. (Habtamu Teka et al., 2017). Land-use change has the potential to affect land cover and vice versa. Land use change affects the biodiversity and aquatic ecosystems, and change in the watershed affects water quality, resulting in an increased runoff consumption, reduced land use, and evacuated groundwater. Therefore, land-use change information for water selection, planning, monitoring, and management is important in order to meet the change in land use due to the demand for human and welfare requirements without compromising the quality and quantity of water (Ang Kane Hawa, 2017). Methodology Case Study The Aliabad watershed of Horand with the southwest-northeast trend is located at the geographical coordinates of the southeastern part of the eastern part of the eastern province of East Azarbaijan and the southeastern part of Horand. Including the Horand, Majidabad and Yali Yurt mountains, the Eight Shrines, the Cay Thai Castle and Mount Everest, it covers an area of 165278 km2. The Ali Abad River is the main river of this basin, which performs the drainage system of the area and the Dojak and Horand Rivers are the most important branches that join this river. Data and research method The data which was used in this study included Landsat images, which included TM and OLI sensors with track 168 and row 33, with a resolution of 30m between 1992 and 2017. To obtain the amount of water created by new gardens, a pure water irrigation project for Iranian crops, which has become a software called NETWAT was used. Landsat images in the pre-processing stage were used for the atmospheric and radiometric FLAASH corrections. The strongest method of atmospheric correction, and rescale operations were performed on corrected images to ensure accurate numerical calculations. Meanwhile, in the 2017 image, to increase the accuracy of the classification, the method of fusion of multinuclear images with a pancreatic image was made and the spatial resolution up to 15m improved. The processing of images to detect and determine the type of land use in two time intervals was done through supervised classification methods. Of four types of classification, the Maximom likelhood method was chosen due to a better processing and the absence of unknown pixels. Finally, the layer Land use in twelve classes was selected by selecting the number of educational specimens including the first class forests (4181 pixels), second class forests (3958 pixels), garden lands (2665 pixels), first class rangeland (32704 pixels), rangeland grade (30837 pixels), agriculture (7544 pixels), residential land (1911 pixels), shore lands (3257 pixels), blueberries (167 pixels), Bayer lands (2332 pixels), blue areas (131 pixels) and river beds (800 pixels). In addition to the necessity of using large-scale images, field observations and the use of lateral information were necessary to identify some activities at different levels of the earth (Zebiri, 92). Therefore, field observations were also needed to enhance the accuracy of the user classification. To analyze the data, ArcGIS, ENVI were used. After the processing and evaluating the accuracy of the images and examining the results of the classification, there were several ways for assessing the accuracy of the classification. The most common way was the selection of a number of pixels of the specified sample and comparing them with the classification that made these data. The ground truths were called reference data (Alawi Panah, 91: 159-152). The net irrigation project of Iran's products was from the National Project Plan (TOTEK). An optimization of the national consumption of Iranian agricultural water was carried out by the Meteorological Organization of the country and the Ministry of Jihad-e-Agriculture in collaboration with Dr. Amin Alizadeh and his research team. In order to estimate the water consumption of the basin in gardening affairs, based on the method of work, this functionality was constructed using the FAO-Penman-Monteith function and based on this function, the annual consumption of trees was calculated. Finally, the consumption of each tree was estimated as the average annual consumption. Results The verification of the accuracy and results of the classification of images by the Kappa coefficient were performed and the obtained coefficient with the acceptable status showed that the classification of the images was done satisfactorily and the images could be cited for the continuation of the research. In land use maps of the AliAbad River watershed, in each of the periods of 1992 and 2017, the lands were divided into 12 classes. Based on the comparison made between the two maps, land use changes in each of the 12 classes were presented. Based on the results of two time intervals in the Aliabad Chay catchment area, it was determined that the area of the cultivated lands increased by about 5.51 km2 (Table 1). In the field studies, it was concluded that the irrigation Garden lands were built on the basis of ribs by the city's people on the upstream gardens until 1992. The Pearson parametric test showed that there was a significantly positive and strong correlation between the increase in the area of the gardens and the increase in the depth of the wells (0.935). It should be noted that by increasing the area of gardens in the land use, the depth of the wells was increased for the extraction of water from the basin. However, the correlation between rainfall changes and depth of wells (Basin flood) was negative (-0.580). The basis of the net irrigation plan for irrigated crops in Iran, and using the produced function, the annual water demand of these products was calculated in terms of planting area (Table 1 and Table 2). (Table 1) Calculation of the water requirement of cultivated trees in the first six months with the NETWAT software Tree type April May June spring season July August September summer season Apple 8 44 91 143 151 138 103 392 Walnut 10 55 109 184 172 160 119 451 Apricot 13 52 86 151 122 117 53 292 Cherry 8 44 91 143 151 134 89 374 Average 39 115 377 621 596 549 364 1509 (Table 2) Calculation of the annual water requirement of cultivated trees with a built-in function Tree type Annual water requirement (cubic meter per sq. Km) Apple 760000 Walnut 886900 Apricot 490000 Cherry 698000 Average consumption of trees 708725 Total consumption in newly built gardens is 5.15 square kilometers 3,649,934 Discussion and conclusion The study area of this research is one of the important agricultural areas of East Azarbaijan Province, and the Ali Abad Chai River is considered as the only source of water supply in the region. The classification of land use in the region, especially the increase of basin gardens, which is the most important water user in the river, was done by Maximim Likelhood method. The Pearson's parametric test was used in the SPSS software to prove that the basin's decline was caused by variation in the gardens, and the 25 year rainfall variations in the basin and the changes in the gardens were investigated with regard to the depth of the wells. There is was significant relationship between rainfall variations in the basin and the decline of the basin, but there was a significant difference between the changes in the use of gardens and the decline of the basin, and there was a very strong and positive correlation between these two variables. Therefore, it should be acknowledged that in the Aliabad watershed, if the irrigation process of the gardens is not scientific and practical and the management of water storage is not done, the flow of the river in general is disturbed in these seasons. In the warm seasons, permanent changes in geomorphologic and ecological activities will be lost and the negative effects will be felt by the inhabitants of the region.
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