Sayyad Asghari Saraskanroud; Rasoul Hassanzadeh; Zahra Miri Atashgah
Volume 6, Issue 19 , September 2019, , Pages 37-56
Abstract
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. ...
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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.
Manijeh Ghahroudi Talli; Taher Valipoor; Lughman Shirzadi
Volume 5, Issue 16 , December 2018, , Pages 43-59
Abstract
Abstract
Introduction
One of the most important factors in the development of a region is the availability of sufficient water resources and its quality status for various uses. Due to Iran's arid and semi-arid climate and water shortage, it is essential to pay attention to the water quality of its ...
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Abstract
Introduction
One of the most important factors in the development of a region is the availability of sufficient water resources and its quality status for various uses. Due to Iran's arid and semi-arid climate and water shortage, it is essential to pay attention to the water quality of its rivers.
Methodology
Pishkooh-Taft Basin is an important watershed inthe east of Yazd province and located between 54º 15’- 53º 40’ east and 31º 50’- 31º 30’ north. Tezerjan fault of Taft Continues to the west with the northsouth trend. There are 3 gauging hydrometric stations in this area. TM images13 October 1991 and ETM+ 15 October 2011 of Landsat 7 were used to change the detection of the land use. In addition, to examine the physical and chemical properties of water in Taft, Islamiyah and Feyz-abad stations during 1361 to 1390 years were used. First of all, the method which was performed included geometric correction for fixing errors and adapting the images by the Digital topographic map scale of 1: 25,000. Then, land use was extracted by supervised classification, training samples, and maximum likelihood techniques. Next, to report the physical and chemical properties of anions and cations, TDS, conductivity and pH of the water, the stations were investigated during 1361 to 1370 and 1371 to 1390 years, and the data was evaluated using Mann-Whitney statistic.
Result
The finding of land use showed that the wasteland and pastures were dominated and there was an increase in pastures compared to 1370, but there was a decline in covered meadows in 1390. To examine the relationship between land use changes and water quality, the elements of the water was dealt with. For this purpose, the physical and chemical properties of anions and cations, TDS, conductivity, and pH of the water between the years 1361 and 1370 and 1371 and 1390 were studied. The results of Mann-Whitney statistic in different elements and three stations showed that the difference between these two periods was significant in Taft station.
Discussion and conclusion
The effect of land use on water quality change over the period of 30 years showed a relative decline of water quality in Taft station and to some extent in Islamiyah station. This can be attributed to the increase in land occupancy and the existence of agricultural lands in Taft and Islamiyah Stations. However, in Feyz-abad station, due to the lack of habitat and agricultural lands and an increase in water flow, there was no decrease in water quality. On the other hand, the examination of the changes in the height of the stations showed that Taft station was in the outlet of the basin and had the minimum height which could affect the quality of the water. Several researchers (Townsend & Popcorn, 2009; Kazi et al., 2009; Travka, 2004; Orion, 1390) have studied the effect of reduction of water quality on increasing agricultural lands and urban areas which are in line with Taft station.
