Application of Satellite
Image Date to Large-scale Water Use System in Arid Areas of Iran
Kiyoshi Torii1
Tahei Yamamoto2, Makio Kamichika2, Kyochi
Otsuki2 Sizuo Hayasi3 Yoshiaki Sinmura4,
Takashi Hoshi, Abbas Keshavarz6 And Ebrahim
Pazira6 Abstract 1Dev. Of Environmental Sci. & Tech. Graduate School of Agriculture, Kyoto Uni., Kitashirakawa, Sakyo, Kyoto, JAPAN Tel. & FAX Int'l-81(0) 75-753-6459, E-Mail : torl@ais, kyoto-u.ac.jp 2Arid Land Research Center, Tottori Univ., 1390 Hamasaka Tottori Japan TEL. Int'l-81-(0)857-21-7040, E-Mail : Otsuki@center.kyoto-u.ac.jp 3Tropical Agric. Center, Kyushu Univ., Nishi-kawazu-chu, Matsu, Japan 4Faculty of Agric., Shimane Univ. Nishi-kawazu-chu, Matsue, Japan FAX Int'l -81-(0)852-32-6592, E-Mail : Shinmura@botan.shimane-u.ac.jp 5Dep. Of Inform. Sci. Ibaraki Univ., Nakanarusaza-chu, Hitachi, Japan TEL. Int'l -81-(0)294-38-5133, E-Mail : hosh@cis.ibaraki.ac.jp 6Iranian Agric. Eng. Research Inst. Min. of Agriculture, Karaj, Iran TEL. Int'l-98-261-241116, Fax Int'l-98-261-226277 The authors had the opportunity of inspecting a large-scale agricultural water use system comprising three irrigation projects in Iran. These included (1) the Dez Irrigation Project extending over over the north of Ahvas, Khuzestan province, (2) Drudzen Irrigation Project developing in Marv Dasht district in the suburbs of Shiraz city, Fars province, and (3) Zayandroud Upstream and Roudasht Irrigation Project extending over the upper and lower stream of Zayanderoud river, Isfahan province. Each of these projects represents a vast irrigation project having more than 100.000 ha, and has been developed in the arid areas lying in the southern part of Iran. They are designed to secure the arid areas lying in the southern part of Iran. They are designed to secure water resources flowing out of Zagros Mountain range by constructing dams water resources flowing out of Zagros Mountain range by constructing dams for dual purposes: (1) to generate electricity and (2) to provide irrigation. The present field trip was rather exploratory and any data on the spot was hardly obtained. Any detailed study involving such big projects require regional regional data utilized as basic data by comparing data obtained from Landsat MSS, SPOT XS and JERS-1 in our possession with the ground-truth data obtained by field survey and study in the project area. Introduction Desertification has been drawing attentions as a serious problem in recent years. The area in arid districts exposed to desertification is said to be 5 million ha annually. As the agriculture in the ancient orient was described "challenge to environment and lose", it is a periodic phenomena accompaying prosperity of culture in human history. Desertification accompanying irrigation, in particular Is affected by the factors related to enforcement of the project inducing erosion of the land and saline problems of water resources and land resulting in unreclamatable production basis. It is important that resarchers and engineers participating in development of arid areas make irrigation plans which can be continued and can harmonize new irrigation techniques with conventional and traditional techniques. The study proceeds with large-scale irrigation projects with emphasis on a sustained irrigation agriculture considering from the present situation and the desertification factor related to shortage of water resources due to irrigation and saline problem. As study areas, Khuzestan province, Fars province and Esfahan province of Iran have been selected. We are planning to propose water utilization and counter-measures to deal with saline problem necessary for a sustained development by measures to deal with saline problem necessary for a sustained development by measures to deal with saline problem necessary for a sustained development by collecting information on natural and social environmental factors, surveying the present state of desertification accompanying irrigation agriculture as well as natural and artificial factors and elucidating the mechanism of saline problem caused by river-dependent irrigation agriculture. In Iran, improvement of infrastructures in irrigation facilities has progressed since 1980 in rural areas and a bit effort has been made to development of agricultural water utilization. As a result, the domestic self-supply rate of agricultural products has been raised greatly. However, saline problems of agricultural land accompanying population growth and rapid enlargement of irrigation area is marked and, in spite of bit general potentiality in Iran, lack of water resources, saline soil and alkaline soil in vast areas and problems of water quality have become big inhibitory factors hindering agricultural development at presenet(1)2). Attempts to apply satellite images of Landsat and SPOT or JERS-1 to deal with such problems have been in progress for several years in Iran3).4).5). In the beginning, emphasis was placed in production of maps from satellite images but application for geographical31*30' information system is increasing in recent years. We are thinking to grasp the state of large-scale agricultural water utilization system and to explore a sustainable agricultural development. Fig. 1 shows the map of whole Iran and locations of the selected areas. Figure 1 Total Map of Iran and study areas 1. Water utilization system and Irrigation project in Khuzestan province Khuzestan province is located in the south-west part of Iran adjacent to Iraq and its area is 6.3 million ha occuying 4% of the whole land. The east and north of the province are bordered by Zagros mountains running from the north-west to the south-east and the south is Persina Gulf. Main rivers flowing inside the province are Krun River, Dez River and Karkhe River from the east and all of them join Thigris-Eufrates River before entering Persian Guld. Krun River enters the province from the northern plain of Shustar passing Ahvas, the capital of the province, to Abadan and it joins Thigris-Eufrates River in Shall-al-Arab before entering Persian Gulf. Dez River enters the province from the northern plain of Dezful flowing in the south-east part connecting to Krun River in Bard-e-Qir. Karkhe River flows in the far west towards the south of the ruins in ancient Shush, where it changes direction westwards. It changes its direction again at the position 40 km north of Ahvas entering Iraq, where it joins Thigris-Eufrates River. In parallel to Karkhe River, small Shavour River flows in Khuzestan plain southwards and joins Dez River, which flows further southwards joining Krun River. Thus, Khuzestan plain is most rich in water resources in the south Iran. Large-scale water uilization development has started in 1970 and various irrigation projects including land rehabilitation of the existing arable land and new development of agricultural land are planned in paralled. Fig. 2 shows the state of development of agricultural land in 1971. The main projects are Dez dam and Dez irrigationproject extending downstream (total area of 125,000 ha and 21,000 ha of them have already been completed as Dez Pilot Project), Haft Tappeh sugar cane project (10,000 ha completed), Shavour Project (6,000 ha completes), Krun Irrigation Project (38,000 ha under development in 1971), and Karkhe Irrigation Project (21,000 ha completed). Another agricultural development is being planned by constructing Krun dam and bring it into Krun Irrigation Project. Figure 2 Irrigation Project in Khuzistan The main crops are wheat, sugar beet, citrus fruits, vegetables and corns and paddle fields are also becoming popular. In the aspect of water quality, the salt concentration is below 0.01% in the vicinity of intake weir of Dez River offering the best water for agricultural irrigation. However, the flow rate is not sufficient to supply water to the whole irrigation area and water quality tends to aggravate as it flows downwards reaching the salt concentration of a few thousand ppm in the middle stream and some ten thousand ppm in the downstrem.
Changes during the past 20 years were analyzed using 4 satellite images. Although JERS-1(SAR) image was also obtained, eligibility of application was explored in the present study using the images in visible range. Fig. 3 shows the image obtained by Landsat 3 in 1976. This expresses 1,000x1,000 pixels without thinning corresponding to a square area of about 70 km in side length. Here Tappeh Project and Shavour Project are recognized clearly but Dez Project is still under development and Krun Project does not appear yet. Fig. 4 is the SPOT image 11 years later. In this image, 1 out of 3 pixels is expressed showing an area of about 60km in width and length. Krun Project is clearly visible suggesting that Krundam has been completed and supply of irrigation water has been started satisfactorily. Fig. 5 is the JERS-1 image observed in August, 1994. Dez river is flowing from the left top to the center of the image while Krun river is flowing from the right top inclining to the left center of the image while Krun river is flowing from the right top inclining to the left slightly. The vast Krun Irrigation Project is developed between the rivers. On the left (west) of Dez river. Haft Tappeh and Dez Irrigation Projects are extending. We can see clearly consolidated farmland. Although the analysis here is restricted to qualitative it is possible to evaluate historical development of large-scale irrigation projects in Iran as ell as future sustainable development. Figure 3 Landsat 2 Image of Dez Irrigation project. 1976.11.5. Figure 4 SPOT HRV path-row 146-286 obs. 1987.7.1. Image of Dez Project Figure 5 JERS-1 OPS(VMIR) Path-row 229-247 observed '94.8.3. Dez Irrigation Project and Krum Irrigation Project 2. Drudzan irrigation project in Fars Province This district has a famous sight-seeing place of Persepolis ruins destructed by Alexander the Great 2,500 year ago. The area called Sivand Plain extends over Marvdash district lying 30 km north of Shiraz city. From Drudzan dam (effective water reservoir of 870 million m3) completed upstream of Kor river in 1971, a water supply of 40 tons/sec is available to the main canal irrigating about 100,000 ha. Water quality appears to be satisfactory as the salt concentration of 200 ppm in irrigation canal and 600 ppm in drainage ditch but potential salinity of water is present since the land is flat in geographical features and water drainage is difficult due to high underground level of several meters. Fig. 6 is the JERS-1 OPS (VNIR) image observed on July 26, 1994. It is the output by very 2 pixels corresponding to the central area of Drudzan Irrigation Project about 35 km in length and 40 km in width. Representation without thinning should offer more detailed plots of farmland and irrigation canal net. Figure 6 JERS-1(OPS) VNIR path-row 221-250 observed 94.7.26. Drudzen irrigation project Shiraz Fars Province 3. Zayandeh-rud watershed in Esfahan Province Esfahan city is called as the ancient city of Iran and famed by a beautiful landscape. This district is located in the center of Iran and Zayandeh-rud river originating from Zayandeh Rud dam with a reservoir capacity of 1.5 billion m3 has been Constructed while Nekoabad diversion dam was constructed downstram in 1975 supplying 15m3/sec of water to the main canal on the right bank and 50 m3/sec of water to the left bank irrigating a total of 65,000 ha of land. The irrigation canal net is still being extended and water quality is very good with the salt concentration of 0.02%. The places where irrigation water is not supplied are depending on well water which is supplied to agricultural lands in the vicinities. The salt concentration in the well was 0.31%. While the downstream basin in. Esfahan is a district where salts are liable to accumulate, Rudasht Irrigation Project covering 45,000 has is implemented using surplus water of Zayandeh rud river. Here, a very interesting experiment is progressing as it is a place where deserification and irritation ares are competing and kannat. Techniques for preventing deserification has been practiced from old times. Wisdom for irrigation such as utilizing surface water not containing salt for irrigation, eliminating soil salts by infiltrating water into deep draining canals and diluting ground water of high salt concentration by surface water which have been used in arid agricultural land for a long time can been seen here and there. Fig. 7 is the JERS-1 OPS (VNIR) observation image of 1993.5.6. It indicates the area where Zayandeh Rud river passing through Esfahan city is flowing down Rudasht project area. The area expands 35 km in length and 40 km in width and expressed by every 2 pixels. Esfahan airport is recognized on the upper left. Figure 7 JERS-1(OPS) VNIR path-row 223-246 observed 93.5.6 Roudasht Irrigation project in Zayandehrud downstream in Eafahan Province Concluding remarks Finally, according to Iranian researchers1), the primary factor hindering extension and development of agriculture in Iran is lack of water . Potential water resources exist, sufficient agricultural land is insured. Further, if water loss reaching 67% in irrigation and water utilization facilities can be reduced and more efficient water management is accomplished, agricultural situation in this country would change for betterment. There is always a possibility that practice of non-scientific irrigation may cause salt accumulation in agricultural land large-scale water distribution system may end totally in ruin. It is warned that at most attention must be paid to efficient supply of irrigation water and proper management. Here, we reviewed large-scale irrigation projects in Iran using satellite image data. Although detailed analysis has not been performed, it was found that they would provide valuable data in places where information and data are scarce. We are thinking of deepening the analysis by processing the images by every pixel and refining crude data, gratitudes to NASDA (National Space Development Agency of Japan) of r supplying data at low costs and Data Processing Center of Kyoto Univ. for enabling enormous amount of data processing. References
|