Vicinity of Tsukuba and Tone River Improvement
Transcription
Vicinity of Tsukuba and Tone River Improvement
Vicinity of Tsukuba and history of Tone river improvement Kamoto 10 Nov. 2014 1 Kinu R. Kokai R. 2 3 4 5 6 7 8 The Kokai River is characterized by the large share of its paddy area in the basin. These paddy fields are supported by irrigation water from the Kinu River and water returned from the 10,000 ha of paddy fields. Over 300 water intakes for agriculture water supply are located on the main Kokai River and its tributaries. The area irrigated by these facilities totals some 24,000 ha. On the other hand, irrigation and drainage canals including Fukuoka, Oka and Toyota Weir known as the three major weirs in Kanto where constructed in the downstream reaches of the Kokai River. These three weirs are well known for using the pond method to pump river water to a high elevation and store a large amount of water in the channel as if it storing water in a pond. 9 10 11 Tone River and Retarding Basin Kinu R. Watarase R. Kokai R. Tone R. Kasumigaura L. 16,840 km2 Tokyo 322 km 12 Sugao Tone Canal Inatoi Tanaka 13 TX 14 Area and Volume ○Inatoi: 4.48km2 95.53 million m3 ○Tanaka: 11.75km2 30.80 million m3 ○Sugao: 5.92km2 28.50 million m3 ○Watarase: 33.00km2 170.68 million m3 15 The peak discharge from Watarase River is controlled by retarding basin Peak Design Flood : 22,000 m3/s at Yattajima The peak discharge from Kinu and Kokai are controlled by retarding basin Control by up stream dams: 5,500 m3/s 1/200 Basin average Precipitation: 319.0 mm/3‐days Unit: m3/s 16 River System Name of dam Year of Comp letion Catch‐ ment area (km2) Reservo Dam ir area height (km2) (m) Dam Effective Flood length Storage control (m) capacity volume (mil. 3) (mil. m3) Up‐ stream Tone Yagisawa 1967 167.4 5.67 131.0 352 Naramata 1991 95.4 2.00 158.0 Fujiwara 1959 207.2 1.69 95.0 Aimata 1959 110.8 0.98 Sonohara 1966 492.2 Shimo‐ kubo 1968 sum 175.80 22.10 85.00 13.00 23.0 35.89 21.20 67.0 80 20.00 9.40 0.91 76.5 128 14.14 14.14 322.9 3.27 129.0 303 120.0 35.00 1395.9 14.52 450.83 114.84 17 River System Name of dam Year of Compl etion Catch‐ ment area (km2) Reservo Dam ir area height (km2) (m) Dam Effective Flood length Storage control (m) capacity volume (mil. m3) (mil. m3) Watara‐ se Kusaki 1976 254.0 1.70 140.0 405 50.50 20.00 Kinu Ikari 1957 271.2 3.10 112.0 267 46.00 14.00 Kawa‐ mata 1966 179.2 2.59 117.0 131 73.10 24.50 Kawaji 1984 503.0 2.20 140.0 321 76.00 36.00 Yunishi‐ gawa 2012 102.0 1.98 119.0 320 70.00 30.00 1055.4 9.87 265.10 104.50 766.43 239.34 Sum Total 18 Locations of the Group of Dams on Kinugawa River Kinunuma (headwaters) Kawamata Dam Yunishigawa Dam (flooded water test) Ikari Dam Kawaji Dam Kinugawa River Yanba Dam (under construction) Tonegawa River 19 3 1. Old bank 2. M33 (1900) 3. S14 (1939) 4. S24 (1949) 5. S55 (1980) 6. Heisei (1989 ~) 20 1783 Tenmei 3 Volcanic Eruption Mt. Asama 1786 Tenmei 6 Flood 1896 Meiji 29 Flood 1910 Meiji 43 Flood 1938 Showa 13 Flood in Kasumi‐ga‐uara 1947 Showa 22 Flood by typhoon Katharine 1986 Showa 61 Flood in Kokai River 21 22 23 24 The Hakojima Retarding Basin The Hakojima Retarding Basin Oya River Kokai River Source: The Shimodate Office of River, Kanto Regional Development Bureau, 25 The Ministry of Land, Infrastructure, Transport and Tourism, “Mitsuka” (or “Mizuka”) refers to a foundation that is elevated in preparation for flooding, including structures on such foundations, if any. Many of them are still seen in low-lying areas in the Kanto region, where people used to suffer from frequent floods. The Yoshida-ke Mituska has been confirmed to be the only one left in downtown Kuki. On June 26, 2008, Kurihashi Town (former Kuki City) designated it as a municipal cultural asset, recognizing its historical importance for passing down local wisdom and the history of old inn town Kurihashi to the future generations. 26 27 28 Nobusima‐Shinden along Kinu River 2014.11.2 “Kasumi-tei,” or open levees, is built by placing multiple levees to overlap each other’s upstream and downstream tips so as to prevent floodwaters from overflowing. Kasumi-tei has been commonly applied particularly to rapid-current streams, such as ones running down through alluvial fans, since years before renovation in modern times. Each levee used for Kasumi-tei looks standing alone, separate from each other, on a plan view. Functionally, however, they are not apart from one another, extending themselves upstream and downstream adequately enough to partially overlap each other. The key is that river water will not overflow because the river water level is lower towards downstream according to the river bed slope, or the slope of the alluvial fan in a broader sense. from Nakao Tadahiko “河川工学の基礎と防災 30 The following are some advantages of Kasumi-tei (1/2): Kasumi-tei works like guide levees, which direct the stream towards the center of the river because each kasumi-tei levee, particularly its downstream part, is angled so as to lead the stream away from the residential and farming area to the center of the river. Because of its unique design, it is the downstream part of each levee that is exposed to the dynamic flow of the rapid current. Thus, the upstream part can avoid the direct hit by floodwaters. This helps us focus more on the downstream part of the levee in terms of levee protection, instead of the entire length of the river. Even if the downstream part of a kasumi-tei levee breaches, the residential and farming areas will still be protected from the direct hit by rapid floodwaters, because the upstream part of the adjacent, downstream levee works as a secondary levee. 31 The following are some advantages of Kasumi-tei (2/2): The gap between two kasumi-tei levees also works as a retarding basin. Traditionally, however, the gap has been considered as extra room or buffer zone rather than officially including it as part of design volume. As the river water level continues rising, floodwaters will start overflowing slowly from the openings of kasumi-tei. However, damage is expected to be not so serious because the floodwaters are not the rapid current from the main stream but the ones with almost no velocity. Kasumi-tei does not require large structures, such as water gates, to lead tributaries into the main stream. They can merge to the main stream through the openings of kasumi-tei. Reversely, floodwaters from the main stream can be led to tributaries through the openings. Since early times, many communities have adopted kasumi-tei for rapidcurrent rivers because of these advantages. In recent years, however, kasumi-tei has been turned into continuous levees by connecting adjacent levees probably because its discontinuous design may not look safe enough. 32 Kasumiga‐Ura Koise R. Sakura R. Ono R. Catchment area 1,915 km² Surface area 220 km² Average depth 4 m Max. depth 7 m Water volume 0.848 km³ Shore length1 252 km Surface elevation 0.16 m Kita‐ura lake Sin‐tone R. Kasumiga‐Ura lake 利根川水系霞ヶ浦圏域 河川整備計画 茨城県より 33 Aoki Weir Photos in 2013 Sep 10 Location Name of river Beneficial area Height of the weir Manager of Facility Sakuragawa City, Ibaraki, Japan Sakura 61 ha 5m Yamato & Sakura Water Supply Association Length of the weir Style of the weir Construction year 19 m Semi Fixed Weir (Steel Slide Gate) 1998 34 Hojo Weir Photo in 2013 Sep 10 Location Name of river Beneficial area Height of the weir Manager of Facility Length of the weir Style of the weir Construction year 2013 Oct. 19 Tsukuba City Sakura 231.8 ha 3.1 m Tsukuba City Land Organization 36.3 m Inflatable Rubber Weir 1999 Improvement 35 Flexible water usage at the drought in 2001 From industry to irrigation 36 1 Town development along the TX line (Katsuragi Area) Development along the TX line <Town development along TX in Ibaraki> 8 locations about 1,700 ha (Town redemarcation project) Planned population: about 100,000 Planned housing land: about 1,000 ha Katsuragi (Kenkyugakuen) Nakane & Kondadai Kamikawarazaki & Nakanishi Tsukuba Sta. Outline of 8 locations Kenkyugakuen Sta. Banpakukinen Sta. Kayamaru (Midorino) Midorino Sta. Location Shimana & Fukudatsubo (Banpakukinenkoen) Miraidaira Sta. Moriya (Moriya) Ina & Yawarakyuryobu (Miraidaira) Moriyahigashi Shimana & Fukudatsubo Kamikawarazaki & Nakanishi Municipality Tsukubamirai Tsukuba Tsukuba Primary contractor Ibaraki Pref . Ibaraki Pref . Ibaraki Pref . Dev elopment area 275ha 243ha 168ha Planned population 16,000 15,000 11,000 Moriy a Sta. Location Nakane & Moriy ahigashi Kay amaru Katsuragi Area Moriya Sta. Chiba Pref. Ina & Y awaraky uury o u Kondadai Municipality Moriy a Moriy a Tsukuba Tsukuba Tsukuba Primary contractor Moriy a association UR UR UR Dev elopment area 39 ha 40 ha 293 ha 485 ha 190 ha Planned population 3,800 2,400 21,000 25,000 8,000 37 Aerial view of Katsuragi Area after project 1 Town development along the TX line (Katsuragi Area) 38 2 Rainwater drainage measures River improvement with town development along TX Yata River (Yata‐gawa) Current After improvement Hasunuma River (Hasunuma-gawa) Current After improvement Nishiyata River (Nishiyata‐gawa) Current After improvement Takaoka River (Takaoka‐gawa) Current After improvement 39 2 Rainwater drainage measures Rainwater drainage measures within the project area Regulating pond 東光台研究団地 Katsuragi‐gawa regulating pond Regulating pond つくばエクスプレス Hasunuma‐gawa regulating pond No.2 Hasunuma‐gawa regulating pond No.1 40 2 Rainwater drainage measures Rainfall detention/infiltration measures Large parks Private houses Small parks Roads Schools Commercial/industrial facilities 41 Tone Canal 42 The construction of the Tone Canal by private initiative began in 1889 to shorten the route of water transport connecting the Tone and Edo rivers when waterborne traffic was bustling. The inland canal stretching about 9 kilometers was completed in 1890. The canal was designed by Dutch engineer Anthonie Thomas Lubertus Rouwenhorst Mulder and, unlike many other canals in Japan, it is curved to create beautiful scenery. The canal shortened the shipping route by some 40 kilometers, thereby increasing the speed of shipment from rice‐producing areas along the Tone River to Tokyo, a major consumption center. 1 outer ring steamboat and Takase ship, during the height, about 100 boats a day had been operated. The canal saw busy traffic through the first half of the 20th century . Over time, it has become the era of the automobile and railway. In 1941, Its embankments were destroyed by a typhoon and it was acquired by the country in 1942, thus ending a half century of its history in waterway shipping. Then, it had become the interim water channel to compensate for the water shortage in Tokyo temporary. It showed a quiet appearance after finishing also the role now, and it is also referred to as “Toneunga eco‐museum”. Noda city is famous for Shoyu (soy source) production. Kikoman Company originates here. 43 Thank for your attention http://whrm‐kamoto.com/top.html 44