Outline of the Water Circulation Mechanism of the Sakuragawa River Basin Flowing Into the Lake Kasumigaura

Total Page:16

File Type:pdf, Size:1020Kb

Outline of the Water Circulation Mechanism of the Sakuragawa River Basin Flowing Into the Lake Kasumigaura 生活大学研究Bulletin of Jiyu GakuenVol. 4 College103~104 of Liberal(2019 )Arts Vol. 4 103–104 (2019) Short Note Outline of the Water Circulation Mechanism of the Sakuragawa River Basin Flowing into the Lake Kasumigaura Shinpei YOSHIKAWA Jiyu Gakuen College (Received 31 August 2018; Accepted 3 October 2018) In October 2018, The 17th World Lake Conference was held in Ibaraki prefecture for the first time in 23 years since 1995. In this paper, we will outline the advanced water circulation mechanism surrounding the Sakuragawa river basin and the Sakuragawa river, which is the inflowing river of Lake Kasumigaura, which is the representative lake in this area. Also, it shows an inventory of survey results related to the Sakuragawa river. KeyWords: Lake Kasumigaura, Sakuragawa river, Water circulation mechanism, River environment, River basin management 1. Outline of Lake Kasumigaura area The Lake Kasumigaura area is located in the eastern part of the Kanto region, the southeastern part of Ibaraki prefecture, and the area is 2,157 km2 (Fig. 1). Among them, the area of the lake is 220 km2, the second largest in the Japan after Lake Biwa. Lake Kasumigaura is connected downstream to Tonegawa river, in confluence point is set on Hitachigawa watergate. And in the usual time it is a slightly higher water area. On the other hand, the lake is made desalinated by preventing saltwater run-up by the flood gate, making it possible to develop present water resources. In addition, “Lake Kasumigaura” is a generic term such as Lake Nishiura, Lake Kitaura, Hitachitonegawa river etc. In this paper we mainly deal with Nishiura (lake area 172 km2). 2. Outline of Sakuragawa river basin The Sakuragawa river is a class “A” river (Ibaraki prefecture man- agement) with a designated extension of 63.41 km (flow path extension of 55 km) and a watershed area of 350.3 km2 extending across the four cities of Sakuragawa City, Chikusei City, Tsukuba City and Tsuchiura City in the southwestern part of Ibaraki Prefecture (Fig. 2). The Sakuragawa river originate in mt. Kuwagara (274 m) in Sakuragawa City, Tsukuba mountain area mt. Tsukuba (877 m), the plains of the western part are flowing southward, towards Lake Kasumigaura (Lake Nishiura) near the central city of Tsuchiura City. Nishiura is a part of Lake Kasumigaura. It is the largest (extension & area) river among the influx rivers. 3. Land use and advanced water circulation mechanism in the Sakuragawa river basin The present time, the plain part of the watershed forms the big agri- cultural area, but in addition to the irrigation of ancient river water and groundwater, in addition to the downstream Lake Kasumigaura use dam as a water source, “Kasumigaura-Canal (completed in 1994)” Fig. 1 Kasumigaura River basin map 103 Bulletin of Jiyu Gakuen College of Liberal Arts Vol. 4 (2019) Fig. 2 Sakuragawa River Fig. 3 Image of advanced water circulation mechanism pipeline network, supported by a stable large-scale irrigation function. On the other hand, the drainage function from the area is carried by rivers in the basin, and the flowing water and substances return to Lake Kasumigaura through rivers. At present, the water quality of Sakuragawa river, it’s not very well. It is considered to be one of pollution load factors of Lake Kasumigaura. Furthermore, the most characteristic is that the complicated and sophisticated artificial hydrological cycle, in which a part of the refluxed water and substance is pumped again from Lake Kasumigaura, in a closed watershed. It can be said that the river basin of the Lake Kasumigaura area (Sakuragawa river and more) has advanced water circulation mechanism nationwide as having “dam lake” downstream of the basin (Fig. 3). 4. The future of the water environment in the Sakuragawa river basin As described above, the drainage from the farmland is accounts for in the river water of the Sakuragawa river. Therefore, in or- der to improve the water quality at a specific point, it is important to reduce the pollutant load amount, but it is not easy. The pres- ent time, “The Kasumigaura water conveyance project” is underway to introduce rich water of the Nakagawa river system to the metropolitan area via Lake Kasumigaura. As this is completed, the water circulation mechanism becomes more complicated, and there is a high possibility that the water of another water system will circulate also to the Sakuragawa river basin. I think that the impact of the project needs to be evaluated not only in Lake Kasumigaura but also in the area where the water is used. In particular there is concern about the spread of alien species. In any case, long-term monitoring of water quality. References 1) Shinpei Yoshikawa, Chikako Ohtsuka, Masaaki Natsui, Chiharu Kumada, Akihisa Jin, Tetsuya Sumi: Water environment in the Sakuragawa river baisn under the advanced water circulation mechanism of Lake Kasumigaura, Visualization of actual water quality by multipoint electric conduction observation (in Japanese), The 17th World Lake Conference, 2018. 2) Chiharu Kumada, Shinpei Yoshikawa, Chikako Ohtsuka, Masaaki Natsui, Akihisa Jin: Current status and issues of water en- vironment of Sakuragawa River aim for water quality improvement (in Japanese), The 17th World Lake Conference, 2018. 3) Shinpei Yoshikawa, Chikako Ohtsuka, Masaaki Natsui, Akihisa Jin, Chiharu Kumada, Tetsuya Sumi: Sakuragawa River ba- sin under the advanced water circulation mechanism in the Lake Kasumigaura, multipoint electric conductivity observation for visualization of water quality characteristics (in Japanese), The 52nd Annual Conference of JSWE, 2018. 4) Shinpei Yoshikawa, Chikako Ohtsuka, Masaabnhji, Akihisa Jin, Chiharu Kumada, Tetsuya Sumi: Characteristics of water circulation mechanism in Kasumigaura inflow Sakuragawa river basin and Actual condition of water quality visualized by electric conductivity observation (in Japanese), Annual Conference of The Kantou Branch of JSCE, 2018. 5) Chiharu Kumada, About the Tone River water system Sakuragawa river as a way of nature and human involvement (in Japanese), Jiyu Gakuen College Graduation Research, 2017. 104.
Recommended publications
  • Hypomesus Nipponensis) Stock Trajectory in Lake Kasumigaura and Kitaura
    Open Journal of Marine Science, 2015, 5, 210-225 Published Online April 2015 in SciRes. http://www.scirp.org/journal/ojms http://dx.doi.org/10.4236/ojms.2015.52017 Factors Affecting Japanese Pond Smelt (Hypomesus nipponensis) Stock Trajectory in Lake Kasumigaura and Kitaura Ashneel Ajay Singh1, Noriyuki Sunoh2, Shintaro Niwa2, Fumitaka Tokoro2, Daisuke Sakamoto1, Naoki Suzuki1, Kazumi Sakuramoto1* 1Department of Ocean Science and Technology, Tokyo University of Marine Science and Technology, Tokyo, Japan 2Freshwater Branch Office, Ibaraki Fisheries Research Institute, Ibaraki, Japan Email: *[email protected] Received 5 February 2015; accepted 26 March 2015; published 30 March 2015 Copyright © 2015 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract The Japanese pond smelt (Hypomesus nipponensis) stock has been observed to fluctuate quite ri- gorously over the years with sustained periods of low catch in Lake Kasumigaura and Kitaura of the Ibaraki prefecture, Japan which would adversely affect the socioeconomic livelihood of the lo- cal fishermen and fisheries industry. This study was aimed at determining the factors affecting the stock fluctuation of the pond smelt through the different years in the two lakes. Through explora- tory analysis it was found that the pond smelt had significant relationship with total phosphorus (TP) level in both lakes. The global mean land and ocean temperature index (LOTI) was also found to be indirectly related to the pond smelt stock in lake Kasumigaura and Kitaura at the latitude band of 24˚N to 90˚N (l).
    [Show full text]
  • Holocene Sea-Level Changes and Coastal Evolution in Japan1)
    第 四 紀 研 究 (The Quaternary Research) 30 (2) p. 187-196 July 1991 Holocene Sea-Level Changes and Coastal Evolution in Japan1) Masatomo UMITSU2) Recent progress in Holocene sea-level studies and studies on coastal evolution in Japan are reviewed. Several studies recorded either a slight fall or slow rise of sea-level in the early Holocene, and some studies recognized minor regressions after the culmination of rapid postglacial transgression. Coastal landforms have changed remarkably during the Holocene. Many drowned valleys were formed in the middle Holocene, and the coast lines in Japan were very rugged at the time. Various types of coastal evolution have been reported in numerous studies. Some of the studies were carried out as cooperative research using a variety of research techniques. published by OTA et al. (1982, 1990), YONEKURA and I. Introduction OTA (1986), OTA and MACHIDA (1987) and ISEKI The Japanese Islands are located along the (1987). Recent studies on sea-level changes in boundaries of the Eurasian, Pacific Ocean and Japan were compiled in the "Atlas of Holocene Sea Philippine Sea Plates, and the landforms of the Level Records in Japan" (OTAet al., 1981) and the islands have been strongly influenced by the "Atlas of Late Quaternary Sea Level Records in Japan, plates movements. Coastal landforms of Japan vol. I" (OTA et al., 1987a). The coastal during the late Quaternary have also changed environments in the Late Quaternary and the and developed under the influence of both Holocene were illustrated in the "Quaternary tectonic and eustatic movements. Regional Maps of Japan" (JAPAN ASSOCIATION FOR QUATERNARY differences and variations can be found in the RESEARCH ed., 1987) and the "Middle Holocene processes of evolution of the coastal landforms, Shoreline Map of Japan" (OTA et al., 1987b).
    [Show full text]
  • Reemerging Political Geography in Japan
    Japanese Journal of Human Geography 64―6(2012) Reemerging Political Geography in Japan YAMAZAKI Takashi Osaka City University TAKAGI Akihiko Kyushu University KITAGAWA Shinya Mie University KAGAWA Yuichi The University of Shiga Prefecture Abstract The Political Geography Research Group (PGRG) of the Human Geographical Society of Japan was established in 2011 to promote political geographic studies in Japan. The PGRG is the very first research unit on political geography in the Society which was established in 1948. Political geography was once one of the weakest sub―fields in Japanese geography with a very limited number of scholars and published works. This, however, is not at all the case now. Political geography is a reemerging field in Japan. In this review paper, four of the PGRG members contribute chapters on general trends in Japanese political geography, legacies of Japanese wartime geopolitics, the introduction of “new geopolitics” into Japan, and geographical studies on environmental movements. All of them have confirmed with confidence that Japanese political geography has been reemerging and making steady progress in terms of theory, methodology, and case study since the 1980s. Although the current stage of Japanese political geography is still in the regenerative phase, they strongly believe that political geography should be firmly embedded in Japanese geography. Key words : political geography, Japanese geopolitics, new geopolitics, environmental movements, Japan I Introduction The Political Geography Research Group (PGRG) of the Human Geographical Society of Japan was established in 2011 to promote political geographic studies in Japan. The PGRG is the very first research unit on political geography in the Society which was established in 1948.
    [Show full text]
  • Umezakia Natans M.Watan. Does Not Belong to Stigonemataceae but To
    Fottea 11(1): 163–169, 2011 163 Umezakia natans M.WATAN . does not belong to Stigonemataceae but to Nostocaceae Yuko NIIYAMA 1, Akihiro TUJI 1 & Shigeo TSUJIMURA 2 1Department of Botany, National Museum of Nature and Science, 4–1–1 Amakubo, Tsukuba, Ibaraki 305–0005, Japan; e–mail: [email protected] 2Lake Biwa Environmental Research Institute, 5–34 Yanagasaki, Otsu, Shiga 520–0022, Japan Abstract: Umezakia natans M.WA T A N . was described by Dr. M. Watanabe in 1987 as a new species in the family of Stigonemataceae, following the rules of the Botanical Code. According to the original description, this planktonic filamentous species grows well in a growth media with pH being 7 to 9, and with a smaller proportion of sea water. Both heterocytes and akinetes were observed, as well as true branches developing perpendicular to the original trichomes in cultures older than one month. Watanabe concluded that Umezakia was a monotypic and only planktonic genus belonging to the family of Stigonemataceae. Unfortunately, the type culture has been lost. In 2008, we successfully isolated a new strain of Umezakia natans from a sample collected from Lake Suga. This lake is situated very close to the type locality, Lake Mikata in Fukui Prefecture, Japan. We examined the morphology of this U. natans strain, and conducted a DNA analysis using 16S rDNA regions. Morphological characters of the newly isolated strain were in a good agreement with the original description of U. natans. Furthermore, results of the DNA analysis showed that U. natans appeared in a cluster containing Aphanizomenon ovalisporum and Anabaena bergii.
    [Show full text]
  • Long-Term Light Environment Variability in Lake Biwa and Lake Kasumigaura, Japan: Modeling Approach
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Tsukuba Repository Long-term light environment variability in Lake Biwa and Lake Kasumigaura, Japan: modeling approach 著者 Terrel Meylin Mirtha, Fukushima Takehiko, Matsushita Bunkei, Yoshimura Kazuya, Imai Akio journal or Limnology publication title volume 13 number 2 page range 237-252 year 2012-08 権利 (C) The Japanese Society of Limnology 2012. The original publication is available at www.springerlink.com URL http://hdl.handle.net/2241/117515 doi: 10.1007/s10201-012-0372-x 1 Long-term light environment variability in Lake Biwa and Lake Kasumigaura, 2 Japan: Modeling approach 3 4 5 Meylin M. Terrel1*, Takehiko Fukushima1, Bunkei Matsushita1, Kazuya Yoshimura1, A. 6 Imai2 7 8 9 1Graduate School of Life and Environmental Sciences, University of Tsukuba 10 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan 11 E-mails: 12 [email protected] 13 [email protected] 14 [email protected] 15 [email protected] 16 17 2 National Institute for Environmental Studies 18 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan 19 E-mail: [email protected] 20 21 *Corresponding Author 22 E-mail: [email protected] 23 24 25 26 27 28 29 30 31 32 “SCRIPTREVISION CERTIFICATION: This manuscript has been copyedited by 33 Scriptrevision, LLC and conforms to Standard American English as prescribed by the 34 Chicago Manual of Style. The Scriptrevision manuscript reference number is B428B618, 35 which may be verified upon request by contacting [email protected].” 36 37 1 38 Long-term light environment variability in Lake Biwa and Lake Kasumigaura, 39 Japan: Modeling approach 40 41 Abstract Light environment variability was investigated in the two Japanese Lakes Biwa 42 and Kasumigaura, which offer a broad range of optical conditions in the water bodies due 43 to their diverse morphometries and limnological characteristics.
    [Show full text]
  • Annual Report on the Environment in Japan 2003 Published By: Ministry of the Environment Translated By: Ministry of the Environment Published in January 2004
    � AnnualAnnual ReportReport onon thethe EnvironmentEnvironment inin JapanJapan 20032003 Local Communities Leading the Transition to a Sustainable Society Ministry of the Environment To Our Readers This booklet was compiled based on the Quality of the Environment in Japan 2003 (White Paper), an annual report on the environment by the Government, published in accordance with a Cabinet decision made on May 30, 2003. The content of this booklet was edited to gear to a wider readership. The theme of this year’s White Paper is “Local Communities Leading the Transition to a Sustainable Society.” It introduces that daily voluntary activities carried out in local communities mark the first step in the transition to a sus- tainable society. The White Paper first shows the close interaction of the environment, society and economy, and the seriousness of the deterioration of the global environment. The Paper demonstrates that steady efforts at the individual and community levels will be essential for resolving global environmental problems. Individual actions are explored with an emphasis on the idea that if more individuals pursue environment-conscious activities, their activities will influence other actors, such as the government and businesses, and make it possible to reform the socio-economy as a whole. Initiatives by local communities are also examined. The Paper concludes that transition to a sustainable society is possible by (1) rais- ing the awareness of the whole community and building capacity (local environmental capacity) for the creation of a better environment and a better community, and (2) creating a model for protecting the environment and reinvigorating the community at the same time, and spreading the practice to other communities.
    [Show full text]
  • Lake Biwa Experience and Lessons Learned Brief
    Lake Biwa Experience and Lessons Learned Brief Tatuo Kira, Retired, Lake Biwa Research Institute, Otsu, Japan Shinji Ide*, University of Shiga Prefecture, Hikone, Japan, [email protected] Fumio Fukada, Retired, Shiga Prefectural Government, Otsu, Japan Masahisa Nakamura, Shiga University, Otsu, Japan * Corresponding author 1. Introduction The history of the lake’s management is also one of confl icts over water utilization and fl ood control between Shiga This brief outlines the major management issues for Lake Biwa, Prefecture and the central government or the downstream the largest freshwater lake in Japan. The lake and its watershed mega-cities, including Kyoto, Osaka and Kobe. The Lake Biwa communities have enjoyed a common history for thousands of Comprehensive Development Project (LBCDP), the largest years, fostering a unique lake culture in the surrounding area. The birth of the lake can 6HDRI-DSDQ 1 be traced back to some four million years ago. As one of few ancient lakes in the world, /<RJR it embraces a rich ecosystem, with fi fty-seven endemic species being recorded. At DNDWRNL5 7 $QH5 the same time, it is a principal /$.(%,:$ ,PD]X <2'25,9(5%$6,1 1DJDKDPD water resource in Japan, $GR5 1RUWK%DVLQ -$3$1 supplying drinking water for 14 'UDLQDJH%DVLQ%RXQGDU\ million people in its watershed 3UHIHFWXUH%RXQGDU\ /DNH 5LYHU %LZD +LNRQH and downstream areas. /DNH Additionally, its catchment 6HOHFWHG&LW\ 6+,*$ area is highly industrialized NP 35() and urbanized, being inhabited .DWDWD 2PL +DFKLPDQ (FKL5 by approximately 1.3 million . .<272 DWVXUD5 +LQR5 people, with the population 35() ,/(& still increasing at one of the .\RWR 6RXWK%DVLQ 2WVX .XVDWVX highest growth rates in Japan.
    [Show full text]
  • Lake Kasumigaura Database Interpretations of Observed Data (2001)
    Lake Kasumigaura Database Interpretations of observed data (2001) Edited by Center for Environmental Biology and Ecosystem Studies Published in May 2012 Remark: This document provides measurement methods and interpretations of observed data, complied from Lake Kasumigaura Database (CD-ROM) published in March 2001. Please refer to the following website for updated information. Data list, Lake Kasumigaura Database http://db.cger.nies.go.jp/gem/moni-e/inter/GEMS/database/kasumi/contents/database/datalist.html Index I. Weather 1. Monitoring system on meteorological and relating parameters (by Kazuo Matsushige) 1 II. Water Quality 2. Nutrients (by Yukihiro Nojiri) 2 3. In-situ observations 3-1. pH (by Morihiro Aizaki) 6 3-2. Water Temperature (by Takehiko Fukushima) 8 3-3. Electric conductivity (by Takehiko Fukushima) 8 3-4. Dissolved oxygen (by Takehiko Fukushima) 9 3-5. Secchi disc transparency and underwater light intensity (by Noriko Takamura) 9 3-6. Water depth (by Tomiji Hagiwara) 11 3-7. Position of station (by Tomiji Hagiwara) 11 4. Other variables 4-1. COD (by Takanobu Inoue) 11 4-2. Pigment (by Kazuo Matsushige) 13 4-3. SS (Suspended Solid) (by Kazuo Matsushige) 15 4-4. POC, PON (by Kazuo Matsushige) 16 4-5. C/N (by Kazuo Matsushige) 16 5. Methane (by Yukihiro Nojiri) 16 6. Heavy Metals 6-1. Heavy metals: Cu and Fe (by Kazuho Inaba) 22 6-2. Main Elements 24 (by Masataka Nishikawa, Reiko Kumata and Miyoko Takano) 7. Properties of bottom sediment (by Kuninori Otsubo) 27 III. Biological Data 8. Bacteria (by Morihiro Aizaki and Noriko Takamura) 29 9.
    [Show full text]
  • A Synopsis of the Parasites from Cyprinid Fishes of the Genus Tribolodon in Japan (1908-2013)
    生物圏科学 Biosphere Sci. 52:87-115 (2013) A synopsis of the parasites from cyprinid fishes of the genus Tribolodon in Japan (1908-2013) Kazuya Nagasawa and Hirotaka Katahira Graduate School of Biosphere Science, Hiroshima University Published by The Graduate School of Biosphere Science Hiroshima University Higashi-Hiroshima 739-8528, Japan December 2013 生物圏科学 Biosphere Sci. 52:87-115 (2013) REVIEW A synopsis of the parasites from cyprinid fishes of the genus Tribolodon in Japan (1908-2013) Kazuya Nagasawa1)* and Hirotaka Katahira1,2) 1) Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan 2) Present address: Graduate School of Environmental Science, Hokkaido University, N10 W5, Sapporo, Hokkaido 060-0810, Japan Abstract Four species of the cyprinid genus Tribolodon occur in Japan: big-scaled redfin T. hakonensis, Sakhalin redfin T. sachalinensis, Pacific redfin T. brandtii, and long-jawed redfin T. nakamuraii. Of these species, T. hakonensis is widely distributed in Japan and is important in commercial and recreational fisheries. Two species, T. hakonensis and T. brandtii, exhibit anadromy. In this paper, information on the protistan and metazoan parasites of the four species of Tribolodon in Japan is compiled based on the literature published for 106 years between 1908 and 2013, and the parasites, including 44 named species and those not identified to species level, are listed by higher taxon as follows: Ciliophora (2 named species), Myxozoa (1), Trematoda (18), Monogenea (0), Cestoda (3), Nematoda (9), Acanthocephala (2), Hirudinida (1), Mollusca (1), Branchiura (0), Copepoda (6 ), and Isopoda (1). For each taxon of parasite, the following information is given: its currently recognized scientific name, previous identification used for the parasite occurring in or on Tribolodon spp.; habitat (freshwater, brackish, or marine); site(s) of infection within or on the host; known geographical distribution in Japan; and the published source of each locality record.
    [Show full text]
  • A Revised and Updated Checklist of the Parasites of Eels (Anguilla Spp.) (Anguilliformes: Anguillidae) in Japan (1915-2017)
    33 69 生物圏科学 Biosphere Sci. 56:33-69 (2017) A revised and updated checklist of the parasites of eels (Anguilla spp.) (Anguilliformes: Anguillidae) in Japan (1915-2017) 1) 2) Kazuya NAGASAWA and Hirotaka KATAHIRA 1) Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan 2) Faculty of Bioresources, Mie University, 1577 Kurima machiya-cho, Tsu, Mie 514-8507, Japan Published by The Graduate School of Biosphere Science Hiroshima University Higashi-Hiroshima 739-8528, Japan November 2017 生物圏科学 Biosphere Sci. 56:33-69 (2017) REVIEW A revised and updated checklist of the parasites of eels (Anguilla spp.) (Anguilliformes: Anguillidae) in Japan (1915-2017) 1) 2) Kazuya NAGASAWA * and Hirotaka KATAHIRA 1) Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan 2) Faculty of Bioresources, Mie University, 1577 Kurima machiya-cho, Tsu, Mie 514-8507, Japan Abstract Information on the protistan and metazoan parasites of four species of eels (the Japanese eel Anguilla japonica, the giant mottled eel Anguilla marmorata, the European eel Anguilla anguilla, and the short-finned eel Anguilla australis) in Japan is summarized in the Parasite-Host and Host- Parasite lists, based on the literature published for 103 years between 1915 and 2017. This is a revised and updated version of the checklist published in 2007. Anguilla japonica and A. marmorata are native to Japan, whereas A. anguilla and A. australis are introduced species from Europe and Australia, respectively. The parasites, including 54 nominal species and those not identified to species level, are listed by higher taxa as follows: Sarcomastigophora (no.
    [Show full text]
  • Kasumigaura 1.Pdf
    IncorporatedIncorporated AdministrativeAdministrative AgencyAgency JapanJapan WaterWater AgencyAgency ToneTone RiverRiver DownstreamDownstream ArealAreal ManagementManagement OfficeOffice Dynamic Lake Kasumigaura Lake Kitaura Lake Nishiura Outline of Lake Kasumigaura Wani River Kitatone River Lake Sotonasakaura ○History of Lake Kasumigaura ○Outline of Lake Kasumigaura Hitachi River Lake Kasumigaura is located about 60km away from Lake Tokyo and in the southeastern part of Ibaraki Prefecture. It 2 2 Lake Nishiura 168.2km , Lake Kitaura Approx. 220km 2 2 is the second largest freshwater lake in Japan. Total space 35.0km , Hitachitone River & others 15.3km Lake Kasumigaura was a part of the Pacific Ocean with Total coastal line 250km Lake Nishiura 121.4km, Lake Kitaura 63.9km, downstream area of Tone River, Lake Inbanuma and Lake length Hitachitone River 64.6km Teganuma about 6,000 years ago. Later, sediment supplied Total capacity Approx. 850 mil. m3 at the time of Y.P.+1.0m from Tone River has separated these lakes from the ocean Max. depth 7m Average depth 4m and made Lake Kasumigaura what it is today. Water exchange Approx. 200 days ○Hydrological/meteorological characteristics Basin The Lake Kasumigaura basin area belongs to East Japan Type climatic zone. In winter, north-west seasonal winds Basin area 2,157km2 Approx. 1/3 of Total Ibaraki Pref. (6,097km2) called “Tsukuba Oroshi” tend to blow down from Mt. Total # of municipality 24 Ibaraki Pref.(17 cities, 4 towns, 1 village), Tsukuba and sunny days tend to last, and there is limited Chiba Pref. (1 city), Tochigi Pref. (1 town) amount of rainfall. In summer, south-east seasonal winds # of municipalities Ibaraki Pref.( 10 cities, 1town, 1village), surrounding the Lake 13 Chiba Pref.
    [Show full text]
  • The Water Quality in Lake Kasumigaura Has Been Deteriorating Since 1970'S [15, 22]
    The Dynamic Optimal Policy to Improve the Water Quality of Lake Kasumigaura•õ Yoshiro HIGANO* and Takayuki SAWADA** 1. Introduction The water quality in Lake Kasumigaura has been deteriorating since 1970's [15, 22]. The local government has constructed the sewerage system, and enacted the ordinance to prevent the deterioration of water quality. As a result, the water quality has been improved, but is still being deteriorated. The average depth of Lake Kasumigaura is only 4 meters and 56 rivers in total flow into the Lake. This is the root cause for the rapid deterioration of water quality. Furthermore, both the rapid population and economic growth in the catchment area due to the suburbaniza tion of the Tokyo Metropolitan Area in 1980's have made the deterioration more serious. The deterioration has had the following negative impacts on the living and the produc tion environment around the lake: a) impacts on the living: stink of the water bloom, decrease in the quality of the drinking water; b) impacts on the production: death of a large number of bred carp, decrease in the catch of fish; c) impacts on the sight-seeing resource: closure of swimming place, injury of the beauty of the lake. The study concerning Lake Kasumigaura has increased in number as the water quality deteriorated. The subjects of the studies are confined to the ecosystem of the lake (Goda, et al. [6]), the relation between the load of the pollutant which leads the deterioration of the water quality and the economic activities in the catchment area (Hosomi, et al.
    [Show full text]