نشریه علوم زمین خوارزمی

نشریه علوم زمین خوارزمی

پتانسیل فرونشست زمین در دشت تهلاب و ارتباط دفع پساب خانگی با رومبندگی چاه‌های فاضلاب شهر ریگ ملک، جنوب شرق زاهدان

نویسندگان
1 دانشگاه تهران
2 دانشگاه سیستان و بلوچستان
چکیده
دشت تهلاب در حوضه‌ی آبریز هامون ماشکیل در جنوب منطقه میرجاوه و در طول نوار مرزی ایران و پاکستان واقع گردیده است. در بیشتر نواحی روستایی این دشت بویژه مناطق شمالی آن در امتداد مرز ایران و پاکستان آثار فرونشست بصورت ترک و شکاف در ساختمان‌ها و چاه‌های جذبی به وفور مشاهده می‌گردد. به منظور ارزیابی این فرونشست‌ها، در ابتدا دشت تهلاب از نظر ریسک فرونشست، پهنه‌بندی گردید. بر پایه نقشه پهنه‌بندی خطر فرونشست مشاهده می‌شود که اکثر مناطق دشت تهلاب از خطر فرونشست کمی برخوردار هست به استثنای منطقه‌ شمال دشت تهلاب که در این منطقه دبی چاههای بهره‌برداری زیاد می‌باشد. برای بررسی دلایل فرونشست زمین و رابطه آن با جنس خاک در مناطق شمالی دشت تهلاب، پتانسیل رمبندگی نمونه‌های خاک ارزیابی گردید. نمونه‌برداری خاک از اعماق مختلف چهار چاهک مطالعاتی انجام گردید. ضریب رمبندگی نمونه‌های خاک بر طبق معیار جنینگز و نایت در دستگاه ادئومتر در آزمایشگاه در حالت اشباع بین 0/21 تا 7/3 اندازه‌گیری گردید که نشان داد خاک این منطقه رمبنده است. در انتها برای بررسی وقوع ریزش ناگهانی در چاههای جذبی در مناطق شمالی دشت آزمایش نفوذپذیری به روش استوانه تک در اعماق مختلف یکی از چاهک‌ها صورت گرفت که نشان داد یک لایه نفوذپذیر با نرخ نفوذپذیری 9/24 سانتی‌متر در ساعت در بین دولایه با نفوذپذیری کم قرار دارد که باعث افزایش سطح آب در چاه‌های جذبی می‌گردد و متعاقب آن حد روانی اکثر نمونه‌های خاک سطحی شهر ریگ ملک کمتر از 30 درصد اندازه‌گیری گردید. نتایج نشان داد که میزان نفوذ‌پذیری خاک به همراه حد روانی تاثیر مستقیمی بر ریزش چاه‌های جذبی دارند.
کلیدواژه‌ها

عنوان مقاله English

Land subsidence potential in the Tahlab plain and the relationship between domestic wastewater and collapse in sewage wells in the Rig-Malek city, southeast of Zahedan

نویسندگان English

Reza Jahanshahi 1
Ebrahim Gamshadzahi Mahboub 2
Hamid Reza Soloki 2
Mehdi Azhdary Moghaddam 2
1 University of Tehran
2 University of Sistan and Baluchestan
چکیده English

The Tehlab plain is located in the Hamoun Mashkil catchment in the south of Mirjavah region and along the Iran-Pakistan border. In most of the rural areas of this plain, especially in the northern parts of the plain along the border of Iran and Pakistan, the effects of land subsidence in the form of cracks and fissures in buildings as well as collapse in sewage wells were observed. In order to evaluate these land subsidences, the Tehlab plain was first zoned in terms of subsidence risk. Based on the land subsidence risk zoning map, it can be seen that most of the areas of the Tahlab plain have a low risk of subsidence, except for the northern region, where there are many exploitation wells in this area. To study the collapse in sewage wells and its relationship with soil type in the northern regions of the plain, the collapsibility of soil samples was investigated. According to Jennings and Knight criteria in the oedometer device in the laboratory in the saturated state. the coefficient of collapsible of soil samples was measured between 0.21 to 7.3, which showed that the soil samples were collapsible in this area. Finally, to investigate the occurrence of collapse in sewage wells in the northern of the plain, an in-situ permeability test (ring) test was performed at different depths of a dug well. This test showed that a soil layer with high permeability rate (9.24 cm/hr) was located between low permeability layers. These low permeability layers caused an increasing the water level in the sewage wells. Moreover, the liquid limit of most surface soil samples was less than 30%. Therefore, the soil permeability and liquid limit were the most important factors controlling collapse in the sewage wells.

کلیدواژه‌ها English

Soil permeability
Liquid limit
Collapsible
Land subsidence
ASTM D4318., 2010. Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils. Annual Book of ASTM Standards, Section 4, (04.08), Soil and Rock; Building Stones. ASTM International, West Conshohocken.
Behniafar, A., Ghanbarzadeh, H., Eshraghi, Ali., 2010. Investigation of effective factors in Mashhad plain subsidence and its geomorphic consequences. Zagros Landscape Geographic Quarterly 2(5), 131-146. (in Persian).
Carminati, E., Martinelli, G., 2002. Subsidence rates in the Po Plain, northern Italy: the relative impact of natural and anthropogenic causation. Engineering Geology 66, 241–255.
Castellazzi, P., Domínguez, N., Martel, R., Calderhead, A., Normand, J., Gárfias, J., Rivera, R., 2016. Land subsidence in major cities of Central Mexico: InterpretingInSAR-derived landsubsidence mapping with hydrogeological data. International Journal of Applied Earth Observation and Geoinformation 47, 102–111.
Embacher, R., 2006. Duration of Spring-Thaw Recovery for Aggregate- Surfaced Roads. TRB Annual Meeting. American Engineering Testing, Inc. 1967(1), 27-35.
Fijani, E., Zarei P., 2024. Evaluation of land subsidence potential in Humand-Absard aquifer using remote sensing methods and its relationship with groundwater abstraction. Hydrogeology 9(1), 1-15. (in Persian).
Hu, R. l., Wang, S.J., Lee, S.F., Li, M.L., 2002. Characteristics and trends of land subsidence in Tanggu, Tianjin, China. Bull Eng Geol Env 61(3), 213–225.
Jehring, S., 2006. Engineering geology problems in loess deposits. http://www.geo.tufreiberg, de/oberseminar/os06-07/susann-jehring, pdf.
Khaloei, F., Elmizadeh, H., 2023. Monitoring the Subsidence of Kazerun Plain Using SENTINEL Images and Radar Interferometric Technique (DInSAR). Journal of Engineering Geology 17(2), 169-186.
Lashkaripour, G., Ghafouri, M., Rezaei, H., Taghavi, S.A., 2013. Mechanism of collapse of Golestan loess. First National Conference of Geotechnical Engineering of Iran, University of Mohaghegh Ardabili. (in Persian).
Mohammadi, S.D., 2008. Development of the application of DCP dynamic probe to determine engineering parameters of sandy soils. Doctoral thesis, Tarbiat Modares University. (in Persian).
Nguyen, Q.T., 2016. The Main Causes of Land Subsidence in Ho Chi Minh City. Sustainable Development of Civil, Urban and Transportation Engineering Conference, Procedia Engineering 142, 333 - 340.
Omidvar, K., 2011. Natural hazards. Yazd University. Yazd. (in Persian).
Rajabi, Al., Khoshakhlagh, A., 2015. Study of land subsidence in Qom plain due to exploitation of groundwater resources. Tehran, Water Engineering Conference and Exhibition. (in Persian).
Ranjbar, M., Jafari, N., 2009. Investigation of effective factors in land subsidence of Eshtehard plain. Scientific Research Journal of the Iranian Geographical Society 6(18-19), 155-166. (in Persian).
Scott, R.F., 1979. Subsidence‐revaluation and prediction of subsidence. Ed.By Saxema, S.K., Proc. Cnof, ASCE,Gainsville, 1-25.
Stairos, C., 2001. Subsidence of Thessaloniki (northern Greece) coastal plain,1960-1999. Engeenering Geology 61, 243-256.
Tafreshi, G, Nakhaei, M., lak, R., 2021. Land subsidence risk assessment using GIS fuzzy logic spatial modeling in Varamin aquifer, Iran. GeoJournal 86(38), 1203-1223.
Taheri, Z., Nadiri, A., Barzegari, Q., 2017. Study of subsidence in Shabestar Plain using GIS. The Second National Conference of Iranian Hydrology, Shahrekord University. (in Persian).
Wang, j., Ma, y., Guo, Q., Chu, D., 2017. Influence of Pressure and Water Content on Loess Collapsibility of the Xixian New Area in Shaanxi Province, China. Earth Sci. Res. J 21(4), 197-202.
Zhang, Y., Xue, Y.Q., Wu, J.C., Yu, J., Wei, Z.X., Li, Q.F., 2008. Land subsidence and earth fissures due to groundwater withdrawal in the Southern Yangtse Delta, China. Environ Geol 55(4), 751–762.
Zhu, L., Gong, H., Li, X., Wang, R., Chen, B., Dai, Z., Teatini, P., 2015. Land subsidence due to groundwater withdrawal in the northern Beijing plain. China Engineering Geology 193, 243–255.