Disastrous Flood of 2013 in the Amur Basin: Genesis, Recurrence Assessment, Simulation Results V
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ISSN 00978078, Water Resources, 2014, Vol. 41, No. 2, pp. 115–125. © Pleiades Publishing, Ltd., 2014. Original Russian Text © V.I. DanilovDanilyan, A.N. Gelfan, Yu.G. Motovilov, A.S. Kalugin, 2014, published in Vodnye Resursy, 2014, Vol. 41, No. 2, pp. 111–122. WATER RESOURCES AND THE REGIME OF WATER BODIES Disastrous Flood of 2013 in the Amur Basin: Genesis, Recurrence Assessment, Simulation Results V. I. DanilovDanilyan, A. N. Gelfan, Yu. G. Motovilov, and A. S. Kalugin Water Problems Institute, Russian Academy of Sciences, ul. Gubkina 3, Moscow, 119333 Russia Email: [email protected] Received October 25, 2013 Abstract—The major formation factors of a disastrous flood in the Amur basin in July ⎯ September 2013 are discussed. The role of the Zeya and Bureya reservoirs in reducing the flood hazard is discussed. Preliminary estimates of the recurrence of peak flood discharge are given. It is shown that, considering the deficiency of data on water discharges along the river and the short duration of the available observation series, the esti mates of flood hazard on the Amur R. obtained by statistical treatment of those data shows considerable uncertainty. A physicalmathematical model was developed to describe runoff formation in the MiddleAmur basin based on the ECOMAG information ⎯ simulation complex and a onedimensional hydrodynamic model describing the motion of flood wave over a 600km segment of the Amur R. was developed based on MIKE 11. The potentialities of the joint use of the proposed models to reproduce the behavior of water dis charges and levels in different parts of the Amur R. during the propagation of the flood in 2013 and to evaluate the effect of withdrawals from the Zeya Reservoir to the water level regime of the Amur downstream of the Zeya R. mouth. Keywords: flood, Amur, risk, simulation, reservoir DOI: 10.1134/S0097807814020055 INTRODUCTION for its higher population abundance and density, where more than 200 are killed or missing, more than The rain flood that formed in Amur basin rivers in 800000 were evacuated, and the total damage caused July ⎯ September 2013 embraced vast territories in the by the flood is estimated at $15 billion. Russian Far East and Northeastern China and became one of the major natural disaster of the XXI century in The analysis of the specific features of formation of terms of duration, the area involved, the number of the flood in the basin as a whole and its individual persons affected, and the economic losses. parts; the assessment of the recurrence of the recorded Almost the entire Amur Basin, which ranks tenth water discharges and levels taken into account climate in the world in size (1.85 million km2), suffered from a changes and the economic activity in the basin; the disastrous flood lasting over two months. Dozens of application of mathematical models to reproduce the populated localities were inundated in the Amur prov spatial pattern of formation of the catastrophic flood ince, Jewish Autonomous Province, and Khabarovsk and its propagation along river channels; the develop Territory. In the largest cities of Khabarovsk and ment, based on those models, of procedures for assess Komsomol’skonAmur, water rise exceeded the ing the hazard and forecasting the flood runoff in the maximal level on record. According to official figures areas in the Amur basin that can suffer from inunda as of midOctober 2013, the total number of persons tion are urgent problems, whose solution will make it affected by the flood was in excess of 168000. More possible to assess the efficiency of protection mea than 12000 houses were destroyed and almost 20% of sures, both being implemented and planned, to them are beyond rebuilding. Tens of thousands per improve the safety of hydroengineering structures sons were evacuated from the disaster zone. The total (HES), and to reduce the damage from the future economic damage is estimated by the Russian govern extraordinary floods in this floodendangered region. ment at 40 billion rubles; however, this amount can be expected to increase. It would not be overstating to say The article gives the first results of solving the above that this flood became a nationalscale catastrophe for listed problems for the MiddleAmur Basin by experts Russia. The effect of the flood was even more disas from Water Problems Institute, Russian Academy of trous for the Chinese part of the Amur Basin, known Sciences. 115 116 DANILOVDANILYAN et al. Highwater stand marks and the duration of inundation during 2013 flood propagation Elevation of the hazardous Maximal observed level Start of the hazard End of the hazard Gage Duration, days phenomena above above gage datum, cm ous phenomenon ous phenomenon gage datum, cm Blagoveshchensk 800 821 Aug. 14 Aug. 24 11 Konstantinovka 750 924 Aug. 5 Aug. 30 26 Poyarkovo 750 833 Aug. 10 Aug. 28 19 Innokent’evka 930 1081 Aug. 12 Aug. 31 20 Pashkovo 1600 1802 Aug. 15 Sep. 2 19 Leninskoe 850 1044 Aug. 7 Sep. 13 38 Khabarovsk 600 808 Aug. 16 Sep. 18 34 Troitskoe 450 610 Aug. 19 Sep. 26 39 Komsomol’sk 650 910 Aug. 25 Oct. 3 40 Mariinskoe 550 707 Sep. 2 Oct. 8 37 NATURAL FACTORS GOVERNING FLOOD There exists an idea that the formation of such FORMATION AND THE ROLE anomalous synoptic phenomena is due to the current OF RESERVOIRS IN REDUCING FLOOD climate changes, accompanied by an increase in the HAZARD IN THE AMUR BASIN number and power of cyclones in the Northern Hemi sphere with a greater occurrence of periods with heavy The flood of 2013 in the Amur basin formed as the precipitation, on the one hand, and greater drought result of an extremely rare combination of unfavorable depths, on the other hand [6]. hydrometeorological factors. The major factor that determined this disaster was a unique synoptic situa Another critical factor of the Amur flood is the high tion that had formed over the territories of the Russian water saturation of soils in the vast areas of river basins Far East and Northeastern China during the devel by the beginning of flood season. According to Roshy oped phase of summer monsoon. According to data of dromet data, the high moisture content of soils was a Roshydromet, this situation can be characterized by result of the cold snowy winter of 2012 ⎯ 2013, which two features: (1) the formation of a high frontal zone, caused the formation of a thick snow cover in those along which deep and moisturesaturated cyclones basins, and a late spring, during which a considerable moved incessantly during two months; (2) the forma portion of snowmelt water was absorbed by soils. The tion of a blocking highpressure domain above the saturation of soils with water has led to a critical drop northwestern Pacific, which hampered a displacement in their water retention capacity and an abrupt of those cyclones from the continent toward the Sea of decrease in the natural regulating capacity of river Okhotsk. A result of those synoptic processes was the basins before the rains. The result was that huge masses formation of rain precipitation with anomalous vol of rainwater, which fell onto the slopes of river valleys ume, duration, and occurrence area in the basins of since July, with minimal losses to infiltration into soil, largest rivers in the region. The precipitation depth in ran to river network, where they caused simultaneous some parts of the Amur basin in July and August 2013 formation of flood waves and an abrupt increase in was in excess of the appropriate annual amount. water discharges and levels in rivers in the basin. In many segments of the river network, water level Similar synoptic processes have repeatedly become exceeded the maximal values recorded during the the major cause of catastrophic floods in different period of instrumental observations in this flood parts of the planet. A vivid example is the formation of endangered region. Thus, according to Roshydromet a giant blocking highpressure domain, which caused data, the maximal water level in Khabarovsk was anomalously hot weather in European Russia, extend 808 cm (against the historical maximum of 642 cm in ing to Kazakhstan and Northwestern China in sum 1897) and that in KomsomolskonAmur was 910 cm mer 2010 and resulting in extremely high and long (the historical maximum of 1959 was 701 cm). As can time precipitation and, hence, a catastrophic flood in be seen from the table, which was constructed based the Indus R., which embraced an area of nearly 1 mil on data of the Center of Register and Cadaster, Fed lion km2 and killed more than 2000 in Pakistan [8]. eral Water Resources Agency, the inundation level all WATER RESOURCES Vol. 41 No. 2 2014 DISASTROUS FLOOD OF 2013 IN THE AMUR BASIN 117 over the Middle and Lower Amur was 1 ⎯ 3 m above the river system. An example of such study is given in the hazardousevent level, and the duration of water stand last section of this article. above this level was almost 1.5 month. The maximal water discharge in this period, recorded by experts from State Hydrological Institute at the propagation of ON THE PROBLEM OF ASSESSING flood peak at Khabarovsk, was 46000 m3/s, which is THE RECURRENCE OF MAXIMAL FLOOD almost twice as large as the normal annual maximal RUNOFF OF 2013 BASED ON THE AVAILABLE discharge in this section (24700 m3/s). OBSERVATIONAL SERIES Continuing further analogies in terms of formation Assessing the peak discharge of flood runoff with a factors with large recent floods in other regions of the given exceedance probability (or recurrence) is of pri world, we have to mention the catastrophic (50 killed, mary importance for the taking of hydroengineering economic damage above $15 billion) flood in the Mis measures aimed to mitigate the effects of floods.