Unravelling the conundrum of river response to rising sea-level from laboratory to field. Part II. The Fly-Strickland River system, Papua New Guinea

被引:57
作者
Parker, Gary [1 ,2 ]
Muto, Tetsuji [3 ]
Akamatsu, Yoshihisa [4 ]
Dietrich, William E. [5 ]
Lauer, J. Wesley [6 ]
机构
[1] Univ Illinois, Hydrosyst Lab, Dept Civil & Environm Engn, Urbana, IL 61801 USA
[2] Univ Illinois, Hydrosyst Lab, Dept Geol, Urbana, IL 61801 USA
[3] Nagasaki Univ, Fac Environm Studies, Nagasaki 8528521, Japan
[4] Univ Ryukyus, Civil Engn & Architecture Program, Okinawa 9030213, Japan
[5] Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA
[6] Seattle Univ, Dept Civil & Environm Engn, Seattle, WA 98122 USA
基金
美国国家科学基金会;
关键词
Autoretreat; deltas; rivers; sea-level; transgression;
D O I
10.1111/j.1365-3091.2008.00962.x
中图分类号
P5 [地质学];
学科分类号
0709 ; 081803 ;
摘要
The most recent deglaciation resulted in a global sea-level rise of some 120 m over ca 12 000 years. A moving boundary numerical model is developed to predict the response of rivers to this rise. The model was motivated by experiments at small scale, which have identified two modes describing the transgression of a river mouth: (i) autoretreat without abandonment of the river delta (no sediment starvation at the topset-foreset break); and (ii) sediment-starved autoretreat with abandonment of the delta. In the latter case, transgression is far more rapid, and its effects are felt much further upstream of the river mouth. A moving boundary numerical model that captures these features in experimental deltas is adapted to describe the response of the Fly-Strickland River system, Papua New Guinea. In the absence of better information, the model is applied to the case of sea-level rise without local climate change in New Guinea. The model suggests that: (i) sea-level rise has forced the river mouth to transgress over 700 km since the last glacial maximum; (ii) sediment-starved autoretreat has forced enough bed aggradation to block a tributary with a low sediment load and create the present-day Lake Murray; (iii) the resulting aggradation was sufficient to move the gravel-sand transition on the Strickland River upstream; (iv) the present-day Fly Estuary may be, in part, a relict river valley drowned by sea-level rise and partially filled by tidal effects; and (v) the Fly River is presently reforming its bankfull geometry and prograding into the Fly Estuary. A parametric study with the model indicates that sediment concentration during floods plays a key role in determining whether or not, and to what extent, transgression is expressed in terms of sediment-starved autoretreat. A sufficiently high sediment concentration can prevent sediment-starved autoretreat during the entire sea-level cycle. This observation may explain why some present-day river mouths are expressed in terms of deltas protruding into the sea, and others are wholly contained within embayments or estuaries in which water has invaded landward.
引用
收藏
页码:1657 / 1686
页数:30
相关论文
共 41 条
[1]  
[Anonymous], QUATERNARY STUDIES
[2]   Deglacial sea-level record from Tahiti corals and the timing of global meltwater discharge [J].
Bard, E ;
Hamelin, B ;
Arnold, M ;
Montaggioni, L ;
Cabioch, G ;
Faure, G ;
Rougerie, F .
NATURE, 1996, 382 (6588) :241-244
[3]   A UNIFIED BAR BEND THEORY OF RIVER MEANDERS [J].
BLONDEAUX, P ;
SEMINARA, G .
JOURNAL OF FLUID MECHANICS, 1985, 157 (AUG) :449-470
[4]   Fluvial responses to climate and sea-level change:: a review and look forward [J].
Blum, MD ;
Törnqvist, TE .
SEDIMENTOLOGY, 2000, 47 :2-48
[5]  
BROWNLIE WR, 1981, KHR43A CAL I TECHN W
[6]  
Cui Y, 1999, SEDIMENT TRANSPORT D
[7]  
Dietrich W., 2004, P INT C CIV ENV ENG, P1
[8]  
Dietrich W.E., 1999, VARIETIES FLUVIAL FO, P345
[9]   ORIGIN OF MEANDERING AND BRAIDING IN ALLUVIAL STREAMS [J].
ENGELUND, F ;
SKOVGAAR.O .
JOURNAL OF FLUID MECHANICS, 1973, 57 (FEB6) :289-302
[10]  
ENGELUND F., 1967, MONOGRAPH SEDIMENT T