UNIVERSITÀ DEGLI STUDI DI PADOVA

Department Of Civil, Environmental and Architectural Engineering

MASTER DEGREE IN ENVIRONMENTAL ENGINEERING

MASTER THESIS

Decompacting Holocene delta sequences to quantify their (proper) weight

Supervisor: Prof. Teatini Pietro Graduate student:Anita Rigoni

Co-supervisors: Claudia Zoccarato

Philip S. J. Minderhoud

1206710

Most of the world major deltas are threatened by relative sea level rise ∆������:

• ��, delta aggradation rate;

• ∆��, sea-level rise;

• ����, natural compaction and ����, anthropogenic compaction;

• ��, downward vertical movement (tectonics).

The aim of this study is to quantify the weight of the Holocene portion of deltas to evaluate the natural component of the land subsidence:

1. Deformation of the Earth crust due to the cumulative load of Holocene (SIA);

2. Natural compaction of Holocene deposits.

The work is organized as follows:

1. Decompaction of Holocene delta sequences;

2. Construction of map of actual (i.e. compacted) delta thickness;

3. Representation of map of natural compaction of Holocene deposits;

4. Integration of 2-D representation over delta extent to compute the weight

5. Application of the modelling procedure to 8 major deltas.

Methodology

1. Decompaction of Holocene representative columns

2. Interpolation of Holocene thickness data

3. Set type of environment (i.e. marine/fluvial, coastal/inner)

4. Calculation of the weight

Methodology

From the combination of the previous flowchart steps, through the Weight Model, it is possible to extrapolate a 3-D grid with Holocene decompacted thickness. The total specific weight is computed as: �� = ��=1 �� ����(��) ∗����.

Po, Italy

Study areas

Pearl, China Krishna, India

Danube, Romania

Mekong, Vietnam

are those specifically addressed in this work. (1) Amazon, ; ( ) Amur, ; ( ) Mexico; (6) Congo, DRC; (7) Danube, Romania; (8) Fly, Papua New Guinea; (9) Ganges, Bangladesh; (10) Godavari, India; (11) Han, Korea; (12) Indus, Pakistan; (13) Irrawaddy, Myanmar; (14) Krishna, India; (15) Limpopo, Mozambique; (16) Magdalena, Colombia; (17) Mahakam, Borneo; (18) Mahanadi, India; (19) Mekong, Vietnam; (20) Mississippi, USA; (21) Niger, Nigeria; (22) Nile, Egypt; (23) Orinoco, Venezuela; (24) Parana, Argentina; (25) Pearl, China; (26) Po, Italy; (27) Rhone, France; (28) Sao Francisco, Brazil; (29) Tigris, Iraq; (30) Tone, Japan; (31) Vistula, Poland; (32) Yangtze, China; (33) Yellow, China.