Worldwide Typology of Nearshore Coastal Systems: Defining the Estuarine Filter of River Inputs to the Oceans

Table 4 Global riverine connection to estuarine filter for river basin area (A _b), coastal length, total population, coastal population (at mouth), water discharge (Q) and sediment load per type

Type	River basin area (A _b; 10⁶ km²)	Percent	Coastline length (km)	Percent	Total population (10⁶ p)	Percent	Coastal population (at mouth) (10⁶ p)	Percent	Water discharge (km³ year⁻¹)	Percent	Sediment load (10⁶ t year⁻¹)	Percent
I—small deltas	21.1	15.2	131,167	30.1	1,273	20.7	405	43.1	6,458	16.5	7,305	42.5
II—tidal systems	34.8	25.0	91,326	21.0	2,163	35.2	281	29.9	10,718	27.4	2,732	15.9
III—lagoons	7.2	5.2	33,286	7.6	399	6.5	102	10.9	1,824	4.7	801	4.7
IV—fjords	8.7	6.3	105,657	24.3	44	0.7	20	2.1	2,732	7.0	815	4.7
V_a—large rivers	20.1	14.5	2,945	0.7	649	10.6	6.8	0.7	4,400	11.3	672	3.9
V_b—tidal large rivers	18.7	13.5	2,945	0.7	972	15.8	10.9	1.2	11,858	30.3	3,746	21.8
VI—karst	0.5	0.4	10,543	2.4	58	0.9	34.4	3.7	310	0.8	284	1.7
VII—arheic	9.1	6.5	35,979	8.3	172	2.8	69.7	7.4	32	0.1	75	0.4
Total exorheic	120.1	86.5	387,103	94.4	5,730	93.3	929.3	99.0	38,333	98.1	16,431	95.6
Endorheic^a	18.8	13.5	24,469	5.6	409	6.7	9.4	1.0	757	1.9	748	4.4
Grand total	138.9	100	411,572	100	6,139	100	938.7	100	39,090	100	17,179	100

^aEndorheic coastline: mostly Caspian and Aral Sea coastlines plus few end lakes