An assessment of nutrient, sediment and carbon fluxes to the Indus Delta

Abstract

Nutrient and carbon flux play a significant role in the deltaic nourishment. These  fluxes significantly  involved  in the stability of deltaic coast. Recent studies reflect that Indus River discharge is subtracted due to Khobar Creek, which is presently the only creek that carries the fresh water of Indus River into the Arabian Sea. There has been a drastic reduction in the load of nutrients brought by Indus River for the last fifty years. This reduction in Indus discharge has a negative impact on the Indus estuary and the productivity of the mangrove forest and fisheries. The Indus River bed sediments have relatively low values of calcium carbonate (< 10%) because sand contains relatively high concentrations of mica (36%), quartz (37%) and feldspar (11%) with very little percentage of detrital carbonate sediments. The organic carbon and calcium carbonate content in the sediment samples obtained from the area averages <1% and <15% respectively.  Low values of the C_org (< 1%) were obtained for the bed samples of the Indus River. The bed sediments are generally composed of fine sand size material. Therefore, they have comparatively less C_org. The Indus River water and sediment discharge to the deltaic area and eventually to Arabian Sea is limited to few days during the months of July and August.