Siltation

About: Siltation is a research topic. Over the lifetime, 1420 publications have been published within this topic receiving 20983 citations.

Coastal Change Detection using GIS in Setiu Lagoon, Terengganu, Malaysia

Abstract: The Peninsular Malaysia coastline, which is covered about 4,800 km in length, is rich by coastal resources and has an abundance of natural biodiversity. The development which occurred along the coastal lines have led to the host of problems such as increased erosion, siltation, and loss of coastal resources and the destruction of the fragile marine habitat. In order to conserve the depleting coastal resources, the changes due to development and associated activities must be monitored. This paper was intended to detect changes of coastal area in Setiu Lagoon, Terengganu and to provide future database in coastal management studies. Analysis was carried out using GIS platform and the results of coastal change were disseminated in digital format which can be used for conducting further geographic analysis. The results showed that from 1980 to 2004, the movement of sand spit was about 7.0 m/yr for shoreline length and 0.8 m/yr for the small islands. This study emphasized that the critical areas were found around the estuary and islands were eroded slowly due to the waves, current and dominant winds actions during monsoon loaded. The other factor was due to depletion of the mangrove forest areas. It is therefore necessary to monitor coastal zone changes because the importance of environmental parameter, storm impact prevention and human disturbance.

Wetlands and still waters

Abstract: INTRODUCTION Wetland and still water habitats are elements of a continuum that depend upon water storage and supply for their continued existence and ecological stability. If inputs of water are significantly reduced, or outputs are increased, the water balance will change and wetland ecology is likely to suffer. Many types of wetland have frequently been damaged by artificial drainage, in what has been termed ‘reclamation’ for economic exploitation such as agriculture, forestry or peat production (see, for example, Gilman, 1994). Also significant in many situations may be a change in water-storage capacity, either by manipulation of the ground surface (peat extraction) or by increased sedimentation caused by accelerated soil erosion as a result of human land-use changes. Cooke et al. (1993) indicated that 25% of lakes assessed in the USA could be described as ‘impaired’ and 20% as ‘threatened’ in some way. Often this was by nutrient enrichment, but other stresses included siltation and inappropriate water levels. Allen & Feddema (1996) suggest that wetland restoration involves actions aimed at improving damaged or deteriorating areas that were once healthy wetlands. In many countries, these natural wetlands are now only a fraction of their historical extent and have been identified as priority habitats for ecological restoration (e.g. Cooke et al. , 1993; Allen & Feddema, 1996; Tallis, 1998). This chapter relates to the fundamental principles that control the physical environment of wetlands and still waters. It concentrates upon fresh waters rather than estuarine or coastal wetlands.

Coastline change detection of the Yellow River Delta by satellite remote sensing

Abstract: We used remote sensing and geographic information system to extracted coastlines of the Yellow River Delta from muti-temporal Landsat TM/ETM+ images(1989~2009),and analyzed the length and area variations of the Yellow River DeltaThe shape and length of the coastline in the Yellow River Delta had significantly changed since 1989Coastal erosion occurred in the Diaokou Estuary area where the shoreline was not protected by damThe whole coastline in Qingshuigou area extended seaward because some parts of it suffered from erosionCoastline in Shenxiangou area changed little because most parts of it were protected by damThe area of the Yellow River Delta increased from 1989 to 2009,though it decreased from 2006 to 2009The annual average of area that erosion occurred or siltation changed from small to largeThe Yellow River Delta was in expansion in the last 20 yearsBut from 2006 to 2009,the area of the Yellow River Delta was decreased and more area had been in erosion or siltation statusDischarge and sediment concentration of the Yellow River,precipitation and water diversion were main factors that influenced the area change of the Yellow River DeltaArtificial dams were able to resist the invasion of sea wave and to maintain the stability of coastlineThe result of this work is contributed to the management and reservation of coastal environment