Development of scenarios for future climate change in Suriname

This paper describes one way of developing climate change scenarios fortemperature and precipitation, using results of five atmospheric-ocean globalcirculation models (AO-GCMs). The scenarios are developed using theMAGICC/SCENGEN model and the GCMs, having a spatial resolution of 0.5º x 0.5ºlongitude/latitude. Four global emission scenarios, SRES A1, A2, B1, B2, and threetime horizons, year 2020, 2050 and 2080, are used. The results shows that there is arelative high correlation (0.66 to 0.86) between the monthly observed temperature dataand the modeled baseline data by the GCMs, while weak correlation (0.02 to 0.47) isfound between the monthly observed precipitation and modeled baseline data by theCSI296, GFDL90 and ECH498 model, and a relative high correlation (0.66 to 0.85) bythe HAD300 and CCSR96 model. Most of the GCMs follow the seasonal pattern ofthe temperature and precipitation in Suriname well. The model outputs show that forboth temperature and precipitation, the A1, B1 and B2 scenarios give similar results,which differ significantly from the A2 scenario. The climate change scenarios forSuriname lead to an annual increase in mean temperature up to 2.9ºC in 2080 forSRES A2, and 2.6ºC for SRES A1, B1, B2, reference to 1961-1990. For the annualprecipitation, an increase is expected up to 342.3 mm (16%) in 2080 for SRES A2 anda decrease in annual precipitation up to 102.6 mm (5%) in 2080 for SRES A1, B1, B2,reference to 1981-2000. The outputs of the SRES A1, B1, B2 indicate an increase inmean precipitation up till 2080 during January and April, and a decrease in meanprecipitation during May and December. The SRES A2 output indicates however anincrease in mean precipitation from December till March, and from July till October,and a decrease from April till June, and in November. The future increase in meantemperature will lead to an increase in evaporation/evapotranspiration andcorrespondingly changes in future precipitation. Wet and dry seasons in Suriname willbe affected, resulting in an overall increase or decrease of water resources. There istherefore a need to develop high resolution scenarios (scale of about 25-50 km), usingregional climate models (RCMs) in order to assess the impact of climate change onsmaller scales

Rainfall variability in Suriname and its relationship with the Tropical Pacific ENSO SST anomalies and the Atlantic SST anomalies

Spatial correlations (r) in the annual rainfall anomalies are analyzed using principlecomponent analyses (PCA). Cross correlation analysis and composites are used tomeasure the influence of sea surface temperatures anomalies (SSTAs) in the tropicalAtlantic and tropical Pacific Ocean with the seasonal rainfall in Suriname. It is shownthat the spatial and time variability in rainfall is mainly determined by the meridionalmovement of the Inter-tropical Convergence Zone (ITCZ). It occurs that the rainfallanomalies are fairly uniformly over the whole country. The strongest correlationbetween the December-January rainfall (short wet season) at station Cultuurtuin isfound with the SSTAs in the Pacific region and is about ckNino 1+2 = 0.59 at lag 1month. In March-May rainfall (beginning long wet season) there is a lagged correlationwith the SSTAs in the Pacific region (clag 3 Nino 1+2 = 0.59). The June-August rainfall(end part of long wet season) shows the highest correlation with SSTAs in the TSAregion and is about c = -0.52 for lag 0. In the September-November long dry seasonthere is also a lagged correlation with the TSA SSTAs of about clag 3 = 0.66. Thedifferent correlations and predictors can be used for seasonal rainfall predictions

Numerical modelling of cohesive sediment transport along a mud dominated coast

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Interaction of mangroves, coastal hydrodynamics and morphodynamics along the coastal fringes of the Guianas

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Managing erosion of mangrove-mud coasts with permeable dams – lessons learned

International audienceMangrove-mud coasts across the world erode because of uninformed management, conversion of mangrove forests into aquaculture ponds, development of infrastructure and urbanization, and/or extraction of ground-water inducing land subsidence. The accompanied loss of ecosystem values, amongst which safety against flooding, has far reaching consequences for coastal communities, exacerbated by sea-level rise. To halt erosion various nature-based solutions have been implemented as an alternative to hard infrastructure sea defenses, including mangrove planting and erection of low-tech structures such as bamboo fences, permeable brushwood dams, etc. These structures have been designed on the basis of best-engineering practice, lacking sufficient scientific background. This paper investigates the use and success of permeable dams over a period of about 15 years, describing their application in Guyana, Indonesia, Suriname, Thailand and Vietnam, summarizing the lessons-learned, and analyzing their functioning in relation to the physical-biological coastal system. Also an overview of relevant costs is given.The basic philosophy behind the construction of permeable dams is the rehabilitation of mangrove habitat through re-establishment of the (fine) sediment dynamics - we refer to Building with Nature as the overarching principle of this approach. Our main conclusions are that a successful functioning of permeable dams requires (1) a thorough understanding of the physical-biological system and analysis of the relevant processes, (2) patience and persistence, including maintenance, as the natural time scales to rehabilitate mangrove green belts take years to decades, and (3) intensive stakeholder involvement. We give a list of conditions under which permeable dams may be successful, but in qualitative terms, as local site conditions largely govern their success or failure