Abstract

There is much discussion in the scientific literature and concern in the wider community about climate

change, recent climate analyses indicate that the magnitude of 21st Century warming is likely to have been the

largest of any century for the last 1000 years over the northern hemisphere. All the IPCC's four reports between

1990 and 2007 concluded that we cannot expect stable climate in the future and we should prepare scenarios

and strategies for the survival of humankind under the conditions of forthcoming global change. In this study,

the applicability of the statistical downscaling model (SDSM) in downscaling temperature in Misurata area -

Libya, was investigated. The investigation includes the calibration of the SDSM model by using large-scale

atmospheric variables encompassing NCEP reanalysis data, the validation of the model were measured daily

temperature data (1961-1990) using independent period of the NCEP reanalysis data and the general circulation

model (GCM) outputs of scenarios A2 and B2 of the HadCM3 model. The model is calibrated and applied at a

daily time series, even though the output is monthly and the prediction of the future regional maximum and

minimum temperature scenarios for three time windows: 2011-2040, 2041-2070 and 2071-2099. The results showed

that: The statistical downscaling model (SDSM) was able to describe the basic statistical properties of daily

minimum and maximum temperature in the period of record, suggesting that it could be used to predict future

trends. Trend analysis in the study area showed an increase in average annual and monthly temperature,

compared to the baseline period for both HadCM3A2a and HadCM3B2a scenarios in both the dry and wet

seasons. However, this increase is higher in dry months than wet months for all future time horizons and for

both HadCM3A2a and HadCM3B2a scenarios. Thus there is likely to be a significant warming in local surface

temperature, which is enough for a significant change on the energy balance and is likely to impact water

availability.

Key words: Statistical downscaling model SDSM Intergovernmental Panel on Climate Change

IPCC General circulation model GCM Special Report on the Emission Scenarios SERS

Maximum and minimum temperature Misurata area Libya

Abstract

Most of Arabic countries are located within the arid and semi-arid zones, which are characterised by the scarcity and the high spatial and temporary variability of rainfall .The influence of rainfall patterns on natural vegetation cover is significant and can be monitored and assessed using NDVI indices derived from remote sensing data. The literature stresses on the wide use of NDVI to study the changes in vegetation cover, because of the sensitivity of vegetation to the Red and Infra-red spectrum. In this paper the SPOT Apparent Green Cover Percentage data and MODIS Vegetation index are used to monitor the vegetation cover change in North western Libya. The aim of this study is to establish the spatial and temporal changes in vegetation cover and their relation to the rainfall pattern. The data and method: The utilized data for research included multi-temporal remotely sensed data (Spot, MODIS, and Landsat ETM), climatic data (ground stations and satellite data) and digital maps (DEM, slope, flow direction and basins). The satellite images were firstly pre-processed. This included the importing of different format images into a standard format of the ERDAS IMAGINE 9.1. Then the dataset were geometrically corrected into the WGS84 latitude/longitude geographic co-ordinate system. The study area was then subseted using a vector file representing the area boundary (AOI). The multibands were stacked to create time series, the NDVI equation was used to convert the DN values into NDVI values.