Climate change and agricultural adaptation in Sri Lanka: a review

Climate change is inevitable and will continue into the next century. Since the agricultural sector in Sri Lanka is one of the most vulnerable to climate change, a thorough understanding of climate transition is critical for formulating effective adaptation strategies. This paper provides an overview of the status of climate change and adaptation in the agricultural sector in Sri Lanka. The review clearly indicates that climate change is taking place in Sri Lanka in terms of rainfall variability and an increase in climate extremes and warming. A number of planned and reactive adaptation responses stemming from policy and farm-level decisions are reported. These adaptation efforts were fragmented and lacked a coherent connection to the national development policies and strategies. Research efforts are needed to develop and identify adaptation approaches and practices that are feasible for smallholder farmers, particularly in the dry zone where paddy and other food crops are predominately cultivated. To achieve the envisaged growth in the agricultural sector, rigorous efforts are necessary to mainstream climate change adaptation into national development policies and ensure that they are implemented at national, regional and local levels

Evapotranspiration fluxes over mixed vegetation areas measured from large aperture scintillometer

Routine measurement of spatially averaged surface fluxes of sensible heat (H) in river basins is now feasible. These fluxes, when combined with net radiation estimates, can be used to derive areally averaged actual evapotranspiration (ET). The scintillation method is shown to be promising method for estimating areally averaged sensible heat fluxes. The large aperture scintillometer (LAS) is an optical device used to monitor fluctuations in refractive index of the turbulent atmosphere over a relatively large area. The study reported here has estimated ET fluxes for an area of mixed vegetation at Horana, a field site about 40 km southeast of Colombo, Sri Lanka. ET estimates derived from the scintillometer and net radiometer were compared with estimates obtained from a remote sensing based surface energy balance algorithm for land (SEBAL). The SEBAL estimating of ET were derived using NOAA satellite images without any a priori calibration. The average deviation of ET estimates between SEBAL and LAS for 10-day periods was 17%. However, this deviation fell to 1% when monthly estimates were considered. This suggests regional ET values derived from remote sensing are reasonable estimates, however, the LAS was used in only one agro-ecosystem to validate the SEBAL model. The LAS is a low cost alternative to other methods of estimating heat fluxes for use in basin scale water use studies. (C) 2002 Elsevier Science B.V. All rights reserved

Impacts of climate change on water resources and agriculture in Sri Lanka: a review and preliminary vulnerability mapping

Climate change / Rain / Water resource management / Crops / Mapping / Sri Lanka

Assessing potential loss and damage for flood hazard using an econometric modelling technique

Agriculture production largely depends on weather conditions and is extremely prone to natural hazards. A more frequent and severe occurrence of natural hazards such as storms and floods has put food security at increased risk in recent decades. Evaluating the true impact (loss and damage) of disaster in the agriculture sector is very challenging. The present study focusses on using a zrandomized field experimental approach at both district and micro agricultural-plot levels to investigate the impact of floods on agricultural yields in Sri Lanka and its effect on farmers who are averse to taking risks and those who are willing to take risks. A detailed site selection technique has been used in the study. The dissimilarity in difference estimates indicates that flood-affected households have experienced the loss of paddy and non-paddy crops. However, the net loss of non-paddy is higher than that in paddy. Farmers offset this loss by expanding crop cultivated areas zthat utilize soaked fields after the flood, though there are risks of pest attack and diseases. The results are not driven by household-specific characteristics and are robust to several specifications, different crop types and alternative flood-severity measures.</jats:p