Utilizing over 100 years of rainfall records in 15 meteorology stations, an analysis was carried out to extract the trends of annual rainfall depth in Sri Lanka over the last century. A statistically significant increasing trend of rate 3.15 mm/year was observed at Colombo and decreasing trends were observed at Nuwara Eliya and Kandy with rates of 4.87 mm/year and 2.88 mm/year respectively. Since no coherent increase or decrease of rainfall in any group of stations in the wet or dry zones was observed, the possibility of large scale change over the past century was ruled out. However, more recent data records (1949 onwards), revealed a decreasing trends in 13 of the 15 stations. Thus, traces of a temporal change seem to be apparent in the rainfall records over the last half century. In general, the downward trends in recent decades are steeper than the long term variations. For the recent data records, the largest downward trend of 11.16 mm/year was observed at Batticaloa. 9 data records maintained by the Department of Meteorology, Sri Lanka [2]. They have applied the necessary quality control checks on the data and estimated missing values using difference and ratio methods suggested by Thom [3]. The recent data records were obtained from the IRI monthly climatic data (IRI/LDEO Climate data Library) and Statistical abstracts from the Department of Meteorology as well as through direct purchase. Table 1 shows a summary of the selected rainfall stations used in this work.

Abstract:Two different spectral analysis methods, the multitaper method (MTM) and the maximum entropy method (MEM) were applied to investigate the presence of low-frequency periodicities in precipitation records of 14 climatological stations in Sri Lanka. The spectral analysis revealed statistically significant periodicities in the range of 2 -3 year and 3 -6 year periods in all parts of Sri Lanka irrespective of the climatic variability. The 2 -3 year band corresponds to the Quasi-Biennial oscillation (QBO), while the 3 -6 year band corresponds to the El-Nino/Southern oscillation (ENSO) higher and lower frequency bands. Cross spectrum analysis showed statistically significant (at 5 %) coherencies for the Indian Ocean dipole (IOD) and Southern oscillation index (SOI) in the 2 -3 year band and the 3 -6 year band, respectively for most of the regions. Thus, it is concluded that the IOD and SOI play important roles as modulators of precipitation in Sri Lanka.

Daily rainfall data recorded at 13 stations were analyzed to study the spatial patterns of rainfall in the dry zone of Sri Lanka. Principal component analysis was utilized to classify the dominant spatial regions. The first 2 eigenvectors accounted for 70.2% (the first eigenvector 54.8% and the second 15.4%) of the total variation, which clearly supports the commonly used major climatic division of Sri Lanka into wet and dry zones. Both the inverse distance weighting method and kriging successfully estimated weekly average rainfall in the North Central dry zone of Sri Lanka. For both methods, high correlation coefficients of 0.88 and 0.91 were observed for the southwest and northeast monsoon periods, respectively, with slightly lower values for intermonsoon periods. For inter-monsoon periods, the inverse distance weighting method produced better results than kriging. This work shows that the strength of the predictions depends on the rainfall seasons as well as the geometrical placement of the stations in the dry zone.

Two models were developed based on the Markov method to predict the occurrence of rainfall. Daily rainfall data from 9 meteorology stations in Sri Lanka namely, Colombo, Ratnapura, Kandy, Galle, Hambanthota, Batticaloa, Anuradhapura, Badulla and Trincomalee were analysed using these models. The results show that the models can forecast the status of a given day at an average of 73%. Higher agreement is seen for stations in the dry zone of Sri Lanka when compared with those in the wet zone. No significant difference was observed between the results obtained using the 1 st order Markov process and the 2 nd order Markov process. The models were not sensitive to the range of data used or the short-term fluctuations.

Laparoscopy is becoming the gold slandered of access to the abdomen and pelvis. However, it's not without unique complications. Trocar site hernia is a rare but a serious complication which can cause diagnostic confusion, in the early post-operative period. It can be potentially life threatening with obstruction, strangulation, incarceration and finally perforation of the bowel, after a seemingly uncomplicated laparoscopy. First ever TSH, reported by "Fear in 1968". Early studies described incidence from 0.002% to 5.2%. With improved surgical techniques & new closure methods, incidence has gone down significantly. Recent study, analyzing 55,244 cases reported it to be 0.016%. We discuss a case of small bowel herniation through the "12 mm lateral port", even after aponeurotic closure with polyglactin. She presented with subacute bowel obstruction needing laparotomy. A diagnostic dilemma can arise in differentiating TSH, from "iatrogenic bowel perforation &peritonitis". This article discusses how to minimize this serious complication, different port closure methods, suture materials, using currently available evidence and recommendations. USS may be less convincing particularly in obese. Diagnosis is commonly aided by plain X-ray film. CECT has significant advantages in differentiating TSH from incarcerated small bowel & ileus. RCOG advices closure of all 7 mm or larger lateral ports & 10 mm or larger midline ports. It can be prevented with proper pre-op evaluation, appropriate port selection, good specimen retrieval techniques, and use of proper closure methods & devices. Conventional J needle, laparoscopic suturing of the rectus sheath under direct vision, port closure devices, all have their own pros & cons. Specially designed port closure devices are encouraged wherever possible, especially in obese as well as patience with other risk factors. European hernia society recommends slowly absorbable monofilament sutures. Suture materials with higher tensile strength such as PDS in comparison to polyglactin may further improve outcome.