Is GIS Appropriate Technology

Abstract. Appropriate technology(AT) has become an integral part if the programmes for decentralized regional development in the third world appropriate techniques are usually low in capital costs-they can be maintained without a high level of expertise, and they do not involve patents, expensive copyrights and royalties. By these criteria a commercial geographical information system(GIS) is not an appropriate technology to be used in decentralized development. However, the use of local renewable resources involves the adoption of end-use analysis for matching end -uses to specific sources so as to minimize the consumption of material and energy ( i.e. minimize entropy ). This matching requires an inverse increase in information which leads to what may be called the information-entropy trade-?; minimization of entropy requires an inverse increase in information. In this respect computers and GIS have an important contribution to make to decentralized regional planning. Drawing on a case study in Sri Lanka, this paper presents some ideas on how to incorporate GIS into local-level planning information systems

Time Course Variation of Some Latex Physiological Parameters Associated with Yield of Rubber (Hevea brasiliensis) Grown in Eastern Province of Sri Lanka

Rubber cultivation in Eastern Province, is predominantly in the intermediate zone of whichclimatic conditions are considered to be sub-optimal for growing rubber. Due to low level ofatmospheric RH%, latex flow tends to cease early after tapping in these areas. Turgidity oflatex vessels associated with the water content of latex vessels decreases with the sunrisewhen evapotranspiration increases. Hence, time of commencing tapping greatly influences onthe latex yield. Therefore, the present study was aimed to identify the best time of the day forlatex harvesting through an assessment on latex physiological parameters. In order to identify the best time for tapping, variations in several physiological parameterstogether with latex yield were assessed at different time intervals, i.e., 04:00, 05:00, 06:00,07:00 and 08:00 in two smallholder sites in the eastern Province. Latex volume, dry rubbercontent (DRC%), initial flow rate (IFR) and plugging index (PI) were analysed along with theenvironmental factors at the time of tapping. Latex volume per day (LVPD) was highly associated with the overall latex yield hence hadbecome the prime factor concerned. The highest LVPD was recorded between 05:00 to 06:00hrs. Dry rubber content of latex had increased after 06:00 h and that could be attributed to thewater status of the trees which was governed by evapotranspiration. During 05:00-06:00 hrstime period, RH% was almost 100% and temperature was around 23° C. When tappingcommenced after 06:00 h, the overall yield declined. There was a tendency of increasing theplugging index (PI) with the delay of tapping. Therefore, the study concluded that high yieldscould be obtained in this agro-ecological region if tapping is performed before 06:00 h. Keywords: Hevea, Intermediate zone, Rubber, Sub-optimal climatic conditions, Tapping tim