Ping River Research Articles

Hydrogeochemistry of the Chiang Mai Basin, northernThailand

Chemical composition of groundwater samples collected from 247 boreholes throughout the Chiang Mai Basin was determined in order to describe the background ion concentrations and to identify the major hydrogeochemical processes that control the observed water chemistry. The investigation results indicate that the groundwater is generally free from heavy metals although exceptionally high Fe, Mn, F and Na are found locally. The groundwater of the Chiang Mai Basin has evolved chemically through water-rock interactions from low TDI and low pH meteoric water recharges principally at basin rims towards higher TDI and pH groundwaters discharges, mainly along the through-flowing Mae Ping River. The average groundwater has hydrochernical facies either of Ca Na or Na Ca bicarbonate type with neutral pH and total dissolved ions (TDI) of about 10 meq/1.

Trends in the Development of Rural Non‑Farm Production and Employment in Lower North Thailand

This study is part of the research work done on rural non-farm produc tion and employment in Thailand, whose promotion is a government policy and a major aim of the National Economic and Social Develop ment Board (NESDB). The areas in the North chosen by the NESDB to be studied are Kamphaeng Phet (agro-economic zone 8), and Sukhothai (agro-economic zone 9). In these two changwat, there is rapid expansion of land utilization and population migration caused by both farm and non-farm activities. In each changwat (province), one amp hoe (a subdivision of a changwat) and one tambon (a subdivision of an amphoe) were selected to represent the rich areas, while another amphoe and tambon were to represent the poor areas. The rich areas were to be compared and con trasted with the poor ones in terms of the production and hiring done by the various non-farm activities. It was found from the areas studied in both changwat that the geographical features of the land had a sig nificant influence on the development and financial status of those who inhabited it. Those who lived in developed areas, whether in the city, amphoe or tambon, invariably occupied land which was geo graphically superior for agriculture, consisting mainly of flat plains and containing large rivers which facilitated crop growing and irriga tion. The developed areas of Kamphaeng Phet occupy land which con sists of 60 per cent plains and is fed by the Ping river, while in Sukho thai, 75 per cent of the developed areas occupy plains which are fed by the Yom river. On the other hand, about two-thirds of the land in the poor amphoe studied is hilly or mountainous and often lacks signifi cant waterways from which irrigation could be developed, resulting in drought during the dry season and flash flooding in the wet season. These geographical limitations lead to unemployment especially during the dry season when there is insufficient water available even for dry cash crops. If these factors are not overcome by technological