Nong Lahan
Location:	15°35'-15°40'N, 101°50'-101°56'E; about 3 km northeast of Chatturat, Chaiyaphum Province.
Area:	2,500 ha.
Altitude:	190m.
Biogeographical Province:	4.10.4.
Wetland type:	14 & 19.
Description of site:	A huge area subject to shallow flooding, between the Mae Nam Chi and the town of Chatturat, near the southwest tip of a basin of several hundred sq.km of rice paddy. The Chi River skirts the wetland at its northern end, passing within less than 500m. Most of the area is seasonally flooded, but there is at least one permanent lake of 90 ha, Nong Bua Ya, at the southern end. Two other such lakes, Nong Hin Tang, with a total area of 70 ha, are included in the Nong Lahan complex, but these may already have been drained. The main outflow is via the Mae Nam Chi; this is probably also the major source of inflow, through flood spillage in the late wet season (July to November). The maximum depth of water is only l.0-l.5m, and there are extensive shallows of 15-25 cm, even as early as December. The lake dries up gradually during the dry season, diminishing in surface area by at least 50% during normal years and exposing extensive areas of mud which become covered with short grass. The site is undoubtedly one of the largest and richest remaining wetlands in the entire northeast of Thailand.
Climatic conditions:	Tropical monsoonal climate with an average annual rainfall of 1,282 mm (range 860-1,633 mm), 85.4% of which falls during the southwest monsoon (May to October). The mean annual temperature is 27.6°C (range 6.3-42.5°C).
Principal vegetation:	Extensive areas of tall "reeds", either Saccharum arundinaceum or Scleria poaeformis, together with some areas of scrubby swamp woodland around the lake margins. Dense mats of Salvinia cucullata cover the water surface and there is much submerged weed (possibly Elodea sp). There is also some Nelumbo nucifera which is actively encouraged. Adjacent areas are mainly under cultivation for rice, but there are scattered trees and small patches of bamboo Bambusicola sp.
Land tenure:	The wetland is state owned and open to public use; surrounding areas are privately owned farmland.
Conservation measures taken:	None.
Conservation measures proposed:	A Fisheries Station is to be established at the wetland. The site should be established as a Non-Hunting Area or other category of reserve.
Land use:	Fishing, cultivation of lotus, raising of domestic ducks, hunting of wintering waterfowl and occasional netting of roosting flocks of small passerine birds. In addition, there is some cattle grazing and rice cultivation around the lake margins. The predominant land use in surrounding areas is rice cultivation (one crop of wet-season rice per year).
Possible changes in land use:
Disturbances and threats:	The principal threats are the reduction in areas of lakeside vegetation due to the cutting of trees for charcoal and the burning of reeds in order to open up areas for lotus cultivation. The area is also heavily over-fished and hunting pressure is intense. Not only is there widespread shooting of larger birds by local people, but occasional netting forays are made by market trappers who sell small passerines (wagtails, weavers and buntings) for food.
Economic and social values:	The lake is of tremendous importance as a source of water in an area prone to drought. Its provides a source of water for the municipality of Chatturat, and also for local villagers who hand-carry water from the lake for household use. Jute, which is grown in the surrounding areas, is soaked in the lake. The lake is also important for watering livestock and ensuring an adequate supply of animal fodder. The marsh grasses are grazed by domestic livestock and some aquatic plants are harvested as fodder, e.g. for feeding to pigs. Lotus Nelumbo nucifera has a variety of uses; the tubers and seeds are eaten, while the leaves are used for wrapping food items. No information is available on the fishery, but this is clearly of great importance.
Fauna:	The area supports a great concentration of wintering waterfowl, including Dendrocygna javanica (over 2,000), Anas querquedula (at least 6,500), Nettapus coromandelianus (30), and Fulica alra (95). In addition, over 30 Ardea cinerea, a few A. purpurea and 200 Anastomus oscilans have been recorded, together with flocks of Ardeola bacchus and three species of Egrella. The area supports many wintering raptors, including Milvus migrans (50-100) and Circus (aeruginosus) spilonotus (10-20). There have been occasional records of Gyps bengalensis, which is close to extinction in Thailand. Several hundred shorebirds are frequently present in order of abundance, these are Tringa glareola, Calidris subminuta, Gallinago gallinago, Pluvialis dominica and Calidris temminckii. Other species have included Tringa nebularia, Calidris alpina and Philomachus pugnax. This is also a regular site for the scarce and local Glareola lactea which may well breed. In addition, there are large roosts of weavers Ploceus spp and the bunting Emberiza aureola. A total of 76 species of birds was recorded in the area during a two day survey in late December 1984. The area has never been surveyed during the wet season, but species recorded during the winter months which are thought to breed at the lake include Tachybaptus ruficollis, Dendrocygna javanica, Nellapus coromandelianus, Porphyrio porphyrio, Metopidius indicus and Hydrophasianus chirurgus. Larger waterbirds such as egrets, storks and herons do not breed because of human disturbance.
Special floral values:	None known.
Research and facilities:	Many groups of bird-watchers have visited the site and have filed their records at the Association for the Conservation of Wildlife in Bangkok.
References:	Land Use Classification Division (1977-79).
Criteria for inclusion:	1b, 1e, 2b, 3b.
Source:	Jim Jintanugool and Philip D. Round.