Kaeng Hin Phoeng

Khlong Pla Kang (Kho Yo 4)

Viewpoint milestone No. 30

Pha Trom Chai Viewpoint (Khao Khiao)

Kong Kaeo Waterfall

Krok I Dok Waterfall

Chet Khot Waterfall

Takhro Waterfall

Than Thip Waterfall

Than Rattana Waterfall

Nang Rong Waterfall

Pha Kluai Mai Waterfall

Sarika Waterfall

Heo Narok Waterfall

Heo Suwat Waterfall

Pha Deo Dai

Khao Yai National Park Nature Trail

Nong Phak Chi

           Khao Yai National Park consists of a complex of mountain ranges such as Khao Rom, which is a 1,351 meters above mean sea level, followed by Khao Laem, 1,326 meters above mean sea level, Khao Khiao, 1,292 meters above mean sea level, Khao Sam Yot, 1,142 meters above mean sea level, and Khao Phapha, 1,078 meters above mean sea level. The north and eastareas are sloping downward
. The south and west are steep, which is the source of five important watersheds as follows:
            - Prachinburi River and Nakhon Nayok River are in the southern part of the area. They are important for the agriculture and socioeconomic systems of the region. The two rivers converge into Bang Pakong River.

             - Lam Ta Khong and Lam Phra Phloeng are in the north, flowing to nourish the agricultural areas of the Khorat Plateau before converging as the Bang Pakong River.
             - Huai Muak Lek is in the northwest used foragriculture in particular, the livestock of this region, flowing into the Pa Sak River in Muak Lek District.

Geology
          Geological conditions and rock characteristics of Khao Yai National Park. Khao Yai National Park covers areas that link Saraburi, Nakhon Ratchasima, Prachinburi and Nakhon Nayok Province. The conditions of areas are high mountains. These mountain ranges are supported by various rock types and loose sediments, a geological heritage that has long been traced back to the formation of rocks in Khao Yai National Park. In the Northwestern
part of Khao Yai National Park, the oldest rocks in Khao Yai are Permian sediments. Limestone, shale, and chert found are classified as the " Saraburi Group", according to the rock classification of Thailand, formed by the chemical sedimentation of seawater in ancient environments on the continental shelf and continental slopes.

           In the western and northeastern parts of Khao Yai National Park, volcanic sedimentary rocks and Permotriassic volcanic rocks formed during the Permian and Triassic periods were found, covering almost half of the park. These rocks consist of volcanic breccia, tufts rock, the rhyolite, andesite, and basalt; and in some areas, igneous rock are found.

           The eastern and central part of Khao Yai National Park is the area ofsedimentary rocks belonging to Khorat group brought by streams, with sandstones and mudstones of the Phu Kradueng Formation overlaid on sedimentary and Permotriassic volcanic rocks. In the central area of the park, on the way from Mo Singto to the sharp bend before reaching the viewpoint of Pha Deao Die, it is the boundary between the sandstone of the Phu Kradung formation and the sandstone of the Phra Wihan formation that overlaid on top.

           The southernmost area of Khao Yai National Park contains sediments of gravel, sand, and quaternary clay, which are results of the erosion of the sandstone in the Phra Wihan formation into gravel-sized sand. Then the currents carried the sands and gravels to accumulate along the area where the waterway flows through.

Water Resources
             Khao Yai National Park is the birthplace of an important watershed used in agriculture, industry and tourism in the region. It covers the four watershed areas, namely the Prachin Buri River Basin, representing 12.17 percent of the watershed class, the Bang Pakong River Basin, representing 5.67 percent, the Mun River Basin, accounting for 1.5 percent, and the Pa Sak River Basin, accounting for 0.4 percent.

            The main watershed of Khao Yai National Park covers the headwaters of the four main watersheds, namely the Prachin Buri River Basin which comprises the Lower Prachin Buri River Basin, and the Hanuman River Basin as its tributaries, accounting for 12.17 percent of the watershed area. The Bang Pakong River Basin is part of the Nakhon Nayok River Basin, accounting for 5.63 percent. The Nam Mun River Basin which comprises Lam Takong Basin and Lam Phra Ploeng Basin which are tributaries, representing 0.5 percent of the watershed class. The Pa Sak River Basin includes the Huai Muak Lek River Basin as its tributary, accounting for 0.4 percent of the watershed class.

        Khao Yai National Park has a dense forest that is influenced by the monsoon, causing seasonal rainfall and the weather is not too hot or too cold, suitable for tourism and various types of recreational activities. The average temperature throughout the year is about 23 degrees Celsius. The highest temperature is between April and May, at about 28 degrees Celsius. From December to January, the temperature is about 17 degrees Celsius. The average relative humidity of Khao Yai National Park is 66%.

          - Summer: Although the weather is hotter than other seasons, in the high mountains of Khao Yai, the weather is still cool and suitable for relaxing.
          - Rainy season: It is a period when nature, forests, and green fields are beautiful. Various waterfalls have streams that flow and are turbulent.
          - Winter: From October until February, it is the peak season for tourists. The weather is quite cool, especially on the high hills.

           The average annual rainfall of Khao Yai National Park is 2,270 millimeters in the Khao Yai National Park Headquarters area
. The area that receives the most rainfall is around the Khlong Tha Dan River Basin, which is the southern part of the area of Khao Khiao and Khao Rom, with rainfall measurements of up to 3,000 millimeters per year. The lowermost area of the southwest and south, with an average annual rainfall of 1,600 mm or less, usually the most rainfall usually occurs between mid-May and October. The lowest rainfall period is between December and January, with an average rainfall of about 15 millimeters per month.
 

            Forests in Khao Yai National Park It covers an area of approximately 1,229,789.63 rai.
(1,967.663408 square kilometers), or about 91.47% of the area, with as many as 2,000-3,000 species of plants. This is because the Khao Yai National Park area is large and a gathering point for various plant propagation.

 There are a variety of plant species as follows.
- 209 tree species.
- 120 types of orchids
- 108 types of lichens
- Hill Evergreen Forest is formed in the cold area, at 1,000 meters above mean sea level, and can be found at Khao Khiao, running in the middle of the park. There is an area of approximately 21,938.71 rai (35.101936 square kilometers), or 1.63% of the total forest area.

     Plants found are softwood such as Podocarpus neriifolius, Assam plum yew, and Dacrydium elatum Wall. Additionally, there are plants in the family Fagaceae, including Lithocarpus lindleyanus (Wall. ex A.DC.) A.Camus and Lithocarpus thomsonii (Miq.) Rehder.Along the ridges, Wild Himalayan Cherry are found.

        The secondary canopy trees contain Dillenia obovata (Bl.) Hoogl., Vaccinium sprengelii., Rhus succedanea L., Metadina trichotoma (Zoll. ex Merr.) Bakh.f, and Jambolan Plum. The undergrowth plants are shrub species such as Ardisia colorata, as well as Paco fern and many types of soil orchids. The trunks and branches of the hill evergreen forest are covered with orchids and various moss.

          - Tropical Rain Forest is found at an altitude of 400-1000 meters above mean sea level. The forest of this kind covers most of the park which is 892,162.48 rai (1,427.459968 square kilometers), or about 66.36% of the total forest area. Along the stream, there are groups of rattans and ferns. On the upper areas there are para rubber trees and upper canopy trees such as Shorea henryana Pierre, Glycosmis pentaphylla (Retz.) DC., and Boramue, and the secondary plants include plants in the family Fagaceae.

          - Dry Evergreen Forest is found at an altitude of 200-600 meters above mean sea level. It covers an area of approximately 1,192.88 rai (1.908608 square kilometers), or 0.9% of the total forest area. The upper canopy layer includes Dipterocarpus alatus, Vatica odorata (Griff.) Symington, Shorea henryana Pierre, Iron Wood, Hopea ferrea Laness, White Myrtle Tetrameles, Ipomoea pileata Roxb., Taluto, and etc. Secondary canopy perennial plants include Hydnocarpus ilicifolius King, Walsura trichostemon Miq., and palms such as Pinanga sylvestris (Lour.) Hodel and Fan Palm. The undergrowth plants consist of Coconut, Chinese taro., Ginger, Galangal, Pandanus Palm, and etc.

          - Mixed deciduous forest is found at an altitude of about 400-600 meters above mean sea level. It covers an area of approximately 185,275.91 rai (296.441456 square kilometers), or 13.78 percent of the total forest area. The forest of this kind appear mainly in the northwest. It consists of deciduous perennials such as Black Rosewood, Burma Padauk, Lagerstroemia , Anogeissus acuminata (Roxb. ex DC.) Guill. & Perr. Var. lanceolata C.B. Clarke, Xylia xylocarpa (Roxb.) Taub. var. kerrii (Craib ex Hutch.) Nielsen., and etc. The undergrowth plants are bamboo and grass on the forest floor, with limestone scatterly springing up. In the dry season, this type of forest is always on fire. It can be seen from the abundance of wild bamboo along the slopes and the densely packed wild bananas along the ravines.

          - Deciduous Deciduous Forest usually grows up on Khao Samo Pun which is a plain on a ridge mixed with stone terraces. Important plants are Burma Sal, Shorea siamensis, Hairy Keruing, Dipterocarpus tuberculatus, and Dipterocarpus intricatus Dyer.

          - Savanna Forest and Second-generation Forest cover approximately 70.15 rai (0.11224 square kilometers) and 129,219.65 rai (206.75144 square kilometers) respectively. This forest condition is a consequence of shifting cultivation in the past before the area was declared a national park. Therefore, this forest condition has arisen. Plants in the savanna forest are mostly Thach grasses mixed with The Khagra reed, Bamboo grass, and Saccharum procerum Roxb. In addition, there are some types of Paco Fern that usually grow in burnt areas. What is remarkable is that after it was declared a national park for more than 10 years, some grasslands that had been prevented from the spread of fires have revived into a grove that in the future will surely be revived as a forest as before. Along both sides of the road, because there is no construction to expand; therefore, various types of fast-growing plants are covering, such as Baliospermum solanifolium (Burm.) Suresh. and Hibiscus macrophyllus Roxb. ex Hornem, etc.

In terms of animal society, due to diverse forest conditions, they have become shelters and food sources for animals and abundant with various kinds of wildlife, as follows:

          - Mammals: There are about 71 species. The mammals that are often seen and that are attractive to visitors are wild elephants, barking deer, deer, etc. Large mammals that are important species in Khao Yai National Park include Wild Elephants, Bengal Tigers, Clouded Leopard, Bulls, White-handed Gibbons, and Pileated Gibbons, etc.

            Wild elephants are one of the most important mammals in Khao Yai and are of great interest to visitors. They are usually found in herds of 5-7 elephants, sometimes up to 30 of them, with a matriarch as a head. While male elephants like to live alone and feed on their own except during the breeding season. A herd of elephants usually moves to find food over long distances. and has a very wide territory. Elephants' favorite foods are bamboo, ginger, wild bananas, grass, etc.

         The elephants' paths are beneficial because they help create natural pathways that link one another like a network which is useful for patrols by rangers and is a walkway for visitors. It is believed that there are around 140-200 of wild elephants in Khao Yai National Park.

         The hoofed animals that are commonly found in the park include Sambar Deer, Barking Deer, Gaur, Wild Boar, and Chamois. Among these hoofed animals, Sambar deer are a huge attraction for visitors. In the evening until dusk, Deer and Barking Deer often come out to graze in roadside pastures, which can be seen with the naked eye and you can use spotlights to light on them from the car at night. Wild boars and bulls usually live in deep forests. They seek food in the old grasslands. Bulls live scatterly in the Khao Yai National Park but in a relatively low density, and no one knows the exact number of them.

            Other lemurs and mammals found in the park include the White-handed Gibbon and the Pileated Gibbon. Normally, these two types of gibbons live separately and independently from each other. But in the forest area of Khao Yai National Park, they may be found living together. The survey found White-handed Gibbons living in the forest area near the national park headquarters and Training Center 2 (Khao Yai), as many as 4 herds per square kilometer. On average, one herd has four members, consisting of a father, a mother, and offspring. Generally, they can be seen along the edge of the forest and around the footpaths in the forest when they are singing together and clambering around on the trees. Macaques can be found in a group of up to 90 in the wild, and they are often found in forests adjacent to the roads.

            Slow lorises are commonly found but often need lights and an alert eye to see them. Other mammal species include squirrels (including the Black Giant Squirrel) and musks. Various musks are easily discovered by the side of the road at night. Bearcats can be found while they are sleeping the top of the trees in the daytime. Jungle tabby cats and marbled cats, of which there are not many, can be infrequently seen running across the road at night. There are also Asiatic Black Bears, and Dhole, but they only occasionally appear.

       - Reptiles : There are about 48 species that are commonly seen, including Oriental garden lizards, various skinks and Green-tailed Snakes, whereas Cobras, and King Cobras are seen in some areas, especially around the undergrowth bushes.

         - Amphibians mostly are frogs such as field frogs, swamp frogs, etc. In addition, frogs in the family Microhylidaeare also found such as Painted Chorus Frog, Micryletta inornata, etc.

         - There are more than 340 species of Birds, the interesting ones include the Wreathed Hornbill, Great Hornbill, Tickell's Brown Hornbill, Oriental pied Hornbill, as well as Coral-billed Ground-Cuckoo, Scarlet Minivet, Blue Pitta and Red-billed Blue Magpie, etc.