ENVIRONMENT MANAGEMENT OF A RIVER IN MYANMAR

Abstract

The Chindwin river is one of the most useful and important rivers in Myanmar. Chindwin River is the largest tributary of the Ayeyarwady River. Chindwin River has a mountainous forested terrain with the only exception of its lowest Southern part which is a vast plain. The highest mountains are in the West and North of the basin where they reach 10,000 feet and more. From East the water-shed passes a mountain chain of 3000-5000 feet high. The source of the river, which in its upper reaches before entering the Hukawng valley, bears the name of TanaiHka, flows at the height of about 7000 feet, then within the distance of 80 miles it goes down to the height of 700 feet and enters the Hukawng valley. There, it receives several tributaries, gets the name of Chindwin and on the whole of its flow of 620 miles down to its confluence with the Ayeyarwady.In its upper reaches the Chindwin river has the gradient around 0.0003and in the down reaches it is around 0.00005.The river flows in a narrow valley crossing a number of vast plains and forms several defiles. Some of its tributaries include Uyu, Mu and Myittha Rivers. Some important urban centers on its banks include Hkamti, Htamanthi, Homalin, Mawlaik, Kalawa, Kalaymyo, Mingin and Monywa. Chindwin River is being used as water transport for communication between the area of the basin and the central part of the country. The numbers of passengers transported annually are around 100,000 and cargo including timber — 200,000 tons. Economically, the Chindwin river basin is poorly developed, but if possess a variety of natural resources i.e. coal, copper, ore, oil, timber, gold, jade etc. Considering importance of this river, an attempt has been made for detailed study on its environment management. The water and wastewater samples were collected and analyzed for evaluating the physical, chemical and biological parameters in the laboratory of Directorate of Water Resources and Improvement of River Systems department and Yangon Technology University. The data taken from the field as well as the data collected from Directorate of Water Resources and Improvement of River Systems department were used to compute the National Sanitation Foundation Water Quality Index (NSFWQI), which is mostly applicable 111 parameter in WHO and India. The result of the NSFWQI of Chindwin River indicates that its water quality is Medium-Good over the stretch considered. Thus Chindwin River water can be safely used not only domestic but also water supplied and agricultural lands in all year round. The other problems found with from environment point of view are bank erosion and sediment deposition. The length of the Chindwin River is about 1100 km.Among them, 816 km length can only be utilized for water transport from Hkamti to Confluence. Water transport is the cheapest and greatest in Myanmar. Myanmar has three seasons namely summer, rainy and cold seasons. Therefore, all the rivers in Myanmar experience large variation in discharge. Normally, more discharge observed from Mid-May to Mid-November. The water level difference in Chindwin River is at least 10 m to 13m. The Chindwin Catchment area has observed less water volume and more sediment deposit year by year due to the Environmental Impact. The average sediment load in Chindwin River is 131 million tons per year. These sediments create sand bars and a lead to the change of river morphology and affect the water transport. Based on data collected, measurements and analysis carried out in the environment management plan of the Chindwin Rive from Hkamti to confluence (816 km), it has been found that 37 sites have problems of bank erosion and sedimentation. Maintenance by means of rive training works in these 37 locations are proposed between Hkamti and confluence to improve the navigation channel of Chindwin river. River training structures are proposed for improvement of navigable channel, stability inland water post, achieve adequate depths for maximum loading capacity of the vessels, prevention of river bank erosion. The details of these structures with cost estimates are presented in the study. It has been estimated that with a cost of Rs. 13.02 millions for a stretch of 125 km Chindwin river conservation plan can be executed.