Fenomena transpor sedimen suspensi yang terjadi di lapangan erat kaitannya dengan sistem air di sungai maupun saluran terbuka. Kompleksitas interaksi antara partikel lumpur dan tanah liat dalam cairan, serta turbulensi dan ketidak-seragaman aliran akan menyebabkan perbedaaan karateristik antara aliran seragam (uniform flow) dengan aliran tidak seragam (non-uniform flow). Permasalahan sedimen suspensi di saluran terbuka pada penelitian ini dipelajari menggunakan metode eksperimen, dengan pengukuran langsung di lapangan pada tampang saluran yang dipersempit dan diperlebar dengan 3 variasi dimensi saluran yang berlokasi di Saluran Mataram Yogyakarta. Pengukuran konsentrasi sedimen suspensi dilakukan dengan alat ukur optik jenis Opcon. Sedangkan untuk mengukur profil kecepatan menggunakan Currentmeter. Pada penelitian ini menggunakan metode Point Integrated Sampling untuk pengambilan data di lapangan. Kondisi aliran yang dipelajari, dalam penelitian ini adalah karakteristik aliran tidak seragam (non-uniform). Hasil penelitian mengenai karakteristik transpor sedimen suspensi pada kondisi aliran tidak seragam (non-uniform), menunjukkan bahwa aliran yang terjadi pada penelitian ini berada pada daerah hidraulik kasar yang ditunjukan dengan nilai (u*ks/� > 70). Perubahan kecepatan rata-rata tampang U sangat berpengaruh terhadap nilai konstanta integrasi numerik Br dan nilai faktor koreksi sedimen Beta pada Persamaan Rouse dan Tanaka yaitu semakin besar kecepatan aliran rata-rata tampang U, nilai konstanta Br dan nilai faktor koreksi Beta semakin kecil. Konsentrasi sedimen suspensi rata-rata tampang C juga berpengaruh terhadap nilai Br dan Beta, yaitu semakin besar nilai konsentrasi sedimen suspensi maka nilai konstanta Br dan nilai faktor koreksi Beta akan semakin besar.

The suspended sediment transport phenomena that occur in the field closely related to water systems in rivers and open channels. The complexity of the interaction between the particles of silt and clay in the liquid, as well as the turbulence and non-uniformities flow will cause the difference between the uniform flow characteristics with a non-uniform flow. The suspended sediment problems in an open channel in this research was studied using the experimental method, with direct measurements in the field of the channel narrowed and widened by 3 dimensional variations of channel which located in Mataram Channel, Yogyakarta. The suspended sediment concentration measurements performed with optical measuring instruments Opcon types. Meanwhile, to measure the velocity profile using Currentmeter. In this research using Point Integrated Sampling methods for collecting data in the field. Flow conditions were studied in this research is non-uniform flow characteristics. The measurement results of this research on sediment transport characteristics of the suspension in non-uniform flow, shows that the flow that occurred in this study include hydraulic rough flow which is indicated by the value of (u*ks / � > 70). Changes in flow velocity U greatly affect for the value of the constant numerical integration Br and the value of the correction factor sediment Beta in Eq Rouse and Tanaka, the greater value of the flow velocity U then the constant Br is getting smaller and the value factor correction Beta is getting smaller too. The suspended sediment concentration C also affect for the value of Br and Beta, ie the greater the value of suspended sediment concentration C then the constant Br will be greater and the value of the correction factor Beta will be greater too.

Kata Kunci : kecepatan aliran, sedimen suspensi, aliran tidak seragam/flow velocity, suspended sediment transport, non-uniform flow