Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Distribution System of Irrigation Water in Bangladesh: a Case Study of Bangladesh Agricultural University Farm

M. B. Hossain
SO
IWM division, BRRI, Gazipur

Niaz Md. Farhat Rahman
SSO
Agricultural Statistics division, BRRI, Gazipur

Abstract/ Executive Summary:

A study was conducted at Bangladesh Agricultural University (BAU) farm in 2010 to evaluate the irrigation water distribution system and determine the conveyance losses of both the lined and unlined irrigation canals. There were 3 Deep Tube wells (DTWs) in 3 blocks at BAU farm mainly used for irrigation purposes. The capacity of DTWs and conveyance losses were measured using cutthroat flume and verified using float method. The discharge of the DTWs were measured at the delivery points and found to be 1.5, 1.3 and 1.2 cusec in DTW1, DTW2 and DTW3 respectively. Efficiency of the DTWs was 75, 65 and 80% respectively. The total length of lined canals in the farm was 1256 m, 1913 m and 640 m and total length of unlined canals was 870 m, 3100 m and 850 m under block no. 1, 2 and 3 respectively. The conveyance losses of lined canal considering a length of 50 m were 1.06%, 3.85% and 8.3% and the same for unlined canals was 12.5%, 33.33% and 37.9% under block no. 1, 2 and 3 respectively. In terms of volume the conveyance losses for unlined canals considering a length of 50 m were 3.49, 6.45 and 8.51 m³/m²/day under block no. 1, 2 and 3 respectively.

Keywords: Irrigation, BAU and Distribution system, Conveyance losses, Lined and unlined canals.

Location: Bangladesh Agricultural University Farm

Start Date: 01-07-2013

End Date: 30-06-2014

Program Area: Crop-Soil-Water Management

Commodity: Water management

Objectives:

This study aims to evaluate the water distribution system of BAU farm and also determine the conveyance losses of water of both lined and unlined canals.

Methodology:

Study Area: The study area was Bangladesh agricultural university farm. The area lies between Kotowali thana of Mymensingh district and it is bounded on the east of the river “Old Brahmaputra”. It has a total area of 1200 acres of which about 200 acres are available for cultivation and are irrigated by DTW. The study area lies approximately between 24?36? to 24?54? west latitude and between 90?15? to 90?30? east longitude. The topography of the land was high. It included mainly the “Old Brahmaputra” flood plain. The texture of the soil was clay loam to silty clay loom. Color of the soil was generally gray. The soil of the study area was considered to be the best agricultural productive soil in the country. The climate of this area was mainly tropical and tends to remain mild throughout the year. Discharge of DTW: The rate of flow passing through a section is termed as discharge. Discharge of DWT was measured using Cutthroat flume of size (3ft × 4inch) and verified it using Floating method. Cutthroat flume: The cutthroat flume is an attempt to improve on the Parshall flume, mainly by simplifying the construction materials. The details of the flume are shown in Fig.1 the flume has a flat bottom, vertical walls and a zero length throat section. Since, it has no throat section; it was given the name cutthroat by the developers (Skogerboe et al., 1973). The most obvious advantage of a cutthroat flume is economy. Any flume length between 45 cm and 3 m can be used while throat widths between 2.5cm and 1.8 cm have been investigated. The cutthroat flume was installed in the canal, the leakage was checked by mud and the flow took place through the flume. When the depth of flume was constant the upstream flow depth “ha” and down steam flow depth “hb” were measured from the scale attached to the flume. The condition of flow (Free flow, submerged flow or not valid) was identified by dividing hb/ha (hb/ha≤0.65 for free flow, hb/ha=0.65 to 0.90 for submerged flow and hb/ha> 0.90 not valid). After identifying the flow condition discharge was calculated with the value of ha and hb for the flume size 4"×3' (By using equation (1) for submerged flow and equation (2) for free flow.). Conveyance Loss Measurement: Inflow-outflow method: This method is very simple method that consists of measuring the quantity of water going out of that reach. The difference gives the amount of water lost. The discharge can be measured by the help of flume, weir, current meter etc. It is necessary to maintain constant water level and allowance should be made of rainfall and evaporation. The accuracy of the method increase with the difference between the quantity of inflow and outflow rates. In present study two identical cut throat flumes were used to estimate the discharge for the selected canal section.

Source of Information: IJISET - International Journal of Innovative Science, Engineering & Technology, Vol. 1 Issue 10, December 2014

Article Link (Online Journal):

Funding Source:

Total Budget (Tk.) :

Achievement/Findings:

The study revealed that discharge performance of DTWs in BAU farm was low in compared to design ones (65 to 80% of design discharge). Overall conveyance loss of lined canal was acceptable (1.06 to 8.3%). But for unlined canals it was not satisfactory (12.5 to 40.0%). High conveyance loss has reduced command area of DTWs. There is large scope to improve existing command area of a DTW sharply by reducing conveyance loss of irrigation canals. Proper design, regular management, compaction and use of lining materials can reduce the conveyance loss and improve the overall efficiency of the irrigation distribution system of BAU farm. It also save power consumption and human drudgery as well as utilize ground water.

Knowledge Management: Journal