[Paper] Indonesia Rice Irrigation System: Time for Innovation

Author: Rose Tirtalistyani, Murtiningrum Murtiningrum, and Rameshwar S. Kanwar

Abstract: Indonesia is likely to face a water crisis due to mismanagement of water resources, inefficient water systems, and weak institutions and regulatory organizations. In 2020, most of the fresh water in Indonesia was used for irrigation (74%) to support the agricultural sector, which occupies 30% of the total land area in Indonesia. Of all agricultural commodities, rice is one of the major and essential commodities, as it is the basic staple food for almost every Indonesian. However, in 2018, the Ministry of Public Works and Housing (MoPWH) reported that 46% of Indonesian irrigation infrastructure is moderately to heavily damaged. Looking at how irrigation can be very crucial to the welfare of Indonesian population, this study conducted an extensive literature review of the historical, current, and future management of irrigated rice production systems in Indonesia. This study has clearly shown that the irrigation systems in Indonesia have existed for thousands of years and, thus, there is a close relationship between irrigation and the socio-cultural life of the Indonesian population. Aside from how climate change influences water availability for irrigation, rice production with a constant water ponding system has been found to contribute to climate change, as it emits methane (CH4) and other greenhouse gases from agricultural fields of Indonesia. Therefore, the required modernization of irrigation systems in Indonesia needs to consider several factors, such as food demands for the increasing population and the impact of irrigated agriculture on global warming. Multi-stakeholders, such as the government, farmers, water user associations (WUA), and local research institutions, need to work together on the modernization of irrigation systems in Indonesia to meet the increasing food demands of the growing population and to minimize the impacts of agriculture on climate change. read more

[Paper] Mathematical Modeling-Based Management of a Sand Trap throughout Operational and Maintenance Periods (Case Study: Pengasih Irrigation Network, Indonesia)

Author: by Ansita Gupitakingkin Pradipta, Ho Huu Loc, Sigit Nurhady, Murtiningrum, S. Mohanasundaram, Edward Park, Sangam Shrestha, and Sigit Supadmo Arif.

Abstract: Surface irrigation networks in Indonesia are damaged by several factors, and sedimentation is among the most severe challenges. Sand traps play a substantial role in improving irrigation system efficiency by reducing sedimentation. There are two periods in sand trap operation: the operational and maintenance periods. Pengasih is one of the irrigation schemes implemented in the Progo Opak Serang (POS) River Basin, which has a high level of erosion. This study aimed to propose an appropriate management strategy for the Pengasih sand trap as the first barrier in irrigation network sedimentation based on mathematical modeling. The HEC-RAS simulation software was used to simulate the sand trap hydraulic behaviour. The results show that the validated Manning’s coefficient was 0.025. The optimal transport parameters were Laursen for the potential function, Exner 5 for the sorting method, and Rubey for the fall velocity method. The recommended flushing timeframe is 315 min, with a discharge of 2 m3/s. We suggest that the sand trap flushing frequency be performed twice a year, and it can be performed at the end of March and October. This coincides with the end of the first and third planting seasons of the irrigation scheme. read more