Focus is on the following sections:

  • Flow condition at Phnom Penh, Tan Chau and Chau Doc
  • Salinity intrusion in Delta
  • River bank erosion, river channel condition and sediment transport, sand mining
  • Flood and drought data
  • Climate change covering greenhouse gas, extreme events, temperature, rainfall
  • Navigation

Climate change is likely to pose major challenges for the Lower Mekong Basin (LMB). Therefore, information on climate change, its impact and climate change adaptation are required to enable decision-making to develop and implement appropriate response measures. A monitoring and reporting system on climate change and adaptation can help to track changes and to store relevant data for assessing status and impacts of climate change in the LMB for supporting adaptation planning.

With this study, the Climate Change Adaptation Initiative (CCAI) of the Mekong River Commission (MRC) offers a review of existing monitoring systems and indicators to improve the understanding of riparian governments, relevant line agencies and others on the status and impacts of climate change. The report should inform the establishment of a database and monitoring system by the CCAI, to build knowledge on climate change and adaptation in the LMB and support information to other activities of the CCAI and MRC programmes.

The review suggests indicators to measure climate exposure, climate impact and climate adaptation activities within the LMB focusing on the thematic areas hydrology, land, agriculture, fisheries, biodiversity, hydropower, food security, and poverty as well as employment. Based on this comprehensive review, recommendations are developed on how to improve baseline data and the sharing of data, what tools are needed for the establishment of the basin wide CCAI monitoring system and what capacity building activities can be useful to this end.

Four types of climate monitoring systems and their time horizon, availability and overall accuracy
Four types of climate monitoring systems and their time horizon, availability and overall accuracy

The Climate Change and Adaptation Initiative (CCAI) is a collaborative regional effort of MRC Member Countries (Lao PDR, Cambodia, Thailand and Vietnam) to support processes of adapting to the new challenges posed by climate change in the Lower Mekong Basin (LMB). The main focus is a basin wide integrated approach to adaptation planning consistent with Integrated Water Resources Management principles and within the Framework of the 1995 Mekong Agreement. The specific aim is to make adaptation a permanent part of development plans and planning process, and to have tools as well as institutional and specialist capacity in place to implement them.

Rice harvesting

The CCAI focuses on the following Outcomes: (1) climate change impact and vulnerability assessment, adaptation planning and implementation in priority locations within the LMB; (2) building knowledge and capacity at different levels (institutional, technical and managerial capacity); (3) regional adaptation strategy supporting national frameworks; (4) regional partnership and collaboration. Currently, the CCAI is developing its first “Status of Climate Change in the Lower Mekong Basin” report. An important component of the Status Report will be the impact of climate change on the agricultural sector and the projected food situation in the LMB.

Analyses on changes in crop production and food demand and supply have clear transboundary dimensions. Changes might be important in the context of imports and exports of agricultural products. Irrigation is an important consumer of water and changes in irrigated areas can have basin-wide consequences. A clear overview of expected changes in crop production and food demand and supply in the LMB is missing. Earlier initiatives are restrictive in terms of: local specific, encompassing only climate change, often based on old climate scenarios, and, most importantly based on different and not comparable approaches and assumptions.

Mekong Delta

FutureWater will contribute to the before mentioned report, by providing an explorative outlook on crop production under climate change, and on food requirements and production under climate change. The analsyis will be carried out for the 15 principal sub-basins of the Lower Mekong Basin, and for three future situations (foreseeable, long-term and horizon).

 

The Mekong River Commission (MRC) has its Climate Change and Adaptation Initiative (CCAI), which is a collaborative regional effort of MRC Member Countries (Lao PDR, Cambodia, Thailand and Vietnam) to support processes of adapting to the new challenges posed by climate change in the Lower Mekong Basin. The CCAI is developing its first “Status of Climate Change in the Lower Mekong Basin” report. An important component of this report will be to provide information on trends in the past climate. For this a detailed and homogenous climate data set is required. Such a data set can also be used for other purposes like hydrological modeling and related assessments.

Mekong

The need of a climate trend analysis over the past is clear. There is still a lot of uncertainty on the direction of climate change in terms of magnitude as well as spatial distribution. Not only the annual trends, but even more importantly are shifts in seasonality and changes of extremes. So far, no harmonized climate database covering the entire Mekong river basin exists.

The number of reanalysis data products is increasing rapidly. Some of these products are strong in one region, while other performs better in other regions. Although reanalysis products are based on observations, differences might occur. The main reason is that not all observational data is included in the reanalysis datasets. Using an extensive database of meteorological observations, correction factors will be applied to the reanalysis data.

In general, reanalysis products with a high spatial resolution have a low temporal resolution and vice versa. Based on proven interpolation techniques it is possible to effectively combine these sets of reanalysis data, which will result in high spatial as well as high temporal resolution.

The overall objectives of this work are:

  • To develop a baseline climate database over the period 1900-2010.
  • To undertake a trend analysis on this database.

The Regional Flood Management and Mitigation Centre (RFMMC) has been established in Phnom Penh, Cambodia under the umbrella of the Mekong River Commission (MRC). The Centre plays an important role in maintaining the national and regional availability of important flood-related tools, data, skills and knowledge; producing accurate regional forecasts with suitable lead time, and a timely and effective dissemination of it; in providing accurate, well documented and consistent tools for basin-wide flood risks assessment and trans-boundary impact assessment.

The main objective of the RFMMC at present is to establish an improved, robust and reliable flood forecasting system for short and especially medium-term forecast periods. This system is identified as the new MRC Mekong Flood Forecasting System (MRC Mekong FFS).

By far the largest source of error in the Mekong system is the inconsistency of accurate precipitation inputs. These errors can accumulate over a season and lead to modeled basin conditions that drift from reality. Previous MRC consultants recommended the RFMMC should investigate methods to use observations from rain gauge measurements to adjust satellite rainfall estimates (SRE) prior to being input to the forecasting system. Implementing this recommendation would allow significant improvements in accuracy for the MRC Mekong flood forecasts.

Taking into account the required and expected performance of the new MRC Mekong Flood Forecasting System (FFS), this project responds to these recommendations and the following outputs were delivered during this assignment:

  • The scientific basis for adjusting the bias of NOAA SRE with rain gauge information available for the Mekong Basin, considering its unique properties
  • A proposed operational methodology/tool to implement rain gauge-based bias correction to NOAA SRE into the MRC Flood Forecast operations
  • Implementation of rain gauge-based bias correction to NOAA SRE into the MRC Mekong FFS (Mekong-FEWS).