A start-up workshop for the Program on Understanding Extreme Climate Events in Vietnam was held on 29-30 April 1999 in Hanoi, Vietnam. The workshop, organized by the Disaster Management Centre of the Department of Dyke Management on Flood and Storm Control of the Ministry of Agriculture and Rural Development, in collaboration with the Asian Disaster Preparedness Centre (ADPC), was attended by 34 participants from different departments and agencies dealing with the consequences of extreme climate events in Vietnam.

The main objectives of the workshop were :

• to finalize an implementation plan for the Program on Understanding Extreme Climate Events in Vietnam; and

• to brainstorm on the different components of this implementation plan and obtain strategic guidance from the key stakeholders.

  An indicative implementation plan for the program identified:

  The key issues that the program should address (what should we look at );

  Appropriate institutional contacts for information gathering and dissemination (who will do what?); and Appropriate time frame for various activities (what time frame?)

Structure of the Workshop

The two-day workshop was mainly divided in two parts:

 

• Presentations by some of the key agencies representing the sectors affected by the impacts of extreme climate events in Vietnam. These presentations helped in highlighting the key issues that need to be addressed by the program in each sector.

• Focused group discussions (two groups) were formed to finalize the implementation plan for the program. Group I consisted of technical experts. Group II consisted of policy/ decision-makers. Representatives of ADPC assisted the groups in their discussions.

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Summary of Discussions

The climate of Vietnam is governed by the following major wind patterns and cold front movements :

• Northeasterly winds ¡ Coastal region of Central Vietnam ¡ August-December
• Southeast monsoon current ¡ North and Central Vietnam ¡ May-October
• Southwest monsoon current ¡ South Vietnam ¡ April-September
• Cold front movements from Siberia ¡ North Vietnam ¡ Winter-Spring season

The ENSO impacts on the monsoon usually affect :

• Position of Inter-Tropical Convergence Zone (ITCZ)
• Dates of onset and termination of rains
• Intra-seasonal variation of rains with clusters of wet and dry spells
• Typhoon and tropical depression incidences

The climatic variability-related natural hazards are:

• Winter-spring drought in North Vietnam
• Winter drought in South Vietnam and highlands of Central Vietnam
• Hot dry weather in summer over coastal plains of Central Vietnam leading to summer droughts
• Typhoons/ floods/ storm surges and inundation in varying magnitude and frequencies affecting most of the provinces in North, Central Vietnam.
• Saline water intrusion either by low flow of rivers due to drought or typhoon/ storm surge forced intrusion.
• Impact of temperature variations affecting winter, spring rice productivity in North Vietnam.
• Forest fires in highlands of Northern and Central Vietnam

Differential ENSO impacts ¡ space and time

• Although there are discernible linkages between ENSO and the above-mentioned climate variability related impacts in Vietnam, ENSO events do not affect Vietnam uniformly and the impact varies from area to area and event to event.
• While more number of tropical depressions and typhoons tend to affect Central and Southern parts of Vietnam during cold ENSO episodes, the lesser number of tropical depressions and typhoons tend to occur during warm episodes.
• In the northern part of Vietnam, there is no discernible impact of ENSO on the incidence of typhoon and tropical depressions.
• During the warm ENSO years, few but strong intensity typhoons and tropical depressions tend to occur earlier than usual (pre-typhoon season).
• Abnormal variations also noticed during non-ENSO years e.g. in 1966, there was no warm ENSO episode but there were less number of tropical depressions and typhoons. In 1960, 1978 and 1980, there were no cold ENSO, but there were large number of tropical depressions and typhoons.

The study on stream flows in respect of Yen Bai (Thau river), Ta Bu (Da river), Dua (Ca river), Nong Son (Thu Bon river), Cung Son (Ba river) stations revealed that the stream flow tend to be lower during warm ENSO and higher during cold ENSO. The magnitude of decrease of river runoff in El Nino years is different from year to year and from river to river. During La Nina year 1998, the runoff of all sample study rivers were lower than normal. The runoff of these rivers in the El Nino year 1997 is higher than long-term mean value. While the rivers of northern parts of Vietnam do not follow variations in consonance with ENSO, the rivers of central Vietnam tend to follow ENSO pattern.

Constraints of using climate forecast information

The above instances reveal the complexity of relationship between ENSO events and local climate variability. The development induced environmental degradation like reduction of forest cover, soil erosion, siltation, etc., which added complexity to local climate variability. Hence, micro-climate variations do not always follow the global ENSO pattern. These uncertainties post operational constraints for utilizing long-range forecast information for decision-making.

Opportunities for using climate forecast information

There is a need to undertake further research studies to establish the linkages or otherwise of local climate variabilities and ENSO indices to provide usable information to decision makers. Delineation of extreme climate event sensitive region based on past history could facilitate empirical measurement of potential effects of ECEs. The documentation of past history of ECE on various region and sectors would be useful to find out whether or not co-relation exists between climate variability related sector impacts and ENSO indices.

 

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The Documentation Methodologies/ Approaches

The Workshop decided to undertake documentation by following three approaches, keeping in view limited availability of time and the resources available for documentation:

1. Time series data (1950-1998)
2. Natural disaster episode history documentation (1950-1998)
3. Case study of recent past ENSO episodes

Time Series Data

Three meteorological observation/ stream flow observation stations may be selected in each of the following nine agro-ecological zones to collect monthly rainfall, temperature, humidity, solar radiation, stream flow level data for the period 1950-1998:

• Northwest (Northwest of Bacbo)
• Northeast (Northeast of BacBo)
• North Midland zone
• Red River Delta
• North Central zone
• South Central zone
• Plateau of Trung-Trung-Bo
• Southeast zone
• Mekong Delta zone

The season-wise crop production data relating to rice, coffee and other secondary crops may be collected keeping in view the jurisdiction of the observation stations for the period 1950-1998.

Natural Hazard Incidence History

All the natural disaster episodes, which occurred in various parts of Vietnam from 1950-1998 could be documented covering the following essential features:

• Year of occurrence
• Season of occurrence
• Dates of occurrence
• Meteorological/ hydrological causes
• Names of affected provinces
• Details of impacts
• Institutional arrangements for response
• Details of response

Case study of distinct recent ENSO episodes

A qualitative assessment of the below-mentioned ENSO episodes may be undertaken to bring out the details of the impacts, the institutional arrangements to receive, process and apply climate forecast information, the type of intervention measures undertaken and the evaluation of the intervention measures.

El Nino

Case study of 1982-83
Case study of 1987-88
Case study of 1991-92
Case study of 1997-98

La Nina

Case study of 1984-85
Case study of 1988-89
Case study of 1995-96
Case study of 1998-99

 

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Guidelines for Documentation

ADPC was requested to provide guidelines for documentation along with checklist for undertaking the documentation process.

Outcomes of the Workshop

The various organizations/ agencies had agreed to undertake documentation process as per the framework presented below :
 

	Documentation details	Collaborative organizations/ agencies	Time frame
Part - I Time series data analysis Physical climate prediction
(i) Indicators : The following indicators may be compiled in respect of three meteorological observations of each of nine agro-ecological zones for the period 1950-1998 Monthly rainfall, temperature, relative humidity, number of sunshine hours data A time series data indicating dates of onset of wet season and dry season. The clusters of dry spell and wet spell incidences in respect of each monsoon season indicating duration in days and intensity of rainfall spells (in mm). The typhoon storm surge spells indicating wind speed (km per hour), rainfall clusters (mm) and the height of storm surge in metres and date of land fall.	HMS	Agro-climate Research Centre	15.6.1999
(ii) Qualitative Assessment Reports on Seasonal forecast advisories with evaluation reports in the last 3 decades ENSO impacts on Vietnam Monsoon, indicating simultaneous and lagged relationships between ENSO indices and local weather variables. Past history of cold surge activities leading to heavy rainfall clusters/ floods/ flashfloods/ landslides Mechanisms of preparation and dissemination of ENSO advisories in the last two decades and evaluation of their utility by climate sensitive sector agencies such as agriculture, water resources, forestry etc. Details of institutional and coordination arrangements to evolve, disseminate and get feedback on weather guidance products at national and provincial levels. Case study of 1997-98 El Nino and 1998-99 La Nina experiences in evolving, disseminating and obtaining feedback on weather guidance products. Constraints and opportunities in evolving and institutionalizing weather forecast into decision making process Impact Assessment Agriculture Sector	HMS	1) Climate Research Centre 2) Agro-climate Research Centre 3) Tropical Climate Research Centre	30.6.1999
(a) Indicators The following information may be compiled in respect of provinces under the three selected rainfall observation stations in each of the nine agro-ecological zones. (i) The existing crop calendar. (ii) Cropped area, crop-production, and crop yield, crop-wise (rice, secondary crop, and commercial crop such as coffee, pepper, rubber) and season-wise for the period 1950-1998 (iii) Cropped area, crop yield and production under irrigated, lowland rain-fed, upland rain-fed and flood-prone rice production systems (1950-98)	Department of Agriculture	1) Department of Irrigation 2) Department of Agricultural extension 3) Central Bureau of Statistics	15.6.1999
(b) Qualitative Assessment Report (i) The impact of normal monsoon, El Nino and La Nina impacted monsoon on rice and coffee production in respect of the ecological zones and winter, spring, summer, autumn seasons, separately from1975 to 1998. (ii) Impact of climate variability in modifying, altering the crop calendars for each season separately. (iii) The role of non-weather factors like market, input cost, and other socio-economic factors (to be specified) on crop production in various seasons from 1975-1998. (iv) The experiences of utilizing climate forecast information for modifying/ altering cropping patterns in respect of each season and each agro-ecological zone in recent years. (v) Constraints and opportunities for utilizing climate forecast information.	Ministry of Agriculture and Rural Development	1) Department of Agriculture 2) Agro-climate Research Centre 3) Department of Agricultural Extension	30.6.99
Water Resources The river observation stations may be selected in consonance with rainfall observation stations selected for compiling climate/ agricultural data as mentioned above. (a) Indicators The following information may be compiled in respect of select stations from 1950-1998 (i) General data on catchment and command areas in hectares. (ii) Month-wise rainfall and water level position for major irrigation sources. (iii) Season-wise cropped area and crop production in respect of each irrigation source (iv) Monthly data on stream flow. (v) The incidences of flood with date of onset, duration and dates of recession. (vi) The impact of the low flow, the normal flow and over flow on crop production in respect of summer, summer autumn and spring seasons separately.	Department of Dyke Management and Flood & Storm Control	1) HMS 2) Hydro-meteorological data centre 3) Hydro-meteorological Research Centre 4) Institute of Meteorological services	15.6.1999
(b) Qualitative Assessment Reports (i) Overview of ENSO impacts on surface and ground water sources by providing information on water levels in major reservoirs in comparison to normal years in the last two decades. (ii) History of flood events in the last two decades with river basin/ province-wise data indicating damages to crops, housing, infrastructure and communication assets. (iii) Management experiences dealing with past flood events in various provinces including flood forecasting arrangements at various levels. (iv)Co-ordination and institutional mechanisms at national, provincial and the reservoir project level to receive process and disseminate climate forecast information for managing water resources during ENSO in comparison to normal years. Part - II* Natural Disaster Documentation	Department of Dyke Management and Flood & Storm Control	1) HMS 2) Hydro-meteorological data centre 3) Hydro-meteorological Research Centre 4) Institute of Meteorological services	30.6.1999
a) Drought b) Floods c) Typhoons and storm surges d) Inundation e) Salt intrusion f) Temperature variations(Cold front) Part - III* Documentation of derived impacts	Dept. of Irrigation Dept. of Dyke Management and Flood and Storm Control HMS	1) Dept. of Agriculture 2) Agro-ecological Research Centre Dept. of Agriculture	15.7.1999
a) Forest and environment ¡ Forest fires b) Public health ¡ epidemics c) National economy ¡ economic impact of ENSO related hazards	Min. of Forest & Environment Min. of Health Min. of Planning and Investment	1) Department of Science and Technology 2) Central Bureau of Statistics	30.6.1999

* As per the check list provided by ADPC

Implementation Plan

The Workshop resolved to constitute a working group to complete the documentation. The agreed implementation plan for completion of the documentation is as under :
 

Activity	Responsibility	Time Frame
Issue of communication to various Ministries/ Departments	Ministry of Agriculture and Rural Development - Department of Dyke Management and Flood & Storm Control - MARD	7.5.1999
First meeting of Working Group to finalize strategies for undertaking documentation with reference to guidelines for documentation prepared by ADPC.	Disaster Management Centre - Department of Dyke Management and Flood & Storm Control	20.5.1999
Completion of part I and part II of the documentation	All members of the Working Group	30.6.1999
2nd meeting of Working Group to review part I of the documentation	All members of the Working Group, ADP	10.7.1999
Completion of assessment reports	All members of the Working Group, ADP	15.7.1999
3rd meeting of the Working Group to review completion of part II of the documentation	All members of the Working Group, ADPC	30.7.1999
Review - documentation	ADPC	7.8.1999
4th meeting of the Working Group to complete the documentation in the light of review of ADPC	All members of the Working Group, ADPC	15.8.1999
Analysis and draft report preparation	All members of the Working Group, ADPC	15.9.1999
5th meeting of the Working Group to review the draft report of the documentation	All members of the Working Group, ADPC	1.10.1999
Presentation of the report at the country level Workshop	All members of the Working Group, ADPC	15.10.1999