ميحرلانمحرلاهللامسب

Islamic Republic of IranMinistry of Jihad Agriculture

Forest, Range and Water shade Organization

Drought and Desertification monitoring Drought and Desertification monitoring and assessment:and assessment:

Early Warning Systems for Mitigating the Early Warning Systems for Mitigating the Effects of DroughtEffects of Drought

CRIC-1Rome-Italy 11-22 Nov. 2002

Table of contents

• 1- Background

• 2- Some managerial activities for drought mitigation

• 3- A case study for monitoring flood management

• 4- Outcome of monitoring

• 5- Conclusion

1- Background

• 1-1- Drought and Desertification

• 1-2- Distribution of Dry lands

• 1-3- Perspectives

• 1-4- Sequence of Drought Impacts

• 1-5- Water resources

• 1-6- Comparison of water resources

1-1-Drought and Desertification

• Although, the meaning of drought depends upon the habitat of the addressees but international organizations have tried to reach to its unique definition.

• According to UNEP, if the amount of yearly average precipitation is less than 0.65 of mean evapotranpiration in an area, in such a case it can be categorized as dry land.

1-2- Distribution of Dry landsArea Hyper

aridArid Semi-

aridDry-sub humid

Total

World 7.5 12.1 17.7 9.9 47.2

Asia 6.5 14.7 16.3 8.3 45.8

Iran 35.5 29.2 20.1 4.9 89.7

1-3- Disciplinary Perspectives on Drought

• Meteorological

• Hydrological

• Agricultural and

• Socio-economic

Hydrological Drought

• Hydrological Drought is associated with the effects of periods of precipitation (including snowfall) shortfalls on surface or subsurface water supply.

• Although all droughts originate from the deficiency of precipitation, hydrologists are more concerned with how this deficiency plays out through the hydrologic system.

1-4- Sequence of Drought Impacts

• The sequence of impacts associated with meteorological, agricultural, and hydrological drought further emphasizes their differences. When drought begins, the agricultural sector is usually the first to be affected of its heavy dependence on stored soil water. Soil water rapidly can be depleted during extended dry periods. If precipitation deficiencies continue, then people depended on other sources of water will begin to feel the effects of the shortage. Those who rely on surface water (i.e. reservoirs and lakes) and subsurface water (i.e. ground water), are usually the last to be affected short-term drought that persists of 3-6 months may have little impact on these sectors, depending characteristics of the hydrologic system and water use requirements.

1-5- Water resources

• It is estimated that total precipitation on the land of the world, is 110 thousand billion cubic meter, about 63.8 percent of this avapo-transpirates and its remaining make our drinkable water resources (Postel, 1997). Asia continent, having only 32.7 percent of total world’s lands, but it controls 37.4 percent of world’s water resources (Gleick, 1997). The portion of Iran is less than 0.37 percent of the worlds water resources, while its land form more than 1.2 percent of world’s lands.

1-6- Comparison of water resources

Land areas

Surface (m.h.)

Precipitation mm.

Precipitation (b cubic meter )

Evapotran. (b cubic meter )

E/P (%) Acquisition capasity b.cubic meter

a.c. %

The world

13012.6

831 110000 

70180 63.8 39820 36.2

Iran 162 243 400 281 70.3 119 29.7

2-Managerial Activities in Drought Mitigation

• -Establishment of drought stroke group in the capital and all provincial centers.

• -Identification of drought affected areas by collecting data and information.

• -Determination of vulnerability indices of different areas and distribution of financial resources.

2-Managerial Activities in Drought Mitigation (cont.)

• Enhancing financial support by the government for affected areas .

• -Determination of priorities, policies, allocation of budget, and facilities, using public participation in plans and projects aimed at mitigating drought effects.

2-Managerial Activities in Drought Mitigation (cont.)

• -Cooperation in setting up workshops, seminars and conferences related to drought in the country.

• -Reporting drought situation to international organizations and distribution of world supported resources.

3-A Case Study for Monitoring flood Management

• 3-1-Goals of flood spreading technique:• 3-1-1-Goals• 3-1-2- Objectives

• 3-2-Scientific Justification

• 3-3-Feasibility Study

3-A Case Study for Monitoring flood Management

• Flood management has been adapted in drylands of Iran for many centuries.This easy to use and applicable approach could be carried out in at least 14 million hectare of lands in Iran to exchange disturbance of floods to profitable water and yield production (Kousar, 1374,1380).

• The method, now, has been supported to be useful for helping 800 million hungry men in the world (FAO).

3-A Case Study for Monitoring flood Management(cont.)

• Assessment of cultivated vast fields, located in uplands of the ghanat in Khorasan province, shows that our grand fathers managed floods to store the god's blessing in order to cope with disaster of drought and also desertification.

• In this way, two functions of flood management merged with each other. In other words, spreading flood in uplands, not only irrigate the cultivated fields but also store flood water to feed the underground aquifers (Kousar, 1372).

3-1- Advantages of flood Spreading technique

• Flood spreading in an alluvial fan, is a multipurpose technique that is also less costly and easy to implement in the field.

• 3-1-1-Goals:

-To control floods

-To store flood water in aquifers for efficient use

3-1- Advantages of flood Spreading technique(cont.)

• 3-1-2-Objectives:• -To Change unproductive alluvial fans to ranges

forests and agricultural forms • -To stabilize the origin of sand dune movement• -To eliminate man-made desertification• -To enhance agricultural based employment

- To improve environmental condition

-To encourage public participation

3-2- Scientific Justification

• In Iran, there is 43 million hectare of lands, 1/4 of the country surface, suitable for storage of water in underground dams, but interestingly, only 14 million-hectare are sufficient for controlling and storing 50-billion cubic meters of floodwater.

3-3-Feasibility Study

To find best and suitable places for establishment of the flood spreading project the following disciplines should be taken into account:

• Meteorological and ecological studies• Watershed assays with its general studies• Pedology of the location• Hydrology• Socio-economic studies• Geomorphology• -Hydrogeology

4-Outcome of Monitoring

• Monitoring of ten stations,totally covering a land area of about 20 million-hectare, has shown:

-Increasing the number of wells and volume of water,-Addition of agricultural land area,-Increasing range production capacity,-Storage of the huge volume of floodwater

5- Conclusion

• Application of specific monitoring system for different drought disciplines(Meteorological, agricultural and hydrological) is essential

• Significance of drought depends upon drought classification

• Hydrological drought is the most dominant type in Iran

• Flood spreading technique is a multipurpose , easy to use and less costly activity

5- Conclusion(cont.)

• Reduction of damages incurred by flood water is considerable

• Reduction of poverty and desertification control

• Monitoring the flood water spreading in this case study has opened a new horizon in coping with drought and desertification impacts