NATIONAL METEOROLOGY AND HYDROLOGY SERVICE DROUGHTS IN PERU. Ing. Constantino Alarcón

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1 NATIONAL METEOROLOGY AND HYDROLOGY SERVICE DROUGHTS IN PERU Ing. Constantino Alarcón December 2009

2 Since Peru is a double-nature country, mountanious and tropical, it is characterized by the presence of multiple micro climates, that are altered by the occurrence of extreme hydrometeorological events such as heat waves, frosts, cold fronts, heavy rainfall, droughts, floods, causing innumerable loss. The presence of the Andes Mountains, together with other climate and oceanographic factors determine the existence of three natural regions: The coast that shows desert, arid and semi-arid characteristics. The mountain region, that shows a hilly relief with deep and narrow valleys. The jungle which is mostly covered by tropical forest..

3 A typical phenomenon of the interannual climate variability in Peru is the occurrence of droughts, that every certain periods of time occur, mainly affecting the mountain region.

5 AGROMETEOROLOGICAL DROUGHT The General Directorate of Agrometeorology carries out the agrometeorological monitoring of the hydrographic basins at national level, it is made using agrometeorological indices and parameters, based on meteorological and phenological records. One of the main activities of this monitoring is to determine rainfall deficit and droughts for 10-day and monthly periods. The indices used for this monitoring are: Humidity index (HI) Standardized precipitation index (SPI) Palmer drought severity index (PDSI)

6 Precipitation index (Pi) It shows the deficit and/or excess of humidity of the crops in the environment, place and considered period of time. The Pi is equal to the relation between precipitation and potential evapotranspiration. Pi=Pre/PET Classification of Precipitation Index (Pi) adapted to rainfall regimen and soil in Peru (SENAMHI- DGA-2002).

7 DECADAL VARIATION OF HUMIDITY INDEX IN THE MOUNTAIN REGION AGRICULTURAL CAMPAIGN

8 Decadal variation of the humidity index Hi = p/eto

9 SPI Ramis river basin Agricultural campaign

10 Monthly Behavior of the SPI in the Ramis river basin Agricultural campaign Agricultural campaing

11 Palmer Drought Severity Index (PDSI) The methodology proposed by the National Agriculture Decision Support System (NADSS) is used. Original and Self-Calibrating Palmer Drought Severity Index.

12 HYDROLOGICAL DROUGHT The General Directorate of Hydrology and Water Resources carries out the hydrological evaluation at national level, based on information from the hydrometeorological network installed in the Peruvian territory. The analysis made focuses on the evaluation of precipitation behavior per pluviometric zone, with and emphasis on hydrological drought. METHOD The SPI method is used to define periods of drought and water excess. Estimation of the SPI at 3, 6, 12 y 24 month scale, using Fortran Spinderx3 program Obtain SPI averages for each time scale, per homogeneous zone Determine regional model stations Determination of the frequency of dry and humid events Identify maximum dry and maximum humid periods per decade Identify the intensity of dry and humid events per period. Identify maximum values and extreme variability of the SPI at time scales.

13 Behavior of the SPI per pluviometric region-southern zone Fuente: DGH-SENAMHI Pluviometric regionalization Southern zone Spatial behavior of the SPI-1 per pluviometric region Southern Zone

14 (Sancho y Cervera, et al., 1980). METEOROLOGICAL DROUGHTS Severity Index (S.I.) Defined as the function of the precipitation deficit, expressed in percentage, compared to the mean annual or seasonal long term rainfall and its duration in a determined region. S.I.= (SUMY-SUMX)/SUMX SUMY<SUMX Where: Y = monthly registered precipitation X = Normal monthly precipitation SI SUMY - SUMX if less than 0.0, there is meteorological drought The severity index of meterological drought was classified into seven classes: Extremely severe (higher than 0.8) Very severe (0.6 to 0.8) Severe (0.5 to 0.6) Very strong (0.4 to 0.5) Strong (0.35 to 0.4) Slight (0.2 to 0.35) Absence (<0.2).

19 THANKS:

Armenian State Hydrometeorological and Monitoring Service

Armenian State Hydrometeorological and Monitoring Service Offenbach 1 Armenia: IN BRIEF Armenia is located in Southern Caucasus region, bordering with Iran, Azerbaijan, Georgia and Turkey. The total territory