1. R APID A SSESSMENT OF P OPULATION S IZE BY A REA S AMPLING IN D ISASTER S ITUATIONS

2. I NTRODUCTION In the initial phase (first phase) of any complex emergency that involving large population displacement within one to two days necessary to prioritie s emergency health responses providing baseline data for immediate planning a valuable public health tool Provide relief workers with the necessary data Help for plan both health-related activities and all aspects of relief planning such as food, water and shelter

3. a rapid population estimate method based on area sampling method proved to be useful to estimate population figures within one or two days total population census or alternative registration methods complete several weeks later when the situation become stabilized

4. A REA SAMPLING AND RAPID POPULATION ASSESSMENT METHOD stage 1: mapping the camp two main stages: stage 2: Estimating population size

5. S TAGE 1: MAPPING THE CAMP At first, a precise map is drawn by walking all around the camp or site A starting-point or landmark is chosen Camp dimensions measured in meter are determined either by measuring the width and length of all camp sections or by measuring all camp sides All external limits of the camp are defined by their bearings

6. C ONTINUE S TAGE 1: MAPPING THE CAMP Bearings are measured in degrees by aiming a compass arrow in that direction Depending on exposure to satellites, in some instances the Global Positioning System (GPS) was used For each new direction taken, when going from one specific landmark to another, distances are measured

7. For large camps, side dimensions are determined by driving around it with the car’s odometer When landmark and distance measures are obtained, the map is outlined on paper at a 1: 10,000 scale (one meter measured at field level corresponds to 0.01centimeter on the paper map) C ONTINUE S TAGE 1: MAPPING THE CAMP

8. The map can also be drawn by entering the latitude and longitude data from GPS in a computer squares drawn The camp surface is obtained by counting on the paper map the total number of squares, or from the computer. C ONTINUE S TAGE 1: MAPPING THE CAMP

9. 1- determine landmark 2- distance measuring (measuring all camp sides) 3- mapping the camp (drawing the map of camp) 4- drawing squares 5- counting total number of square 6- obtaining the camp surface by counting the total number of squares S UMMARY OF S TAGE 1: MAPPING THE CAMP

10. S TAGE 2: E STIMATING POPULATION SIZE This is a step-by-step procedure A random sample of five to 12 square blocks is selected on the paper camp map or by computer Depending on the size of the camp, blocks’ dimensions vary from 25 by 25m2 to 100 by 100m2

11. With the compass or GPS co-ordinates, from a given camp side, each square selected can be identified at field level population data are collected in each block selected by interviewing all heads of households The average population per block is then calculated C ONTINUE S TAGE 2: E STIMATING POPULATION SIZE

12. extrapolating the average population per block the total camp population is obtained by extrapolating the average population per block to the total camp surface C ONTINUE S TAGE 2: E STIMATING POPULATION SIZE

13. Usually, population tends to be more densely gathered in the middle of the camp, while it is dispersed at the periphery For such camps, several ‘density zones’ can be defined by observation while walking around the camp, or better, by measuring distances between households For practical reasons, density zones are usually limited to two or three C ONTINUE S TAGE 2: E STIMATING POPULATION SIZE

14. The total camp population is determined by adding up estimates obtained for each population-density area C ONTINUE S TAGE 2: E STIMATING POPULATION SIZE

15. S UMMARY OF STAGES 1&2 1- Estimate the total camp surface(m 2 ) by measuring the length and width 2- Numbering square (25 by 25m or 100 by 100m) 3- Define & Number High- and low-density zones 4- Random sampling (5-12 square block) 5- Counting average population per square 6- Estimate population per zone 7- Extrapolation total population

16. the number of blocks varied from five to 26, and the dimensions of blocks’ sides varied from 25 meters for five camps, to 100 meters for one camp selecting a higher number of small blocks would be better than relying on fewer 100 by 100m blocks

17. LIMITATIONS the use of GPS depends on a good exposure and an easy access to satellites Issues related to population density The number of square blocks needed The size of blocks to be selected the empirical selection of the population density zones