All articles

  1. After extracting all the data from GRUMP and adding up population by country to get country population totals, should the totals add up to match exactly the totals reported in the country summary?

  2. Are extreme events considered in the model?

  3. Are farmers' capacity to adapt to climate change included in the model?

  4. Are the quadrilaterals formed by the meridians and parallels of the Urban/Rural Area grids proportional to the area on the globe?

  5. Are there any EPI reports before the 2006 EPI? What is the difference between the Pilot 2002 EPI and the Pilot 2006 EPI?

  6. Are there any published papers about GPWv4?

  7. Can I use GPW to study how population in Syria and the surrounding countries is being affected by conflict?

  8. Can PLACE I, PLACE II, and PLACE III country values be compared directly?

  9. Can the PLACE I and PLACE II country values be compared directly?

  10. Clarify the differences between being a party to a convention/treaty and being a signatory and what are the legal implications.

  11. Could you please let me know if there is any link between the ESI and Corporate Triple Bottom Line (TBL) Reporting? Alternatively, would you regard the ESI as a proxy for national TBL reporting?

  12. Could you please tell me how and with what kind of weighting the ecological footprint has been factored into the 2002 ESI?

  13. Do you have the China maps available that are subdivided at the prefecture level for 1995? I have seen the county level ones on your website but these are too detailed for my purposes.

  14. Exactly how is the Human Footprint Value calculated? I need to know how the normalization was performed.

  15. For which part of the earth's land surface is the human footprint data available?

  16. GPWv4 releases data for five years: 2000, 2005, 2010, 2015, 2020. I would like to know if it is advisable to compare data sets of different years in order to assess changes in population density over time, or if there are any constraints in using the GPWv4 data as a time series?

  17. Hello! I want to know in what unit is the field ‘Area’ in the China Admin ArcInfo file?

  18. How big is the file (.ascii) of GRUMP data? I am downloading from a very fast connection and it is still taking a really long time.

  19. How can I access the 1980 and 1990 Census, STF3a files?

  20. How do I convert .BIL format in Arcview/ArcInfo?

  21. How do I create a Treaty Status Matrix?

  22. How do I determine which countries are Party or Signatory to a given treaty?

  23. How do I get GPW data into GRASS?

  24. How do I get permission to reprint a GPW map?

  25. How do I open ArcInfo Interchange file (.e00) in ArcGIS?

  26. How do I search within a set of treaties to find the ones that a specific set of countries have signed?

  27. How do I unsubscribe from this list?

  28. How do I use the Data Cart?

  29. How does GPW convert census data into a global grid?

  30. How does GPWv4 compare to previous versions of GPW?

  31. How is SEDAC’s Gridded Species data different than the IUCN Red List?

  32. How is the Composite map of the Human Influence Index performed (0-64)?

  33. How often is the CIESIN Geospatial Metadata Writer's Guide updated?

  34. How often will the ESI be updated?

  35. How should I cite the GPW3 data?

  36. How should I cite the GPWv4 data?

  37. How should I interpret the yield changes? Expanded question: Let's take an example of India where wheat production is projected to decline by '- 2897341.18' tonnes by 2020 compared to 1990 production (ActChWHA1F2020). Since India produced '49850000' tonnes of wheat in 1990, according to this database it is likely to produce 46952658.8 tonnes ('49850000' - '2897341.18') in 2020. Since India produced '80,680,000' tonnes of wheat in 2009-10, the projected decline in 2020 is likely be 42% of the 2009-10 production. I understand that these numbers are not meant to be taken literally and are just indicative in nature. However, I want to know if I am correct in my interpretations.

  38. How up to date are the data in ENTRI?

  39. How was the Data Context layer created?

  40. I am a graduate student. I am interested in all the chinese information and maps at your website and trying to design a small project for my class. But I find there are no information about the map projection. The administrative Region map projection is different from that of the Fundamental Maps.

  41. I am attempting to download and use your 1990 Adjusted Population Numbers for Africa. I have successfully downloaded the zipped BIL file. In order to convert this for use in my GIS software (I am using IDRISI) I need to know information which I cannot find in any of the documentation files you have made accessible. Please can you answer the following questions regarding the BIL format: 1. Is there a header - if so what is its size? 2. What are the maximum and minimum grid co-ordinates for your Africa data? 3. Are the data 8-bit or 16-bit? 4. What reference system do you use, and what the reference units measured in?

  42. I am currently a student in Scotland and I am looking for information regarding laws on pollution and industry to help with my first year dissertation on Venezuela. Any information that you could send me would be greatly appreciated.

  43. I am currently evaluating different indices of sustainable development and came across the 2002 ESI profile for Belgium (Annex 5, p. 93). Could you explain why air quality is above average when the emission of air pollutants ('reducing air pollution') is extremely high?

  44. I am having difficulties locating the metadata for your population density data of the world, GPWv3. Is the metadata available online?

  45. I am having difficulties locating the metadata for your population density data of the world, GPWv3. Is the metadata available online?

  46. I am in the process of developing a new interactive desertification website. I have found your website by surfing the web and have found it a wonderful site that I would like to refer a link to. In addition I would like permission to enter some articles that are on your site onto our site.

  47. I am looking for gridded population data and elevation data on the same grid. I saw on your website that you have compiled a population dataset - is there an elevation dataset that can go with this, and can you help me obtain it?

  48. I am looking for projection information for your Mexican Municipios data. I need to reproject the data and I need to know what the original projection was for the coverage.

  49. I am looking for the ESI reports for 2003 and 2004.   Is the ESI available for these years?

  50. I am looking for the population and the surface area (in square kilometers) for several cities throughout the globe.  I found several datasets available in GRUMP, but I didn't find anything with both population and surface area.

  51. I am participating in a research study and am in need of population density maps for select countries in Africa and Asia. Can your organization provide me with such maps?

  52. I am slightly confused as to what is meant by "urban extent" and "settlement points" - please could you send me a definition? Also, I have found the global map which shows "urban extent" - which I guess is the areas of the Earth's surface which are covered by urban areas. I am wondering if you, or anyone else you know of, has a time-series of such maps, showing how urban coverage has changed over time?

  53. I am trying to find China's Agenda 21 policy document. Do you have it on your web site?

  54. I am trying to get population densities for world metropolitan areas (e.g., # of residents per square kilometer or square mile) and if possible comparison figures for previously points in time (e.g., the latest available estimate versus 1 year ago, 5 years ago, etc.).  Can I use the GRUMP data ?

  55. I am trying to locate maps online of the Metropolitan Statistical Areas (MSAs) for all US states and Puerto Rico and haven't had much luck. Can you tell me where I might find these maps?

  56. I am using the GPW data (version 3) for China and I have some problems with understanding the proportional allocation mechanism. The reason that I am asking is that there are so many zeroes and I can not understand how there can be any zero?

  57. I am using the multibandread function in MATLAB to read in the glds95agi15.bil file I downloaded from CIESIN. I need help setting some of the input parameters for the function. * what is the height (rows), width (elements or columns), and depth (bands) of the file or how do I figure it out? * what is the number format? integer or float? how many bytes?

  58. I am very interested in the gridded population density data for Africa.The source for the maps you provide is cited as the UN, but having contacted them they are unsure of the data you have used to produce your maps.Is it possible to obtain these data from you, including population numbers for different regions of Africa as well as the density calculations that you have mapped?

  59. I am working on a map of Mexico that details population dynamics at the state level and am wondering if you have such information (e.g., total fertility rate, natural increase, inward and outward migration), or if you have a suggestion as to who I might contact.

  60. I compared GRUMP Alpha population grid and GPW v3 population grid for the year 2000 in 1° grid. I am surprised to see that there are some huge differences (the largest difference that I noticed is 8.77x106 people).  How do you explain these huge differences?

  61. I download GRUMP 2000 population count data set. It sees that maximum population count is 1,346,772 in the cell of that data set. I would like to know that is right or not, because I think that the value is very large. Could you give me advice about maximum population count in GRUMP?

  62. I downloaded GRUMPv1's Population density. From the metadata associated with the files I understand that each cell/pixel is the average population density in units of person per sq km. When I zoomed in to Chicago, IL and NY there appear to be a suite of pixels with population densities greater than 20,000 people per sq km which seems off by a factor of 10. Would you mind confirming those values.

  63. I downloaded the ArcInfo interchange files and tried (after import) to open them with the ARCGIS 8 software but each time it failed to open the file. I think the sta.adf file is missing (or another one). Could you please help me?

  64. I downloaded the global level data file I looked into the file content on a unix system using 'more', and found most grid values to be less than 1. This is unexpected, as I expected the number of inhabitants per cell. What did I do wrong?

  65. I downloaded the GPWv3 Population Density .ascii format. I'm having trouble parsing this data correctly. I read in the meta data at the top of the file (lower-left latitude/longitude origin of the grid, cell size, etc) and these seem to make sense. But when I plot all cells with a density greater than 300, the points are not syncing up with the map (i.e. I'm seeing large blobs of population in the Pacific). Am I correct in assuming that the rows of the file begin at the lower-left point given, with the columns representing increasing longitude and rows representing increasing latitude?

  66. I downloaded the urban extents grid from GRUMP (alpha).  When opened in ArcGIS, there are only two values 1 and 2.  What do these values mean ?

  67. I have a list of states that are parties to a given treaty. The states are listed in one column and "Date Entered into Force" in another column. What does it mean when a state is listed in the left hand column but no date is entered in the second column (it is blank)?

  68. I have a question regarding the data set Contours of China and the Surrounding Areas. What Surrounding Areas are included in the data? What is the difference between the file and the

  69. I have been trying to download the GRUMP/GPW datasets but the web download does not seem to be working.

  70. I have been trying to download the GRUMP/GPW datasets but the web download does not seem to be working.

  71. I have downloaded India 1995 population data (GPW2). Why is there no variation in colours when I view the files in ArcView?

  72. I have downloaded some of SEDAC's 1980 census tract boundary files in "BNA" format, but am unable to read them in Arc GIS 8.1. I was told that there should be a conversion program "bna2shp.exe" somewhere on your site but am unable to find it.

  73. I have imported the country-specific population density grid maps in ArcGIS for Argentina, Mexico and Honduras. I'm trying to join a table of points by latitude/longitude to these maps and export a table with all the data. The problem I'm having is that there does not seem to be any geographic data even though the maps are projected with WGS1984 correctly. I downloaded it from the site in the .bil format.

  74. I have read with interest the Environmental Sustainability Index that has been developed at Columbia University. For my Master's Thesis I am looking at developing a framework for measuring sustainability. I am particularly interested in measuring differences at the regional/state level. Would you see the application of the Environmental Sustainability Index at the state level as effective? Would it need to be modified or could it serve as a useful comparison for states to national achievements.

  75. I have successfully downloaded the GPW global datasets for the years 1990, 1995 and 2000. I would like to know if it is advisable to compare datasets of different years in order to assess changes in population densities and therefore migration patterns, or if there are constraints that hinder such operation.

  76. I looked at your website and I am very interested in working for SEDAC. How do I apply for a job there?

  77. I need some gridded population information so I downloaded GRUMPv1, which seems like it should be perfect for my needs. However the number in the file naup00g.asc (North America unadjusted population counts in the grid) are small floating point numbers. I had expected that they would be population counts in the grid cell, which is what the documentation seems to say. Not sure how to interpret values like "2.35144e-005" as a population count! Am I misinterpreting these somehow?

  78. I need to use the GIS coverage of Mexican States in some of my current institutional projects. I did the download from your site, but I don't have ArcInfo in my PC and I know that all the files are in ArcInfo export format. I was trying to open the files from ArcView, but it was not possible. Do you know if this information is also available in some Arc/view format?

  79. I plan to use the global population data. I would like to know what information is stored in the *.stx and *.blw files. Also is there a way to map the grids to (latitude, longitude) ?

  80. I read the 2002 Environmental Sustainability Index (ESI) where Uruguay is on 6th place. Its component score ranks range from 19th to 35th. Are other countries much more variable so their high ranking components are counterbalanced by low ranking components? I want to know which variables where the most important to put Uruguay in such a good place in the world list?

  81. I see you have country-level estimates for the low elevation coastal zone data. Is it possible to get the gridded data?

  82. I see you have data on mammals and amphibians, do you also have richness grids for bird species?

  83. I want to visualize/mashup many of your Web Map Services in ArcGIS Online, or even ArcMap. But, I'm not having much luck with ArcGIS. Is there some guidance you can provide to help me here. I'm sure I'm not alone with this request and as ArcGIS Online is becoming more proliferate other will want to leverage your great services themselves in their own mashups.

  84. I was excited to see you have anthropogenic biome data, which would be useful in my research. What are the differences between the Anthropogenic Biomes of the World, v1 data and the Anthropogenic Biomes of the World, v2 data for 2000?

  85. I was interested in obtaining a Geographic Correspondence file, particularly Block Group to Block, for every state, containing allocation factors for Population, Land Area & Housing Units. Is it possible to obtain these .csv files directly from you?

  86. I was wondering if I could get more information on how these treaties have been sorted in your database. What was the criteria for classifying these as "international environmental treaties"? Some of them seem to deal only with fisheries jurisdiction or other similar issues. I am planning to use this information for a graduate research project on the factors that influence how many international environmental treaties a nation is involved in. More information on how the classification was done would be extremely helpful.

  87. I would like to do a time series analysis to look at the change in environmental sustainability in specific countries, but I am unsure if the data for your 2001 and 2002 ESI is different, or whether the 2002 ESI is just the result of fine-tuning definitions and categories.

  88. I would like to download GPW and GRUMP data, but I'd like to know if it is possible to download files by some coordinate extent, rather than by country?

  89. I would like to use the population estimates service, but don't know exactly how it works. I installed uDig with a WPS plugin, but I wonder which URL I have to use to connect to the sedac website.

  90. I'm looking for all of the administrative boundaries in your China Administrative map but I could not find the administrative boundary, for Chongqing.

  91. I'm new to the list, is there any way I can see old messages/threads that were posted to the list.

  92. I'm preparing an article about "human migration and environment". Do you have any data or information relevant to this topic (causes, effects, links)?

  93. I'm studying the Yangtze river flood (July-August 1998) and I need a detailed map of this area of China. I will grateful if you help me to find it.

  94. I'm using population density data, 2.5' grid.  My question is -- If a small populated island is the only land in a given cell, and its area is smaller than the cell's, how is the population density for the cell computed?  Is the population of the island distributed over the whole cell's area?  Or is the population density of the island applied to the whole cell?

  95. I'm working with the 1980 PUMS. I just want to make sure I understand the coding of age. Does the age variable refer to the person's age on Dec 31, 1980. If not, what exactly does it measure?

  96. I've managed to read in the 2.5 min GPWv3 population grid (95ag). When I inspect the file, I see "lines" of blended values between the population subregions (which are a field of a single number, presumably indicating the population in that subregion). I presume these "blended" values on the borders between subregions are artifacts of how the files were created, and do not represent valid population numbers. Am I correct?

  97. I've visited your China Dimensions website but it was not clear if the maps are raster maps or vector maps. I am actually looking for vector maps. Based on the fixed scale given as 1:1M, can I assume that they are raster maps?

  98. In GPW data that is comprised of 2.5 arc min cells, are the cells georeferenced from the cell center, or right/left and upper/lower corner?  I understand that xllcorner and yllcorner give the starting lat/lon for overall grid position, but are the cell data themselves valued at each lower left corner?

  99. In GPWv3 Population Density Grid data, .ASCII format, what is the definition of "xllcorner" and "yllcorner" values?

  100. In GPWv3, how do you consider the population density in a bin (0.25 deg x 0.25 deg) when it is partly landmass and partly water (e.g., sea, ocean)? Do you evaluate the density as the total number of humans over the total surface of this bin (so, approximately, let's say 30 km x 30 km, even if depending on latitude) or just only over the landmass part?

  101. In GPWv3, what exactly does "No Data" (-9999) mean?

  102. In reviewing the latest statistics on environmental sustainability from your website, I noted that the Faroe Islands was not listed. Could you please advise me on the criteria regarding who is included in the 2002 ESI rankings?

  103. In the China County-level Data on Provincial Economic Yearbooks, each of the DBF files has its meaning, such as 1990B1.dbf is about the General Survey. But when I open the file, all the item names are given as sequential number codes, such as B1990001, B1990002, B1990003. I want to know about each item's name -- what's the value meaning?

  104. In the Urban extents data, how were the urban areas identified?

  105. In UN-adjusted 2000 density data, how is the data adjusted to match UN totals ? The Africa UN-adjusted map shows some significant chunks of zero density (e.g, much of Gabon) that don't seem realistic.

  106. Is it possible to do a time series analysis on the ESIs?

  107. Is the data symmetrical from the Equator?  In the ascii format using a 0.5 degree resolution, the yllcorner equals -58 degrees. Since there are 286 rows, this represents a total of 143 degrees. Is the upper left corner then at 85 degrees latitude (-58 + 143)?

  108. Is the information I provide to the URS safe?

  109. Is there any way to find out how block groups from the 1990 census match with block groups from the 1980 census? I need to find or create data that would show the change in block group characteristics over time. I tried MABLE but it only has block group information for 1990 census.

  110. I downloaded your Population Grid maps for the United States and the World both at a resolution of 2.5 arc minutes, and I have a few questions. First, what are the units of the grid values? From what I've noticed, they run anywhere from the thousands to 1e-9, which seems kind of strange. Also, at the same resolution, why does the United States have more columns than the world?  The data at the top says there are 8688 columns at a cell size of 0.0416666, which would imply 362 longitudinal degrees of data.

  111. I’ve downloaded the GRUMP 30 arc-second area grid (ASCII format), and am confused by the units. The meta data says that the units are km2 of land area, but when I unzip the file (using gunzip), producing gluareag_alpha1.asc, then the land cells have values of 56 (or less, if not completely land). Also, the missing value should be -9999 but the data file has 0 instead.

  112. My question is about the grid pixel, is the grid center of the pixel or not? I mean, if the latitude begins from 5° and longitude from 65°, is (65,5) the center or one edge of pixel?

  113. On the "Prevalence of Child Malnutrition" data set using the 1/4 degree raster file called "UW", the values for the visualized raster data ranges from near 0 to over 500. But this does not make sense, because according to the documentation and the readme file, the "UW" file is supposed to represent the percent of children under age 5 who are malnutritioned. By that definition the values should only range from 0-100.

  114. Please help me to understand about ozone, I am very confused. Environmentalists tell me the ozone layer is being depleted and allowing harmful UV rays in. The health department says there's too much ozone and it is causing health problems. This conflicting information is very confusing. Do we have too much or too little ozone? Can someone please explain?

  115. Regarding the uniform field of values that fill each population subregion, my hope when I downloaded the 2.5 minute GPWv3 population grid (95ag) file was that they would indicate the population in that 2.5 minute cell, since the documentation refers to 2.5 minute resolution. However, I suspect that they actually represent the sum of the population in the total area of the subregion. What do the values in each cell actually represent?

  116. Regarding the EPI 2010. Could you clarify if the EPI scores can be, in fact, taken as a percentage (%).

  117. Since the footprint data uses the spheroid GRS1980, can I just define it as NAD1983? I know that NAD1983 uses GRS1980, but I am not sure if I can define this layer as datum-based instead of spheroid-based.

  118. The maps on the GPW web site report population in the thousands.  Is this the same for the grid or is it unscaled?

  119. There is a slight misalignment between the pop density and the urban extent data layers for Africa, due to differences in the BLW files. The former layer has 0.00833333333330 0.00000000000000 0.00000000000000<br/><br/> -0.00833333333330 -25.99583333333335 37.99583333303735<br/><br/>and the latter has<br/><br/> 0.00833333000000<br/><br/> 0.00000000000000<br/><br/> 0.00000000000000<br/><br/> -0.00833333000000<br/><br/> -25.99583333500000<br/><br/> 37.99580373499999<br/><br/> <br/><br/>This makes a difference of a couple of hundred meters. Is this just because the analysts were rounding? Is it okay to use the same BLW data for both files?

  120. We are looking for a high-resolution gridded population data for our project. It seems to us that compared to the GPW3 data, the GRUMP data offer a higher spatial detail and probably a more accurate spatial distribution of population. Which would you recommend ?

  121. We are looking for a high-resolution gridded population data for our project.  It seems to us that compared to the GWP3 data, the GRUMP data offer a higher spatial detail and probably a more accurate spatial distribution of population.  Which would you recommend ?

  122. We are updating our list of ratifiers to treaties, and can't seem to find a current list of the parties to the 1991 Madrid Protocol to the Antarctic Treaty. Could you help? I've checked several Websites and seen several member lists, but they are not up-to-date.

  123. We have been using the GPW data extensively, but one question I cannot understand is why the data appear not to be available in database format rather than GIS format.

  124. We have downloaded the population estimate data for France (frap05ag.asc). When we use this file to calculate population for a given polygon, it does not match the response returned by the Population Estimation Service provided. We were wondering what is your criteria for including a grid cell in the calculation? Are you giving weight to a cell based on polygon intersection area? Also, wanted to clarify the xll, yll corner values - do the values -6, 40 represent the center of the bottom left cell or do they represent bottom left corner of the bottom left cell?

  125. We just finished reading Esty and Cornelius' Environmental Performance Measurement: The Global Report 2001-2002, where the ESI was discussed. We also looked at the 2002 ESI online. We are finding that the methodology sections (both in the book and online) are insufficient to allow us to replicate the rankings. We are interested in seeing how the rankings change if we impute our own weighting schemes, but to do so requires that we understand how they were done in the first place. So, here are our questions: 1. How were the z-scores for each of the variables converted to a percentile? 2. How were the percentiles converted to the indicator? Was this a sum of all the percentiles, an average of the percentiles, or something different? 3. How were the indicators compiled to create the overall ESI? 4. Were missing values included in all the above computations or were values imputed in the above prior to the computation of z-scores?

  126. We would very much appreciate you informing us on how you base your calculations on the profitability on water, or possibly its quality.

  127. What are family richness grids?

  128. What are the advantages of GPW over other products?

  129. What are the differences between GPW, GRUMP and Landscan?

  130. What are the differences between GPW, GRUMP and Landscan?

  131. What are the restrictions on use and redissemination of data?

  132. What are the restrictions on use and redissemination of data?

  133. What are the restrictions on use and redissemination of data?

  134. What are the species grids maps about?

  135. What do the numbers "mean?"  That is, if Uganda's value is 0.65, does that mean that on a scale of 1-4 (1 being the least) that Uganda is very unlikely to be exposed to the 6 hazards you describe?

  136. What does a zero in the population density grid mean? What does No Data mean?

  137. What does the "z" score for a peer group mean?

  138. What does the Peer Group ESI mean?

  139. What has happened to .e00 format option? It appears to have been replaced by something called "grid"?

  140. What is a .BIL image file format?

  141. What is SEDAC?

  142. What is the difference between ""  and "...g" files?  For example, I've downloaded the population grid for the whole world for 1990, in "grid" format, and there are two sets of raster files.  When I open them in ArcGIS, they seem to show similar data, but the range of values for the raster is somewhat different: 0 to 1.24 million versus 1 to 1.17 million.

  143. What is the difference between GPW and GRUMP population grids?

  144. What is the difference between GPW and GRUMP population grids?

  145. What is the difference between PLACE I and PLACE II?

  146. What is the difference between PLACE II and PLACE III?

  147. What is the difference between the Population Count and the UN-Adjusted Population Count data sets? Or between the Population Density and the UN-Adjusted Population Density data sets?

  148. What is the difference between the water mask grid and the water area grid?

  149. What is the exact spatial domain of the .asc urban extent grid? Is it from -56.0 to +84.0 *included*?

  150. What is the Human Footprint Index?

  151. What is the Human Influence Index?

  152. What is the main strength of the data?

  153. What is the most recent version of the ESI?

  154. What is the projection that the Census use for its ArcInfo files?

  155. What is the projection used for the data?

  156. What is the projection used for the GPWv4 data?

  157. What is the reason that an EPI was established as a complement to the ESI?

  158. What is the reason that an EPI was established as a complement to the ESI?

  159. What is the spatial extent domain for the different file formats of 30" GRUMPv1 Urban Extent Grid?

  160. What is the User Registration System and why do I have to register?

  161. What source data is used in GPWv4?

  162. What types of crops were included in the study?

  163. What version of the FGDC Metadata Standard does SEDAC use?

  164. What were the data sources used for the 2001 ESI?

  165. What year(s) is this data from?

  166. What years are the data available for?

  167. When will the grids of census variables (sex, age, and urban/rural designation) be released?

  168. When will the new 2002 PUMS be available/released?

  169. Where are the attribute tables for the GPWv3/GRUMP data? I would eventually like to extract statistics (such as population count) using features in another layer, but am not sure that I'll be able to do so given that there are no accompanying attribute tables. Could you advise as to how I should proceed?

  170. Where are the attribute tables for the GPWv3/GRUMP data? I would eventually like to extract statistics (such as population count) using features in another layer, but am not sure that I'll be able to do so given that there are no accompanying attribute tables. Could you advise as to how I should proceed?

  171. Where can I find help in using the commands associated with this list?

  172. Where can I find land area data for 1990 census tracts? I am trying to determine the median square mileage of census tracts.

  173. Where can I find more information about the ESI 2002 methodology?

  174. Where can I find the latest HIV figures for sub-saharan Africa?

  175. Where can I learn more about user registration?

  176. Where is aerosol optical depth on the app?

  177. Which are the last updated and the next scheduled GPW collected data?

  178. Which ellipsoid / spheroid is the geographical data of the Fundamental GIS: Digital Chart of China based on?

  179. Why can't I make the Import71 work with the GPW data?

  180. Why does Egypt look different than the rest of northern Africa in the population count and density grids?

  181. Why is it that the total population of the settlement points is not equal to the country total population?

  182. Why is there a difference between the population estimates of UN and National Statistical Offices estimates?

  183. Why was gROADS developed?

  184. Will SEDAC develop other similar regional collections?

  185.  What is the Last of the Wild?

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