User Manual - Department of Hydrology and Meteorology
Contents
1. Nepal Climate Data Portal User Manual DRAFI v0 4 Asian Disaster Preparedness Center 979 66 70 24th Floor SM Tower Phaholyothin Road Samsen Nai Phayathai Bangkok 10400 T 66 2298 0681 92 F 66 2298 0012 http www adpc net AidIQ http aidig com Asian Development Bank Department of Hydrology and Meteorology DHM Asian Disaster Preparedness Center AidIQ Asian Development Bank DHM Table of Contents Disclaimer Overview Purpose intent A useful way to see the Nepal Climate Data Portal Features Definitions Tour of the User interface Map view components Side panel components Climate Data Types of data available Names and naming conventions Basic usage How to display observed data on the map How to download a printable map image How to generate a chart from the map overlay How to filter the map overlay Colour Key Filter Box Examples Nepal Climate Data Portal User Manual YN VN OO Oo OG oO BB BP BP WHO BO WO DN Asian Disaster Preparedness Center AidIQ Asian Development Bank DHM Simple data comparisons Performing a simple comparison Example Annual aggregation Explanation What difference does the Annual aggregation checkbox make Month selection The Previous December checkbox What difference does checking the months make Flexible data queries Overview Queries are shown in the Legend Query Box Editing query expressions Example Expressions and operators available in the query syntax Stati2. 12 Nepal Climate Data Portal User Manual 14
3. series charts or downloadable data Like a spreadsheet which is another sophisticated calculator it uses a simple language to represent arithmetic and statistical operations The point of this is just like any calculator it is dumb in the sense that it basically just applies the instructions it is given to the data it has been given lt isn t smart i e ultimately it cannot recognise bad data or instructions although it does have some mechanisms to cope with bad data and it can also use some meta data data about data to help users validate results For example the portal can t and doesn t try to detect incorrect outliers but the map overlay colours will visually and obviously show those outliers and the user can edit the colour scale to exclude those outliers and see a useful map As another example the system doesn t know what the values mean but does know about units so it can dimensionally analyse expressions and then show the output units The portal will complain when units are incorrectly mixed in an expression Nepal Climate Data Portal User Manual 1 Asian Development Bank Asian Disaster Prevention Center AidlQ Features e Easy selection and display of Observed Station Data Observed Gridded Data Projected Data e Easy comparison of data e Ability to aggregate data e Flexible data queries which allows more sophisticated data analysis by giving the user the ability to enter expressions e Dimensional and delt
4. a analysis of expressions to aid data validation e Generation of time series charts with regression lines and ability to combine and resize charts e Filtering map by places values e Ability to show observation stations as a separate layer e Popup boxes to show values e Filtering of places shown on the map with shape files e Printable images of the map overlay e Download of data e Data purchase facility e Management of data purchases Nepal Climate Data Portal User Manual Asian Development Bank Asian Disaster Prevention Center AidlQ Definitions For clarity certain terms are used with precise meanings in the rest of this document Definition Sets of numeric values of a given variable specifically e at a particular place e over a particular time range Internally these are stored as positive numbers wherever possible This is important These sets of data have associated units e g mm for rainfall These sets of data are stored in a database used by the Nepal Climate Data Portal A geographical position at a fixed latitude and longitude Places may or may not be observation stations Places may or may not have other attributes including elevation name station ID and a list of regions the place is inside These attributes may be used in filtering Observation Station A real weather observation station These usually have names and elevation information Nepal Climate Data Portal User Manual 2 Asian Developm
5. an Development Bank Asian Disaster Prevention Center AidlQ Basic usage How to display observed data on the map 1 Select Data On the Select data panel you can select the type of climate data you want to view You can choose what type of data you want to view how you want that data to be aggregated on the map and charts and the time range you wish to view the data over 2 Click Show on Map The climate data which you have selected will be overlaid on the map The map overlay will show climate data which has been aggregated over time according to the Aggregation option you have selected on the Select data panel How to download a printable map image Click Download printable image to download an image of this map to use in reports and presentations The image is generated on the server so please be patient as it may take some time to generate depending on the server load This image will be in the PNG image format to preserve colours correctly may be of a different size and will not display the various map controls Some other things may not look exactly the same as what you see in the browser e g fonts may differ depending on the server configuration Nepal Climate Data Portal User Manual 5 Asian Development Bank Asian Disaster Prevention Center AidlQ How to generate a chart from the map overlay 1 Select places on the map overlay You can click on a single grid on the map or select a range of points by
6. an Development Bank Asian Disaster Prevention Center AidlQ Editing query expressions To edit query expressions simply click with the mouse inside the query box A flashing cursor should appear You can now edit the expression As soon as you start editing a button will appear labelled Compute and show on map When you are happy with your edited expression click the button to update the map overlay Maximum Observed Temp Max From 195 To 210 Compute and show on map The Compute and show on map button This appears whenever the query has been edited Example A meteorologist is producing a using projected temperature data for 2030 2060 and needs to understand the C V of the data C V is Standard Deviation divided by the mean so we can enter the expression StandardDeviationC Projected Temp Max RegCM4 A1B From 20 30 To C2060 Average Projected Temp Max RegCM4 A1B From 2030 ToC2060 Nepal Climate Data Portal User Manual 12 Asian Development Bank Asian Disaster Prevention Center AidlQ iors 0 07 nits between queries StandardDeviation Projected Te Reg M4 A1B From 203 To 206 Average Projected Max Reg M4 A1B a From 2030 To 2060 Pe 81 01834 30 23764 Directly entering an expression to calculate C V Nepal Climate Data Portal User Manual 13 Asian Development Bank Asian Disaster Prevention Center AidlQ Expressions and operators available in th
7. cified E g if the date range is 2000 to 2010 the value for 2000 Dec 1999 Jan 2000 Feb 2000 The data for December 2010 will be ignored as it now falls outside of the range The data will differ from the D J F case DJ FMAMJJASOND Not allowed system will complain that it doesn t make sense to aggregate 4 OOOOOQ0O000M annually using both December and the PreviousDecember The user interface PreviousDecember and December will not allow both D s to be checked at the same time Nepal Climate Data Portal User Manual 10 Asian Development Bank Asian Disaster Prevention Center AidlQ Flexiole data queries Overview Internally the Nepal Climate Data Portal uses a simple specialised query language which is used to query the database This language can be used directly to formulate more complex queries than a simple user interface could easily allow This feature can be used for more advanced statistical analysis such as computing Coefficient of Variation to show the dispersion of the climate data and interpret its reliability These query expressions are simple mathematical expressions similar to those you might write in a spreadsheet Only queries can be written The language is deliberately too simple to allow the writing of general programs this is important for security as the queries run on the server Internally the output of these expressions is a mapping of keys to values When generating a map overla
8. clicking and dragging the mouse or holding the SHIFT key while you click multiple grids 2 Click Show chart for selected places A chart window will pop up showing a chart for those places The chart will show climate data which has been aggregated from each of the selected grids according to the Aggregation option you have selected on the Select data panel Click Download on the chart popup window to download the chart image You can resize the Chart popup window to show more detail You can add more lines to the chart by simply selecting different data To clear the chart and start a new one simply close the chart popup window Nepal Climate Data Portal User Manual Asian Development Bank Asian Disaster Prevention Center AidlQ How to filter the map overlay There are two ways to filter the map overlay Colour Key The Colour Key will filter out any places whose value on the map overlay lies outside the range in the Colour Key However more powerful filtering is possible with the Filter Box Filter Box The Filter Box accepts simple mathematical and logical expressions You can refer to any attribute of a place and the value The list of attributes depends on what data has been loaded into the system To see the list of attribute hover over a place on the map overlay All the attributes listed in the popup are available in the expression For example latitude longitude elevation and name The filter expression
9. e query syntax Statistical expressions These always have a double quoted data name as their first argument Expression Meaning Notes Maximum dataset Maximum sample value Be Minimum ataset Minimum sample value Be Average dataset Average of the sample values re StandardDeviation dataset Standard deviation of the sample values Gives a delta value Sum ataset Sum of the sample values Be Count dataset Count of the number of samples Gives a dimensionless value Mathematical operators Operator Meaning Notes It is an error to add or subtract expressions that use different e owe OC OCOCC d Raise to power Only integral powers or integral ratios are allowed l e n must be a whole number and not a statistical expression It may Root F f f S be an error if the resulting units do not make sense Expressions used inside aggregation expressions Expression Meaning From Year Month Day Specify start date If month is not given January will be used If day is not given 1 will be used To Year Month Day Specify end date If month is not given December will be used If day is not given the last day of the month will be used Months Specify which months Only data from the specified months will be used to aggregate Months can be specified by name or number i e PrevDec PreviousDecember O Jan January 1 Feb February 2 Dec December
10. ent Bank Asian Disaster Prevention Center AidlQ Tour of the User interface sates A imema Colour Key EEO openSirasthisp MapQuest AJ Lock limits between queries 4 B Sj Overlays a i Filter box AO Observation stations m EM Query resut values a Select data A a iq Py a a Parameter Observed Temp Max gy lt Statistic Maximum a ad a be Annual a a Annual A S a Map overlay APETEETETEETI a eee O a a From 1950 v x a y as wa To 2011 x per Side E pa E Bee riya m a aa a a m Show on map A nel 2 A n a PRADESH B Ep a Compare with data B v E ee a a enes aris C a e ag S anne oS kanbur Q end Qu ry 8 7 Birat R d E Lo 100km o Mau SIN Ta ra nem 50 m Maximum Observed Temp Max From 195 To 2100 j lini _ oF a SS 80 60086 28 09856 Map view components Component Purpose Description notes Map overlay Shows values above the base map layer Values from the query are shown as coloured squares Legend Controls the data being shown in the map Query box overlay Place value based filtering of the map overlay Can filter based on any attribute e g elevation gt 1000 Colour Key Control the colours shown in the map overlay This is set to sensible values from the query data It is also editable and lockable Side panel components Component Purpose Description notes Select Data A Easily generates a query to di
11. h year of the selected time range This actually makes no difference to the map overlay but does make notable differences to the time series charts i e it aggregates monthly values into a single yearly value What difference does the Annual aggregation checkbox make Annual aggregation Difference to the map overlay Difference to charts checkbox Checked No difference because values Charts lines will have one value per year shown as displayed on the map overlay must all circles joined by lines be aggregated into a single value single coloured square per place anyway Unchecked Monthly time series will be shown as just lines without circle markers Over many years this is often a waveform with a period of one year Month selection Below the Annual aggregation checkbox are 13 labelled checkboxes D J F M A M J J A S O N D These allow the user to select which months to aggregate For example the user may only be interested in yearly values for the summer months only Thus they might select only J J A June July and August Nepal Climate Data Portal User Manual 9 Asian Development Bank Asian Disaster Prevention Center AidlQ The Previous December checkbox By default the checkboxes starting from the first J January until the last D December are specified This selects every month in the year However there is another typical use case wherein a user may wish to look at seasonal changes T
12. idded or Projected When referring to Details and Limitations Some areas of Nepal have better station coverage than others Some stations have been collecting data for a longer period of time Some types of data may not be available at certain points in time E g some stations have not been collecting rainfall data for as long as they have been collecting temperature data Some data may be incorrect due to misreported data or temporary faults in equipment Coloured square size remains constant while zooming in or out Grid sizes may be different This is important to understand when comparing data Data are compared by place Interpolated data will have greater uncertainty the further it lies geographically and temporally from observed data The places on the grid do not represent Observation Stations These projections are produced by third parties outside the system The mechanism of producing these projections is too technical to describe here Please refer to the documentation for the model used in the projection Some projections may have long gaps in the data For example the earlier data e g 1970 2009 can be used to compare the model against real observed gridded data The later data e g 2030 2060 can be used to make predictions Data in a query the name must always be given in double quotes This allows for flexible and therefore clear naming Nepal Climate Data Portal User Manual Asi
13. increased flood hazards due to glacial melting The Compare with subtract from panel allows the differences between data to be displayed as a map overlay unfiltered ct data A Parameter Projected Temp Max Reg Y a Parameter Projected Temp Max Reg Y Statistic Maximum ia Annual D aggregation From 2060 y To 2060 Maximum Projected Temp Max Reg M4 A1B From 2060 pe To 2060 Maximum Projected Temp Max Reg M4 A1B Son Y From 2030 To 2030 Permati 86 47854 25 63897 Using the Compare with Data sub panel to compare two data sets Select the two data sets as you would for Select data Click Compare on map B A A query is generated subtracting the top selection from the bottom Note Charts can also be used to visually compare different types of climate data and climate data from different places This is done by keeping the plot window open selecting different climate data and clicking Show chart for selected places This data will be added to the existing chart Using the check boxes the user can combine multiple charts in order to compare different climate data This is useful for analysis Nepal Climate Data Portal User Manual 8 Asian Development Bank Asian Disaster Prevention Center AidlQ Annual aggregation Explanation The checkbox Annual aggregation allows the user to aggregate monthly values into a single yearly value for eac
14. splay data S Compare with data B Easily generates a query to compare data Used together with Select Data A Buy data button Allow the user to purchase data l Show chart for Show a time series chart for selected Places on the map overlay need to be selected selected places to enable this button Download printable Downloads a generated server side PNG Side panel and unnecessary map widgets will map image image of the map not appear on the image Nepal Climate Data Portal User Manual 3 Asian Development Bank Asian Disaster Prevention Center AidlQ Climate Data Types of data available Three main types of data are available It is important to understand the distinctions between and the limitations of these types in order to interpret the data from the system properly Type name Observed Observed Gridded Projected Explanation Data that has been collected at various observation stations in Nepal It has not been interpolated or generated Data that has been interpolated from the observed data into a grid of points on the map A grid is an arbitrary collection of places on the map l e the system is flexible in whatever grid pattern is used Projected Data has been produced using a variety of different climate models and emissions scenarios This is also given on a grid Names and naming conventions Data will always have a name Names will always start with one of Observed Gr
15. stical expressions Mathematical operators Expressions used inside aggregation expressions Nepal Climate Data Portal User Manual o O O O OO 10 11 11 11 12 12 14 14 14 14 Asian Disaster Preparedness Center AidIQ Asian Development Bank DHM Disclaimer The Nepal Climate Data Portal is a software product designed to meet various requirements of various types of users As such it may change in the future and this manual cannot guarantee that it will adequately describe future versions Also screenshots in this manual may show user interface layouts and data set names that differ slightly to the live version Nepal Climate Data Portal User Manual Asian Disaster Preparedness Center AidIQ Asian Development Bank DHM Overview Purpose intent The Nepal Climate Data Portal is designed to facilitate the analysis of climate meteorological geographical and projection data using a publicly accessible web based interface Its intended audience are climate research scientists meteorologists hydrologists and anyone who needs to understand past and future projected weather patterns It also serves to allow the purchase of data that has been collected by the Department of Hydrology and Meterology in Nepal A useful way to see the Nepal Climate Data Portal To avoid confusion it is useful to see the portal as essentially a somewhat sophisticated calculator with its own database Its calculation results are maps time
16. will be give a boolean true false value The expression will be evaluated on each place If the expression evaluates to true the place will be shown otherwise it will not be shown Examples 1 Selecting a region by name name DARCHULA 2 Using the boolean operators and and or elevation gt 1000 and value lt 10 3 Once a region shape file has been loaded you can also use the special function within withinC FWDR If no filter has been specified the Filter Box will show unfiltered and all places will be shown Special filter functions Filtering can also use some special filter functions that are described in the table below These filter functions allow filtering by location Special filter function within Area name Only shows places within the named area Multiple area names may be specified separated by commas within_Nepal Only shows places within Nepal Nepal Climate Data Portal User Manual 7 Asian Development Bank Asian Disaster Prevention Center AidlQ simole data comparisons Performing a simple comparison The Nepal Climate Data Portal allows different climate data to be compared for analysis These could be the same type of climate data compared over different time periods or different types of climate data Example A meteorologist needs to know how much the maximum yearly temperature will increase between the years 2030 and 2060 to determine the risk of
17. y the keys will be places on the map When generating a chart the keys will be time periods Whether the keys are places or times is implicit and depends on the context of usage but not on the expression itself Thus you do not need to modify their query expression to generate a graph or a map overlay Queries are shown in the Legend Query Box You may have already noticed examples of the data query syntax in the preceding chapters The box at the bottom of the map shows the expression being evaluated whilst also serving as a map legend This is set to an initial expression when the browser first loads the page It will also be updated every time you use the graphical user interface in the side panel to change the data being displayed Thus you can use this feature to quickly see examples of the syntax Maximum Observed Temp Max From 195 To 210 ka i i The Legend Query box This is an editable box located at the bottom of the map viewer Let s break down this example into parts Maximum Observed Temp Max From 1950 To 2100 Statistic name Data set name This is always in Start date End date Remember to l e Return the double quotes and always starts inclusive l e use inclusive l e match closing maximum value with Observed Projected or values from 1st use values until braces for each key Gridded Jan 1950 31st Dec 2011 Nepal Climate Data Portal User Manual 11 Asi
18. ypically the only difference this makes is the special treatment of the December of the previous year l e when we talk about Winter 2011 we actually mean December 2010 January 2011 and February 2011 The first D checkbox is allowed to make this possible Within the system to distinguish this concept from the normal concept of December it is identified with a special name PreviousDecember This name can be used in expressions within the Months filter PrevDec is a shorter alias of this name When the first D checkbox is checked then PreviousDecember is specified in the month filtering and two things happen 1 The December of the previous year is counted as part of that year 2 Ifthe date range is specified in terms of years no months then each year starts in December and ends in November i e if the year range is From 2000 To 2011 then the actual dates will be from December 1999 to November 2011 Note that when months are specified in the date range e g March 2000 to October 2011 together with PreviousDecember behaviour is currently undefined What difference does checking the months make Months selection example Outcome DJFMAMJJASO SAAE Default Every month in the year will be aggregated into a single value E g 2011 will use values from Jan 2011 to Dec 2011 DJFMAMJJASOND Only values from the winter months will be aggregated together into a single SS8S8000000G0G0 vate PreviousDecember spe
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