SEA START Climate Change Analysis Tool v1.1

Transcription

1 SEA START Climate Change Analysis Tool v1.1 SEA START RC has developed tool to aid data analysis for the future climate data which is downloaded from Climate Data Distribution System ( The dataset which is disseminated via the website: would come in text file format and arranged as 1 variable and 1 year per each file. This tool will assist in analyzing data from multiple files and reformat the data for other software for further analysis, especially Microsoft Excel. The primary functions of this tool include: - To rearrange data into suitable format for other software, Excel -transpose data or sort files by year - To analyze and process- trend analysis, calculate annual precipitation in long term, area average precipitation. System requirement - Window XP -.Net Framework version 2.0 Figure1: Climate Data Distribution System

2 Instruction: Using SEA START Climate Change Analysis Tool Figure 2: SEA START Climate Change Analysis Tool (CDDS) STEP 1: Rename filename Description of filename Filename of the files as automatically assigned by Climate Change Data Distribution System (CDDS) contains 4 parts as follow; _PC1960_ECHAM4_A2.txt Part1: indicates date/time that data is retrieved from CDDS Part 2: indicates climate variable PC = Precipitation TX = Maximum temperature TN = Minimum Temperature SL = Solar Radiation

3 WS = Wind Speed WD = Wind Direction Part3: indicates year of data Part4: indicates climate model (GCM), future GHG scenarios (IPCC SRES) and file extension (.txt) After user downloaded data from CDDS, the files should be renamed by removing the first part following these steps. 1. Copy SEA START Climate Change Analysis Tool to the same folder as downloaded climate data files. 2. Select button Rename in SEA START Analysis tool to rename files that list in the appearing window. 3. Enter first part of the filename that user want to remove in the blank space at the top of window (For example, _ ) then click Rename 4. Filename beginning with _ will have only part 2-4 left. The result from Rename function is as following example _PC1960_ECHAM4_A2.txt PC1960_ECHAM4_A2.txt

4 Analysis functions: Analysis functions consist of Rainfall Analysis, MaxTemp and Min Temp analysis as listed in the dashed line area. STEP 2: Analyze data Please note that the data that is distributed via CCDS is grid data with resolution 20km*20 km resolution and the reference coordinate represent center of each grid as shown in figure below.

5 When distributed, the data would be written into file in the following format. Grid data format: Latitude, longitude, day 1,, day 360 The data consists of center coordinate of grid and daily climate data and separated by comma (,). Please also note that, for dataset from ECHAM4 model, there are exactly 360 days per year. 2.1 Specify data file for analysis From the data files that has been renamed, user may specify the set of files for further analysis PC1960_ECHAM4_A2.txt Variable 1 st Year Suffix with extension Specify variable: PC=precipitation TX= Maximum temperature TN= Minimum Temperature SL= Solar Radiation WS = Wind Speed WD = Wind Direction Specify 1 st Year: Define first year of the period for the analysis Specify suffix with file extension: to define climate model (GCM), future GHG scenarios (IPCC SRES) and file extension (.txt) part.

6 Specify number of years for the analysis: For example, if the first is specified as 1960, and number of years is specified as 10 years, the system would analyze data from the period of 1960 to Analyze climate change Part 1: Analysis tool: This part is set of tools for basic calculation. o Areal Average: Averaging same day data from multiple grids during userdefined period. For example, user may want to analyze average rainfall for a watershed which covers multiple grids as shown in figure below, climate data from every grids that represent the watershed area will be analyzed to represent daily value climate variable of the watershed.

7 o Daily Average: This function is to calculate daily average value of climate variable of each grid by averaging throughout the defined period (may be 10 years). For example, calculate daily average for each grid from o Annual Average: This function is to calculate average annual value of temperature and sum total annual precipitation for each grid. The output is shown in consecutive year analysis which is useful for climate change trend analysis in long term period. o Monthly average: This function is to calculate monthly average value of temperature and summary total monthly precipitation throughout the analysis period for each grid in the data file. The output will be separated in 12 files by month, i.e., 01_Jan_Average.out, 02_Feb_Average.out,., 12_Dec_Average.out. The output in each file is shown in figure below. For

8 example, user may want to analyze changing in September rainfall in 120 years period form Part2: Additional tool for analyze climate change: Tools in this part is suitable for analyzing annual climate pattern i.e. rainfall, maximum temperature, and minimum temperature. o Rain fall analysis: to summarize and analyze annual rainfall for the area in the data file, which covers: Total annual rainfall

9 Number of rainy days (which user can specify threshold of minimum rainfall as rainy day) Highest daily rainfall in each year o Max Temp analysis: to summarize annual output for maximum temperature Annual average maximum temperature Number of days in each year that maximum temperatures exceed specific threshold value (hot days) Hottest day of the year o Min Temp -To summarize annual output for minimum temperature Annual average minimum Temperature Number of days that minimum temperatures is under specific threshold values (cool days) Coolest day of the year

10 Step 3: Rearrange data for Microsoft EXCEL If user may want to further analyze this climate data using Microsoft Excel, it needs to be rearranged using Transform Tool which consist of 3 functions. Transpose (File extension: *.trp): This function rearrange data from the downloaded text file into row and column by creating new file. This is essential for user who uses EXCEL2003 which has limitation in number of columns at 256 columns, which is not sufficient for this climate dataset which requires 362 columns. The new file will switch data column to row.

11 In case that user may want to analyze multiple years which data comes in multiple files, other utilities provides is available for merging data from multiple text file into single file. Append Row (The file extension is *.hpn): This function combines daily data from consecutive years into single file. For example, combine two years data from the same grid, data in each file contains Lat, Lon, Day 1,..., 360, the new output file format will be Lat, Lon, Day 1,..., 360,..., 720. The first year data will be from Day 1,, 360 and the second year will be from Day 361,..., 720. The file can be used to analyze in Excel as shown in figure below in case user wants to analyze data for multiple years consecutively. Year 1980 New file Year 1981 Append column (File extension is *.vpn): This function will merge data from each file to multiple rows. In this utility, user can specify number rows at heading of file to be omitted from the merging. There are 2 cases that this utility may be used.

12 Firstly, if user may want to merge data from single grid from many files into single file, user has to specify 1 in No. Row of Header file. Output will contain daily climate data from start year shown in the first row and the next year till the rest of the set of files as following rows. - Year 1980 Year 1981 Year 1982 Year 1983 Secondly, user may want to rearrange data from multiple grids and multiple years into single file, user has to specify 2 in No. Row of Header file Output file contains daily climate data from which starts from first year to last year and the data from second year onward will be added at the last row of the first year data with header is omitted. For example, in the illustration below, the first 2 lines are latitude and longitude of grid, and then Day 1 to 360 of year 1980 is merged by Day 1 to 360 of year 1981 and onward.

13 Year 1980 Year 1981 Year 1982 Note: When utility completes its run, the program will be automatically closed, then output file be placed in the same folder. The format of the output file is text file which can be opened in notepad or excel.

14 STEP 4: Using Microsoft Excel to analyze climate data Text file output which has been properly prepared and merged from SEA START Climate Change Analysis Tool can be further analyzed by Microsoft Excel following these steps: 4.1 Open file in Microsoft Excel (Set Files of type to All Files (*.*) ) 4.2 Open file, then Text Import Wizard-Step 1 to 3 window will appear, user selects Delimited then click Next

15 4.3 In Text Impart Wizard step 2 of 3, user selects Comma to separate each field, then click Finish. The result will separate column correctly in suitable format for further analyis.