Lecture5.ppt

1、Overview of Geographic Information System (GIS),Components and Applications of GIS,Listening -Special English,AGRICULTURE REPORT - Raising Chickens By Gary Garriott This is Steve Ember with the VOA Special English Agriculture Report. Raising chickens or other birds for their eggs and meat is a popul

2、ar family and business activity almost everywhere in the world. The birds eat grain, seeds and grasses. They also eat small pieces of food that people throw away. Many of these materials would be wasted if the birds did not eat them. Chicken eggs and meat contain high quality protein and other subst

3、ances important in the human diet. For many centuries, chickens were allowed to run free to find food for themselves. Then people used fences to keep small groups of birds from running away. After the chickens were kept inside a fence, people had to provide food for them.,Early in the last century,

4、raising flocks of thousands of birds became a successful business for many people. But the size of these flocks caused some serious problems, including pollution caused by chicken waste. Disease is one of the biggest problems in large flocks. The birds are kept close together all the time. So if one

5、 bird becomes sick, the sickness spreads. All the chickens in a flock can die from a serious disease. Avian flu, for example, can in some cases also spread to humans. Diseases that affect chickens are different in different areas of the world. One current example in Asia is an outbreak of avian flu

6、in South Korea. Troops have been helping to kill and bury chickens and ducks that became infected at farms in North Chungcheong Province.,To help prevent disease, experts advise these steps: Feed the birds a balanced diet. This will help them resist infections. Do not add adult birds to your flocks.

7、 If you must add adult birds, keep them separate from the flock for five to fifteen days to make sure they are healthy. Cover the floor of the buildings where the chickens are kept with material like straw, rice husks or sawdust. Change this material often. After you sell the chickens, completely em

8、pty the building where they were kept. Clean and wash the building. Then leave it empty for four weeks before putting in new chickens.,Diseases affecting birds are not simple to understand and treat, so expert medical advice is important. You can get more information about caring for chickens and ot

9、her birds from Volunteers in Technical Assistance. VITA is on the Internet at v-i-t-a dot o-r-g. This VOA Special English Agriculture Report was written by Gary Garriott. This is Steve Ember.,2. Speaking -Popular English,李华是在纽约上大学的中国学生。现在她正在和Michael这个美国学生谈有关她学习方面的问题。今天Michael 会教李华两个常用语：to take a hik

10、e 和 to blow off。 L: Michael，我真烦死了，我们那个经济学教授非要我们分成小组来完成一个项目，可小组里一个同学嘛一声不啃，另一个我说什么他都反对。 M: If I were you, I would have told him to take a hike. L: 你要对他说什么？ Take a hike? 是什么意思啊？ M: Take a hike is to tell someone to leave, or to tell someone to leave you alone. L: Take a hike就是叫谁走开，或者是告诉某人不要来打搅我。对吗？ M:

11、Thats correct. In fact, you told me theres that one guy who always bothers you in the study hall. You should tell him to take a hike.,M: Yes, Li Hua, I suppose you could. L: Michael, 你昨晚上不是说好要跟Bob去看电影吗？你怎么一个晚上都呆在家里呢？ M: Bob and I did make plans to go out last night. But he blew me off. He decided to

12、 go out with his girlfriend. It wasnt the first time he blew me off. L: 原来说好去看电影，到最后一分钟打电话给你说要和女朋友出去 玩。Michael，你刚才说了两遍blew me off ? 是不是取消原定约会的意思？ M: Yes, to blow off means to break off plans you had with someone. L: 也就是说你和Bob约好去看电影，可是他为了跟女朋友玩而把你给甩了。,M: Youre right. L: To blow off 还能用在什么场合呢？ M: If so

13、meone has been friendly to you in the past, but he suddenly seems to ignore you, you can say that person blew you off. L: 噢，to blow off 还可以指某人突然对你很冷淡。 M: Yes. For instance, when I was at a party last weekend, Nancy acted like she didnt even know who I was. I can say Nancy blew me off. L: Nancy上个周末在聚

14、会上看见你好象不认识你？这不可能，她不是跟你很好的吗？ M: Yes, but thats ok. Li Hua, you can also use this phrase to talk about things you blow off, such as something you dont want to do.,L: 我不想做什么事，也可以用to blow off。我不是告诉你我不想参加 那经济学的小组吗？可是，要是我blow it off，我这门课就会不及格。 M: Yeah, there are some things in life you just shouldnt blow

15、off. L: 唉，生活中有些事是非得做的，就象和你一起吃午饭一样。 M: Oh, Li Hua, take a hike. 在今天的对话中，Michael教了李华两个常用语，一个是：take a hike，意思是叫某人走开；另一个是to blow off，这是指取消约会，或者是不做自己不想做的事。这次的流行美语就到此结束，我们下次再会。,3. Glossary,FEATURE FEATURE CLASS FIELD FILE NAME FILE NAME EXTENSION,GENERALIZATION GEOCODE GEODETIC（测量） REFERENCE SYSTEM 1980 G

16、EOGRAPHIC COORDINATES GEOGRAPHIC COORDINATE SYSTEM GEOGRAPHIC INFORMATION SYSTEM GEOGRAPHY GEOREFERENCE GLOBAL POSITIONING SYSTEM (GPS),GRADIENT（梯度） GRADUATED COLOR MAP GRADUATED SYMBOL MAP GRATICULE（格子线） GRAYSCALE GREAT CIRCLE ROUTE GRID GRID CELL GRID REFERENCE SYSTEM,4. Translation - Components a

17、nd Applications of GIS,Components 组成of GIS GIS constitutes of five key components: Hardware Software Data People Method HardwareIt consists of the computer system on which the GIS software will run. The choice of hardware system range from 300MHz Personal Computers to Super Computers having capabili

18、ty in Tera兆 FLOPS. The computer forms the backbone骨干 of the GIS hardware, which gets its input through the Scanner扫描仪 or a digitizer board数字化仪. Scanner converts转化 a picture into a digital image for further进一步. The output of scanner can be stored 储存in many formats e.g. TIFF, BMP, JPG etc. A digitizer

19、 board is flat board平板 used for vectorisation向量化 of a given map objects对象. Printers打印机 and plotters绘图仪 are the most common output devices设备 for a GIS hardware setup.,SoftwareGIS software provides the functions功能 and tools needed to store, analyze, and display geographic information. GIS softwares in

20、 use 在用的are MapInfo, ARC/Info, AutoCAD Map, etc. The software available can be said to be application specific. When the low cost GIS work is to be carried out desktop桌面 MapInfo is the suitable option合适的选择. It is easy to use and supports many GIS feature. If the user intends to carry out extensive 大

21、量的analysis on GIS, ARC/Info is the preferred option. For the people using AutoCAD and willing to step into GIS, AutoCAD Map is a good option. DataGeographic data and related tabular data 表格数据can be collected in-house 部门内or purchased from a commercial data provider商业数据供应商. The digital map forms the b

22、asic data input for GIS. Tabular data related to the map objects can also be attached to被连接到 the digital data. A GIS will integrate spatial data with other data resources and can even use a DBMS数据库管理系统, used by most organization to maintain维护 their data, to manage spatial data.,PeopleGIS users range

23、 from technical specialists技术专家 who design and maintain the system to those who use it to help them perform完成 their everyday work. The people who use GIS can be broadly 大体上classified into 分为two classes. The CAD/GIS operator, whose work is to vectorise the map objects. The use of this vectorised data

24、 to perform进行 query查询, analysis or any other work is the responsibility of a GIS engineer/user. MethodAnd above all首先 a successful GIS operates运转 according to 取决于a well-designed plan and business rules, which are the models and operating practices unique to each organization. There are various techn

25、iques used for map creation 创建and further usage for any project. The map creation can either be automated自动 raster to vector creator or it can be manually手动 vectorised using the scanned images. The source of these digital maps can be either map prepared by any survey agency 测量机构or satellite imagery卫

26、星图像.,GIS ApplicationsComputerized mapping and spatial analysis have been developed simultaneously 同时in several related fields. The present status目前的情况 would not have been achieved without close interaction密切的交流 between various fields such as utility networks实用网络, cadastral mapping地籍测绘, topographic m

27、apping地形测绘, thematic cartography专题制图, surveying 测量and photogrammetry remote sensing摄影测量遥感, image processing图像处理, computer science, rural and urban planning农村和城市规划, earth science, and geography. The GIS technology is rapidly迅速 becoming a standard tool for management of natural resources. The effectiv

28、e use of large spatial data volumes is dependent upon the existence存在 of an efficient geographic handling and processing system处理系统 to transform转换 this data into usable information.,The GIS technology is used to assist协助 decision-makers决策者 by indicating 标示出various alternatives备选方案 in development and

29、 conservation保护 planning and by modelling the potential可能 outcomes结果 of a series of scenarios情况. It should be noted that any task begins and ends with the real world. Data are collected about the real world. Of necessity, the product is an abstraction抽象; it is not possible (and not desired) to handle every last detail每一个细节. After the data are analysed, information is compiled汇总 for decision-makers. Based on this information, action