FORECASTING OF AGRICULTURAL PRODUCTION RESULTS IN SOUTH DENPASAR USING QUADRATIC TREND METHOD BASED GIS OF AGRICULTURAL PRODUCTION RESULTS IN SOUTH DENPASAR USING QUADRATIC TREND METHOD BASED GIS.”

: Agriculture is an activity of exploiting natural resources performed by humans to meet their needs, especially as staple food. Agricultural activities can produce foodstuffs, raw materials for industry, energy and also can balance the natural ecosystems. People may have forgotten the function of agriculture for several factors. Mentioning one, the population growth, with the result that land conversion is done to housing. Another, an economic concern that being a farmer does not guarantee the future, so that people have turned to other livelihoods that are considered promising, and other factors. Based on these facts that there has been a decline in agricultural land from 2011-2014 in Denpasar area, especially South Denpasar District, which can affect the amount of agricultural production as staple food. Total production of staple crops, especially rice plants, has decreased significantly in 2014.It became great concern to government and people in finding a solution. Due to lack of information on the impact of agricultural land conversion that affects the production, so that food needs are not met. Based on those problems, it is necessary to forecast the number of agricultural production using Quadratic Trend Method based on GIS (Geographic Information System) application using ArcView software. The results of this forecast that are implemented with a digital map can be used as a reference to the government in making decisions and create people awareness how important it is to preserve agriculture .


Introduction
Agriculture is one of the main sectors in Indonesia economy as well as a source of ancestral livelihood in the past. Agriculture is an activity in exploiting the natural resources undertaken by humans, to meet human needs, especially staple food [1]. Agricultural activities can produce foodstuffs, raw materials for industrial enterprises, energy and can balance natural ecosystems.
People may have forgotten the function of agriculture for several factors. Mentioning one, the population growth, with the result that land conversion is done to housing. Another, an economic concern that being a farmer does not guarantee the future, so that people have turned to other livelihoods that are considered promising, and other factors.
Based on these facts that there has been a decline in agricultural land from 2011-2014 in Denpasar area, especially South Denpasar District, which can affect the amount of agricultural production as staple food. The primary crops observed are staple crops grown in South Denpasar region such as rice plants, soybeans, green vegetables, spinach, red onion, water spinach and long beans. The total production of staple crops, especially rice plants, has decreased significantly in 2014. It became great concern to government and people in finding a solution. Due to lack of information on the impact of agricultural land conversion that affects the production, so that food needs are not met.
Based on those problems, it is necessary to forecast the number of agricultural production using Quadratic Trend Method based on GIS (Geographic Information System) application using ArcView software. This forecasting calculation starts from 2015, 2016, 2017, 2018 and 2019. Forecasting method used is Quadratic Trend Method. This method is a trend method that is short and medium term; the possibility of trend will follow the pattern of linear [6]. The results of this forecast that are implemented with a digital map can be used as a reference to the government in making decisions and create people awareness how important it is to preserve agriculture using modern technology methods of agriculture as one of the solutions.

Forecasting Concept
Previous data analyzing is very important because human behavior is influenced much by the earlier condition or time [7]. A company, a person or a particular agency made their decisionbased on previous data and conditions. Periodic series can be used to predict future statuses. Periodic series have four components: trends (tendencies), season variations, cyclical variations, and irregular variation.
Trend is a long-term tidal movement that is obtained from the average change over time and its value is quite flat or smooths [6]. Periodic data trends may take the form of a steadily increasing and declining. A trend whose value increases is called a positive trend and a downward trend is called a negative trend. Trends show relatively long and stable time changes. Potency that can influence trends is population change, price, technology and productivity. Quadratic Trend Methods for short and medium term trends; chances are those trends will follow a linear pattern. However, in the long run, the pattern may change to not be linear. Therefore, if the pattern is not linear and predicted by a linear equation, the result of the prediction will be different or unsuitable. One of the nonlinear methods is the quadratic method. The equation of quadratic trends is formulated as follows: Y' = a + bX +cX2

The Concept of GIS (Geographic Information System)
Geographic Information System (GIS) consists of three terms, namely system, information and geography, is a set of components or elements that are interconnected between components/elements to achieve goals [3]. Information concept is the result of data processing and geography of the Earth's surface study. The concept of GIS is a collection of components that interact with each other in data processing to produce geographical information that implemented in the form of digital maps. GIS can also be defined as an information system that can analyze, store, update, integrate and display all forms of information related to the earth's surface.
Considering efficiency of Geographic Information System and its capability in managing data with a complex and large-scale structures, can be a help for decision-making process. There are several reasons why the concepts of GIS and its applications are attractive to use in various disciplines [4]:  Geographic Information System (GIS) is very effective in helping the process of forming, developing or improving the map and always co-exist with the real-world physical environment filled with visual impressions.  Geographic Information System (GIS) can be used as an interactive, interesting and challenging tool or tutorial to improve understanding, learning and education on ideas or concepts of location, space, population, and elements geographically located on the surface of earth and an attribute data attached to it.  Geographic Information System (GIS) using spatial data and non-spatial data (attributes) in an integrated manner so that the system can answer spatial and non-spatial questions.  Geographic Information System (GIS) has ability to decipher the elements contained on the surface of earth into a layer that can model real shapes.  Geographic Information System (GIS) application can be customized using scripting language commands owned by relevant Geographic Information System (GIS) software to meet user needs automatically, at fast, more attractively, informatively and user friendly.
Method used in this research consists of several stages as follows:  Literature Study At this stage, researcher conducts a literature study from various supportive references comprising of books and supporting journals.
 Agricultural Land Observation in South Denpasar District Conduct direct observation to South Denpasar District; see the remaining agricultural land due to agricultural land transform.

 Data Collection
Collecting data of agricultural land coverage in South Denpasar District and the amount of crop production from 2011-2014. This data is used as a reference to forecast the amount of crop production from 2015-2019. The main agricultural crops are rice, soybeans, green vegetables, spinach, red onions, water spinach and long beans.
 Forecasting Calculation Process Forecasting calculation using Quadratic Trend Method is performed at this stage.
 Analyzing Spatial Data and Non-Spatial Data At this stage, spatial data analysis for South Denpasar District is done, geographically along with non-spatial data in the form of attributes, total production of agricultural products in 2011-2014.
 Layer Identification Process Identifying each layer for digitization.
 Digitized Map Process Digitized map is done using ArcView desktop software, at this stage.

Digital Map
The process of calculating forecasting The process of analyzing spatial data and non spatial data

Layer identification process
Combination process digitasi with ArcView Software Figure 1: illustrates the flow of systematics writing   The data of agricultural crops production that grown in South Denpasar District will be processed and predicted    Table 3 shows the results of forecasting calculations for all basic crops grown in the South Denpasar District ranging from rice crops, soybeans, green vegetables, spinach, red onions, water spinach and long beans. Non Spatial Data for South Denpasar District implemented in Avenue GIS, in the form of tables, is the area of each Village, data of agricultural land area, data of production quantity and data forecasting of agricultural production amount. First thing to be implemented is the area covered in the following     The graph of agricultural production in South Denpasar District is shown in Figure 6. It can be seen that the largest number of plants is rice, the decrease in rice plants from 2011-2014 is not as significant as other plants.  Based on the graph in figure 7, it can be seen that significant decrease were green vegetables whose value was negative.