Geospatial analysis of contributing factors on nitrate-nitrogen content in groundwater in Nakhonpathom, Thailand | |
| Author | Yongyoot Witheetrirong |
| Call Number | AIT Diss. no.RS-12-04 |
| Subject(s) | Groundwater--Remote sensing--Thailand--Nakhon Pathom Groundwater--Geographic Information Systems--Thailand--Nakhon Pathom Groundwater--Nitrogen content--Thailand--Nakhon Pathom |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Technical Science in Remote Sensing and Geographic Information Systems |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. RS-12-04 |
| Abstract | Water is needed for life, but its availability at a sustainable quality and quantity is threatened by many factors. Water suppliers drill wells through soil and rock into aquifers to reach the ground and supply the public with drinking water. In agricultural land, the chemicals from fertilizers practice can enter the soil and rock, polluting the aquifer and eventually the well. Nitrogen fertilizer is one of the most effective tools for increasing yields, and its use on a global basis grew more than fivefold from 1960 to 1990. Fertilizer consumption in developing countries is projected to double by 2020, with especially rapid growth in Africa and South Asia. Fe rtilizer is considered to be the major source of this nitrate in groundwater. Intensification of agricultural production carries several potential risks to water supplies. Chemical fertilizers are used in most parts around the world, although less so in de veloping countries because of the high cost. Nitrate -nitrogen ( NO 3 − - N) is now also considered a potential pollutant because excess applied amounts of NO 3 − -N can move into streams by runoff and into groundwater by leaching. Widespread occurrence of nitrate contamination in groundwater is reported from different parts around the world. More than 50% of the world’s population depends on groundwater for drinking w ater. A more recent estimate by Pure Water for the World states that 1,200 million people in developing countries do not have access to safe water and that 25 million people die each year through disease contracted by contaminated water. The strength occur rence case is an India; late publication indicated that nitrate in groundwater was in the range 0.1–870 mg/l with an average of 65 mg/l. The latest European Commission report, 20 % of EU stations had concentrations in excess of the maximum allowable concen tration and 40 % were in excess over the guide value in the drinking water directive. The global objective of the study is to identify the relation of soil texture and nitrate - nitrogen content in groundwater a based on part data and analyze probable factors responsible for NO3--N using GIS and remote sensing to develop an approach for groundwater -nitrate contamination zone. The specific objectives are (1) explore the relationship between crops and nitrate -N concentrations in groundwater using spatial autoc orrelation analysis and (2) an approach of Analytical Hierarchy Process (AHP) to explore the influence on contamination factors of nitrate -N concentration in groundwater. To achieve the first objective, an attempt was made to provide information to prepar e the spectral analysis on the relationship between crops and nitrate -N concentrations in groundwater by comparing two different spatial soil textures. Nakhon Pathom province, Thailand, was selected as a study area where the terrain is mostly represented b y a flat topography. This investigation is aimed to contribute the concepts and methods to the innovation development and application of Geographic Information Systems (GIS) and remote sensing regarding nitrate -nitrogen content in monitoring groundwater st ations. An interpolation of NO 3 − -N contents from 32 observation groundwater ponds were generated and compared. The most suitable result, which is the closest mean of an interpolation method to the observed data, was Kriging with Gaussian model. In this study, there were only two classes of main top soil textures: loam (36.7%) and clay (63.3%). The effect of soil texture on nitrate -nitrogen content in groundwater was directly observed by its reflectance values through remote sensing. It was found that NO3 − - N measured through the loam in sugarcane, with Moran’s values of 0.0054 (p < 0.05) was lower than clay represented in paddy, with Moran’s values of 0.0305 (p < 0.05). This had a significant negative impact on the assumption; the quantity of nitrogen leached into groundwater through loam was higher than through clay. According to the research and local statistical data, farmers always apply excess fertilizer to paddy fields. This is a main reason for the higher quantity of NO3 − -N found in clay than in loam in this study. This case might be an exceptional study in terms of the quantity of fertilizers applied to agricultural fields. |
| Year | 2012 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. RS-12-04 |
| Type | Dissertation |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Remote Sensing (RS) |
| Chairperson(s) | Sarawut Ninsawat |
| Examination Committee(s) | Tripathi, Nitin Kumar ;Taravudh Tipdecho ;Preeda Parkpian |
| Scholarship Donor(s) | Government of Thailand Silpakorn University |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2012 |