1	An Aspect of Geostatistics in Land Evaluation H. Ikawa, N. V. Hue, & G. Y. Tsuji University of Hawaii at Manoa February 2004
2	Abstract Environmental features, such as temperature, are used in land evaluation. Geostatistics and kriging, a statistical interpolation (prediction) method, can be used with such temperature data to predict or estimate temperatures at locations where measurements were not taken. Agricultural application of such studies and temperature distribution maps will be shown for a section of Oahu. Suggestions on using kriged data in land evaluation will also be made.
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4	Objectives Apply geostatistics and kriging to some temperature data for land evaluation. Show examples of agricultural application of kriged data. Suggest how kriging can be used in land evaluation.
5	Some Definitions Geostatistics Kriging Land evaluation
6	Geostatistics
7	Kriging
8	Land Evaluation Process of matching land-use require-ments with land characteristics for a specified use. Example of requirement is temperature for crop growth. Example of characteristics is temperature of study area.
9	Example for Coffee Slope: 0-6 % Depth: >40 in. Drainage: well Soil pH: 5.5-7.0 Rainfall: 60-100 in. Air temp.: >65°F
10	Background Information There is a need for alternative uses of agricultural lands on Oahu. Role of temperature is used in this study. Rainfall, soil proper-ties, land features, even socio-economic factors should also have been used.
11	Oahu Weather Stations—76 Sites
12	Kriged Map of 72 Sites
13	Kriged Map of 28 Sites
14	Co-Kriging and Using Elevation as A Co-Variable
15	Co-Kriged Map of 66 Sites
16	Comparison of 28 and 66 Sites
17	Proposed Site for Crops
18	View toward Waialua
19	Irish Potato
20	Tea According to Zee et al. (2003), optimum shoot growth of tea occurs at 65-77ºF. Potential sites: Mealani (62.0ºF); Volcano (60.8 ºF).
21	Cymbidium
22	Relation to Soil Map Units Opaeula-Helemano Area
23	Soil Map Units Opaeula-Helemano Area
24	Co-kriged Overlay on Soil Map
25	Kriged Data and Land Evaluation
26	ModelBuilder and Land Evaluation
27	Summary Geostatistics and kriging can be used to estimate temperature more precisely. Matching land-use requirements (e.g., crop) and site features are essential in land evaluation. The overlap of the kriged temperature map, with other features in different layers, can be used in land evaluation. ModelBuilder may also be used.
28	References Amer. Orchid Soc. 1999. Ortho’s All About Orchids, pp. 12-13. Meredith Books, Des Moines. Bittenbender, H. C. & V. E. Smith. 1999. Growing coffee in Hawaii. CTAHR, ISBN 1-929325-06-1 Ikawa, H., G. Tsuji, R. Yost, & N. Fujii. 2001. Compilation of selected weather data for Oahu, Hawaii http://agrss.sherman.hawaii.edu/land_eval/climate Zee, F. et al. 2003. Small-scale tea growing and processing in Hawaii, UH NPH-9.
29	Discussion