Yoav Tal
Director
National Spatial Databases
Survey of Israel,Israel

Biography
Yoav Tal holds a BA from Tel-Aviv University, Israel (Geography). Yoav served as an officer with the Israeli Defense Force. He worked as a manager in various private and governmental organizations. Mr Tal is currently the Director for National Spatial Databases at the Survey of Israel.

Abstract
Building Intelligent Spatial Data Layers

In the past databases used to as organized containers of data. Nonetheless modern information systems require that the data should be organized and modelled to meet the need of their applications and support complex processes requiring these information. Thus modern databases should be built around the concepts of Hierarchy, Logical Consistency (Topology, connectivity), and Multi-Dimensionality that supports rich content. The presentation provides a brief overview of the framework datasets of the Israeli Spatial Data Infrastructure. It outlines the principals of the Israeli open data policy. Then the presentations describes a unique project aims at building an intelligent national hydrographical layer. This project was completed recently and included three phases: Preliminary Data processing: preliminary datasets included master plans from local water authorities, photogrammetric data collected from aerial photographs at 1:40000 scale of water courses from the national topographic database, and topographic channels derived from DTM analysis. Data compilation: The three spatial data sources were compiled using semi-automatic methods and algorithms. Many contradictions between the dataset had to be interactively resolved using hydrological principles and logical understanding. Data modelling: The complete datasets was analysed and an hierarchical structure was developed using the accumulation length for water course. Then an hydrology ordering (Strahler) was created. This advanced and intelligent national hydrographical layer is being used by many organizations in Israel including the Agricultural Ministry, Forestry Department, Environmental Protection Ministry and the Israeli Water Authority. A new process was developed to update this layer using information from local authorities. Conclusions and future plan for the continuation of the project will be described as well.