Description: These data represent a land use survey of northern Mono County conducted by the California Department of Water Resources, North Central Regional Office staff. The field work for this survey was conducted between July 12, 2010 and July 15, 2010 by staff visiting each field and noting what was grown. The survey field results are a snapshot in time of the crops and conditions of the study area visited. The southern boundary of the northern Mono County survey is the boundary between the North and South Lahontan Hydrologic Regions and does not include the Mono Lake area. Land use field boundaries were digitized using ArcGIS 9.3 then ArcGIS 10.0 using 2009 National Agriculture Imagery Program (NAIP) one-meter imagery as the base. Field boundaries were not drawn to represent legal parcel (ownership) boundaries, nor are they meant to be used as parcel boundaries. Images and land use boundaries were loaded onto laptop computers that were used as the field data collection tools. Staff took these laptops into the field and essentially all the areas were visited to positively identify the land uses. Land use codes were digitized in the field using ESRI ArcMAP software, version 10.0. Global positioning system (GPS) units connected to the laptops were used to confirm the field team's location with respect to the fields. The field team used a customized menu program to facilitate the gathering of field data. Before final processing, standard quality control procedures were performed jointly by staff at DWR’s North Central Region, and at DSIWM headquarters under the leadership of Jean Woods, Senior Land and Water Use Supervisor. Attributes and field borders were visually reviewed using 2010 NAIP and Landsat 5 imagery for quality control. Water boundaries were not updated to match the 2010 NAIP imagery. Landsat 5 image dates spanned the period from June 20, 2010 to October 10, 2010. After quality control procedures were completed, the data was finalized. The positional accuracy of the digital line work, which is based upon the orthorectified NAIP imagery, is approximately 6 meters. The land use attribute accuracy for agricultural fields is high, because almost every delineated field was visited by a surveyor. The accuracy is 95 percent because some errors may have occurred. Possible sources of attribute errors are: a) Human error in the identification of crop types, b) Data entry errors..
Copyright Text: Department of Water Resources, Division of Integrated Regional Water Management, North Central Region Office, Land and Water Use and Conservation Section.