KGS OFR 2003-55E: Assessment of Riparian Areas Inventory, State of Kansas.

by Brownie Wilson, Kansas Geological Survey.

This open file report is one of five assessment reports under KGS OFR 2003-55 conducted by the Kansas Geological Survey for the Kansas Water Office and the State Water Plan. This report series serves in part as the contract completion of KWO Contract No. 03-121 entitled, "Assessment: Water Management and Water Conservation." This contract was supported by the State Water Plan Fund.

By 2010, maintain, enhance, or restore priority wetlands and riparian areas

INTRODUCTION

In the FY 2003 Kansas Water Plan (KWP), the Kansas Water Authority approved objectives for the year 2010. The objectives were developed to define targets to quantify achievements as part of the implementation of the KWP. The above objective is included in the Wetland and Riparian Sections of the FY 2004 Kansas Water Plan.

In support of this objective, this assessment report summarizes stream bank miles for assorted land-use classification from the Riparian Area Inventory GIS dataset. The Kansas Water Office (KWO) used KWP funds to contract with the Kansas Geological Survey to complete and finalize this assessment as part of the contract "Assessment: Water Management and Water Conservation", KWO contract no. 03-121.

ASSESSMENT DATA SETS

The USDA Natural Resources Conservation Service developed the Riparian Areas Inventory (RAI) GIS Database in August of 2001. It is based on 1:24,000 scale hydrography with land-use classifications assigned within 100 feet of these features, excluding sewage lagoons. Land use classifications represent 1991 ground conditions and are based on interpretations from 1:12,000 scale Digital Orthophotograph Quarter Quadrangles.

The RAI data set is tiled by USGS 1:24000 scale quadrangles (almost 1,500 files for Kansas) and contains attribute information for hydrography (lines) and from that, a 100-foot buffered land use (polygons). The hydrography attributes are coded based on USGS Digital Line Graph standards of major and minor codes (Table 1) and the polygon attributes are coded based on photo interpretations of the land-use type (Table 2).

The RAI quadrangles where obtained from the Data Access and Support Center at the Kansas Geological Survey, imported, and mapjoined together into a seamless statewide data layer. The RAI data were then combined with Hydrologic Unit Level 14 Code (HUC14) subbasins in order to summarize the total land use by bank miles for each HUC14 subbasin. The HUC14 data set outlines surface water drainage areas and is based off of 1:24000 scale USGS topographic maps. Each HUC14 drainage area covers roughly 40 square miles.

Using an automated GIS script, within each HUC14 subbasin the land use adjacent to each hydrographic feature was selected and the bank miles of the hydrologic feature recorded. This summary is based on all the map data being set in a Universal Transverse Mercator projection, Zone 14, North American Datum of 1927. The total bank miles for each hydrologic feature type were then summarized for every HUC14 subunit. For this assessment, the HUC14 subbasin summarizes were further totaled for each of the 12 KWO planning basins in the state.

ASSESSMENT RESULTS

Results of the statewide summary indicate Pasture/Grass Land is the dominant riparian land use type in Kansas, accounting for over 142,000 bank miles or roughly 38.2 percent of all land use types (Table 3, Figure 1). Crop land is the second leading category with over 83,000 bank miles (22.3 percent), followed by Forest land at over 67,000 bank miles (18 percent). These three land use types account for 78.5 percent of all the riparian land use bank miles in Kansas. Include Pasture/Tree Mix and Crop/Tree Mix and these land use classifications account for over 97 percent of the state riparian land use total. Schrub/Scrub, Urban, Urban/Tree Mix, Barren Land, and Animal Production Areas account for only 2.12% of the state total.

Table 4 and Figure 2 show the riparian areas land use bank miles summary by individual KWO planning basin. The proportion of land use classifications and total number of hydrographic bank miles is a reflection of a basin's size (drainage area), physiographic characteristics, and regional land-use practices. In general, the western basins in Kansas have higher proportions of pasture/grass and cropland riparian bank miles while eastern Kansas has greater proportions of forest of mixed tree land uses.

The Kansas - Lower Republican has the highest number of hydrographic bank miles followed closely by the Smoky Hill -Saline Basin. This is a reflection of the basins' larger size and higher annual precipitation and corresponding potential runoff amounts. The Cimarron Basin has the lowest total number of bank miles, attributed to its low annual precipitation levels, followed by the Missouri, which is the smallest basin in terms of total drainage area in Kansas. The riparian land use summaries by stream type for each KWO planning basin are shown in Appendix A.

CONCLUSION

This assessment provides an estimate of the total riparian land-use bank miles in Kansas. Based on the Riparian Areas Inventory data set projected to a UTM Zone 14 NAD27 coordinate system, Pasture/Grass Land is the dominant land-use type accounting for roughly 38.2 percent of all the land-use types. Crop Land is the second leading category followed by Forest Land at 22 percent and 18 percent of the statewide totals. The spatial distribution and proportion of riparian land-use types by KWO planning basin is a reflection of the basin's drainage areas, physiographic characteristics, and regional land-use practices. In general, the western basins have greater proportions of pasture/grass and crop land while the eastern basins have greater forest and mixed tree land uses.

Return to KGS OFR 2003-55.

Appendix A