• Phase II - Excess/Insufficient Water

Potential At-Risk Maps and Information

The following are the proposed model potential at-risk maps produced during the Arkansas Resource Assessment - Phase II. The NRCS definition of the natural resource concern and the input layers and land use designation weights that were used for modeling each of the natural resource concerns within the Excess/Insufficient Water Resource Concern are listed to the right of each map. More detailed maps are available by clicking the link below each map.
Ponding, Flooding, Seasonal High Water Table,
seeps and drifted snow
  (View Individual Data Layer Extents)

    NRCS Definition:
        Surface water or poor subsurface drainage restricts land use and
        
management  goals. Wind-blown snow accumulates around and over
        surface structures, restricting access to humans and animals.

    Land Use Designation Weights:
        Crop (Weight 3); Pasture (Weight 2);
        Forest, Range, and Urban (Weight 1); Water and Assoc. Agland (Weight 0)

    Binary Input Layers and Associated Weights:
        – SSURGO Flooding Frequency     Frequently Flooded,
                                                           Long or Very Long Duration (Weight 2)
        – SSURGO Depth To Water Table <=15, April-June (Weight 1)
        – SSURGO Ponding Frequency     Frequent, for long or
                                                           very long duration (Weight 1)
        – SSURGO Drainage Class           Poorly or Very Poorly (Weight 1)
        – SSURGO Land Capability Subclass - w (Weight 1)



Inefficient Use of Irrigation Water (View Individual Data Layer Extents)

    NRCS Definition:
        Irrigation water is not stored, delivered, scheduled, or applied efficiently.
        Aquifer or surface water withdrawals threaten sustained availability of
        ground or surface  water. Available irrigation water supplies have been
        reduced due to aquifer  depletion, competition, regulation, drought, or
        some combination of these.

    Land Use Designation Weights:
        Crop (Weight 1); Pasture, Forest, Range,
        Urban, Assoc. Ag and Water (Weight 0)

    Binary Input Layers and Associated Weights:
        – SSURGO Depth To Water Table <=15, April-June (Weight 1)
     
    Classified Input Layers and Associated Weights:
          –   10-Year Change in Groundwater by 12-digit HUC
            where change is negative. (Weight 1)

            -0.46 – -1.99 (Weight 1)

            -2.35 – -4.75 (Weight 2)

            -5.12 - -13.35 (Weight 3)
       
        
– Acres of Irrigated Ag Land by County
            < 1,000 (Weight 0)
            1,000 – 99,999 (Weight 1)
            100,000 – 199,999 (Weight 2)
            > 200,000 (Weight 3)
        – Total Acrefeet of Groundwater Used for Irrigation by 8-digit HUC8
            < 1,000 (Weight 0)
            1,000 – 99,999 (Weight 1)
            100,000 – 350,000 (Weight 2)
            > 350,000 (Weight 3)
        – Depth to Groundwater model (ANRC Groundwater Decline Raster)
            1 - 44 (Weight 1)
            45 - 87 (Weight 2)
            88 - 131 (Weight 3)




Inefficient Moisture Management (View Individual Data Layer Extents)

    NRCS Definition:
        Natural precipitation is not optimally managed to support desired land use
        goals or ecological processes.

    Land Use Designation Weights:
        Crop and Pasture (Weight 2), Forest and Range (Weight 1);
        Urban, Assoc. Agland and Water (Weight 0)

    Binary Input Layers and Associated Weights:
        – SSURGO Available Water Capacity <= 10 (AWC-100cm) (Weight 1)
        – SSURGO Ksat >= 14 (Weight 1)
        – SSURGO Hydrologic Groups A and B (Weight 1)

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