the 69th Annual International Conference of the Soil and Water Conservation Society

Making Waves in Conservation: Our Life On Land and its Impact on Water‐Water Resources

Paper ID 97 : Assessing subsurface hardpan and pond formation using feature extraction technique in a sandy 

irrigation Scheme, Eastern Saudi 

YOUSEF ALRUMIKHANIKing Abdulaziz City for Science and TechnologyP.O.BOX 6086. Riyadh 11442. Saudi Arabia

E‐Mial: byaalrumi2kacst.edu.sa07/28/2014

Study Objectives.I. To o draw an attention to the problem of  water logging in irrigated agriculture in Saudi 

Arabia.

II. To demonstrate the causes of water logging in the center pivot irrigation scheme.

III. To determine and affirm the presence and distribution of the subsurface hardpan; which is the main cause of  water logging in the affected irrigation scheme.

IV. TO develop an appropriate feature extracting technique that isolate the water logged areas of the irrigation scheme  for further analysis

Location and Problem Statement

The elevation of the ground surface topography   is highly variable and covered with light color sand dunes.  

Geologically the area is part of the Arabian shelf with an undulating topography dipping northeasterly; that confirms with the regional trend. 

The center pivot water logged irrigation  scheme  is 

10 x 10 km2 (10000 ha.). It is  located 47 km west of the Arabian  gulf coast.

The location and nature of irrigation scheme

Problem Statement:The irrigation scheme consists of 79 center pivots, each 1‐kilometer diameter, utilized in grid patterns. 

Original set up After water logging

Ponded Lakes

A5

A5

A6

A6

C6

C6

B5

B5

B6

B6

F5

F5

F6

F6

G6

G6

H6

H6

0 1000 2000 3000 4000 5000 6000 7000 8000

-400

-300

-200

-100

0

-400

-300

-200

-100

0

(depth in meters from sea level)FORMATION TAPPED IN SHADCO WELLS

SECTION NO.3, SHOWING UMM ER RADHUMA

Irrigation Water SourceCross Section showing Umm Er Radhuma Formation tapped in SHADCO wells

Sand Layer in Eastern Region is very thin With a high infiltration rate of 30cm/hour.

Causes of Water logging in Irrigation Scheme.

1- Imprevious layer.

Excessive irrigation is required because of high Evapotranspiration rate

Due to excessive Irrigation, Water can not percolate which results in the formation of ponds in low lying areas.

Cross-section showing the Impervious Layer (Marl)

The preliminary excavation in several parts of the project   indicates a hard material (hardpan) underlined the irrigation scheme and causing  the percolated irrigation water to rise upwards forming water logged areas. 

SOIL SAMPLING  RESULTS

SOIL SAMPLING LOCATIONS

SAMPLING DEPTHS. Centimeters

0‐15

15‐30

30‐60

60‐90

Clay % Silt % Sand % Grade F.C  % P.W.P   % Available Water % Hydraulic Conductivity. Mete/day5.4 13.5 81.1 Loamy sand 2.14 0.91 1.23 5

2‐ Soil Nature

0‐15 CM DEPTH

30‐60 CM DEPTH

60‐90 CM DEPTH

Hydraulic Head. cm

Hydraulic Head. cmHydraulic Head. cm

Hydraulic Head. cm

Hydraulic Conductivity of Site Soil(Permeability)

15‐30 CM DEPTH

SAMPLING DEPTHS. Centimeters

0‐15

15‐30

60‐90

WATER

PLANTSSOIL

AREA OF INTREST

Spectral Range. nm

Pancromatic 450‐800

Blue 450‐510

Green 510‐580

Red 650‐690

Infra Red 780‐920

GeoEye‐1 Satellite Sensor (0.46m)Date:   6/6/2011

Supervised Classification Technique

‐ Training stage: collect spectra from component.‐Classification stage: assign each pixel into a class‐Output Stage: Result clean up and output maps and  statistics.

Feature Extraction Technique for the irrigation Scheme

Component Area. Ha Percentage. %WATER 2195.7 23PLANT 1147.5 12.8SOIL 6011 64.5

PLANTWATER

SOIL

‐Water conservation is a process that should be initiated at the very early stages of site selection and before project implementation. 

‐Water wastage should not be only blamed on the natural features, but also on the inappropriate irrigation practices during project operation. 

‐ Non‐availability of qualified professionals to manage this type of irrigation projects has significantly contributed to the problem.

- The installation of a drainage network in the project may require huge capital investments

- It is certain that continuing farming with center pivot irrigation systems, is not feasible.

- It is suggested that implementing drip irrigation for vegetable crops, with low irrigation water requirements, grown in green houses should be practiced.

- This sort of experience should add to the awareness and knowledge of the concerned specialist regarding the importance of a comprehensive reconnaissance survey of subsurface hardpan presence before the inception of irrigation projects.

Thank You.

The END