DETECTION AND ANALYSIS OF 1974 DROUGHT IN CENTRAL USSR

Created: 1/1/1974

OCR scan of the original document, errors are possible

national security information

DETECTION AND ANALYSIS4 DROUGHT IN CENTRAL USSR

INTRODUCTION

total USSR drain production4 probably hastress condition which affected llio spring wliont crop inand northernelected this strewnnd potential yield reduction at the end of Mny and followed thethis condition through the remainder of tho growing season. An examinationhe development of the problem and iu detection and delineal ion shouldi methodology andasis for the future analysis of

THE AREA AND CROP

drought area stretched frnm Aktyubinsk In Krasnoyarsk,Semipalatinsk. I'avlodnr, Allay, and Krasnoyarskaffectedhe prinicipal crop in this area in spring wheat.soils, and climate in much of the area are analogous to those of theof Canada.

DETECTION

The first indicationtress problem in the drought nrrn was obtainedomputer-assisted Agromet model. This model calculates daily plant stress bused on moisture availability and the growth stage of the crop. For example, moisture stress at heading time is much more detrimental to crop yield than the same amount of stress just after emergence. The modelotential lor significant yield reduction in the area by the end of Mayv mid-luly, stress had accumulatedegree thai, atubstantial yield reduction hud occurred and theretrong possibility that the crop was lost. Rains in the area during late -July and early August could not appreciably improve the yield of the crop.

<t. The potontial drought condition was also indicated by collateral as early as the end of May but was not detected until early .July, when reports became more specific. The computerized collateral file has been completed and will enable faster and more extensive analysis of the data,ould make collateral indications of agricultural problems detectable at an earlier date.

SEC^T

>ElRET

DELINEATION

arly May imageryormal situation in most of the drought area. Imagery at the end of May, which was received and analyzed at the end of June,rought condition. The analysis of subsequent photography reinforced this conclusion. End-of-July magery analyzed the first week in August

misiu-ui-oui;

provided additional confirming evidence (photo B,RTS imageryune received in mid-Julyetter delineation of the affected area.

ll three element*the Agromet model, collateral, and imagerypredictive information on the drought. The modrl provided indications ofsituation about one month before the other elements. However,the collateral data provided subtle indications about as early asmodel. By mid-July the convergence of evidence clearly displayedTheapproach to estimate spring wheal production

problem, ib

otential problem at the end of May and confirmed and quantified the problem by mid-July, which enabled an adjustment,sable time frame, in the estimate of total production.

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Original document.

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