By this mail I send to you my report on the same topic printed in 1872. I was led to write it after reading Minister Marsh's book on the Earth as Modified by Man. Yours, truly, DANIEL DRAPER Mr. LEVER. Of what is Professor Huntington a professor-the Yale man? Professor MOORE. I think he is a professor of physical geography, or an assistant professor. He is a geologist, too. This is from Mr. L. J. Le Conte, United States assistant engineer, written on the stationery of the Engineer Office of the United States Army at San Francisco. Mr. STANLEY. Is he the author of a work on geology? He says: WAR DEPARTMENT, 706 Chronicle Building, San Francisco, Cal., February 21, 1910. Prof. WILLIS L. MOORE, LL. D., Sc. D., Chief of Weather Bureau, Washington, D. C. MY DEAR PROFESSOR: I was greatly pleased with your pamphlet on The Influence of Forests on Climate and on Floods, placed on file to-day. If not asking too much, I would be greatly pleased to have a copy for my private library. Thanking you in advance for the courtesy, I am, sincerely, L. J. LE CONTE, U. S. Assistant Engineer. Here is a letter from Prof. Frank Leverett, geologist, of Ann Arbor, Mich. It is quite a long letter. He takes issue with me on this ground: He says that in the Ohio basin, which we are discussing and through which he has traveled extensively, there has been little or no deforestation in forty years, unless it has been in the southeastern portion of the region. That is the pith of his paper. He says: Dr. WILLIS L. MOORE, ANN ARBOR, MICH., February 23, 1910. Chief of the United States Weather Bureau, Washington, D. C. DEAR SIR: I have read with much interest your report on the influence of forests on climate and on floods just issued by the Committee on Agriculture of the House of Representatives. On the matter of the influence on climate I do not feel qualified to make any criticisms, but on the question of the effect on floods there are certain points I should like to raise. You appear to have demonstrated very clearly in the tables and discussion in reference to the Ohio River basin (pp. 30 to 37) that the run-off and precipitation are in very close correspondence. The chief point I would raise in reference to your discussion and conclusions is that of the extent of the deforestation. Are you certain that there has been any marked amount of deforestation in the last thirty-eight years? I have been over the northern part of the Ohio drainage basin in western New York, western Pennsylvania, northwestern West Virginia, northern Kentucky, and the portions in Ohio, Indiana, and Illinois in considerable detail in the course of several years of glacial investigations, embracing probably two-thirds of the area of the drainage basin, and I feel quite certain that in the part with which I am familiar the amount of deforestation is a negligible quantity for the period covered by your run-off and precipitation tables. It is an old farming district, from which the timber has been largely cleared forty or fifty years ago and in some cases at a much more remote period. Such deforestation as would be of a magnitude sufficient to have a bearing on this problem of the influence of forests on floods I should say must be looked for in the southeastern third of the Ohio River basin. I am not myself in possession of data on that region from which to form a judgment. Your data, I see, are based upon the portion of the Ohio basin above the mouths of the Cumberland and Tennessee rivers and most of the rivers of Kentucky. So there really remains only the mountainous portion of eastern Ken tucky and West Virginia in which there is a chance for deforestation that would affect the run-off at Cincinnati, and this is a very small part of the portion of the Ohio basin above Cincinnati. I question whether, in view of this meager chance for deforestation to influence the run-off, you made a good selection in taking the Ohio drainage basin as a test. I certainly would not assent to your italicised statement, on page 33, that deforestation has probably been as great in the basin of the Ohio River above Cincinnati as in any other part of the country during recent times. In my opinion the Great Lake region has experienced a much greater percentage of deforestation in the course of the past fifty years than the Ohio River basin. Unfortunately, this region has not full data on run-off in relation to precipitation, the observation stations for precipitation being less widely distributed than would seem necessary for statistical work. You seem to have had in mind on discussing the ratio of the forested area to the total watershed (pp. 24 and 25) a thought similar to what I am seeking to convey, namely, that the area subject to deforestation is too small to greatly affect the run-off in the lower course of the Ohio. Your thought, however, is to emphasize the unimportance of forested areas, while my thought is that you have made a poor selection to take the Ohio as a test case. I fail to understand why you should have taken this drainage basin as a test case unless you are under the impression that a large part of the Ohio drainage basin has suffered deforestation in the past thirty-eight years, and this I am sure is not the case. Another point on which I would express a view somewhat different from yours is that of the importance of checking the flow of water in the upper reaches of the stream. Your statements on pages 24 and 25 would seem to indicate that the multitude of small headwaters are inconsequential, yet it is from them that the major tributaries are formed. The little childhood jingle"Little drops of water, little grains of sand, Make a mighty ocean and the beauteous land," should not be forgotten in considering what goes to make up the major tributaries and large features. This letter is an outcome of your invitation, on page 27, for discussion of the matters with a view to "finding common ground upon which all well-meaning persons may stand." I trust that the whole matter of influence of forests upon floods will be given the most thorough study in determining the policy of the Government in reference to conservation. Very respectfully, FRANK LEVERETT. Geologist. You will observe that he says there has been very little deforestation in the Ohio River catchment basin. I introduce it because I believe it to be the contention of the Forest Service that there has been a remarkable increase in the floods in the Ohio section, and that this is due to the effect of deforestation. I do not know anything about the extent of deforestation. You will notice also he says he has traveled for many years through the region. Mr. LEVER. If your statement is correct, then your figures as to the Ohio River would be of no value at all. Professor MOORE. Certainly they would be of just as much value as before to show that there has been no change in the flow of the river as the result of cultivation, and of course it would show further that if his statement is true, all of the alarming flood reports of the foresters and others that have been put out by three different investigators to prove to the nation that floods have increased because of deforestation are worthless as an argument upon which this committee might base action. If Professor Leverett's statement is true, that there has been no deforestation there, then you do not need to consider the region. Then the whole argument in regard to the increase of floods in the Ohio Valley practically fails. Mr. STANLEY. I do not like to interrupt you, but is it a fact that there is no available data as to the deforestation itself? I thought that was the basic fact upon which all this discussion was founded. Professor MOORE. I have taken the position in all this discussion that if a river has been found to increase in flood intensity then it is up to the forester to show that that increase in the flood intensity is due to deforestation. But I have never yet seen any figures to show what is the increase in deforested area within recent times. Of course we know that in a hundred years there has been an enormous decrease in forest area. I am inclined to think there has been more of a decrease in forest area than Professor Leverett's report would indicate. The CHAIRMAN. If the Michigan man is correct in saying that there has been practically no change in the Ohio watershed, then the gentlemen who have appeared before the committee and in other places declaring that floods have enormously increased will have to seek some other explanation for it besides deforestation? Professor MOORE. Yes. Mr. MCDERMOTT. The Ann Arbor professors do not seem to agree. Professor Roth did not agree with you, and here is one that does. Professor MOORE. I am giving you all opinions. I do not pretend to be infallible. I rather resent the position of those who do claim to be infallible. Now, I would like to introduce this letter. Here is a letter I sent to the Conservation Commission on August 24, 1908, in which I made an estimate that in twelve years the total loss by floods had been about $260,000,000, a trifle more than $20,000,000 a year. I introduced that because when I submitted that report the Conservation Commission people wrote me a letter, calling my attention to the fact that they had estimates of much greater loss as a result of floods, and suggesting that I raise my figures. In answering, I said that I could not change my figures. Now, if you will look in the conservation report you will find that their estimate of the loss of floods annually-I am speaking by recollection only-is from forty or fifty to two hundred and thirty-seven millions annually. I only cite the fact that this report as filed with them, showing an average of a little more than twenty million per annum, was the result of an estimate by the subordnates under me who have charge of the varous river districts and by Prof. H. C. Frankenfield and myself. It is only an estimate, however, only individual opinions, without statistics back of it. And likewise the estimate in the conservation report. That is an estimate that has no statistics behind it that would, I believe, justify any such statement as to such losses by floods. The CHAIRMAN. Do you happen to have the letter before you to which you refer? Professor MOORE. I have my letter making my estimate. The CHAIRMAN. I was inquiring in regard to the letter that you received, asking that your estimate be increased. Professor MOORE. I believe I have it here. Yes; let me read this. Yes; this is the letter of the National Conservation Commission: Prof. WILLIS L. MOORE, WASHINGTON, November 13, 1908. Chief, United States Weather Bureau, Washington, D. C. DEAR PROFESSOR MOORE: Mr. M. O. Leighton, of the Geological Survey, has furnished the National Conservation Commission with a set of estimates of the amount of loss by floods in each year since 1900, which are greatly in excess of the figures given by your office. Mr. Leighton's figures are based upon data furnished him by a certain proportion of railroads reporting on the damage done to their property. For example, in the year 1906, when your office reports but $1,150,000 damage as a total of all kinds, Mr. Leighton has received from railroads, representing only 37 per cent of the total mileage of the country, an amount not less than $2,700,000, showing, apparently, that the estimates of your office are far too low. Will you be kind enough to look into this matter? I inclose herewith a copy of Mr. Leighton's estimate and a description of his method of estimating. Yours, very truly, HENRY GANNETT, Geographer. I will submit, also, my letter of August 24, addressed to the National Conservation Commission, and the reply I wrote to their letter of the 13th of November, 1908: HENRY GANNETT, Esq., UNITED STATES DEPARTMENT OF AGRICULTURE, GENERAL OFFICE OF THE WEATHER BUREAU, National Conservation Commission, Census Bureau, Washington, D. C. SIR: In reply to question 3, Section E, page 31 of the Schedule of Inquiries, or Bulletin 3, of the National Conservation Commission, which reads-How much damage do they (floods) do? I beg leave to submit the following data for the years from 1897 to 1908 (July), inclusive. It has uniformly been a matter of much difficulty to obtain reliable data of this nature, but those given below are believed to be conservative. Ten per cent have been added to the computed amounts in order to cover the many small floods that occur annually in the smaller rivers for which no data were available. As an indication of the general awakening on this subject, I also beg leave to inclose a clipping from the Galveston News of August 30, 1908. It is believed that this line of action was prompted largely by the Weather Bureau Circular, dated June 16, 1908, a copy of which is also inclosed. Very truly, yours, WILLIS L. MOORE, Chief, U. S. Weather Bureau. NOVEMBER 17, 1908. HENRY GANNETT, Esq., National Conservation Commission, United States Census Bureau, Washington, D. C. SIR: I have your letter of the 13th instant relative to discrepancies in the estimates of losses by floods in the United States as furnished by the Weather Bureau and by the United States Geological Survey, and beg leave to say in reply thereto that the Weather Bureau can see no reason for modifying the figures given in my letter to you of August 24, 1908. As I understand the situation, Mr. Leighton's figures are based entirely upon estimates, while those of the Weather Bureau are only partially so estimated. The Weather Bureau has 52 different river centers, and after every flood the official in charge of each district by inquiry, correspondence, and personal observation calculates the resulting losses. Of course estimates figure largely, but there is also a large basis of actual facts, whereas, if I correctly understand your letter, Mr. Leighton's figures are based almost entirely upon the assumption that 90 per cent of the flood losses are calculated from estimates regarding the remaining 10 per cent. The figures given by the Weather Bureau may be too low. In fact, we endeavor to be as conservative as possible, and underestimated rather than overestimated, but I am inclined to believe that Mr. Leighton's figures are entirely too high, principally for the reason that his primary assumptions were in error. The facts given by Mr. Leighton for the year 1906 may be more nearly correct than ours. The year 1905 was not a flood year, and it is not at all improbable that a number of floods in some of the smaller rivers were not considered in our figures. In any event the total amounts were comparatively small during that year. Very respectfully, WILLIS L. MOORE, Chief, U. S. Weather Bureau. Now, I would like to introduce this letter, dated October 17, 1908: HENRY GANNETT, Esq., UNITED STATES DEPARTMENT OF AGRICULTURE, National Conservation Commission, Census Bureau, Washington, D. C. DEAR SIR: In reply to question 1, section E, page 31, of the Schedule of Inquiries, or bulletin 3, of the National Conservation Commission, which reads, "Are floods increasing; and, if so, why?" I beg leave to say that the Weather Bureau is not prepared to give a definite answer to this question at the present time. A great amount of data has been examined, but a careful inspection thereof reveals nothing upon which to base a positive statement. Perhaps the only fact that stands forth clearly is that floods are entirely dependent upon rainfall distribution. If they have been more than usually frequent during recent years, it was because the precipitation has been more abundant, and there is no reason to believe that a reaction will not occur within a reasonable time. Very respectfully, WILLIS L. MOORE, Chief U. S. Weather Bureau. Just one more thing I would like to introduce, Mr. Chairman, and then I am through, and would be glad then to take up the answering of inquiries. I am quoting now from the Engineering News under date of October 29, 1908. In this is a translation from a work of M. Ernst Lauda, chief of the Hydrographic Bureau of the Austrian Government. I will say, briefly, that he discussed the floods of the river Danube. He had information of the floods of the Danube for eight hundred years. As the result of the discussion he came to the conclusion that as the forests disappeared in the valley of the Danube the floods had slowly and constantly decreased. I would like to read a little from his paper: For example, it is universally believed that forests have an influence in moderating and preventing floods, and deforestation upon their origin and more frequent occurrence; yet this belief is no better established from a hydrographic standpoint than the entirely unfounded belief that the floods of the past few years in Austria are due to deforestation. Likewise untenable are the frequent assertions that the greater frequency of floods in recent times is the result of artificial interference with stream flow, due to works of river regulation. (3) No doubt the interests of hydrography are indirectly affected by forests through their property of preserving the earth's surface from denudation and the water courses from sediment; and also through the protection of snow masses deposited during the winter from the action of the sun's rays, the wind, and warm rains. |