| Show evaporation STUDIES IN THE SALTON SEA preliminary arrangements have been made by which the most moist extensive and useful study of evaporation and allied phenomena over ever m made w will bo carried on in the salton sea under cooperative arrangement made and entered into by tho the united states geological survey the united states weather bureau and tho united states reclamation service the breaking in of the colorado ri river v to the salton sink in southern california and the greatest engineering conquest that has been waged to drive the waters back into their old channel are a r a ma matters aters quite familiar to th the e general gen oral public the flooding of the salton basin to a depth of about eighty feet has caused great loss to property and improvements there arc are however a few favorable features con fectea with it not tho the least of which I 1 in a importance is tho the opportunity afforded for studying evaporation here is an inland sea suddenly placed in an old basin in a warm climate where evaporation is great and without any important water supply running in in tho the future tho the restoration of the colorado river to its old channel practically cut off all influx to the sea the water which remains can readily be measured and accounted counted for and it will be merely necessary to observe the rato rate of recession of this great lake and to take account of the attendant phenomena in fact the chance tor for decisive work along this line is one that could hardly be expected to occur in the passage of a millennium the rate of evaporation from water surfaces in the arid country especially is exceedingly important because it is a large factor to be taken into consideration in connection with the determination of the amount of water available for irrigation A reservoir of large surface extent constantly exposed to sun and wind will lose by evaporation sufficient water to irrigate many acres so far the meae meas ure ments that have been made are unsatisfactory and when the engineer desires to know the rate of evaporation he has at hand only the old data that may or may not be suitable for this purpose nevertheless in determining the number of acres that can be irrigated from a certain reservoir the engineer must make some allowance for the amount of evaporation and must decrease the number of acres to be irrig irrigated atad by that amount in the case of 0 tho the new now roosevelt reservoir in arizona bonet it has been estimated that the evaporation will amount to about six feet per year inasmuch as the total area of the reser skir will be acres the amount of water lost will be acre feet sufficient to irrigate acres assuming a duty af pf water equivalent to twenty tour four inches per annum thore therefore in estimating tho the number ot of acres that can be irrigated from the roosevelt sevelt reservoir it is necessary to exclude nearly acres that might be served were it not for evaporation it will be appreciated from this that tho the evaporation from reservoir surfaces is an in important matter and anything that can con be done to provide data by which the engineer eug ineer can make accurate computations will eventually mean a saving of enormous sums of money A conference commit committee teo from the three bureaus u represented presented consisting of W 0 mendenhall for the geological survey C F marvin tor for the weather bureau and C E grunsky for the reclamation service have recently made a proposal for the evaporation work that has been approved by the various bureaus and a nd the work will be carried on under the direction of pro im fessor frank bigelow of the weather bureau and dr G K gilbert of the geological survey the recommendations ions in brief are that the observations ions be continued over several years and that they be undertaken ab soon as after the summer floods of 1007 1907 provided the protective structures which have been built to force the colorado river into its nor mal channel withstand withe tand these floods and thereby indicate that evaporation studies will not be interrupted by further extensive influx of colorado river waters since the results are primarily a contribution to meteorology although the greatest value to engineers the observations will be made by trained representatives of the weather bureau supplementary studies of the character of the basin inflow of surface waters and subsurface waters and of engineering and geologic questions that may arise will be carried on by the geological survey the expense of installing unusual and expensive equipment that may be found to be necessary will be born borno by the three operating cooperating co bureaus professor bigelow and dr gilbert wilt will meet for conference at yuma A T on or about may and will proceed to the salton basin to determine upon the details of the investigation |
