遥感水文应用中的尺度问题

遥感技术在水文科学中的广泛应用，极大地拓宽了其研究的领域和范围，增加了其研究的深度。但同时也应该看到，遥感信息的空间分辨率和时间分辨率，以及水文科学自身尺度问题的复杂性，一方面对遥感水文的应用产生困难和问题，限制了水文遥感的应用；另一方面又对水文尺度问题提供了新的技术手段，为遥感水文应用增添了新的亮点。从水文机理与空间尺度、遥感信息的空间分辨率、水文参数的空间延拓，以及遥感技术与水文科学的发展等 4个方面探讨了遥感水文的空间尺度问题；从瞬时遥感信息的时间拓展和遥感信息的时间分辨率 2个方面讨论了遥感水文的时间尺度问题。

SCALE ISSUES ON THE APPLICATIONS OF REMOTE SENSING TO HYDROLOGY

The applications of remote sensing to hydrology, which can roughly be divided into the direct remote sensing applications and the indirect remote sensing applications, have been extended in last a few decades However, its spatial and temporal resolutions of remote sensing information, together with the complex issue of hydrological scales, have double roles to applications of remote sensing on hydrology In one side, they meet difficulties because of different spatial and temporal scales; on the other side, they bring new techniques to hydrological scale issues and this will definitely promote the development of hydrology, such as the development of global hydrology This paper approaches the spatial scale issue of remote sensing hydrology from four aspects: hydrological process mechanisms at varied scales, spatial resolution of remote sensing information, hydrological parameters gathered at one scale to be used in making predictions at other scale, and the development of hydrology with the aid of remote sensing The expansion of instantaneous remote sensing information to a long time scale and temporal resolution of remote sensing information are discussed with temporal scale issue taking into account