Abstract. Climate classification systems are useful for investigating future climate
scenarios, water availability, and even socioeconomic indicators as they
relate to climate dynamics. There are several classification systems that
apply water and energy variables to create zone boundaries, although there has
yet to be a simultaneous comparison of the structure and function of multiple
existing climate classification schemes. Moreover, there are presently no
classification frameworks that include evapotranspiration (ET) rates as a
governing principle. Here, we developed a new system based on precipitation
and potential evapotranspiration rates as well as three systems based on ET rates, which were all compared against four previously established climate
classification systems. The within-zone similarity, or coherence, of several
long-term hydroclimate variables was evaluated for each system based on the
premise that the interpretation and application of a classification framework
should correspond to the variables that are most coherent. Additionally, the
shape complexity of zone boundaries was assessed for each system, assuming
zone boundaries should be drawn efficiently such that shape simplicity and
hydroclimate coherence are balanced for meaningful boundary
implementation. The most frequently used climate classification system,
Köppen–Geiger, generally had high hydroclimate coherence but also had high
shape complexity. When compared to the Köppen–Geiger framework, the
Water-Energy Clustering classification system introduced here showed overall
improved or equivalent coherence for hydroclimate variables, yielded lower
spatial complexity, and required only 2, compared to 24, parameters for its construction.
Changes in Arid Climate over North China Detected by the Koppen Climate Classification
